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PTR Principles.

ptr 1
Working principles of PTR

The Kore PTR instruments are chemical analysis tools that combine a proton transfer reactor (PTR) with a time-of-flight mass spectrometer (TOF-MS) to make a PTR-TOF-MS.

 

Proton transfer is a ‘soft’ chemical ionisation method that allows a neutral gas molecule, such as a low concentration analyte in air, to be ionised without significant fragmentation of the molecule. This contrasts with other ionisation techniques such as electron impact (EI) that cause molecules to fragment, thus creating complex mass spectral patterns.

Overview
Ionisation and Detection of Organic Molecules

The most common form of the proton transfer method uses a ‘primary’ or ‘reagent’ ion beam of H3O+, i.e. a water molecule with a proton attached. The ‘proton affinity’ of H2O is 691kJ/mol. If a protonated water molecule (known as ‘hydronium’) collides with another gas molecule and the proton affinity of that neutral molecule is greater than 691kJ/mol, then the proton is transferred. The ionisation cross-section is practically the same as the collision cross-section. Such a molecule is now charged and can be focused electrostatically and then measured in a mass spectrometer for characterisation. The common constituents of air (N2, O2, Ar, CO2) all have proton affinities less that water, and these molecules are not ionised by this method. Most organic molecules have proton affinities greater than water and are ionised with little or no fragmentation. This makes the technique very suitable to the characterisation of volatile organic constituents in air, although of course the technique is not limited to air analysis and other molecules such as hydrogen sulphide (H2S), hydrogen cyanide (HCN) and ammonia (NH3) can be detectable by this H3O+ PTRMS method.

 

The H3O+ ion beam is created in an ion source, in Kore’s case a hollow cathode glow discharge source, and then injected into the transfer reactor at ~1mbar pressure. Under the influence of an electric field and also the viscous flow of the gas, the ions travel through the reactor. Analyte gas is injected into the reactor, and the molecules undergo collisions with the H3O+ ions. Protons are transferred where this is energetically favourable. This PTR drift section has a set of parallel plate electrodes defining a field gradient, and the ions move toward the end of the PTR section under the influence of that field. The value of the electric field divided by the number of molecules gives the Townsend Number (E/n). When the E/n value is high, the analyte molecules can collide too energetically and fragmentation results. However, if the E/n ratio is too low, water molecules in the primary beam begin to form clusters, and these are less effective at ionising the analyte molecules.

 

It is typical for the method to operate with a large excess of H3O+ ions compared to the concentration of organic species in the analyte sample, so that losses of protons from the H3O+ population are negligible and the H3O+population is essentially constant. The relationship between the counts of analyte vs. analyte concentration is thus linear through to ~50ppm concentration.

 

The ionised organic molecules emerge from the reactor at ~1mbar pressure into a lower pressure region at ~1 x 10-4mbar. At this pressure, the flow changes from viscous to molecular flow, and conventional electrostatic ion optics can be used to extract the divergent ion beam and focus the ions into the mass spectrometer. At this stage the ion beam is still continuous. In the next section of the instrument, the TOF ion source, the ion beam is converted into a pulse of ions suitable for the time-of-flight method. Typically a pulse of ions is extracted from the beam at intervals of ~20-50 microseconds. The extraction pulse is initiated by a high performance time-to-digital converter (TDC) designed by Kore, and the pulse of ions then travels in and out of the reflectron analyser to an ion detector. Within each cycle, the light ions arrive at the ion detector first, followed by successively heavier ions. The ion arrival signals are timed to an accuracy of 0.25 nanosecond. This arrival time is converted by software into a mass (strictly a mass/charge ratio). If the repetition rate is 20kHz (50 µs cycles), then in a ten second measurement there are 200,000 cycles in which data is accumulated into a mass spectrum.

 

Below is a table of proton affinities for various gaseous components. Any molecule with a proton affinity less than that of water will not be ionised by H3O+, and either other PTR reagents with lower proton affinities such as NO+ or O2+ or other ionisation methods such as electron impact ionisation or chemical ionisation by ion-molecule reactions (Ar, Kr, Xe) need to be used to ionise those components.

 

Proton Affinities for Common Analytes
SpeciesNamePA (kJ/mol)
HeHelium178
ArArgon369
O2Oxygen421
H2Hydrogen422
N2Nitrogen493
NONitric Oxide532
CO2Carbon Dioxide541
CH4Methane543
N2ONitrous Oxide550
HClHydrochloric Acid557
NO2Nitrogen Dioxide591
COCarbon Monoxide594
O3Ozone625
C3H8Propane626
COSCarbonyl Sulphide628
SO2Sulphur Dioxide672
C4H10Butane677
H2OWater691
C2H5ClEthylene Chloride693
H2SHydrogen Sulphide709
HCNHydrogen Cyanide712
C6H6Benzene750
CH3OHMethanol754
C2H5OHEthanol776
C4H61, 3 Butadiene783
C7H8Toluene784
PH3Phosphine785
C8H10Ethyl Benzene788
C8H10p-Xylene794
NH3Ammonia854

If you are interested in a particular compound and want to know whether it is suitable for PTR-MS analysis, the first thing is confirm that it has a proton affinity greater than that of water (691kJ/mol). We have provided a list of commonly used compounds with proton affinities greater  than that of water sorted by name.

 

