proton affinitieS
Proton affinity is a uful parameter for describing gas pha ion-molecule reactions in fields such as atmospheric chemistry, plasma chemistry, mass spectrometry, and astrophysics . The pro-ton affinity E pa (often designated in the literature as PA) of a mo-lecular species M is defined as the negative of the enthalpy change for the gas pha reaction
M + H+→ MH+ .
A cloly related quantity is the gas pha basicity Δba G° (of-ten designated as GB), which is the negative of the Gibbs energy change for the same reaction . Thus the two are related by
Δba G° = E pa + TΔS,
where T is the temperature and ΔS is the entropy change in the reaction (which can be calculated if the molecular structure of M and M+ is known) .
Direct measurement of the proton affinity is possible for only a few molecules, mainly olefins and carbonyl compounds . However, the measurements have been ud to establish a scale of E pa values that permits proton affinities to be determined for many other molecules, including unstable spe
cies and reaction interme-diates . The basis for this scale is described by Hunter and Lias in Reference 1 .
The E pa and Δba G° values at a temperature of 298 K are tabu-lated below for lected molecules . Many values are given to one decimal place, but the majority are not accurate to better than one or two kilojoules per mole . The methods of measurement are de-scribed in Reference 1, which contains a much more extensive and detailed tabulation .
Compounds are listed by molecular formula in the Hill order, but with all compounds that do not contain carbon appearing be-fore tho that do contain carbon .
references
1 . Hunter, E . P . L ., and Lias, S . G .,J. Phys. Chem. Ref. Data27, 413,
1998 .
2 . Hunter, E . P ., and Lias, S . G ., “Proton Affinity Evaluation”, in NIST
Chemistry WebBook, NIST Standard Reference Databa No . 69, Linstrom, P . J ., and Mallard, W .
G ., Eds ., March 2003, National Institute of Standards and Technology, Gaithersburg, MD 20899, <webbook .nist .gov> .
3 . Do, K ., Klein, T . P ., Pommerening, C . A ., Bachrach, S . M ., and
Sunderlin, L . S ., J. Am. Chem. Soc . 120, 6093, 1998 .
4 . Kim, H .-T ., Green, R . J ., Qian, J ., and Anderson, S . L ., J. Chem. Phys.
112, 5717, 2000 .
5 . Park, S . T ., Kim, S . K ., and Kim, M . S ., J. Chem. Phys. 114, 5568, 2001 .
温州机电技师学院
6 . Hiraoka, K ., Mizuno, T ., Eguchi, D ., Takao, T ., and Ino, S ., J. Chem.
Phys. 116, 7574, 2002 .
7 . Oresmaa, L . O ., Haukka, M ., Vainiotalo, P ., and Pakkanen, T . A ., J. Org.
Chem . 67, 8216, 2002 .
8 . Wang, F ., Ma, S ., Zhang, D ., and Cooks, R . G ., J. Phys. Chem. A 102,
2988, 1998 .
9 . Bouchoux, G ., Gal, J .-F ., Szulejko, J . E ., McMahon, T . B ., Tortajada, J .,
Luna, A ., Yanez, M ., and Mo, O ., J. Phys. Chem. A 102, 9183, 1998 . 10 . van Beelen, E ., Koblenz, T . A ., Ingemann, S . and Hammerum, S ., J.
Phys. Chem. A 108, 2728, 2004 .
