return to home page Computational Chemistry Comparison and Benchmark DataBase Release 18 (October 2016) Standard Reference Database 101 National Institute of Standards and Technology
You are here: Home > Ions > Proton Affinity > Calculated Proton affinity OR Calculated > Energy > Ion > Calculated Proton affinity

Proton Affinity

Click on formula for calculated relative enthalpies.
Name Species   Species Name
Hydrogen atom anion H- H2 Hydrogen diatomic
Hydrogen atom H H2+ Hydrogen cation
Helium atom anion He- HeH Helium hydride
Helium atom He HeH+ Helium hydride cation
Lithium atom anion Li- LiH Lithium Hydride
Lithium atom Li LiH+ lithium hydride cation
Beryllium atom anion Be- BeH beryllium monohydride
Beryllium atom Be BeH+ beryllium monohydride cation
Boron atom anion B- BH Boron monohydride
Boron atom B BH+ boron monohydride cation
Carbon atom anion C- CH Methylidyne
Carbon atom C CH+ Methylidyne cation
Nitrogen atom anion N- NH Imidogen
Nitrogen atom N NH+ imidogen cation
Oxygen atom anion O- OH Hydroxyl radical
Oxygen atom O OH+ hydoxyl cation
Fluorine atom anion F- HF Hydrogen fluoride
Fluorine atom F HF+ hydrogen fluoride cation
Neon atom anion Ne- NeH neon hydrogen
Neon atom Ne NeH+ neon hydrogen cation
Sodium atom anion Na- NaH sodium hydride
Sodium atom Na NaH+ sodium hydride cation
Magnesium atom anion Mg- MgH magnesium monohydride
Magnesium atom Mg MgH+ magnesium monohydride cation
Aluminum atom anion Al- AlH aluminum monohydride
Aluminum atom Al AlH+ aluminum monohydride cation
Silicon atom anion Si- SiH Silylidyne
Silicon atom Si SiH+ silicon monohydride cation
Phosphorus atom anion P- PH phosphorus monohydride
Phosphorus atom P PH+ phosphorus monohydride cation
Sulfur atom anion S- HS Mercapto radical
Sulfur atom S HS+ sulfur monohydride cation
Chlorine atom anion Cl- HCl Hydrogen chloride
Chlorine atom Cl HCl+ hydrogen chloride cation
Argon atom Ar ArH+ Argon hydride cation
Potassium atom anion K- KH Potassium hydride
Potassium atom K KH+ Potassium hydrogen cation
Calcium atom anion Ca- CaH Calcium monohydride
Calcium atom Ca CaH+ Calcium monohydride cation
Scandium atom Sc ScH+ Scandium monohydride cation
Titanium atom anion Ti- TiH Titanium monohydride
Manganese atom Mn H+ Hydrogen atom cation
Copper atom anion Cu- CuH Copper monohydride
Zinc atom anion Zn- ZnH Zinc monohydride
Gallium atom anion Ga- GaH Gallium monohydride
Gallium atom Ga GaH+ Gallium monohydride cation
Germanium anion Ge- GeH germylidene
Germanium atom Ge GeH+ Germaniun monohyrdide cation
Arsenic anion As- AsH Arsenic monohydride
Arsenic atomic As AsH+ Arsenic monohydride cation
Selenium atom anion Se- HSe Selenium monohydride
Selenium atom Se HSe+ selenium monohydride cation
Bromine atom anion Br- HBr hydrogen bromide
Bromine atom Br HBr+ hydrogen bromide cation
Iodine atom anion I- HI Hydrogen iodide
Hydrogen diatomic H2 H3+ hydrogen trimer cation
berylium monohydride anion BeH- BeH2 beryllium dihydride
beryllium monohydride BeH BeH2+ Beryllium dihydride cation
boron monohydride anion BH- BH2 boron dihydride
Boron monohydride BH BH2+ Boron dihydride cation
methylidyne anion CH- CH2 Methylene
Methylidyne CH CH2+ methylene cation