CompoundProton Affinity
((CH3)2N)2C=N-(4-CH3O-C6H4)1047.7 kJ/mol
((CH3)2N)2C=N-(4-CH3-C6H4)1044.3 kJ/mol
((CH3)2N)2C=N(4-FC6H4)1030.1 kJ/mol
((CH3)2N)2C=N(4-ClC6H4)1028.0 kJ/mol
((CH3)2N)2C=N(i-C3H7)1055.6 kJ/mol
((CH3)2N)2C=N(t-C4H9)1061.9 kJ/mol
((CH3)2N)2C=NC2H51051.4 kJ/mol
((CH3)2N)2C=N-C6H51038.5 kJ/mol
((CH3)2SiH)2O845.2 kJ/mol
(?5-Cyclopentadienyl)dicarbonylrhodium882.4 kJ/mol
(1-adamantyl)2CS912.1 kJ/mol
(C12H25(OC2H4)7OH1006.7 kJ/mol
(C2H5)(i-C3H7)NH959.8 kJ/mol
(C2H5)2N-C(CH3)=N(n-C3H7)1038.1 kJ/mol
(C2H5)3PO936.8 kJ/mol
(C2H5)3SiOH822.2 kJ/mol
(C5H5)Cr(CO)3CH3859.8 kJ/mol
(C6H5)3AsO906.3 kJ/mol
(C6H5)3PO906.3 kJ/mol
(C6H5)3PS906.3 kJ/mol
(C6H5CH2)Cr(CO)3852.3 kJ/mol
(c-C3H5)2CS904.2 kJ/mol
(CD3)2O780.3 kJ/mol
(CF3CH2)2NH838.1 kJ/mol
(CF3CH2)2O702.5 kJ/mol
(CH2)5PCH3969.4 kJ/mol
(CH2=CHCH2)2O827.6 kJ/mol
(CH3)2(C6H5)PO908.8 kJ/mol
(CH3)2(n-C3H7)N962.7 kJ/mol
(CH3)2(t-C4H9)SiN(CH3)2969.9 kJ/mol
(CH3)2C=C(CH3)C(CH3)=CH2869.9 kJ/mol
(CH3)2C=CHC(CH3)=CH2886.6 kJ/mol
(CH3)2C=NC2H5976.1 kJ/mol
(CH3)2Ge=CH2851.0 kJ/mol
(CH3)2N(CH2)4N(CH3)21046.4 kJ/mol
(CH3)2N(CH2)6N(CH3)21036.0 kJ/mol
(CH3)2N-C(4-CH3-C6H4)=NCH31038.1 kJ/mol
(CH3)2N-C(C2H5)=N(i-C3H7)1036.8 kJ/mol
(CH3)2N-C(C2H5)=N(n-C5H11)1038.1 kJ/mol
(CH3)2N-C(C2H5)=N(t-C4H9)1043.5 kJ/mol
(CH3)2NC(C2H5)=CHCH3991.6 kJ/mol
(CH3)2N-C(C6H5)=NCH31033.4 kJ/mol
(CH3)2NC(CH3)=CHCH31005.4 kJ/mol
(CH3)2N-C(CH3)=NCH31023.4 kJ/mol
(CH3)2N-C(CH3)=N(n-C6H13)1033.4 kJ/mol
(CH3)2N-C(CH3)=N(n-C5H11)1034.7 kJ/mol
(CH3)2N-C(CH3)=N(i-C3H7)1031.8 kJ/mol
(CH3)2N-C(CH3)=N(n-C3H7)1030.1 kJ/mol
(CH3)2N-C(CH3)=N(t-C4H9)1038.5 kJ/mol
(CH3)2N-C(CH3)=N(c-C3H5)1024.2 kJ/mol
(CH3)2N-C(CH3)=N(CH2)2OCH31036.4 kJ/mol
(CH3)2N-C(CH3)=NC2H51029.3 kJ/mol
(CH3)2NC(CH3)=N-(CH2)3N(CH3)21077.4 kJ/mol
(CH3)2NC(CH3)=N(CH2)2N(CH3)21048.5 kJ/mol
(CH3)2NC(CH3)=N(1-Ad)1050.6 kJ/mol
(CH3)2NC6H4(t-C4H9)961.1 kJ/mol
(CH3)2NCH=CH2956.9 kJ/mol
(CH3)2N-CH=N-(1-Ad)1033.4 kJ/mol
(CH3)2N-CH=N-(1-methylethyl)1013.4 kJ/mol
(CH3)2N-CH=N-(1-methylpropyl)1018.0 kJ/mol
(CH3)2N-CH=N-(1,1-dimethylpropyl)1022.2 kJ/mol
(CH3)2N-CH=N-(2-propenyl)1005.0 kJ/mol
(CH3)2N-CH=N-(2-propynyl)993.3 kJ/mol
(CH3)2N-CH=N-(2-methylpropyl)1014.6 kJ/mol
(CH3)2N-CH=N-(2-methoxyethyl)1018.8 kJ/mol
(CH3)2N-CH=N-(4-cyanophenyl)952.3 kJ/mol
(CH3)2N-CH=N-(4-acetylphenyl)979.9 kJ/mol
(CH3)2N-CH=N-(4-bromophenyl)981.1 kJ/mol
(CH3)2N-CH=N-(4-methylphenyl)988.7 kJ/mol
(CH3)2N-CH=N-(4-nitrophenyl)950.2 kJ/mol
(CH3)2N-CH=N-(c-propyl)1006.3 kJ/mol
(CH3)2N-CH=N-(c-hexyl)1020.5 kJ/mol
(CH3)2N-CH=N-(CH2)3N(CH3)21057.7 kJ/mol
(CH3)2N-CH=N(CH2)2N(CH3)21028.8 kJ/mol
(CH3)2N-CH=N-(n-propyl)1011.7 kJ/mol
(CH3)2N-CH=N-(n-butyl)1012.9 kJ/mol
(CH3)2N-CH=N-(n-hexyl)1017.5 kJ/mol
(CH3)2N-CH=N(n-C5H11)1018.0 kJ/mol
(CH3)2N-CH=N-(phenylmethyl)1014.2 kJ/mol
(CH3)2N-CH=N(t-C4H9)1020.9 kJ/mol
(CH3)2N-CH=N-C2H51008.8 kJ/mol
(CH3)2N-CH=N-CH2CN948.1 kJ/mol
(CH3)2N-CH=N-CH2CH2CN980.7 kJ/mol
(CH3)2N-CH=N-CH2CF3966.1 kJ/mol
(CH3)2N-CH=N-CH31002.5 kJ/mol
(CH3)2N-CH=N-OCH3948.1 kJ/mol
(CH3)2N-CH=N-phenyl983.7 kJ/mol
(CH3)2NCOCN828.9 kJ/mol
(CH3)2NCOOC2H5896.6 kJ/mol
(CH3)2NCOOCH3878.2 kJ/mol
(CH3)2Pb=CH2938.1 kJ/mol
(CH3)2Sn=CH2893.7 kJ/mol
(Ch3)3cch2N(ch3)2970.7 kJ/mol
(CH3)3CONO864.0 kJ/mol
(CH3)3Si(CH2)2N(CH3)2980.3 kJ/mol
(CH3)3Si(CH2)3N(CH3)2980.3 kJ/mol
(Ch3)3sin(ch3)2966.9 kJ/mol
(CO)6V800.0 kJ/mol
(E)-Dimethyldiazene865.3 kJ/mol
(i-C3H7)2(C2H5)N994.1 kJ/mol
(i-C3H7)3PO954.4 kJ/mol
(i-C3H7)N(C2H5)2996.2 kJ/mol
(n-C3H7)2(CH3)P983.7 kJ/mol
(sec-C4H9)(CH3)2N975.7 kJ/mol
(t-C4H9)2CS882.0 kJ/mol
(t-C4H9)2NH987.8 kJ/mol
(t-C4H9)C(CH3)2N(CH3)2982.4 kJ/mol
(t-C5H11)(CH3)2N982.4 kJ/mol
(Z) CH3CH=C(CH3)COOH822.6 kJ/mol
(Z)-1-Phenylpropene836.4 kJ/mol
?5-Cyclopentadienylnitrosylnickel827.2 kJ/mol
?-Butyrolactone840.1 kJ/mol
[(C5H5)(CO)Fe]2(:-CO)(:-C=CH2)982.0 kJ/mol
1-(1-adamantyl)pyrazole954.4 kJ/mol
1-(2,3-dihydro-5-benzofuranyl)-ethanone902.5 kJ/mol
1-(3-pyridinyl-1-oxide)ethanone912.9 kJ/mol
1,1-(Dimethylthio)ethene930.9 kJ/mol
1,1,1-Trifluorotrimethylamine802.9 kJ/mol
1,16-Dimethyldodecahedrane876.5 kJ/mol
1,1'-Biphenyl, 2-methyl-815.9 kJ/mol
1,1'-Biphenyl, 3-methyl-828.0 kJ/mol
1,1'-Biphenyl, 4-methyl-818.0 kJ/mol
1,1'-Bipiperidine981.1 kJ/mol
1,1'-Diadamantyl ketone894.1 kJ/mol
1,2,3-Propanetriol874.9 kJ/mol
1,2,3-Trifluorobenzene724.3 kJ/mol
1,2,4-Trifluorobenzene729.7 kJ/mol
1,2-Benzenediamine896.6 kJ/mol
1,2-Benzenediamine, N,N,N',N'-tetramethyl-982.4 kJ/mol
1,2-Butadiene779.1 kJ/mol
1,2-Diazabicyclo[2.2.2]octane, 2-methyl-969.0 kJ/mol
1,2-Ethanediamine, N,N,N',N'-tetramethyl-1012.9 kJ/mol
1,2-Ethanediol815.9 kJ/mol
1,2-Propadiene775.3 kJ/mol
1,3,2-Dioxaphospholane,2-methoxy-895.0 kJ/mol
1,3,2-Dioxaphosphorinane,2-methoxy-4,6-dimethyl-(2a,4a,6a)-951.4 kJ/mol
1,3,2-Dioxaphosphorinane,2-methoxy-4,6-dimethyl-(2ß,4a,6a)-946.4 kJ/mol
1,3,2-Dioxaphosphorinane,2-methoxy-925.5 kJ/mol
1,3,3-Trimethylcyclopropene895.4 kJ/mol
1,3,5-Triazine848.9 kJ/mol
1,3,5-Trifluorobenzene741.8 kJ/mol
1,3,5-Trimethoxybenzene926.8 kJ/mol
1,3,5-Trimethylpyrazole949.3 kJ/mol
1,3-Benzenediamine930.1 kJ/mol
1,3-Benzenedicarbonitrile779.5 kJ/mol
1,3-Benzenedicarboxylic acid dimethyl ester843.5 kJ/mol
1,3-Butadiene783.2 kJ/mol
1,3-Butadiene, 2,3-dimethyl-835.1 kJ/mol
1,3-Butadiene, 2-methyl-826.3 kJ/mol
1,3-Butadiyne737.2 kJ/mol
1,3-Cyclohexadiene836.8 kJ/mol
1,3-Cyclohexanedione881.2 kJ/mol
1,3-Cyclopentadiene821.7 kJ/mol
1,3-di-(t-C4H9)-5-CH3-C6H3853.5 kJ/mol
1,3-Diazine885.8 kJ/mol
1,3-Dimethyl-2-imidazolidinone918.4 kJ/mol
1,3-dimethyl-5-ethoxycarbonylpyrazole925.1 kJ/mol
1,3-dimethyl-5-phenylpyrazole956.5 kJ/mol
1,3-Dimethylpyrazole933.9 kJ/mol
1,3-Dioxane825.5 kJ/mol
1,3-Pentadiene, (E)-834.3 kJ/mol
1,3-Pentadiene, 2-methyl-864.8 kJ/mol
1,3-Propanediamine987.0 kJ/mol
1,3-Propanediamine, N,N-dimethyl-1025.1 kJ/mol
1,3-Propanediamine, N,N,N',N'-tetramethyl-1035.1 kJ/mol
1,3-Propanediol876.1 kJ/mol
1,4,4-(CH3)3-1,2,3,4-tetrahydropyridine979.9 kJ/mol
1,4,4-Trimethylpiperidine965.7 kJ/mol
1,4,5,6-Tetrahydropyrimidine1002.1 kJ/mol
1,4,7,10,13,16-Hexaoxacyclooctadecane966.9 kJ/mol
1,4-Benzenediamine905.8 kJ/mol
1,4-Benzenediamine, N,N-dimethyl-955.2 kJ/mol
1,4-Benzenedicarbonitrile779.1 kJ/mol
1,4-Benzenedicarboxylic acid dimethyl ester843.1 kJ/mol
1,4-butanediamine1005.4 kJ/mol
1,4-Butanediol915.5 kJ/mol
1,4-Cyclohexadiene836.8 kJ/mol
1,4-Cyclohexadiene,3,6-bis(methylene)-900.4 kJ/mol
1,4-Cyclohexanedione812.5 kJ/mol
1,4-dimethyl-3,5-di-t-butylpyrazole979.5 kJ/mol
1,4-Dimethylimidazole976.5 kJ/mol
1,4-Dimethylpyrazole928.4 kJ/mol
1,4-Dioxane797.5 kJ/mol
1,4-Dioxin, 2,3-dihydro-823.4 kJ/mol
1,4-Dioxyl radical803.3 kJ/mol
1,5,7-triazabicyclo [4.4.0]dec-5-ene1054.8 kJ/mol
1,5-Diaminopentane999.6 kJ/mol
1,5-Diazabicyclo[3.3.3]undecane971.1 kJ/mol
1,5-diazabicyclo[4.3.0]non-5-ene1038.5 kJ/mol
1,5-diazabicyclo[4.4.0]dec-6-ene (DBD)1046.4 kJ/mol
1,5-dimethyl-3-ethoxycarbonylpyrazole933.5 kJ/mol
1,5-dimethyl-3-phenylpyrazole954.4 kJ/mol
1,5-Dimethylimidazole977.8 kJ/mol
1,5-Dimethylpyrazole934.3 kJ/mol
1,5-Diphenylpentane824.7 kJ/mol
1,6-Diazabicyclo[4.4.4]tetradecane947.3 kJ/mol
1,6-Diazabicyclo[4.4.0]decane978.6 kJ/mol
1,6-Dicarbahexaborane(6)864.0 kJ/mol
1,6-Diphenylhexane825.9 kJ/mol
1,6-Hexanediamine999.6 kJ/mol
1,7-Diaminoheptane998.3 kJ/mol
1,8-diazabicyclo [5.4.0]undec-7-ene1048.1 kJ/mol
1,8-Naphthalenediamine, N,N,N',N'-tetramethyl-1028.0 kJ/mol
1,8-Naphthalenediamine944.3 kJ/mol
10,5-metheno-5H-bisazepino[1,2-d:2',1'-g][1,4]diazepine,7,8-dihydro962.7 kJ/mol
11,5-metheno-5H,7H-bisazepino[1,2-a:2',1'-d][1,5]diazocine,8,9-dihydro974.5 kJ/mol
12,5-metheno-5H-bisazepino[1,2-a:2',1'-d][1,5]diazonine,7,8,9,10-tetrahydro972.8 kJ/mol
12-Crown-4927.2 kJ/mol
13,5-metheno-5H,7H-bisazepino[1,2-a:2',1'-d][1,5]diazecine,8,9,10,11-tetrahydro994.1 kJ/mol
14,5-metheno-5H-bisazepino[1,2-a:2',1'-d][1,5]diazacycloundecine,7,8,9,10,11,12- hexahydro978.6 kJ/mol
15,16-diazatricyclo[8.4.1.13,8]hexadeca-1,3,5,7,9,11,13-heptaene,15,16-dimethyl984.5 kJ/mol
15,16-diazatricyclo[8.4.1.13,8]hexadeca-1,3,5,7,9,11,13-heptaene983.7 kJ/mol
15-Crown-5943.9 kJ/mol
1-Adamantanecarboxamide912.9 kJ/mol
1-Adamantyl methyl ketone864.8 kJ/mol
1-Azabicyclo[1.1.0]butane887.0 kJ/mol
1-Azabicyclo[2.2.2]oct-2-ene969.4 kJ/mol
1-Azabicyclo[2.2.2]octane,4-N,N-dimethylamino-984.1 kJ/mol
1-Azabicyclo[2.2.2]octan-3-one936.0 kJ/mol
1-Azabicyclo[2.2.2]octane-4-carbonitrile933.0 kJ/mol
1-Azabicyclo[2.2.2]octane, 3-methylene977.4 kJ/mol
1-Azabicyclo[2.2.2]octane, 4-methyl-979.5 kJ/mol
1-azabicyclo[2.2.2]-octane, 3-methyl982.4 kJ/mol
1-azabicyclo[2.2.2]-octane, 3-cyano935.5 kJ/mol
1-azabicyclo[2.2.2]-octane, 2-chloro950.6 kJ/mol
1-azabicyclo[2.2.2]-octane, 2-cyano926.3 kJ/mol
1-azabicyclo[2.2.2]-octane, 2-methyl987.0 kJ/mol
1-Azabicyclo[3.3.3]undecane978.6 kJ/mol
1-Azabicyclo[4.4.4]tetradecane897.0 kJ/mol
1-Butanamine921.3 kJ/mol
1-Butanamine, N-butyl-968.6 kJ/mol
1-Butanamine, N,N-dimethyl-969.0 kJ/mol
1-Butanethiol801.7 kJ/mol
1-Butanol789.1 kJ/mol
1-Butyne, 3-methyl-815.0 kJ/mol
1-Cyclopropyl-2-methylbenzene840.6 kJ/mol
1-Decanamine930.5 kJ/mol