Molecular formula
E paΔba G°
Name kJ/mol kJ/mol Notes
Ar Argon 369 .2 346 .3 AsF3Arnic(III) fluoride 636 .7 604 .2 AsH3Arsine 747 .9 712 .0 BHO2Metaboric acid 763 .0 730 .5 BH3O3Boric acid 728 .1 698 .4 B2H6Diborane 615 586 .0 B3H6N3Borazine 802 .5 772 .8 B4H10Tetraborane(10) 605 572 .5 B5H9Pentaborane(9) 699 .4 666 .9 BaO Barium oxide1215 .41187 .6 Br Bromine (atomic) 554 .4 531 .2 BrH Hydrogen bromide 584 .2 557 .7 BrLi Lithium bromide 819 792 .5 CaO Calcium oxide1190 .61162 .3 Cl Chlorine (atomic) 51
3 .6 490 .1 ClH Hydrogen chloride 556 .9 530 .1 ClLi Lithium chloride 827 800 .5 Co Cobalt 742 .7 719 .8 Cr Chromium 791 .3 768 .4 CsHO Cesium hydroxide1117 .91092 .2 Cs2O Cesium oxide1442 .91412 .2 Cu Copper 655 .3 632 .4
F Fluorine (atomic) 340 .1 315 .1
FH Hydrogen fluoride 484 456 .7 FO Fluorine oxide 508 .7 482 .2 F2Fluorine 332 305 .5 F2O2S Sulfuryl fluoride 605 .5 580 .5
10-174
Molecular formula
E paΔba G°
紫石英
Name kJ/mol kJ/mol Notes
F3N Nitrogen trifluoride 568 .4 538 .6
F3OP Phosphoryl fluoride 694 .0 664 .2
F3P Phosphorus(III) fluoride 695 .3 662 .8
F4Si Tetrafluorosilane 502 .9 476 .6
F6S Sulfur hexafluoride 575 .3 550 .7
Fe Iron 754 731 .1
FeO Iron(II) oxide 907 880 .5
GeH4Germane 713 .4 687 .1
HI Hydrogen iodide 627 .5 601 .3
HKO Potassium hydroxide1101 .81075 .4
HLi Lithium hydride1021 .7 996 .4
HLiO Lithium hydroxide1000 .1 972 .1
HNO3Nitric acid 751 .4 731 .5
HN3Hydrazoic acid 756 .0 723 .5
HNa Sodium hydride10951070 .6
HNaO Sodium hydroxide1071 .81044 .8
HO Hydroxyl 593 .2 564 .0
HO2Hydroperoxy 660 627 .5
HP Phosphorus monohydride 670 .3 639 .6
H2Hydrogen 422 .3 394 .7
H2N2O2Nitramide 757 .4 725 .0
H2O Water 691 660 .0
H2O2Hydrogen peroxide 674 .5 643 .8
H2O4S Sulfuric acid 717 681Ref . 3
H2P Phosphino 709 .2 675 .7
H2S Hydrogen sulfide 705 673 .8
H2Se Hydrogen lenide 707 .8 676 .4
H2Si Silylene 839 .2 804 .1
H2Te Hydrogen telluride 735 .9 704 .5
H3N Ammonia 853 .6 819 .0
H3P Phosphine 785 750 .9
H4N2Hydrazine 853 .2 822 .4
H4Si Silane 639 .7 613 .4
H6OSi2Disiloxane 749 718 .3
He Helium 177 .8 148 .5
I Iodine (atomic) 608 .2 583 .5
K2O Potassium oxide1342 .51311 .8
Kr Krypton 424 .6 402 .4
La Lanthanum1013 991 .9
Li2Dilithium11621133 .1
Li2O Lithium oxide12061175 .3
Lu Lutetium 992 970 .6
Mg Magnesium 819 .6 797 .3
MgO Magnesium oxide 988 959 .4
Mg2Dimagnesium 919 886 .5
Mn Mangane 797 .3 774 .4
N Nitrogen (atomic) 342 .2 318 .7
NO Nitric oxide 531 .8 505 .3
NO2Nitrogen dioxide 591 .0 560 .3
NP Phosphorus nitride 789 .4 757 .0
N2Nitrogen 493 .8 464 .5
N2O Nitrous oxide 549 .8 523 .3Protonation at N
N2O Nitrous oxide 575 .2 548 .7Protonation at O
Na2Disodium1146 .81118 .2
Na2O Sodium oxide1375 .91345 .2
Ne Neon 198 .8 174 .4
Ni Nickel 737 714 .1
O Oxygen (atomic) 485 .2 459 .6
OP Phosphorus monoxide 682 649 .5
OSi Silicon monoxide 777 .8 750 .4Protonation at O
Proton Affinities 10-175
秋天的Molecular formula
E paΔba G°
Name kJ/mol kJ/mol Notes
OSi Silicon monoxide 533 500 .5Protonation at Si
OSr Strontium oxide12091180 .7
O2Oxygen 421 396 .3
O2S Sulfur dioxide 672 .3 643 .3
O3Ozone 625 .5 595 .9
O3S Sulfur trioxide 588 .3 560 .3
O4Os Osmium(VIII) oxide 676 .9 650 .6