Imidogen anion NH- NH2 Amino radical
Imidogen NH NH2+ Amino cation
hydroxide anion OH- H2O Water
Hydroxyl radical OH H2O+ water cation
Hydrogen fluoride HF H2F+ dihydrogen fluoride cation
lithium oxide anion LiO- LiOH lithium hydroxide
boron nitride anion BN- HNB hydrogen nitrogen boron
Beryllium monoxide anion BeO- BeOH beryllium hydroxide
carbon diatomic anion C2- C2H Ethynyl radical
Carbon diatomic C2 C2H+ Ethynyl cation
magnesium monohydride anion MgH- MgH2 magnesium dihydride
boron monoxide anion BO- HBO Boron hydride oxide
cyanide anion CN- HNC hydrogen isocyanide
cyanide anion CN- HCN Hydrogen cyanide
Cyano radical CN HCN+ hydrogen cyanide cation
aluminum monohydride anion AlH- AlH2 aluminum dihydride
aluminum monohydride AlH AlH2+ aluminum dihydride cation
Carbon monoxide CO COH+ Carbon Monoxide, protonated
carbon monoxide anion CO- HCO Formyl radical
Carbon monoxide CO HCO+ Formyl cation
nitrogen diatomic anion N2- NNH Dinitrogen monohydride
Nitrogen diatomic N2 NNH+ Dinitrogen monohydride cation
silicon monohydride anion SiH- SiH2 silicon dihydride
Silylidyne SiH SiH2+ silicon dihydride cation
carbon monofluoride anion CF- HCF Fluoromethylene
nitric oxide anion NO- HNO Nitrosyl hydride
Nitric oxide NO HNO+ Nitrosyl hydride cation
nitric oxide anion NO- NOH NOH
Nitric oxide NO NOH+ nitric oxide O-protonated
phosphorus monohydride anion PH- PH2 Phosphino radical
phosphorus monohydride PH PH2+ Phosphino cation
oxygen diatomic anion O2- HO2 Hydroperoxy radical
Oxygen diatomic O2 HO2+ Hydroperoxy cation
mercapto anion HS- H2S Hydrogen sulfide
Mercapto radical HS H2S+ Hydrogen sulfide cation
flourine oxide anion FO- HOF Hypofluorous acid
Hydrogen chloride HCl H2Cl+ dihydrogen monochloride cation
flourine diatomic anion F2- FHF FHF
sodium oxide anion NaO- NaOH sodium hydroxide
magnesium oxide anion MgO- MgOH magnesium hydroxide
boron monosulfide anion BS- HBS hydrogen boron sulfide
carbon monophosphide anion CP- HCP HCP
carbon monosulfide anion CS- HCS Thioformyl radical
carbon monosulfide CS HCS+ Thioformyl cation
carbon monochloride anion CCl- HCCl Chloromethylene
nitrogen sulfide anion NS- HNS HNS
phosphorus monoxide anion PO- HPO HPO
Phosphorus monoxide PO HPO+ HPO cation
chlorine monoxide anion ClO- HOCl hypochlorous acid
sulfur dimer anion S2- HS2 Thiosulfeno radical
Arsenic monohydride AsH AsH2+ Arsenic dihydride cation
selenium monohydride anion HSe- H2Se Hydrogen selenide
Selenium monohydride HSe H2Se+ Hydrogen selenide cation
hydrogen bromide HBr H2Br+ protonated hydrogen bromide
Bromine monoxide anion BrO- HOBr Hypobromous acid
Bromine monoxide BrO HOBr+ Hypobromous acid cation
Phosphorus monoselenide PSe PH+ phosphorus monohydride cation
boron dihydride anion BH2- BH3 boron trihydride
boron dihydride BH2 BH3+ boron trihydride cation
methylene anion CH2- CH3 Methyl radical
Methylene CH2 CH3+ methyl cation
amino anion NH2- NH3 Ammonia
Amino radical NH2 NH3+ ammonia cation
Water H2O H3O+ hydronium cation
Ethynyl anion C2H- CCH2 vinylidene
Ethynyl anion C2H- C2H2 Acetylene
Ethynyl radical C2H C2H2+ acetylene cation
Hydrogen cyanide anion HCN- HCNH HCNH
Hydrogen cyanide HCN HCNH+ HCNH+