1H,5H-Pyrazolo[1,2-a]pyrazole,tetrahydro-977.8 kJ/mol
1H-1,2,3-Triazole879.5 kJ/mol
1H-1,2,4-Triazole886.2 kJ/mol
1H-1,2-Diazepine, hexahydro-1,2-dimethyl966.9 kJ/mol
1-H-Azepine, hexahydro-1-phenyl956.5 kJ/mol
1H-Azepine, hexahydro-956.9 kJ/mol
1H-Benzimidazole954.0 kJ/mol
1-Heptanamine923.4 kJ/mol
1-Hexanamine927.6 kJ/mol
1-Hexene805.0 kJ/mol
1-Hexyne800.0 kJ/mol
1H-Imidazole942.7 kJ/mol
1H-Imidazole, 1-methyl-959.4 kJ/mol
1H-Imidazole, 1,2-dimethyl-984.5 kJ/mol
1H-Imidazole, 2-methyl-963.6 kJ/mol
1H-Imidazole-4-ethanamine, N,N-dimethyl-1022.2 kJ/mol
1H-Indazole900.8 kJ/mol
1H-Indole, 2,3-dihydro-957.3 kJ/mol
1H-Purine, 6-methyl-939.3 kJ/mol
1H-Pyrazole894.1 kJ/mol
1H-Pyrazole, 3,5-dimethyl-933.5 kJ/mol
1H-Pyrrole, 2,5-dimethyl-918.8 kJ/mol
1H-Pyrrolo[2,3-b]pyridine940.1 kJ/mol
1-Methoxycyclohexane840.6 kJ/mol
1-Methyl-2,6-t-butylpiperidine1011.3 kJ/mol
1-methyl-3,5-di-t-butylpyrazole970.7 kJ/mol
1-methyl-3,5-diethoxycarbonylpyrazole913.4 kJ/mol
1-methyl-3,5-dinitropyrazole788.7 kJ/mol
1-methyl-3,5-diphenylpyrazole959.0 kJ/mol
1-methyl-3-aminopyrazole937.2 kJ/mol
1-Methyl-3-methylenecyclobutene891.2 kJ/mol
1-methyl-3-nitropyrazole847.7 kJ/mol
1-methyl-3-phenylpyrazole932.6 kJ/mol
1-methyl-3-t-butylpyrazole944.3 kJ/mol
1-methyl-5-aminopyrazole949.3 kJ/mol
1-Methyl-5-nitroimidazole895.4 kJ/mol
1-methyl-5-nitropyrazole850.2 kJ/mol
1-methyl-5-phenylpyrazole932.2 kJ/mol
1-methyl-5-t-butylpyrazole939.3 kJ/mol
1-methylbenzimidazole966.9 kJ/mol
1-methylbenzotriazole931.4 kJ/mol
1-Methylcyclopropene856.0 kJ/mol
1-Methylethenylamine941.8 kJ/mol
1-methylindazole922.6 kJ/mol
1-methylpyrazole912.1 kJ/mol
1-Naphthalenamine907.1 kJ/mol
1-Octanamine928.8 kJ/mol
1-Pentanamine923.4 kJ/mol
1-Phenylethyl radical836.4 kJ/mol
1-Piperidinyloxy, 2,2,6,6-tetramethyl-882.4 kJ/mol
1-Propanamine918.0 kJ/mol
1-Propanamine, 2-methyl-924.7 kJ/mol
1-Propanamine, 2-methyl-N-(2-methylpropyl)-958.1 kJ/mol
1-Propanamine, N,N-dipropyl-991.2 kJ/mol
1-Propanamine, N,N-diethyl-978.6 kJ/mol
1-Propanamine, n-propyl-962.3 kJ/mol
1-Propanethiol795.0 kJ/mol
1-Propanethiol, 2,2-dimethyl-809.6 kJ/mol
1-Propanethiol, 2-methyl-802.5 kJ/mol
1-Propanol786.6 kJ/mol
1-Propanol, 2,2-dimethyl-795.4 kJ/mol
1-Propanol, 2-methyl-793.7 kJ/mol
1-Propanol, 3-amino-962.3 kJ/mol
1-Propanone, 1-phenyl-867.3 kJ/mol
1-Propen-1-amine, N,N,2-trimethyl-966.9 kJ/mol
1-Propene, 2-methyl-802.1 kJ/mol
1-Propene, 2-methoxy-895.0 kJ/mol
1-Propene, 3-ethoxy-833.9 kJ/mol
1-Propyne, 3,3'-oxybis-784.1 kJ/mol
1-t-Butylimidazole987.0 kJ/mol
2(1H)-Pyridinone, 1-methyl-925.9 kJ/mol
2(1H)-Pyrimidinone872.8 kJ/mol
2(1H)-Pyrimidinone, 4-amino-949.8 kJ/mol
2-(C3H7)-pyridine955.6 kJ/mol
2-(CF3)-pyridine887.0 kJ/mol
2-(CH3OCH2)-pyridine958.1 kJ/mol
2-(i-C3H7)-pyridine956.5 kJ/mol
2-(t-C4H9)-pyridine961.9 kJ/mol
2,2,2-Trifluoroethylamine846.8 kJ/mol
2,2,2-Trifluoroethyl formate745.6 kJ/mol
2,2,2-Trifluoroethyl methyl ether747.7 kJ/mol
2,2,4-Trimethyl-3-pentanone856.9 kJ/mol
2,2-Dimethyltetrahydrofuran847.7 kJ/mol
2,3-(CH3)=C6H3-COCH3874.5 kJ/mol
2,3-(CH3)2-C6H3-COOCH3863.6 kJ/mol
2,3,4,5-tetramethylfuran915.5 kJ/mol
2,3,5,6-(CH3)4-C6H-COOCH3865.3 kJ/mol
2,3,5-Trimethylimidazo(1,2-a)-pyridine1005.4 kJ/mol
2,3-Butanedione802.1 kJ/mol
2,3-Cyclobutenopyridine954.0 kJ/mol
2,3-Diazabicyclo[2.2.1]heptane, 2,3-dimethyl-977.8 kJ/mol
2,3-Diazabicyclo[2.2.2]octane, 2,3-dimethyl-980.7 kJ/mol
2,3-Dimethylimidazo(1,2-a)pyridine998.3 kJ/mol
2',3'-O-Isopropylideneuridine874.0 kJ/mol
2,4-(CH3)2-C6H3-COOCH3868.2 kJ/mol
2,4-(CH3)2C6H3-COCH3882.4 kJ/mol
2,4-(t-C4H9)2 -pyridine983.7 kJ/mol
2,4,6-(CH3)3-C6H2-COOCH3866.5 kJ/mol
2,4,6-Cycloheptatrien-1-one920.9 kJ/mol
2,4-Dicarbaheptaborane(7)697.5 kJ/mol
2,4-Dimethylfuran894.5 kJ/mol
2,5-(CH3)2-C6H3-COOCH3864.8 kJ/mol
2,5-(CH3)2C6H3-COCH3873.6 kJ/mol
2,5,8,11-Tetraoxadodecane946.4 kJ/mol
2,5-Dimethylimidazo(1,2-a)pyridine996.2 kJ/mol
2,5-Norbornadiene849.4 kJ/mol
2,6-(C2H5)2-pyridine972.4 kJ/mol
2,6-(CH3)2-C6H3-COOCH3855.2 kJ/mol
2,6-(CH3)2C6H3-COCH3856.9 kJ/mol
2,6-(i-C3H7)2-pyridine979.1 kJ/mol
2,6-(t-C4H9)2-pyridine982.8 kJ/mol
2,6,7-Trioxa-1-phosphabicyclo[2.2.1]heptane802.9 kJ/mol
2,6,7-Trioxa-1-phosphabicyclo[2.2.2]octane868.6 kJ/mol
2,6-Di-t-butylpiperidine992.4 kJ/mol
2,7-Dimethylimidazo(1,2-a)pyridine1000.4 kJ/mol
2,8,9-Trioxa-1-phosphadamantane899.1 kJ/mol
2-Aminothiazole930.5 kJ/mol
2-Azetidinone852.7 kJ/mol
2-Butanamine929.7 kJ/mol
2-Butanamine, 2-methyl-937.6 kJ/mol
2-Butanamine, N-(1-methylpropyl)-980.7 kJ/mol
2-Butanethiol813.0 kJ/mol
2-Butanol815.0 kJ/mol
2-Butanone827.2 kJ/mol
2-Butanone, 3,3-dimethyl-840.1 kJ/mol
2-Butanone, 3-methyl-836.4 kJ/mol
2-Butenal830.9 kJ/mol
2-Butenal,2-methyl-(Z)-843.9 kJ/mol
2-butenamide887.0 kJ/mol
2-Butene, (E)-746.8 kJ/mol
2-Butene, 2,3-dimethyl-813.8 kJ/mol
2-Butene, 2-methyl-808.8 kJ/mol
2-Butenoic acid, 3-methyl-823.0 kJ/mol
2-Butenoic acid, methyl ester, (E)-851.4 kJ/mol
2-Butyne775.7 kJ/mol
2-C6H13(c-C5H4N)963.6 kJ/mol
2-Cl-4-(CH3)-pyridine921.3 kJ/mol
2-Cl-6-(CH3)-pyridine907.9 kJ/mol
2-Cyclohexen-1-one, 3,5,5-trimethyl-893.7 kJ/mol
2-Cyclohexen-1-one,3-methoxy,5,5-dimethyl-922.6 kJ/mol
2-Cyclohexenone,3-(N,N-dimethylamino)-5,5-dimethyl-983.7 kJ/mol
2-Cyclohexenone, 5,5-dimethyl-869.9 kJ/mol
2-Cyclohexenone,3-amino,5,5-dimethyl-946.8 kJ/mol
2-Fluoropyridine884.5 kJ/mol
2H-1,4-Ethanoquinoline, 3,4-dihydro-979.9 kJ/mol
2H-Azetidin-2-one, 2-methyl-882.4 kJ/mol
2H-Benzotriazole, 2-methyl-889.9 kJ/mol
2-Hexyne806.3 kJ/mol
2H-Pyran, 3,4-dihydro-865.7 kJ/mol
2H-Pyran, tetrahydro-823.0 kJ/mol
2H-Thiopyran, tetrahydro-855.6 kJ/mol
2-Imidazolidinethione921.7 kJ/mol
2-Me-phenoxy874.5 kJ/mol
2-Methyl-2H-indazole941.4 kJ/mol
2-Methylallyl radical777.8 kJ/mol
2-methylbenzofuran859.4 kJ/mol
2-Methylenebicyclo[2.2.1]-heptane860.6 kJ/mol
2-Methylimidazo(1,2-a)pyridine990.8 kJ/mol
2-Methylthiazole930.5 kJ/mol
2-Naphthalenol, 3-aminodecahydro-, (2a,3ß,4aa,8aß)946.8 kJ/mol
2-Norbornanone847.3 kJ/mol
2-Norbornene836.4 kJ/mol
2-OH-benzyl878.6 kJ/mol
2-Pentanone832.6 kJ/mol
2-pentenal(E)838.9 kJ/mol
2-Pentene, 2,4-dimethyl-812.1 kJ/mol
2-Pentene, 2-methyl-812.1 kJ/mol
2-Pentyne810.0 kJ/mol
2-Phenyl-2-propyl radical842.2 kJ/mol
2-Piperidinone, 1-methyl-924.2 kJ/mol
2-Propanamine923.8 kJ/mol
2-Propanamine, 2-methyl-934.3 kJ/mol
2-Propanamine, N-(1-methylethyl)-971.9 kJ/mol
2-Propanamine, N,N,2-trimethyl-979.5 kJ/mol
2-Propanamine, N,N-dimethyl-970.7 kJ/mol
2-Propanamine, N-methyl-952.3 kJ/mol
2-Propanethiol803.7 kJ/mol
2-Propanethiol, 2-methyl-816.3 kJ/mol
2-Propanimine932.2 kJ/mol
2-Propanone, 1,1,3,3-tetrafluoro-698.7 kJ/mol
2-Propanone, 1,1,1-trifluoro-723.8 kJ/mol
2-Propanone, 1-fluoro-795.4 kJ/mol
2-Propen-1-amine909.6 kJ/mol
2-Propen-1-amine, 2-methyl-917.6 kJ/mol
2-Propen-1-amine, N,N-di-2-propenyl-972.4 kJ/mol
2-Propen-1-amine, N-2-propenyl-949.3 kJ/mol
2-Propenal797.1 kJ/mol
2-Propenal, 2-methyl-808.8 kJ/mol
2-propenamide, N,N,2-trimethyl-911.7 kJ/mol
2-propenamide, N,N-dimethyl904.2 kJ/mol
2-Propenenitrile784.5 kJ/mol
2-Propenoic acid, 2-methyl-816.7 kJ/mol
2-Propenoic acid, 2-methyl-, methyl ester831.4 kJ/mol
2-Propenoic acid, methyl ester825.9 kJ/mol
2-Propyn-1-amine, N,N-dimethyl-940.1 kJ/mol
2-Propyn-1-amine, N,N-di-2-propynyl-925.1 kJ/mol
2-Propyn-1-amine, N-2-propynyl-910.0 kJ/mol
2-Pyridinamine947.3 kJ/mol
2-Pyridinecarbonitrile872.8 kJ/mol
2-Pyrrolidinone, 1-methyl-923.4 kJ/mol
2-Silaisobutene947.7 kJ/mol
3-(2-(N-methylpyrrolidinyl))pyridine963.6 kJ/mol
3-(2-pyrrolidinyl)pyridine964.0 kJ/mol
3(5),4-dimethylpyrazole927.2 kJ/mol
3(5)-aminopyrazole921.3 kJ/mol
3(5)-ethyl-5(3)-phenylpyrazole935.5 kJ/mol
3(5)-methyl-5(3)-t-butylpyrazole946.0 kJ/mol
3(5)-methyl-5(3)-phenylpyrazole932.2 kJ/mol
3(5)-methyl-5(3)-ethoxycarbonylpyrazole902.5 kJ/mol
3(5)-methylpyrazole905.8 kJ/mol
3(5)-nitropyrazole820.9 kJ/mol
3(5)-phenyl-5(3)-ethoxycarbonylpyrazole899.6 kJ/mol
3(5)-phenylpyrazole914.2 kJ/mol
3(5)-t-butylpyrazole923.0 kJ/mol
3-(C2H5)-pyridine947.3 kJ/mol
3-(CF3)-C6H4-CN791.2 kJ/mol
3-(CF3)-pyridine892.4 kJ/mol
3-(CH2Cl)-C6H4-CN811.3 kJ/mol
3-(CH3)2NC6H4C(CH3)=CH2946.0 kJ/mol
3-(CH3)2NC6H4CN894.5 kJ/mol
3-(CH3)2NC6H4COCH3928.0 kJ/mol
3-(CH3)2NC6H4COOCH3930.1 kJ/mol
3-(CH3SO2)-C6H4-CN799.6 kJ/mol
3-(NO2)C6H4C(CH3)=CH2812.1 kJ/mol
3,3,6,9,9-pentamethyl-2,10-diazabicyclo[4.4.0]dec-1-ene1039.3 kJ/mol
3,4-(CH3)2C6H3-COCH3882.8 kJ/mol
3,4-(CH3)3-C6H3-CO2CH3868.6 kJ/mol
3,4,5-(CH3)3-C6H2-CO2CH3875.3 kJ/mol
3,4,5-Trimethylpyrazole949.3 kJ/mol
3,4-Cyclobutenopyridine957.3 kJ/mol
3,4-dimethylfuran869.0 kJ/mol
3,5-(CF3)2C6H3N(CH3)2884.9 kJ/mol
3,5-(CH3)=C6H3-COCH3876.1 kJ/mol
3,5-(CH3)2-C6H3-CCH850.6 kJ/mol
3,5-(CH3)2-C6H3-COOCH3864.4 kJ/mol
3,5-diethoxycarbonylpyrazole881.6 kJ/mol
3,5-diethyl-4-methylpyrazole952.7 kJ/mol
3,5-dinitropyrazole759.4 kJ/mol
3,5-diphenylpyrazole946.4 kJ/mol
3,5-di-t-butyl-4-methylpyrazole967.3 kJ/mol
3,5-di-t-butylpyrazole952.7 kJ/mol
3-Amino-1-azabicyclo[2.2.2]octane985.3 kJ/mol
3-Amino-tricyclo [7.3.0.04,8]dodecan-2-ol928.0 kJ/mol
3-BrC6H4CH=CH2822.6 kJ/mol
3-BrC6H4NH2873.2 kJ/mol
3-Buten-2-one, 3-methyl-843.1 kJ/mol
3-C2H5C6H4NH2897.9 kJ/mol
3-CF3C6H4C(CH3)=CH2823.8 kJ/mol
3-CF3-C6H4-CCH806.3 kJ/mol
3-CF3C6H4CH=CH2810.9 kJ/mol
3-CF3-C6H4-COCH3835.5 kJ/mol
3-CF3-C6H4CON(CH3)2907.1 kJ/mol
3-CF3-C6H4CONH2866.9 kJ/mol
3-CF3-C6H4-COOCH3827.6 kJ/mol
3-CF3C6H4N(CH3)2908.3 kJ/mol
3-CH3C6H4C(CH3)=CH2871.1 kJ/mol
3-CH3-C6H4-C(Si(CH3)3)=CH2868.2 kJ/mol
3-CH3C6H4CHO840.1 kJ/mol
3-CH3-C6H4CON(CH3)2927.2 kJ/mol
3-CH3CO-C6H4-COCH3851.9 kJ/mol
3-CH3OC6H4C(CH3)=CH2872.8 kJ/mol
3-CH3O-C6H4CON(CH3)2927.2 kJ/mol
3-CH3O-C6H4-COOCH3856.9 kJ/mol
3-CH3S-C6H4-COCH3866.5 kJ/mol
3-CH3S-C6H4-COOCH3853.5 kJ/mol
3-CH3SC6H4NH2902.1 kJ/mol
3-CH3SO2-C6H4-COOCH3830.5 kJ/mol
3-Chloro-1-azabicyclo[2.2.2]octane954.4 kJ/mol
3-Chloro-5,5-dimethylcyclohex-2-enone867.8 kJ/mol
3-Chlorobenzamide877.4 kJ/mol
3-chloro-pyridine-1-oxide902.1 kJ/mol
3-Cl-4-CH3O-C6H3-CCH871.9 kJ/mol
3-Cl-4-CH3O-C6H3-COCH3883.7 kJ/mol
3-Cl-4-CH3O-C6H3-COOCH3858.6 kJ/mol
3-Cl-4-CH3S-C6H3-CCH868.6 kJ/mol
3-Cl-4-CH3S-C6H3-COCH3880.3 kJ/mol
3-Cl-4-CH3S-C6H3-COOCH3856.5 kJ/mol
3-ClC6H4CCH812.1 kJ/mol
3-ClC6H4CH=CH2841.4 kJ/mol
3-Cl-C6H4CON(CH3)2928.0 kJ/mol
3-Cl-C6H4-COOCH3835.5 kJ/mol
3-CN-C6H4-COCH3827.2 kJ/mol
3-CN-C6H4-COOCH3817.6 kJ/mol
3-F-4-CH3O-C6H3-CCH871.9 kJ/mol
3-FC6H4C(CH3)=CH2839.7 kJ/mol
3-FC6H4CCH808.8 kJ/mol
3-FC6H4CHO814.2 kJ/mol
3-F-C6H4CON(CH3)2928.0 kJ/mol
3-F-C6H4-COOCH3833.0 kJ/mol
3-Fluorobenzyl radical836.4 kJ/mol
3-fluoro-pyridine-1-oxide900.0 kJ/mol
3-F-pyridine902.1 kJ/mol
3-Hexanone843.1 kJ/mol
3-hexen-2-one(E)865.7 kJ/mol
3-HO-C6H4-COOCH3850.2 kJ/mol
3-I-C6H4NH2878.6 kJ/mol
3-Me-phenoxy877.4 kJ/mol
3-Methoxy-N,N-dimethylbenzenamine920.5 kJ/mol
3-methyl-2-butenal856.9 kJ/mol
3-methyl-3-penten-2-one(Z)866.5 kJ/mol
3-Methylene-1,5,5-trimethylcyclohexene905.0 kJ/mol
3-Methylphenylacetylene843.1 kJ/mol
3-NH2-C6H4CON(CH3)2944.3 kJ/mol
3-NH2-C6H4CONH2900.8 kJ/mol
3-Nitroacetophenone825.9 kJ/mol
3-NO2-C6H4CON(CH3)2900.8 kJ/mol
3-O2N-C6H4-COOCH3815.9 kJ/mol
3-OH-benzyl885.3 kJ/mol
3-Pentanone836.8 kJ/mol
3-Pentanone, 2,2,4,4-tetramethyl-861.5 kJ/mol
3-Pentanone, 2,4-dimethyl-850.2 kJ/mol
3-Penten-2-one864.4 kJ/mol
3-Penten-2-one, 4-methyl-878.6 kJ/mol
3-Pyridinamine954.4 kJ/mol
3-Pyridinecarbonitrile, 1-oxide879.5 kJ/mol
3-Pyridinecarbonitrile877.0 kJ/mol
3-Pyridinol929.7 kJ/mol
3-SO2F-C6H4-COOCH3806.3 kJ/mol
4-((CH3)3Si)C6H4C(CH3)=CH2878.6 kJ/mol
4-(1-adamantyl)-pyrazole912.9 kJ/mol
4-(C2H5)-pyridine951.0 kJ/mol
4-(C2H5COO)-pyrazole880.7 kJ/mol
4-(C6H5)-pyrazole905.8 kJ/mol
4-(CH2Cl)-C6H4-CN813.0 kJ/mol
4-(CH3)2NC6H4C(CH3)=CH2964.4 kJ/mol
4-(CH3)2NC6H4COOCH3920.5 kJ/mol
4-(CH3SO2)-C6H4-CN798.7 kJ/mol
4-(i-C3H7)-C5H4N955.6 kJ/mol
4-(n-C8H17)C6H4NH2894.5 kJ/mol
4-(NO2)C6H4C(CH3)=CH2815.5 kJ/mol
4,4,4-Trifluorobutylamine903.3 kJ/mol
4,4-dimethyl-2-imidazoline988.3 kJ/mol
4-Aminobenzenecarbonal910.4 kJ/mol
4-BrC6H4CH=CH2838.9 kJ/mol
4-Bromopyridine918.0 kJ/mol
4-CF3C6H4C(CH3)CH2825.5 kJ/mol
4-CF3-C6H4-COCH3836.8 kJ/mol
4-CF3-C6H4CONH2862.7 kJ/mol
4-CF3-C6H4-COOCH3826.8 kJ/mol
4-CF3C6H4N(CH3)2903.3 kJ/mol
4-CH3C6H4C(CH3)CH2882.0 kJ/mol
4-CH3-C6H4-C(Si(CH3)3)=CH2877.0 kJ/mol
4-CH3COO-C6H4-COCH3853.1 kJ/mol
4-CH3OC6H4C(CH3)=CH2911.3 kJ/mol
4-CH3O-C6H4-C(Si(CH3)3)=CH2902.9 kJ/mol
4-CH3O-C6H4-CCH886.6 kJ/mol
4-CH3SC6H4C(CH3)=CH2946.0 kJ/mol
4-CH3S-C6H4-CCH886.6 kJ/mol
4-CH3S-C6H4-COCH3888.3 kJ/mol
4-CH3S-C6H4-COOCH3864.4 kJ/mol
4-CH3SO2-C6H4-COOCH3827.6 kJ/mol
4-Chloro-1-azabicyclo[2.2.2]octane949.3 kJ/mol
4-Chlorobenzoic acid methyl ester842.2 kJ/mol
4-Chloropyridine916.3 kJ/mol
4-ClC6H4C(CH3)=CH2854.4 kJ/mol
4-ClC6H4N(C2H5)2930.9 kJ/mol
4-Cl-pyrazole868.6 kJ/mol
4-Cyanobenzoic acid methyl ester816.7 kJ/mol
4-Cyanopiperidine912.1 kJ/mol
4-Ethylcamphor865.3 kJ/mol
4-ethynyl-pyridine930.1 kJ/mol
4-FC6H4C(CH3)=CH2862.7 kJ/mol
4-F-C6H4-C(Si(CH3)3)=CH2858.1 kJ/mol
4-FC6H4CCH827.6 kJ/mol
4-F-C6H4-COOCH3841.4 kJ/mol
4-fluoropyrazole863.2 kJ/mol
4-F-phenoxy854.4 kJ/mol
4-F-pyridine912.9 kJ/mol
4-H2NC6H4C(CH3)=CH2929.7 kJ/mol
4-H2N-C6H4-CCH912.5 kJ/mol
4-HC(O)-C6H4-COOCH3833.0 kJ/mol
4-Heptanone845.2 kJ/mol
4H-Pyran-4-one, 2,6-dimethyl-941.4 kJ/mol
4-Hydroxy-4-methylpentan-2-one823.0 kJ/mol
4-Me-phenoxy884.5 kJ/mol
4-Methyl-2,3-dihydrofuran868.6 kJ/mol
4-Methyl-2,6,7-trioxa-1-phosphabicyclo[2.2.1]heptane823.8 kJ/mol
4-Methyl-2,6,7-trioxa-1-phosphabicyclo[2.2.2]octane882.8 kJ/mol
4-Methylcamphor863.2 kJ/mol
4-Methylene-2,5-cyclohexadiene-1-one923.8 kJ/mol
4-Methylimidazole952.7 kJ/mol
4-methylpyrazole906.7 kJ/mol
4-N,N-Dimethylaminoacetophenone932.6 kJ/mol
4-NH2-C6H4CON(CH3)2956.9 kJ/mol
4-NH2-pyrazole907.5 kJ/mol
4-Nitrobenzoic acid methyl ester813.4 kJ/mol
4-Nitropyridine874.5 kJ/mol
4-NO2-C6H4CH2OH810.4 kJ/mol
4-NO2-pyrazole822.2 kJ/mol
4-OH-benzyl896.6 kJ/mol
4-phenyl-pyridine939.7 kJ/mol
4-Pyridinamine979.9 kJ/mol
4-Pyridinamine, N,N-dimethyl-997.5 kJ/mol
4-Pyridinecarbonitrile, 1-oxide873.2 kJ/mol
4-Pyridinecarbonitrile880.7 kJ/mol
4-Pyridinecarboxaldehyde904.6 kJ/mol
4-SO2F-C6H4-COOCH3802.5 kJ/mol
4-Tert-butylbenzoic acid methyl ester866.9 kJ/mol
4-Trifluoromethylbenzoic acid nitrile787.0 kJ/mol
4-Trifluoromethylpiperidine925.1 kJ/mol
5,5-Dimethyl-3-(diethylamino)-cyclohex-2-en-1-one1001.2 kJ/mol
5,5-Dimethyl-3-(piperidino)cyclohex-2-en-1-one1000.8 kJ/mol
5,5-Dimethyl-3-pyrrolidino-cyclohex-2-en-1-one1001.2 kJ/mol
5,6-Dihydrouridine874.0 kJ/mol
5-amino-tricyclo[4.4.0.03,8]decan-4-ol928.4 kJ/mol
5H-1-Pyrindine, 6,7-dihydro-957.3 kJ/mol
5H-2-Pyrindine, 6,7-dihydro-962.3 kJ/mol
5-Methylimidazo(1,2-a)pyridine987.4 kJ/mol
5-Nonanone853.5 kJ/mol
6-Chloro-1-methyl-2(1H)pyridinone918.4 kJ/mol
6-Chloropurine873.6 kJ/mol
6H-Purin-6-one, 2-amino-1,7-dihydro-959.4 kJ/mol
7-ethyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene (ETBD)1068.2 kJ/mol
7-isopropyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene (ITBD)1071.5 kJ/mol
7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene1062.7 kJ/mol
7-Methylimidazo(1,2-a)pyridine994.5 kJ/mol
7-Oxabicyclo[2.2.1]heptane844.3 kJ/mol
9,5-metheno-5H,7H-pyrimido[1,6-a:3,4-a']bisazepine930.9 kJ/mol
9H-Purine920.1 kJ/mol
Acenaphthene851.9 kJ/mol
Acetaldehyde768.6 kJ/mol
Acetaldehyde, trichloro-722.2 kJ/mol
Acetaldimine884.9 kJ/mol
Acetamide863.6 kJ/mol
Acetamide, N,N-dimethyl-907.9 kJ/mol
Acetamide, N,N-diethyl-925.5 kJ/mol
Acetamide, N-ethyl-897.9 kJ/mol
Acetamide, N-hydroxy-N-methyl876.1 kJ/mol
Acetamide, N-methyl-888.7 kJ/mol
Acetamide, N-methoxy879.1 kJ/mol
Acetamide,N-hydroxy854.0 kJ/mol
Acetic acid783.7 kJ/mol
Acetic acid ethenyl ester813.8 kJ/mol
Acetic acid, 1-methylethyl ester836.8 kJ/mol
Acetic acid, chloro-765.3 kJ/mol
Acetic acid, fluoro-765.3 kJ/mol
Acetic acid, methyl ester821.7 kJ/mol
Acetic acid, trichloro-769.9 kJ/mol
Acetic acid, trichloro-, ethyl ester790.4 kJ/mol
Acetic acid, trifluoro-711.7 kJ/mol
Acetic acid, trifluoro-, ethyl ester759.0 kJ/mol
Acetone812.1 kJ/mol
Acetonitrile779.1 kJ/mol
Acetonitrile, (dimethylamino)-884.5 kJ/mol
Acetonitrile, chloro-745.6 kJ/mol
Acetonitrile, trichloro-723.0 kJ/mol
Acetophenone861.1 kJ/mol
Acetophenone, 3'-chloro-846.8 kJ/mol
Acetophenone, 4'-methoxy-895.8 kJ/mol
Acetophenone, 4'-nitro-824.2 kJ/mol
Acetophenone, 4'-amino-908.8 kJ/mol
Acetophenone, 4'-hydroxy-883.7 kJ/mol
Acetylacetone873.6 kJ/mol
Acetylpyrrolidine925.5 kJ/mol
Acridine972.8 kJ/mol
Acrylamide870.7 kJ/mol
Adamantylmethylether860.2 kJ/mol
Adenine942.7 kJ/mol
adenosine989.1 kJ/mol
Alanine901.7 kJ/mol
Allyl radical736.0 kJ/mol
a-Methylstyrene864.0 kJ/mol
Amino radical773.2 kJ/mol
Ammonia853.5 kJ/mol
Aniline882.4 kJ/mol
Aniline, N-methyl-916.7 kJ/mol
Anilino radical949.8 kJ/mol
Anthracene877.4 kJ/mol
Anthracene, 1,2,3,4,5,6,7,8-octahydro-845.6 kJ/mol
Anthracene, 2-methyl-887.4 kJ/mol
Anthracene, 9-methyl-896.6 kJ/mol
Anthranilic acid901.7 kJ/mol
Arsabenzene784.9 kJ/mol
Arsine748.1 kJ/mol
Arsine, trimethyl-897.5 kJ/mol
Arsine, triphenyl-908.8 kJ/mol
Aspartic acid908.8 kJ/mol
Azetidine943.5 kJ/mol
Azetidine, N-methyl-882.4 kJ/mol
Aziridine, 1-methyl-934.7 kJ/mol
Aziridine, 1-phenyl-926.3 kJ/mol
Aziridine, 2-methyl-925.1 kJ/mol
Azulene925.1 kJ/mol
Azulene, 1,4-dimethyl-7-(1-methylethyl)-983.2 kJ/mol
B(OH)3728.0 kJ/mol
B5H8763.6 kJ/mol
Barium monoxide1215.5 kJ/mol
B-Borazinyl radical802.9 kJ/mol
Benzaldehyde833.9 kJ/mol
Benzaldehyde, 3-chloro-813.0 kJ/mol
Benzaldehyde, 3-methoxy-843.9 kJ/mol
Benzaldehyde, 4-(dimethylamino)-924.7 kJ/mol
Benzaldehyde, 4-chloro-831.4 kJ/mol
Benzaldehyde, 4-nitro-795.0 kJ/mol
Benzaldehyde, 4-methoxy-881.2 kJ/mol
Benzaldehyde, 4-methyl-851.9 kJ/mol
Benzaldehyde, 4-fluoro-827.2 kJ/mol
Benzamide892.0 kJ/mol
Benzamide, 3-fluoro-877.4 kJ/mol
Benzamide, 3-nitro-854.4 kJ/mol
Benzamide, 4-amino-928.0 kJ/mol
Benzamide, 4-chloro-877.4 kJ/mol
Benzamide, 4-methyl-900.8 kJ/mol
Benzamide, 4-nitro-845.2 kJ/mol
Benzamide, N,N-dimethyl-932.6 kJ/mol
Benzamide, N,N-dimethyl-4-nitro-900.8 kJ/mol
Benzenamine, 2,6-dimethyl-901.7 kJ/mol
Benzenamine, 2-methyl-890.8 kJ/mol
Benzenamine, 2-methoxy-905.0 kJ/mol
Benzenamine, 3-(trifluoromethyl)-856.9 kJ/mol
Benzenamine, 3-fluoro-867.3 kJ/mol
Benzenamine, 3-methyl-895.8 kJ/mol
Benzenamine, 3-methoxy-912.9 kJ/mol