hydrogen isocyanide HNC HCNH+ HCNH+
Hydrogen cyanide anion HCN- H2CN H2CN
Hydrogen cyanide HCN H2CN+ hydrocyanonium cation
hydrogen isocyanide HNC H2CN+ hydrocyanonium cation
Hydrogen cyanide anion HCN- CNH2 CNH2
Hydrogen cyanide HCN CNH2+ CNH2+
hydrogen isocyanide HNC CNH2+ CNH2+
aluminum dihydride anion AlH2- AlH3 aluminum trihydride
aluminum dihydride AlH2 AlH3+ aluminum trihydride cation
formyl anion HCO- H2CO Formaldehyde
Formyl radical HCO H2CO+ formaldehyde cation
formyl anion HCO- HOCH hydroxycarbene
silicon dihydride anion SiH2- SiH3 Silyl radical
silicon dihydride SiH2 SiH3+ Silyl cation
Nitrosyl hydride anion HNO- H2NO nitroxide
Phosphino anion PH2- PH3 Phosphine
Phosphino radical PH2 PH3+ Phosphine cation
Hydroperoxy anion HO2- H2O2 Hydrogen peroxide
Hydroperoxy radical HO2 H2O2+ Hydrogen peroxide cation
Hydrogen sulfide H2S H3S+ Sulfonium cation
FHF- FHF- H2F2 Hydrogen fluoride dimer
cyanate NCO- HNCO Isocyanic acid
fulminate CNO- HNCO Isocyanic acid
cyanate NCO- HOCN cyanic acid
fulminate CNO- HOCN cyanic acid
cyanate NCO- HCNO fulminic acid
fulminate CNO- HCNO fulminic acid
azide anion N3- HN3 hydrogen azide
Carbon dioxide anion CO2- HOCO Hydrocarboxyl radical
Carbon dioxide CO2 HOCO+ Hydrocarboxyl cation
Carbon dioxide anion CO2- HCOO formate neutral radical
Nitrous oxide N2O NNOH+ Nitrous Oxide, O-protonated
Nitrous oxide N2O HNNO+ Nitrous oxide, N-protonated
Thioformyl anion HCS- H2CS Thioformaldehyde
Carbonyl fluoride FCO HFCO+ formyl fluoride cation
Nitrogen dioxide anion NO2- HNO2 Nitrous acid
Nitrogen dioxide NO2 HNO2+ nitrous acid cation
Difluoromethylene anion CF2- CHF2 difluoromethyl radical
Ozone O3 O3H+ protonated ozone
Sulfur dioxide SO2 SO2H+ protonated sulfur dioxide
Thiosulfeno radical HS2 H2S2+ hydrogen disulfide cation
Chlorine dioxide anion OClO- HOClO Chlorous acid
germylene anion GeH2- GeH3 Germyl radical
germylene GeH2 GeH3+ germyl cation
Arsenic dihydride AsH2 AsH3+ Arsine cation
Hydrogen selenide H2Se H3Se+ Hydrogen Selenide, protonated
dichloromethylene anion CCl2- CHCl2 dichloromethyl radical
boron trihydride anion BH3- BH4 borohydride
methyl anion CH3- CH4 Methane
Methyl radical CH3 CH4+ Methane cation
Ammonia NH3 NH4+ ammonium cation
Acetylene C2H2 C2H3+ vinyl cation
vinylidene CCH2 C2H3+ vinyl cation
formaldehyde anion H2CO- CH3O Methoxy radical
Formaldehyde H2CO CH3O+ Methoxy cation
hydroxycarbene HOCH CH3O+ Methoxy cation
formaldehyde anion H2CO- CH2OH Hydroxymethyl radical
Formaldehyde H2CO CH2OH+ hydroxymethyl cation
hydroxycarbene HOCH CH2OH+ hydroxymethyl cation
Silyl anion SiH3- SiH4 Silane
Silyl radical SiH3 SiH4+ Silane cation
Phosphine PH3 PH4+ phosphonium cation
Hydrogen peroxide H2O2 H3O2+ hydrogen peroxide, protonated
ketenyl radical HCCO CH2CO+ Ketene cation
formate anion HCO2- HCOOH Formic acid
formate anion HCO2- CH2O2 Dioxirane
formate anion HCO2- H2COO dioxymethyl
Thioformaldehyde H2CS H2CSH+ Thioformaldehyde, protonated
carbonate CO3-- HCO3- bicarbonate anion
nitrate anion NO3- HNO3 Nitric acid
Trifluoromethyl anion CF3- CHF3 Methane, trifluoro-
Nitrogen trifluoride NF3 NF3H+ protonated nitrogen trifluoride
Sulfur trioxide anion SO3- HSO3 HOSO2
chlorate anion ClO3- HClO3 Chloric Acid