Benzenamine, 4-chloro-N,N-dimethyl-923.0 kJ/mol
Benzenamine, 4-methoxy-900.4 kJ/mol
Benzenamine, 4-methoxy-N,N-dimethyl-948.9 kJ/mol
Benzenamine, N,N,2,6-tetramethyl-954.0 kJ/mol
Benzenamine, N,N,3,5-tetramethyl-956.0 kJ/mol
Benzenamine, N,N,2-trimethyl-951.9 kJ/mol
Benzenamine, N,N,3-trimethyl-942.2 kJ/mol
Benzenamine, N,N,4-trimethyl-950.2 kJ/mol
Benzenamine, N,N-diphenyl-908.8 kJ/mol
Benzenamine, N,N-dimethyl-3-nitro-894.1 kJ/mol
Benzenamine, N,N-diethyl-3-methyl-964.0 kJ/mol
Benzenamine, N,N-dimethyl-941.0 kJ/mol
Benzenamine, N,N-diethyl-959.8 kJ/mol
Benzenamine, N,N-diethyl-4-methyl-962.7 kJ/mol
Benzenamine, N,N-dimethyl-4-nitro-896.6 kJ/mol
Benzenamine, N-ethyl-924.7 kJ/mol
Benzenamine, N-methyl-4-nitro-891.6 kJ/mol
Benzene750.2 kJ/mol
Benzene, (1-methylethyl)-791.6 kJ/mol
Benzene, (2,2-dimethyl-1-methylenepropyl)-859.4 kJ/mol
Benzene, (methoxymethyl)-816.7 kJ/mol
Benzene, (methylthio)-872.8 kJ/mol
Benzene, 1-(2,2-dimethyl-1-methylenepropyl)-3-(trifluoromethyl)-830.9 kJ/mol
Benzene, 1-(2,2-dimethyl-1-methylenepropyl)-4-methoxy-897.9 kJ/mol
Benzene, 1-(2,2-dimethyl-1-methylenepropyl)-4-methyl-874.5 kJ/mol
Benzene, 1-(2,2-dimethyl-1-methylenepropyl)-3-methyl-867.3 kJ/mol
Benzene, 1-(2,2-dimethyl-1-methylenepropyl)-3-fluoro-838.9 kJ/mol
Benzene, 1-(2,2-dimethyl-1-methylenepropyl)-3,5-dimethyl-874.5 kJ/mol
Benzene, 1-(2,2-dimethyl-1-methylenepropyl)-4-(methylthio)-895.0 kJ/mol
Benzene, 1,1'-(1,3-propanediyl)bis-820.1 kJ/mol
Benzene, 1,1'-(1,4-butanediyl)bis-822.2 kJ/mol
Benzene, 1,1'-ethenylidenebis-[4-methyl-900.4 kJ/mol
Benzene, 1,2,3,4-tetrafluoro-700.4 kJ/mol
Benzene, 1,2,3,5-tetrafluoro-747.3 kJ/mol
Benzene, 1,2,3,5-tetramethyl-845.6 kJ/mol
Benzene, 1,2,4,5-tetrafluoro-746.4 kJ/mol
Benzene, 1,2-difluoro-731.4 kJ/mol
Benzene, 1,2-dimethyl-795.8 kJ/mol
Benzene, 1,3,5-tri-tert-butyl-848.9 kJ/mol
Benzene, 1,3,5-trimethyl-836.4 kJ/mol
Benzene, 1,3,5-trimethyl-2-nitro-823.8 kJ/mol
Benzene, 1,3-difluoro-749.8 kJ/mol
Benzene, 1,3-dimethyl-812.1 kJ/mol
Benzene, 1,4-difluoro-718.8 kJ/mol
Benzene, 1-bromo-4-methyl-775.3 kJ/mol
Benzene, 1-bromo-3-methyl-782.0 kJ/mol
Benzene, 1-bromo-2-methyl-775.3 kJ/mol
Benzene, 1-chloro-2-methyl-790.4 kJ/mol
Benzene, 1-chloro-3-(2,2-dimethyl-1-methylenepropyl)-839.7 kJ/mol
Benzene, 1-chloro-3-methyl-784.1 kJ/mol
Benzene, 1-chloro-4-ethynyl-832.2 kJ/mol
Benzene, 1-chloro-4-methyl-762.7 kJ/mol
Benzene, 1-cyclopropyl-4-methyl-846.4 kJ/mol
Benzene, 1-cyclopropyl-3-methyl-836.0 kJ/mol
Benzene, 1-ethenyl-4-methyl-861.9 kJ/mol
Benzene, 1-ethenyl-3-methyl-849.4 kJ/mol
Benzene, 1-ethenyl-2-methyl-855.2 kJ/mol
Benzene, 1-ethynyl-4-methyl-853.1 kJ/mol
Benzene, 1-fluoro-2-methyl-773.2 kJ/mol
Benzene, 1-fluoro-3-methyl-785.3 kJ/mol
Benzene, 1-fluoro-4-methyl-764.0 kJ/mol
Benzene, 1-iodo-2-methyl-780.3 kJ/mol
Benzene, 1-methyl-2-(1-methylethenyl)-857.7 kJ/mol
Benzene, 1-methyl-3-(1-methylethenyl)-867.8 kJ/mol
Benzene, 1-methyl-4-nitro-815.0 kJ/mol
Benzene, 1-propenyl-, (E)-834.3 kJ/mol
Benzene, 2,4-dimethyl-1-nitro-830.9 kJ/mol
Benzene, 2-chloro-4-(2,2-dimethyl-1-methylenepropyl)-1-methoxy-882.8 kJ/mol
Benzene, azido-820.1 kJ/mol
Benzene, bromo-754.0 kJ/mol
Benzene, butyl-792.0 kJ/mol
Benzene, chloro-753.1 kJ/mol
Benzene, cyclopropyl-834.7 kJ/mol
Benzene, fluoro-756.0 kJ/mol
Benzene, hexamethyl-860.6 kJ/mol
Benzene, isocyano-868.6 kJ/mol
Benzene, methoxy-839.7 kJ/mol
Benzene, nitro-800.4 kJ/mol
Benzene, nitroso-854.4 kJ/mol
Benzene, pentamethyl-850.6 kJ/mol
Benzene, propyl-789.9 kJ/mol
Benzene,1-methyl-3-(2-phenylethyl)-833.5 kJ/mol
Benzeneacetonitrile805.4 kJ/mol
Benzeneethanamine936.4 kJ/mol
Benzenemethanamine, N,N-dimethyl-968.6 kJ/mol
Benzo[ghi]perylene876.1 kJ/mol
Benzoic acid820.9 kJ/mol
Benzoic acid, 2-methyl-838.9 kJ/mol
Benzoic acid, 2-methyl-, methyl ester858.1 kJ/mol
Benzoic acid, 3-amino-864.8 kJ/mol
Benzoic acid, 3-methyl-829.7 kJ/mol
Benzoic acid, 3-methyl-, methyl ester857.7 kJ/mol
Benzoic acid, 4-hydroxy-, methyl ester863.6 kJ/mol
Benzoic acid, 4-amino-, methyl ester884.1 kJ/mol
Benzoic acid, 4-methyl-836.8 kJ/mol
Benzoic acid, 4-methyl-, methyl ester861.5 kJ/mol
Benzoic acid, 4-methoxy-, methyl ester870.7 kJ/mol
Benzoic acid, methyl ester850.6 kJ/mol
Benzonitrile811.7 kJ/mol
Benzonitrile, 3-amino-842.2 kJ/mol
Benzonitrile, 3-nitro-781.6 kJ/mol
Benzonitrile, 4-acetyl-826.8 kJ/mol
Benzonitrile, 4-(dimethylamino)-889.1 kJ/mol
Benzonitrile, 4-formyl-797.1 kJ/mol
Benzonitrile, 4-nitro-775.7 kJ/mol
Benzophenone882.4 kJ/mol
Benzoxazole891.6 kJ/mol
Benzyl alcohol778.2 kJ/mol
Benzyl methyl ketone842.7 kJ/mol
Benzyl radical831.4 kJ/mol
Benzylamine913.4 kJ/mol
Benzyne841.0 kJ/mol
Bibenzyl801.7 kJ/mol
Bicyclo[2.2.1]hept-2-en-5-one845.2 kJ/mol
Bicyclo[2.2.1]hept-2-ene, 7-oxa-837.2 kJ/mol
Bicyclo[2.2.1]hept-2-en-7-one830.1 kJ/mol
Bicyclo[2.2.1]hept-2-ene, 2-methyl-845.2 kJ/mol
Biphenyl813.8 kJ/mol
Biphenylene848.1 kJ/mol
Borazine802.5 kJ/mol
Boric acid, trimethyl ester815.9 kJ/mol
Boron oxide hydroxide763.2 kJ/mol
Butanal792.9 kJ/mol
Butane, 1-methoxy-820.5 kJ/mol
Butanenitrile798.3 kJ/mol
Butanoic acid, methyl ester836.4 kJ/mol
Butenamide, N,N-dimethyl-930.1 kJ/mol
Butyltrimethylhydrazine970.7 kJ/mol
C2H5CH(OC2H5)CH2CN807.1 kJ/mol
C2H5OCH=CHCH3876.5 kJ/mol
C2H5OCOOCH3842.7 kJ/mol
C2H5S(OCH3)CO833.9 kJ/mol
C2S869.4 kJ/mol
C3S933.0 kJ/mol
C6H11CH2OCH3833.5 kJ/mol
C6H5(CHC2H5) radical842.2 kJ/mol
C6H5CD3789.5 kJ/mol
C6H5CH=NH911.7 kJ/mol
C6H5COCCl3818.8 kJ/mol
Calcium monoxide1190.8 kJ/mol
Camphor859.4 kJ/mol
Carbon diselenide725.1 kJ/mol
Carbon monoselenide831.8 kJ/mol
Carbon monosulfide791.6 kJ/mol
Carbon trimer766.9 kJ/mol
Carbonic acid, dimethyl ester830.1 kJ/mol
Carbonochloridic acid, ethyl ester764.8 kJ/mol
Carbonodithioic acid, o,s-dimethyl ester862.7 kJ/mol
Carbonothioic dichloride752.7 kJ/mol
c-C(CH3)(C2H5)NHNH903.7 kJ/mol
c-C4H6N(2-OCH3)957.7 kJ/mol
c-C5H10N(2-OCH3)969.9 kJ/mol
c-C5H9N,2-CH2Cl,1-CH3964.8 kJ/mol
c-C6H11CH2N(CH3)2975.7 kJ/mol
c-C6H11CH2NH2926.8 kJ/mol
c-C6H11CH2SH813.8 kJ/mol
c-C6H11COCH3841.4 kJ/mol
c-C6H11COOCH3846.0 kJ/mol
c-C6H11SCH3864.4 kJ/mol
CCCO880.3 kJ/mol
CCl3CH2N(CH3)2912.9 kJ/mol
CCl3COCH3768.2 kJ/mol
Cesium hydroxide1118.0 kJ/mol
CF2HCON(CH3)2864.0 kJ/mol
CF3C(O)OCH3740.6 kJ/mol
CF3CH2COOC2H5797.5 kJ/mol
CF3CH2NHCH3881.2 kJ/mol
CF3CH2SC2H5797.5 kJ/mol
CF3CO2(n-C3H7)764.0 kJ/mol
CF3CO2(n-C4H9)764.8 kJ/mol
CF3CON(CH3)2848.9 kJ/mol
CF3CONH(n-C4H9)850.2 kJ/mol
CF3COOCH2CH2F735.5 kJ/mol
CF3COSCH3765.3 kJ/mol
CF3OCH3719.2 kJ/mol
CF3SO3H699.6 kJ/mol
CFH2COCFH2762.7 kJ/mol
CH2=(CH3)OSi(CH3)3930.5 kJ/mol
CH2=C(CH3)-SCH3888.7 kJ/mol
CH2=C(CH3)-SeCH3879.5 kJ/mol
CH2=C(SeCH3)2921.3 kJ/mol
CH2=CH-SeCH3851.0 kJ/mol
CH2CH2CH2OH736.0 kJ/mol
CH2CH2OH745.2 kJ/mol
CH2CHO774.0 kJ/mol
CH2COCH3820.1 kJ/mol
CH2NH2832.6 kJ/mol
CH3(C6H5)2PO908.8 kJ/mol
CH3C(=NH)NH2970.7 kJ/mol
CH3C(=S)OCH3846.0 kJ/mol
CH3C(N(CH3)2)=NN(CH3)2995.8 kJ/mol
CH3C(OCH3)=CHCOOCH3916.7 kJ/mol
CH3-CC-CC-CH2819.2 kJ/mol
CH3CH=C(CH3)C2H5813.0 kJ/mol
CH3CH=C(CH3)CH=CH2852.3 kJ/mol
CH3CH=CHN(CH3)2966.9 kJ/mol
CH3CH2NNN877.8 kJ/mol
CH3COCH2CH2COCH3892.0 kJ/mol
CH3COCN746.8 kJ/mol
CH3CONHCH(CH3)COOCH3938.5 kJ/mol
CH3CONHCH2COOCH3892.0 kJ/mol
CH3COOCN745.6 kJ/mol
CH3NCCCO920.1 kJ/mol
CH3NHCH2CH2NHCH3989.1 kJ/mol
CH3NHCH2CN864.0 kJ/mol
CH3NHCOOC2H5888.7 kJ/mol
CH3O(CH2)4OCH3931.4 kJ/mol
CH3O(CH2)5OCH3931.4 kJ/mol
CH3O[CH2CH2O]4CH3954.0 kJ/mol
CH3OC(S)N(CH3)2900.0 kJ/mol
CH3SCH2CN784.9 kJ/mol
CH3SO3H761.5 kJ/mol
c-hexane-1,2-dione849.8 kJ/mol
Chlorofluoromethylene772.4 kJ/mol
Chloromethylene874.0 kJ/mol
Chromium791.2 kJ/mol
Chromium hexacarbonyl739.3 kJ/mol
Chromium,dicarbonyl(?5-2,4-cyclopentadien-1-yl)nitrosyl-819.2 kJ/mol
Chrysene841.0 kJ/mol
Cinnoline936.4 kJ/mol
cis-1,2-Cyclopentanediol885.8 kJ/mol
cis-1,3-cyclohexandiol882.4 kJ/mol
cis-3-Aminobicyclo[2.2.2]octan-2-ol948.5 kJ/mol
Cl(CH2)2CN773.2 kJ/mol
ClCON(CH3)2846.0 kJ/mol
Cobalt742.7 kJ/mol
CoCH2937.6 kJ/mol
c-OP{N(CH3)2}N(CH3)CH2CH2N(CH3)961.9 kJ/mol
Coronene861.5 kJ/mol
c-P(O)CH3N(CH3)CH2CH2N(CH3)947.7 kJ/mol
Crotonic acid823.8 kJ/mol
CTe892.0 kJ/mol
CTe2771.1 kJ/mol
Cubane859.8 kJ/mol
Cyanamide805.4 kJ/mol
Cyanamide, dimethyl-852.3 kJ/mol
Cyanogen bromide749.8 kJ/mol
Cyanogen chloride722.2 kJ/mol
Cyanoketene784.1 kJ/mol
Cyclobutane carboxylic acid817.6 kJ/mol
Cyclobutanone802.5 kJ/mol
Cyclobutene784.5 kJ/mol
Cyclobutene, 1,2-dimethyl-838.1 kJ/mol
Cyclobutene, 1-methyl-841.4 kJ/mol
Cycloheptanone845.6 kJ/mol
Cycloheptatrienyl radical832.2 kJ/mol
Cyclohexanamine934.3 kJ/mol
Cyclohexanamine, N,N-dimethyl-983.7 kJ/mol
Cyclohexanecarboxylic acid823.8 kJ/mol
Cyclohexanecarbonitrile815.0 kJ/mol
Cyclohexanemethanol802.1 kJ/mol
Cyclohexanone841.0 kJ/mol
Cyclohexanone, 4-methyl-844.7 kJ/mol
Cyclohexene784.5 kJ/mol
Cyclohexene oxide848.1 kJ/mol
Cyclohexene, 1-methyl-825.1 kJ/mol
Cyclononanone852.7 kJ/mol
Cyclooctanone849.4 kJ/mol
Cyclopentadienyl radical831.4 kJ/mol
cyclopentane carboxylic acid817.6 kJ/mol
Cyclopentane, methylene-832.2 kJ/mol
Cyclopentanone823.8 kJ/mol
Cyclopentene766.5 kJ/mol
Cyclopentene, 1-methyl-816.3 kJ/mol
Cyclopentene, 1,2-dimethyl-822.6 kJ/mol
Cyclopropane750.2 kJ/mol
Cyclopropane, (1-methylethenyl)-871.5 kJ/mol
Cyclopropane, 1-ethenyl-1-methyl-855.6 kJ/mol
Cyclopropane, 1,1'-ethenylidenebis-904.6 kJ/mol
Cyclopropanecarbonitrile808.3 kJ/mol
Cyclopropanecarboxylic acid821.3 kJ/mol
Cyclopropanecarboxylic acid, methyl ester842.2 kJ/mol
Cyclopropene818.4 kJ/mol
Cyclopropene, 3,3-dimethyl-847.7 kJ/mol
Cyclopropenyl radical734.3 kJ/mol
Cyclopropenylidene951.0 kJ/mol
Cyclopropyl radical738.9 kJ/mol
Cyclopropylamine904.6 kJ/mol
Cytidine982.4 kJ/mol
Deoxyadenosine991.6 kJ/mol
Deoxycytidine988.3 kJ/mol
Deoxyguanosine995.4 kJ/mol
Di(1-pyrazolyl)methane924.7 kJ/mol
Dicarbon monoxide774.9 kJ/mol
Dicesium monoxide1443.1 kJ/mol
Dichloromethylene861.1 kJ/mol
Diethanolamine953.1 kJ/mol
Diethyl sulfide856.9 kJ/mol
Difluoroethanol727.6 kJ/mol
Difluoromethylene764.8 kJ/mol
Diimide802.9 kJ/mol
Diisopropyl ether855.6 kJ/mol
Diisopropyl sulfide876.5 kJ/mol
Dilithium monoxide1205.8 kJ/mol
Dimethyl ether792.0 kJ/mol
Dimethyl sulfide830.9 kJ/mol
Dimethyl sulfoxide884.5 kJ/mol
Dimethyl thioacetamide925.5 kJ/mol
Dimethyl(2,2-difluoroethyl)amine902.9 kJ/mol
Dimethyl(trimethylsilylmethyl)amine974.5 kJ/mol
Dimethylphenylphosphine969.0 kJ/mol
Di-n-butyl sulfide871.9 kJ/mol
Di-n-propyl ether838.1 kJ/mol
Diphenylmethane802.1 kJ/mol
Dipotassium oxide1342.6 kJ/mol
Di-sec-butyl ether866.1 kJ/mol
Disiloxane748.9 kJ/mol
Disiloxane, hexamethyl-846.4 kJ/mol
Disodium1146.8 kJ/mol
Disodium oxide1375.7 kJ/mol
Disulfide, dimethyl815.5 kJ/mol
Di-tert-butyl ether887.4 kJ/mol
Di-tert-butyl sulfide893.7 kJ/mol
Dithiouracil911.3 kJ/mol
dodecahedrane843.9 kJ/mol
Endo-2-aminonorbornane935.1 kJ/mol
Ethanamine, 2-methoxy-928.4 kJ/mol
Ethanamine, N-(2-propylidene)973.2 kJ/mol
Ethanamine, N,N-dimethyl-960.2 kJ/mol
Ethanamine, N-butylidene-955.6 kJ/mol
Ethanamine, N-ethyl-N-methyl-971.1 kJ/mol
Ethanamine, N-ethyl-952.3 kJ/mol
Ethanamine, N-ethyl-N-hydroxy-914.6 kJ/mol
Ethanamine, N-ethylidene941.8 kJ/mol
Ethanamine, N-methyl-942.2 kJ/mol
Ethane, (methylthio)-846.4 kJ/mol
Ethane, 1,1'-oxybis[2-methoxy-918.8 kJ/mol
Ethane, 1,2-dimethoxy-858.1 kJ/mol
Ethane, isocyano-851.4 kJ/mol
Ethane, methoxy-808.8 kJ/mol
Ethane, nitro-765.7 kJ/mol
Ethanethioamide884.5 kJ/mol
Ethanethioic acid, s-methyl ester828.9 kJ/mol
Ethanethiol789.5 kJ/mol
Ethanol776.6 kJ/mol
Ethanol, 1,1-dimethyl-802.5 kJ/mol
Ethanol, 2,2,2-trichloro-729.3 kJ/mol
Ethanol, 2,2,2-trifluoro-700.4 kJ/mol
Ethanol, 2-bromo-766.1 kJ/mol
Ethanol, 2-chloro-766.1 kJ/mol
Ethanol, 2-fluoro-715.5 kJ/mol
Ethanol, 2-methoxy-768.6 kJ/mol
Ethanolamine930.1 kJ/mol
Ethanone, 1-(3-fluorophenyl)-845.6 kJ/mol
Ethanone, 1-(3-hydroxyphenyl)-863.6 kJ/mol
Ethanone, 1-(3-methoxyphenyl)-871.1 kJ/mol
Ethanone, 1-(3-methylphenyl)-868.2 kJ/mol
Ethanone, 1-(3-pyridinyl)-916.3 kJ/mol
Ethanone, 1-(4-chlorophenyl)-856.5 kJ/mol
Ethanone, 1-(4-fluorophenyl)-858.6 kJ/mol
Ethanone, 1-(4-methylphenyl)-875.3 kJ/mol
Ethanone, 1-(4-pyridinyl)-914.6 kJ/mol
Ethanone, 1,1'-(1,4-phenylene)bis-850.6 kJ/mol
Ethanone, 1-[4-(1,1-dimethylethyl)phenyl]-882.4 kJ/mol
Ethanone, 1-cyclopropyl-854.8 kJ/mol
Ethanone, 2,2,2-trifluoro-1-phenyl-799.1 kJ/mol
Ethenamine898.7 kJ/mol
Ethene, 1,1-difluoro-733.9 kJ/mol
Ethene, 1,1-dimethoxy-956.9 kJ/mol
Ethene, ethoxy-870.3 kJ/mol
Ethene, fluoro-728.9 kJ/mol
Ethene, methoxy-859.4 kJ/mol
Ethene, trifluoro-699.6 kJ/mol
Ethenylcyclopropane816.3 kJ/mol
Ether, ethyl 2,2,2-trifluoroethyl762.3 kJ/mol
Ethoxy ethane828.4 kJ/mol
Ethyl acetate835.5 kJ/mol
Ethyl radical, 1-hydroxy720.1 kJ/mol
Ethylamine912.1 kJ/mol
Ethylamine, 2,2-difluoro-870.7 kJ/mol
Ethylamine, 2-fluoro-892.0 kJ/mol
Ethylbenzene787.8 kJ/mol
Ethylene carbonate814.2 kJ/mol
Ethylene oxide774.0 kJ/mol
Ethylene, 1,1-diphenyl-885.8 kJ/mol
Ethylenediamine951.4 kJ/mol
Ethylenimine905.4 kJ/mol
Ethynyl radical753.1 kJ/mol
Exo-2-aminonorbornane935.1 kJ/mol
F(CH3)Si=CH2771.1 kJ/mol
F2Si=CH2742.2 kJ/mol
FCH2CH2CH2NH2920.9 kJ/mol
FCO2C2H5756.9 kJ/mol
Ferrocene863.6 kJ/mol
Fluoranthene828.4 kJ/mol
Fluorene831.4 kJ/mol
Fluoromethylene797.9 kJ/mol
Formaldehyde713.0 kJ/mol
Formaldehyde, seleno-764.0 kJ/mol
Formamide822.2 kJ/mol
Formamide, N,N-dimethyl-887.4 kJ/mol
Formamide, N-methyl-851.4 kJ/mol
Formic acid741.8 kJ/mol
Formic acid, 1-methylethyl ester811.3 kJ/mol
Formic acid, butyl ester805.8 kJ/mol
Formic acid, ethyl ester799.6 kJ/mol
Formic acid, propyl ester805.0 kJ/mol
Fulminic acid758.1 kJ/mol
Furan803.3 kJ/mol
Furan, 2,3-dihydro-5-methyl-910.4 kJ/mol
Furan, 2,3-dihydro-866.9 kJ/mol
Furan, 2,5-bis(1,1-dimethylethyl)-894.5 kJ/mol
Furan, 2,5-dihydro-823.4 kJ/mol
Furan, 2,5-dimethyl-866.1 kJ/mol
Furan, 2-methyl-866.1 kJ/mol
Furan, 3-methyl-854.0 kJ/mol
Furan, tetrahydro-822.2 kJ/mol
Furan, tetrahydro-2-methyl-841.0 kJ/mol
Germane713.4 kJ/mol
Glycine886.6 kJ/mol
Glycylglycylglycylglycine973.6 kJ/mol
Guanidine986.2 kJ/mol
guanosine993.3 kJ/mol
H2C=Te795.8 kJ/mol
H2NCH2CH2CN866.5 kJ/mol
H2N-NO2757.3 kJ/mol
H2SiO841.0 kJ/mol
H2SiOH738.1 kJ/mol
H3PO3821.3 kJ/mol
H3SiO700.0 kJ/mol
H3SiOH746.4 kJ/mol
HCCCH2CH()CCH748.9 kJ/mol
HCOH (hydroxymethylene)966.1 kJ/mol
HCOONH2834.7 kJ/mol
Heptamethylenesulfide860.6 kJ/mol
Histamine1000.0 kJ/mol
HNCCCO861.1 kJ/mol
HOCH2CH(OH)CH2CH2OH905.8 kJ/mol
HSiO810.0 kJ/mol
HSiOH840.1 kJ/mol
Hydrazine853.1 kJ/mol
Hydrazine, 1,1-dimethyl-927.2 kJ/mol
Hydrazine, 1,2-dimethyl 1,2-dineopentyl-977.8 kJ/mol
Hydrazine, 1,2-dimethyl-1,2-dipropyl971.9 kJ/mol
Hydrazine, 1,2-di-isobutyl 1,2-dimethyl-979.9 kJ/mol
Hydrazine, methyl-898.7 kJ/mol
Hydrazine, N,N'-dibutyl-N,N'-dimethyl-975.7 kJ/mol
Hydrazine, N,N'-dimethyl-N,N'-dipentyl-977.4 kJ/mol
Hydrogen azide756.0 kJ/mol
Hydrogen cyanide713.0 kJ/mol
Hydrogen isocyanide772.4 kJ/mol
Hydrogen selenide707.9 kJ/mol
Hydrogen sulfide705.0 kJ/mol
Hydrogen telluride736.0 kJ/mol
Hydromanganese pentacarbonyl835.5 kJ/mol
Hydroxylamine, o-methyl-844.7 kJ/mol
Hypoxanthine912.1 kJ/mol
i-C3H7(C6H5)2PO908.8 kJ/mol
i-C3H7CON(CH3)2923.8 kJ/mol
Imidazo[1,2-a]pyridine971.9 kJ/mol
Indene848.9 kJ/mol
Indole933.5 kJ/mol
Iodoethane724.7 kJ/mol
Iron754.0 kJ/mol
Iron monoxide907.1 kJ/mol
Iron pentacarbonyl833.0 kJ/mol
Iron, methylene-937.6 kJ/mol
Iron,methyldicarbonyl-?5-cyclopentadienyl792.0 kJ/mol
Isocyanic acid753.1 kJ/mol
Isoleucine917.6 kJ/mol
Isopropyl alcohol792.9 kJ/mol
Iso-propyl nitrite845.6 kJ/mol
Isoquinoline951.9 kJ/mol
Isoquinoline, 5,6,7,8-tetrahydro-966.5 kJ/mol
Isoxazole848.5 kJ/mol
Ketene825.5 kJ/mol
Lanthanum1012.9 kJ/mol
L-Arginine1051.0 kJ/mol
L-Asparagine928.8 kJ/mol
L-Cysteine903.3 kJ/mol
Leucine914.6 kJ/mol
L-Glutamic acid912.9 kJ/mol
L-Glutamine937.6 kJ/mol
L-Histidine987.8 kJ/mol
LiOH1000.0 kJ/mol
Lithium bromide818.8 kJ/mol
Lithium chloride827.2 kJ/mol
Lithium dimer1161.9 kJ/mol
Lithium hydride1021.7 kJ/mol
L-Methionine935.5 kJ/mol
L-Phenylalanine923.0 kJ/mol
L-Serine914.6 kJ/mol
L-Tryptophan948.9 kJ/mol
Lutetium992.0 kJ/mol
Lysine995.8 kJ/mol
Magnesium819.6 kJ/mol
Magnesium dimer918.8 kJ/mol
Magnesium monoxide987.8 kJ/mol
Malononitrile723.0 kJ/mol
Manganese797.5 kJ/mol
Manganese, pentacarbonylmethyl-764.4 kJ/mol
Manganese, tricarbonyl[(1,2,3,4,5-?5)-1-methyl-2,4-cyclopentadien-1-yl]-833.9 kJ/mol
m-Chloroaniline868.2 kJ/mol
Mercaptomethyl radical733.9 kJ/mol
Mercury, dimethyl-771.5 kJ/mol
Methacrylamide880.3 kJ/mol
Methanamine, N,N-dimethyl-, N-oxide983.2 kJ/mol
Methanamine, N-methyl-929.7 kJ/mol
Methanamine, N-methyl-N-nitro-828.4 kJ/mol
Methane, diazo-859.0 kJ/mol
Methane, isocyano-838.9 kJ/mol
Methane, isocyanato-764.4 kJ/mol
Methane, isothiocyanato-799.1 kJ/mol
Methane, nitro-754.8 kJ/mol
Methanediamine, N,N,N',N'-tetramethyl-952.3 kJ/mol
Methanethioamide, N,N-dimethyl-906.3 kJ/mol
Methanethiol773.2 kJ/mol
Methanimine852.7 kJ/mol
Methanone, dicyclopropyl-880.3 kJ/mol
Methinophosphide699.1 kJ/mol
Methoxyacetonitrile758.1 kJ/mol
Methyl alcohol754.4 kJ/mol
Methyl azide833.0 kJ/mol
Methyl diazene845.2 kJ/mol
Methyl dithioacetate860.6 kJ/mol
Methyl formate782.4 kJ/mol
Methyl nicotinate925.5 kJ/mol
Methyl nitrate733.5 kJ/mol
Methyl nitrite798.7 kJ/mol
Methyl propyl ether815.0 kJ/mol
Methyl radical, methoxy-756.0 kJ/mol
Methyl rhenium pentacarbonyl774.9 kJ/mol
Methyl vinyl ketone834.7 kJ/mol
Methyl vinyl sulfide858.1 kJ/mol
Methylamine899.1 kJ/mol
Methyldodecahedrane855.6 kJ/mol
Methylketene834.3 kJ/mol
m-Methoxybenzamide900.8 kJ/mol
Molybdenum hexacarbonyl762.7 kJ/mol
Morpholine924.2 kJ/mol
m-Toluamide900.8 kJ/mol
N-(N-Glycylglycyl)glycine966.9 kJ/mol
N,3,5-Trimethylpiperidine978.2 kJ/mol
N,N,2,6-Tetramethylaniline,4-carboxylic acid, methyl ester945.6 kJ/mol
N,N,2,6-Tetramethyl-4-nitroaniline918.4 kJ/mol
N,N,2,6-Tetramethylaniline,4-bromo-935.5 kJ/mol
N,N,2,6-Tetramethylaniline,4-fluoro943.1 kJ/mol
N,N,2,6-Tetramethyl-4-cyanoaniline913.4 kJ/mol
N,N,4-Trimethyl benzamide927.2 kJ/mol
N,N,N',N',N",N'-Hexamethylphosphorotriamide958.6 kJ/mol
N,N,N',N',N''-Pentamethylguanidine1047.7 kJ/mol
N,N,N',N'-Tetramethylphosphorotriamide947.7 kJ/mol
N,N,N',N'-Tetramethylguanidine1031.8 kJ/mol
N,N,N'-Trimethyl-1,8-naphthalenediamine984.5 kJ/mol
N,N'-Bipyrrolidine979.9 kJ/mol
N,N-Di-(n-propyl)benzenamine963.2 kJ/mol