Trichloromethyl anion CCl3- CHCl3 Chloroform
vinyl anion C2H3- C2H4 Ethylene
vinyl C2H3 C2H4+ Ethylene cation
vinyl anion C2H3- CH3CH methylmethylene
Methanimine CH2NH CH2NH2+ methyleneamine cation
methoxy anion CH3O- CH3OH Methyl alcohol
Methoxy radical CH3O CH3OH+ Methyl alcohol cation
Hydroxymethyl radical CH2OH CH3OH+ Methyl alcohol cation
diiminomethane HNCNH NCNH3+ Cyanamide, protonated
diazirine CH2NN NCNH3+ Cyanamide, protonated
diazomethane CH2NN NCNH3+ Cyanamide, protonated
cyanamide NH2CN NCNH3+ Cyanamide, protonated
diiminomethane HNCNH HNCNH2+ diiminomethane, protonated
diazirine CH2NN HNCNH2+ diiminomethane, protonated
diazomethane CH2NN HNCNH2+ diiminomethane, protonated
cyanamide NH2CN HNCNH2+ diiminomethane, protonated
Oxirene C2H2O CH3CO+ acetyl cation
Ketene CH2CO CH3CO+ acetyl cation
ethynol HCCOH CH3CO+ acetyl cation
Formic acid HCOOH CH3OO+ methylperoxy cation
Dioxirane CH2O2 CH3OO+ methylperoxy cation
dioxymethyl H2COO CH3OO+ methylperoxy cation
thiomethoxy CH3S CH3SH+ Methanethiol cation
bicarbonate anion HCO3- H2CO3 Carbonic acid
Nitric acid HNO3 H2NO3+ Nitric Acid, Protonated
sulfate SO4-- HSO4- bisulfate anion
perchlorate anion ClO4- HClO4 perchloric acid
Ethylene anion C2H4- C2H5 Ethyl radical
Ethylene C2H4 C2H5+ Ethyl cation
methylmethylene CH3CH C2H5+ Ethyl cation
Methyl alcohol CH3OH CH3OH2+ Methanol, protonated
Hydrazine N2H4 N2H5+ protonated hydrazine
Propargyl anion C3H3- CH2CCH2 allene
Propargyl anion C3H3- CH3CCH propyne
Propargyl anion C3H3- C3H4 cyclopropene
acetonitrile anion CH3CN- CH3CHN methylmethaniminyl radical
acetonitrile anion CH3CN- CH2CHNH vinylazine
Acetyl anion CH3CO- CH3CHO Acetaldehyde
Acetyl anion CH3CO- C2H4O Ethylene oxide
Acetyl anion CH3CO- CH2CHOH ethenol
formamide CHONH2 H2CONH2+ protonated formamide
formaldoxime CH2NOH H2CONH2+ protonated formamide
nitrosomethane CH3NO H2CONH2+ protonated formamide
1,2-oxaziridine CNOH3 H2CONH2+ protonated formamide
hydroxymethylimine HOCHNH H2CONH2+ protonated formamide
methylperoxy anion CH3OO- CH2(OH)2 methanediol
methylperoxy anion CH3OO- H2OH2CO water formaldehyde dimer
methylperoxy anion CH3OO- CH3OOH Methyl peroxide
Carbonic acid H2CO3 H3CO3+ carbonic acid, protonated
bisulfate anion HSO4- H2SO4 Sulfuric acid
Ethyl anion C2H5- C2H6 Ethane
Ethyl radical C2H5 C2H6+ ethane cation
methyl amine CH3NH2 CH3NH3+ protonated methylamine
propyne CH3CCH C3H5+ Allyl cation
allene CH2CCH2 C3H5+ Allyl cation
cyclopropene C3H4 C3H5+ Allyl cation
Acetaldehyde CH3CHO CH3CHOH+ acetaldehyde, protonated
Ethylene oxide C2H4O CH3CHOH+ acetaldehyde, protonated
ethenol CH2CHOH CH3CHOH+ acetaldehyde, protonated
Methyl phosphine CH3PH2 CH3PH3+ methyl phosphine, protonated
methyl azide CH3N3 CH3NHN2+ methyl azide, protonated
acetate anion CH3COO- C2H4O2 1,3-dioxetane
acetate anion CH3COO- CHOCH2OH hydroxy acetaldehyde
acetate anion CH3COO- CH3COOH Acetic acid
acetate anion CH3COO- CH3OCHO methyl formate
Methane, nitro- CH3NO2 NH3COOH+ protonated Carbamic acid
Carbamic acid NH2COOH NH3COOH+ protonated Carbamic acid
Methyl nitrite CH3ONO NH3COOH+ protonated Carbamic acid
Methane, nitro- CH3NO2 NH2COOH2+ Carbamic acid, O-protonated