N,N'-Diethyl-N,N'-dimethylhydrazine963.6 kJ/mol
N,N-Dimethyl 4-methoxybenzamide948.1 kJ/mol
N,N-Dimethyl isobutylamine968.6 kJ/mol
N,N-Dimethyl p-chlorobenzamide928.0 kJ/mol
N,N-Dimethyl p-fluorobenzamide928.0 kJ/mol
N,N'-Dimethyl-1,8-naphthalenediamine960.2 kJ/mol
N,N-Dimethyl-1-adamantylcarboxamide949.3 kJ/mol
N,N-Dimethyl-2-pyridinamine968.2 kJ/mol
N,N-Dimethyl-3-pyridinamine969.4 kJ/mol
N,N-Dimethyl-4-fluoroaniline924.7 kJ/mol
N,N-Dimethyladamantylamine993.7 kJ/mol
N,N-Dimethylallyl amine957.7 kJ/mol
N,N-Dimethylbenzenamine,2,4-di-t-butyl973.2 kJ/mol
N,N-Dimethylbutyramide921.7 kJ/mol
N,N-Dimethyl-p-trifluorobenzamide904.6 kJ/mol
N,N-Dimethyl-tert-butylcarboxamide927.2 kJ/mol
Naphthacene905.4 kJ/mol
Naphthalene802.9 kJ/mol
Naphthalene, 1-methyl-834.7 kJ/mol
Naphthalene, 2-methyl-831.8 kJ/mol
n-Butyl ether845.6 kJ/mol
n-Butylpyrazole928.8 kJ/mol
n-C3H7NHCHO878.2 kJ/mol
NCC(CH3)CO797.9 kJ/mol
NCCH2NH2825.1 kJ/mol
NCCOOC2H5745.6 kJ/mol
N'-cyano-N,N-dimethyl formamidine889.5 kJ/mol
neo-C5H11CON(CH3)2927.6 kJ/mol
Neopentyl, t-butyl amine991.6 kJ/mol
Neopentylamine928.4 kJ/mol
N-Ethyl-N-methylaniline938.9 kJ/mol
NH2(CH2)4OH984.5 kJ/mol
NH2(CH2)6OH969.0 kJ/mol
Niacinamide918.4 kJ/mol
Nickel736.8 kJ/mol
Nickel tetracarbonyl742.2 kJ/mol
Nickelocene935.5 kJ/mol
Nikethamide941.0 kJ/mol
Nitric acid751.4 kJ/mol
Nitrous acid, ethyl ester818.8 kJ/mol
N-Methyl methanimine884.5 kJ/mol
Norbornan-7-one832.2 kJ/mol
N-Phenylazetidine933.0 kJ/mol
N-Phenylpiperidine952.7 kJ/mol
N-Phenylpyrrolidine941.4 kJ/mol
n-Propyl acetate836.8 kJ/mol
O(CH2CH2CN)2813.8 kJ/mol
o,o',o''-Trimethyl thiophosphate883.7 kJ/mol
OP(CH2N(CH3)2)3997.9 kJ/mol
OP(N(C2H5)2)3974.9 kJ/mol
OP(N(CH3)2)(CH3)2935.5 kJ/mol
OP(n-C3H7)3948.1 kJ/mol
Oxazole876.5 kJ/mol
Oxepane834.3 kJ/mol
Oxetane801.2 kJ/mol
o-Xylylene898.7 kJ/mol
p-Aminobenzoic acid864.8 kJ/mol
p-Benzoquinone799.1 kJ/mol
p-CF3C6H4CHO805.4 kJ/mol
p-Chloroaniline873.6 kJ/mol
Pentaborane(9)699.6 kJ/mol
Pentamethylphosphonic diamide951.4 kJ/mol
Pentanal796.6 kJ/mol
Pentane, 1,1'-oxybis-852.7 kJ/mol
Pentanenitrile802.5 kJ/mol
Perfluoro-tert-butylamine783.7 kJ/mol
Perylene888.7 kJ/mol
p-Fluoroaniline871.5 kJ/mol
p-Fluorobenzamide877.4 kJ/mol
Phenanthrene825.5 kJ/mol
Phenanthrene, 1,2,3,4,5,6,7,8-octahydro-846.0 kJ/mol
Phenazine938.5 kJ/mol
Phenol817.1 kJ/mol
Phenol, 2-amino-898.7 kJ/mol
Phenol, 3-amino-898.7 kJ/mol
Phenoxy radical857.7 kJ/mol
Phenyl 3-pyridyl ketone934.3 kJ/mol
Phenyl radical884.1 kJ/mol
Phenylacetylene832.2 kJ/mol
Phosphabenzene817.6 kJ/mol
Phosphine784.9 kJ/mol
Phosphine, dimethyl-912.1 kJ/mol
Phosphine, methyl-851.4 kJ/mol
Phosphine, methyldiphenyl-971.9 kJ/mol
Phosphine, triethyl-984.5 kJ/mol
Phosphine, trimethyl-959.0 kJ/mol
Phosphine, triphenyl-972.8 kJ/mol
Phosphino radical709.2 kJ/mol
Phosphirane802.5 kJ/mol
Phosphonic acid, dimethyl ester895.0 kJ/mol
Phosphoric acid, trimethyl ester890.8 kJ/mol
Phosphorothioic triamide, hexamethyl-941.8 kJ/mol
Phosphorous acid, trimethyl ester929.7 kJ/mol
Phosphorous triamide, hexamethyl-930.1 kJ/mol
Phosphorus mononitride789.5 kJ/mol
Phosphorus monosulfide697.9 kJ/mol
Picene851.4 kJ/mol
Piperazine943.5 kJ/mol
Piperidine954.0 kJ/mol
Piperidine, 1-(2-methyl-1-propenyl)-978.2 kJ/mol
Piperidine, 1-(2-methylpropyl)-974.5 kJ/mol
Piperidine, 1-carbonitrile-876.5 kJ/mol
Piperidine, 1-methyl-971.1 kJ/mol
Piperidine, 2,2,6,6-tetramethyl-987.0 kJ/mol
p-Methoxybenzamide900.4 kJ/mol
p-Nitroaniline866.1 kJ/mol
Potassium hydroxide1101.6 kJ/mol
Proline920.5 kJ/mol
Propanal786.2 kJ/mol
Propanal, 2-methyl-797.5 kJ/mol
Propanamide876.1 kJ/mol
Propanamide, 2,2-dimethyl-889.1 kJ/mol
Propanamide, 2-methyl-878.6 kJ/mol
Propanamide, N-methyl-920.5 kJ/mol
Propane, 1,1'-thiobis-864.8 kJ/mol
Propane, 1,3-dimethoxy-897.0 kJ/mol
Propane, 1-isocyano-856.9 kJ/mol
Propane, 1-methoxy-2,2-dimethyl-825.9 kJ/mol
Propane, 2-ethoxy-842.7 kJ/mol
Propane, 2-ethoxy-2-methyl-856.0 kJ/mol
Propane, 2-methoxy-2-methyl-841.4 kJ/mol
Propane, 2-methoxy-826.3 kJ/mol
Propane, 2-methyl-2-(1-methylethoxy)-870.7 kJ/mol
Propanenitrile794.1 kJ/mol
Propanenitrile, 2,2-dimethyl-810.9 kJ/mol
Propanenitrile, 2-methyl-803.7 kJ/mol
Propanoic acid797.1 kJ/mol
Propanoic acid, 2,2-dimethyl-, methyl ester845.2 kJ/mol
Propanoic acid, 2-methyl-, methyl ester836.8 kJ/mol
Propanoic acid, methyl ester830.1 kJ/mol
Propargyl radical741.0 kJ/mol
Propargylamine887.4 kJ/mol
Propene751.4 kJ/mol
Propiolonitrile751.0 kJ/mol
Propylamine, 3,3,3-trifluoro-887.0 kJ/mol
Propylene oxide803.3 kJ/mol
Propyltrimethylhydrazine966.9 kJ/mol
Propyne748.1 kJ/mol
p-Toluidine896.6 kJ/mol
p-Xylene794.5 kJ/mol
Pyrazine877.0 kJ/mol
Pyrazolidine, 1,2-dimethyl-959.4 kJ/mol
Pyrene869.0 kJ/mol
Pyridazine907.1 kJ/mol
Pyridazine hexahydro-1,2-dimethyl-966.1 kJ/mol
Pyridine930.1 kJ/mol
Pyridine, 1-oxide923.4 kJ/mol
Pyridine, 2-(methylthio)-937.6 kJ/mol
Pyridine, 2,3-dimethyl-959.0 kJ/mol
Pyridine, 2,4-dimethyl-962.7 kJ/mol
Pyridine, 2,5-dimethyl-959.0 kJ/mol
Pyridine, 2,6-dimethyl-963.2 kJ/mol
Pyridine, 2-bromo-905.0 kJ/mol
Pyridine, 2-chloro-6-methoxy-910.0 kJ/mol
Pyridine, 2-chloro-900.8 kJ/mol
Pyridine, 2-ethyl-952.3 kJ/mol
Pyridine, 2-methyl-948.9 kJ/mol
Pyridine, 2-methoxy-934.7 kJ/mol
Pyridine, 3-(methylthio)-936.4 kJ/mol
Pyridine, 3,4-dimethyl-957.3 kJ/mol
Pyridine, 3,5-dimethyl-955.2 kJ/mol
Pyridine, 3-bromo-910.0 kJ/mol
Pyridine, 3-chloro-903.3 kJ/mol
Pyridine, 3-methyl-, 1-oxide935.1 kJ/mol
Pyridine, 3-methyl-943.5 kJ/mol
Pyridine, 3-methoxy-942.7 kJ/mol
Pyridine, 4-(1,1-dimethylethyl)-957.7 kJ/mol
Pyridine, 4-(methylthio)-955.2 kJ/mol
Pyridine, 4-ethenyl-943.9 kJ/mol
Pyridine, 4-methyl-947.3 kJ/mol
Pyridine, 4-methoxy-961.9 kJ/mol
Pyridine, 4-trifluoromethyl-893.7 kJ/mol
Pyridine, pentafluoro-764.8 kJ/mol
Pyridine-1-oxide, 4-nitro-868.2 kJ/mol
Pyridine-4-carboxylic acid, methyl ester926.8 kJ/mol
Pyrrole875.3 kJ/mol
Pyrrolidine948.1 kJ/mol
Pyrrolidine, 1-(4-chlorophenyl)937.2 kJ/mol
Pyrrolidine, 1-(1-cyclopenten-1-yl)-1019.2 kJ/mol
Pyrrolidine, 1-(4-methoxyphenyl)961.1 kJ/mol
Pyrrolidine, 1-(4-methylphenyl)910.0 kJ/mol
Pyrrolidine, 1-methyl-965.7 kJ/mol
Quinoline953.1 kJ/mol
Quinoline, 1-oxide943.5 kJ/mol
Quinoline, 5,6,7,8-tetrahydro-966.1 kJ/mol
Quinoxaline903.7 kJ/mol
Quinuclidine983.2 kJ/mol
Rhodium768.2 kJ/mol
Ruthenium774.0 kJ/mol
Ruthenium, bis(?5-cyclopentadienyl)899.1 kJ/mol
Sarcosine921.3 kJ/mol
Scandium914.2 kJ/mol
Silane, ethenyltrimethyl-833.0 kJ/mol
Silane, methoxytrimethyl-846.8 kJ/mol
Silane, trimethyl(3-phenyl-2-propenyl)-878.6 kJ/mol
Silane,trimethyl(1-phenylethenyl)-861.1 kJ/mol
Silanol, trimethyl814.2 kJ/mol
Silicon836.8 kJ/mol
Silicon monoxide777.8 kJ/mol
Silylene839.3 kJ/mol
SiNH853.1 kJ/mol
SiOH732.6 kJ/mol
SiS710.0 kJ/mol
Sodium hydride1095.0 kJ/mol
Sodium hydroxide1071.9 kJ/mol
Stannane, tetramethyl-823.8 kJ/mol
Stibine, triphenyl-845.6 kJ/mol
Strontium monohydroxide1019.2 kJ/mol
Strontium monoxide1209.2 kJ/mol
Styrene839.3 kJ/mol
Styrene, a-tert-butyl-p-(trifluoromethyl)-825.5 kJ/mol
Sulfine798.7 kJ/mol
Sulfone, methyl phenyl812.5 kJ/mol
Sulfuric acid699.6 kJ/mol
t-C4H9(C6H5)2PO908.8 kJ/mol
Tert-butyl isocyanide870.7 kJ/mol
Tert-butyl trimethylhydrazine968.6 kJ/mol
Tetraborane(8)784.9 kJ/mol
Tetraethylhydrazine964.4 kJ/mol
Tetralin809.6 kJ/mol
Tetramethylhydrazine948.5 kJ/mol
Thiazole904.2 kJ/mol
Thietane834.7 kJ/mol
Thiirane807.5 kJ/mol
Thiirane, methyl-833.5 kJ/mol
Thioacetic acid, o-ethyl ester863.6 kJ/mol
thiocamphor884.1 kJ/mol
Thiocyanato radical751.0 kJ/mol
Thiocyanic acid, methyl ester796.6 kJ/mol
Thioformaldehyde759.8 kJ/mol
Thioketene826.3 kJ/mol
Thiophene815.0 kJ/mol
Thiophene, 2-methyl-859.0 kJ/mol
Thiophene, tetrahydro-848.9 kJ/mol
Thiourea893.7 kJ/mol
Thiourea, N,N'-dimethyl-925.9 kJ/mol
Thiourea, tetramethyl-947.7 kJ/mol
Threonine922.6 kJ/mol
Thymidine948.1 kJ/mol
Thymine880.7 kJ/mol
Titanium876.1 kJ/mol
Toluene784.1 kJ/mol
trans-1,3-cyclohexanol828.4 kJ/mol
trans-1,4-dibenzylcyclohexane805.8 kJ/mol
trans-1,4-diphenylcyclohexane804.2 kJ/mol
trans-3-Aminobicyclo[2.2.2]octan-2-ol933.0 kJ/mol
trans-Alpha,beta-penteneoic acid823.4 kJ/mol
trans-CH3CH=CH-OC2H5877.0 kJ/mol
trans-dimethylamino acrylonitrile896.6 kJ/mol
Tributylamine998.3 kJ/mol
Tricyclo[3.3.1.13,7]decane-1-amine948.9 kJ/mol
Tricyclo[3.3.1.13,7]decane-1-carboxylic acid, methyl ester864.0 kJ/mol
Tricyclo[3.3.1.13,7]decane-1-carbonitrile834.3 kJ/mol
tricyclo[4.4.0.03,8]decan-4-ol-5-amino, stereoisomer948.9 kJ/mol
tricyclo[4.4.0.03,8]decan-4-ol-5-amino, stereoisomer946.8 kJ/mol
Triethyl phosphate909.2 kJ/mol
Triethylamine982.0 kJ/mol
Triethylenediamine963.6 kJ/mol
Trifluoronitrosomethane703.3 kJ/mol
Trimethylamine948.9 kJ/mol
Trimethylphosphine oxide909.6 kJ/mol
Triphenylene819.2 kJ/mol
Tris(2-methylallyl)amine980.3 kJ/mol
Tris(dimethylamino)phosphine selenide934.3 kJ/mol
Tungsten hexacarbonyl758.1 kJ/mol
Tyrosine925.9 kJ/mol
Uracil872.8 kJ/mol
Uranium995.4 kJ/mol
Urea, N,N'-dimethyl-903.3 kJ/mol
Urea, tetramethyl-930.5 kJ/mol
Uridine947.7 kJ/mol
Valine910.4 kJ/mol
Vanadium859.4 kJ/mol
Vinyl radical755.2 kJ/mol
vinylimine912.1 kJ/mol
Yttrium966.9 kJ/mol

The Kore PTR-TOF-MS is delivered with a water vapour system that produces H3O+ reagent ions from the ion source, but the glow discharge ion source can be operated with other gas species. Alternative gases can be supplied to the glow discharge ion source as a standard instrument feature.

 

O2+ Reagent Ions

These ions can be generated by passing pure O2 gas into the glow discharge ion source. It is also the case that allowing air to the glow discharge will also produce copious amounts of O2+. Also produced with an air feed are NO+ ions, but the ionisation energy for this species is 9.26eV, as opposed to 12.07eV for O2+, and thus the dominating ionisation method for most analytes is by charge exchange with O2+.

 

BTX sample in water (ppm level) with O2+ reagent ions. Note how the molecular ions are M+ species, not (M+H)+, as is observed with H3O+ reagent ions.

 

NO+ Reagent Ions

NO gas can also be fed directly into the glow discharge, where it produces an intense beam of NO+ ions at mass 30 (see above). The low intensity peaks at mass 31 and 32 are due to ions 14N17O and 15N16O, and 14N18O and 15N17O respectively.

 

Ar+, Xe+, Kr+ Reagent Ions

We have also operated the Kore glow discharge source on various noble gases such as argon, xenon and krypton. In this mode, the ion source is run on an inert gas such as argon, xenon or krypton, instead of N2/H2O mixture.

 

The primary ion produced from the glow discharge source has a specific energy in its ionised state. If it impacts a molecule in the collision cell and that molecule requires less energy to be ionised, then that molecule can become ionised and the primary ion will convert to a neutral particle. The sequence is as follows:

Kr+ (13.99 eV) + CO → CO+ (13.98 eV) + Kr
(Chemical Ionisation by Ion-Molecule Reaction)

 

However, if the molecule requires more energy than is available in the rare gas ion, the molecule remains neutral, e.g.

Kr+ (13.99 eV) + N2 → Kr+ + N2
(No Chemical Ionisation)

 

This is because 15.5 eV is required to ionise N2.

 

Notice that N2 and CO both have masses of 28. Their exact masses are 28.0061 and 27.9949 respectively. Ordinarily, a mass spectrometer would need to have a certain ‘resolving power’ to separate these two masses. However, by using a chemical ionisation technique, it is possible to achieve selective ionisation of such ‘isobaric interferences’.

 

Ionisation energies of inert gases that can be run in the glow discharge source:

Ar+(15.76 eV)
N2+(15.50 eV)
Kr+(13.99 eV)
Xe+(12.13 eV)

 

The glow discharge has been run with both Ar and Xe, producing Ar+ and Xe+ ion beams Krypton may also be used.

 

The table below lists the ionisation energies of various components, and the primary ion beams that could be used.

 

Ionisation Energies of Common Compounds
Species of InterestIonisation Energy (eV)Primary Species
CO13.98Ar+, Kr+
CO213.78Ar+, Kr+
SO212.32Ar+, Kr+
CH4 (methane)12.61Ar+, Kr+
O212.07Ar+, Kr+
C2H6 (ethane)11.52Ar+, Kr+
COS11.18Ar+, Kr+, Xe+
C3H8 (butane)10.94Ar+, Kr+, Xe+
C2H4 (ethylene)10.51Ar+, Kr+, Xe+
H2S10.45Ar+, Kr+, Xe+
NO29.75Ar+, Kr+, Xe+
C4H8 (isobutene)9.55Ar+, Kr+, Xe+
NO9.26Ar+, Kr+, Xe+
Benzene9.25Ar+, Kr+, Xe+
Toluene8.82Ar+, Kr+, Xe+
Xylene8.56Ar+, Kr+, Xe+

 

Organic molecules have lower ionisation energies. In a collision, if the difference in ionisation energy is large, then the excess energy can cause fragmentation of the organic molecule. Thus the ionising gas species should be matched where possible to the analyte molecules of interest. For this reason, some researchers also run a primary ion source on Hg vapour to produce Hg+ ions (10.44eV) to minimise fragmentation.

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