Carbamic acid NH2COOH NH2COOH2+ Carbamic acid, O-protonated
Methyl nitrite CH3ONO NH2COOH2+ Carbamic acid, O-protonated
trifluoro acetate anion CF3COO- CF3COOH trifluoroacetic acid
Ethane C2H6 C2H7+ Ethane, protonated
Aziridine C2H5N C2H5NH+ Protonated Aziridine
aminoethene CH2CHNH2 C2H5NH+ Protonated Aziridine
N-methylmethanimine CH2NCH3 C2H5NH+ Protonated Aziridine
ethanimine CH3CHNH C2H5NH+ Protonated Aziridine
Urea NH2CONH2 CH5N2O+ urea, N-protonated
Urea NH2CONH2 H2NCOHNH2+ urea, protonated
imidizolyl anion C3H3N2- C3H4N2 1H-Pyrazole
imidizolyl anion C3H3N2- C3H4N2 1H-Imidazole
imidizolyl anion C3H3N2- C3H4N2 4H-Imidazole
imidizolyl anion C3H3N2- C3H4N2 2H-Imidazole
2-Chloroethanol CH2ClCH2OH CH2ClCH2OH2+ 2-chloroethanol, protonated
Cyclopropane C3H6 C3H7+ Isopropyl cation
Propene CH2CHCH3 C3H7+ Isopropyl cation
Guanidine CH5N3 CH6N3+ guanidinium
pyrrolide anion C4H4N- C4H5N 2H-pyrrole
pyrrolide anion C4H4N- C4H5N 3H-pyrrole
pyrrolide anion C4H4N- C4H5N (E)-2-Butenenitrile
pyrrolide anion C4H4N- C4H5N (Z)-2-Butenenitrile
pyrrolide anion C4H4N- C4H5N Pyrrole
pyrrolide anion C4H4N- C4H5N Cyclopropanecarbonitrile
Ethylamine CH3CH2NH2 (CH3)2NH2+ dimethylammonium cation
Dimethylamine CH3NHCH3 (CH3)2NH2+ dimethylammonium cation
Ethylamine CH3CH2NH2 CH3CH2NH3+ ethylamine, protonated
Dimethylamine CH3NHCH3 CH3CH2NH3+ ethylamine, protonated
cylopentadienyl anion C5H5- C5H6 Cyclopropylacetylene
cylopentadienyl anion C5H5- C5H6 Bicyclo[2.1.0]pent-2-ene
cylopentadienyl anion C5H5- C5H6 1-Buten-3-yne, 2-methyl-
cylopentadienyl anion C5H5- C5H6 3-Penten-1-yne, (Z)-
cylopentadienyl anion C5H5- C5H6 1,3-Cyclopentadiene
cylopentadienyl anion C5H5- C5H6 3-Penten-1-yne, (E)-
Pyrrole C4H5N C4H6N+ pyrrole, protonated
(E)-2-Butenenitrile C4H5N C4H6N+ pyrrole, protonated
(Z)-2-Butenenitrile C4H5N C4H6N+ pyrrole, protonated
Cyclopropanecarbonitrile C4H5N C4H6N+ pyrrole, protonated
3H-pyrrole C4H5N C4H6N+ pyrrole, protonated
2H-pyrrole C4H5N C4H6N+ pyrrole, protonated
Pyrrole C4H5N C4H6N+ pyrrole, alpha-protonated
(E)-2-Butenenitrile C4H5N C4H6N+ pyrrole, alpha-protonated
(Z)-2-Butenenitrile C4H5N C4H6N+ pyrrole, alpha-protonated
Cyclopropanecarbonitrile C4H5N C4H6N+ pyrrole, alpha-protonated
3H-pyrrole C4H5N C4H6N+ pyrrole, alpha-protonated
2H-pyrrole C4H5N C4H6N+ pyrrole, alpha-protonated
phenyl anion C6H5- C6H6 1,2,4,5-Hexatetraene
phenyl anion C6H5- C6H6 Fulvene
phenyl anion C6H5- C6H6 Hexa-1,5-diene-3-yne
phenyl anion C6H5- C6H6 Benzene
phenyl anion C6H5- C6H6 Trimethylenecycopropane
phenyl anion C6H5- C6H6 2,4-Hexadiyne
Pyridine C5H5N C5H6N+ Pyridinium
Bicyclo[1.1.0]butane-1-carbonitrile C5H5N C5H6N+ Pyridinium
2-Propanamine CH3CH(NH2)CH3 C3H7NH3+ n-propylamine, protonated
Trimethylamine N(CH3)3 C3H7NH3+ n-propylamine, protonated
1-Propanamine NH2CH2CH2CH3 C3H7NH3+ n-propylamine, protonated
2-Propanamine, 2-methyl- C(CH3)3NH2 NC4H12+ tetramethyl ammonium cation
1-Propanamine, 2-methyl- C(NH2)H2C(CH3)HCH3 NC4H12+ tetramethyl ammonium cation
1-Butanamine C(NH2)H2CH2CH2CH3 NC4H12+ tetramethyl ammonium cation
diethylamine NH(C2H5)2 NC4H12+ tetramethyl ammonium cation
2-Butanamine CH3C(NH2)HCH2CH3 NC4H12+ tetramethyl ammonium cation