P Phosphorus 626 .8 604 .8
Pd Palladium 696 673 .4
Rh Rhodium 768 745 .4
Ru Ruthenium 774 751 .4
S Sulfur 664 .3 640 .2
SSi Silicon monosulfide 627 596 .6Protonation at Si
SSi Silicon monosulfide 683 660 .2Protonation at S
Sc Scandium 914 892 .0
Si Silicon 837 814 .1
Ti Titanium 876 853 .7
U Uranium 995 .2 973 .2
V Vanadium 859 .4 836 .8
Xe Xenon 499 .6 478 .1
Y Yttrium 967 945 .9
Zn Zinc 608 .6 586 .0
CBrF3Bromotrifluoromethane 580 .0 550 .3
CBrN Cyanogen bromide 749 .8 719 .2
CClF3Chlorotrifluoromethane 571 .3 541 .5
CClN Cyanogen chloride 722 .1 691 .5
CCl2Dichloromethylene 861 828 .5
CCl2S Carbonothioic dichloride 752 .5 721 .8
CFN Cyanogen fluoride 632 601 .3
CF2Difluoromethylene 765 732 .5
CF2O Carbonyl fluoride 666 .7 637 .0
CF3I Trifluoroiodomethane 628 .0 598 .2
CF3NO Trifluoronitrosomethane 703 .3 670 .8
CF4Tetrafluoromethane 529 .3 503 .7
CHCl Chloromethylene 874 .1 839 .9
CHF Fluoromethylene 797 .9 763 .8
CHF3Trifluoromethane 619 .5 589 .7
CHF3O3S Trifluoromethanesulfonic acid 699 .4 666 .9
CHN Hydrogen cyanide 712 .9 681 .6
CHN Hydrogen isocyanide 772 .3 739 .8
CHNO Isocyanic acid (HNCO) 753 718 .8
CHNO Fulminic acid 758 725 .5
CHO Oxomethyl (HCO) 636 601 .8
CHO2Formyloxyl 623 .4 590 .9
CH2F2Difluoromethane 620 .5 589 .7
CH2N2Diazomethane 858 .9 826 .7
CH2N2Cyanamide 805 .6 774 .9
CH2O Formaldehyde 712 .9 683 .3
CH2O2Formic acid 742 .0 710 .3
CH2S Thioformaldehyde 759 .7 730 .5弘扬
CH2Se Selenoformaldehyde 764 .0 734 .9
CH3Br Bromomethane 664 .2 638 .0
CH3Cl Chloromethane 647 .3 621 .1
CH3F Fluoromethane 598 .9 571 .5
CH3I Iodomethane 691 .7 665 .5
CH3NO Formamide 822 .2 791 .2
CH3NO2Nitromethane 754 .6 721 .6
CH3NO2Methyl nitrite 798 .9 766 .4
CH3NO3Methyl nitrate 733 .6 714 .8
CH3N3Methyl azide 833 800 .5
10-176 Proton Affinities
Molecular formula
E paΔba G°
Name kJ/mol kJ/mol Notes
CH4Methane 543 .5 520 .6
CH4N Methylamidogen 832 .8 801 .6
CH4N2O Urea 873 .5 841 .6Protonation at O; Ref . 8
CH4N2S Thiourea 893 .7 863 .9
CH4O Methanol 754 .3 724 .5
CH4O3S Methanesulfonic acid 761 .3 728 .9
CH4S Methanethiol 773 .4 742凝成的意思
CH5N Methylamine 899 .0 864 .5
CH5NO O-Methylhydroxylamine 844 .8 812 .3
CH5N3Guanidine 986 .3 949 .4
CH5P Methylphosphine 851 .5 817 .6
CH6N2Methylhydrazine 898 .8 866 .4
CN Cyanide>595>564Protonation at N
CNS Thiocyanate 751 718 .5
CO Carbon monoxide 594 562 .8Protonation at C
CO Carbon monoxide 426 .3 402 .2Protonation at O
COS Carbon oxysulfide 628 .5 602 .6Protonation at S
COSe Carbon oxylenide 670 644 .1Protonation at Se
CO2Carbon dioxide 540 .5 515 .8
CS Carbon monosulfide 791 .5 760
储蓄网上银行CS2Carbon disulfide 681 .9 657 .7
CSe Carbon monolenide 831 .8 800 .2Protonation at C
CSe2Carbon dilenide 725 700 .9
C2ClF3O Trifluoroacetyl chloride 681 .6 649 .8
C2Cl3N Trichloroacetonitrile 723 .2 692 .6
C2F3N Trifluoroacetonitrile 688 .4 657 .7
C2H Ethynyl 753 720 .8
C2HCl3O Trichloroacetaldehyde 722 .3 690 .5
C2HCl3O2Trichloroacetic acid 770 .0 739 .1
C2HF Fluoroacetylene 686 661 .3
C2HF3Trifluoroethene 699 .4 666 .9
C2HF3O2Trifluoroacetic acid 711 .7 680 .7
C2H2Acetylene 641 .4 616 .7
C2H2ClN Chloroacetonitrile 745 .7 715 .1
C2H2F21,1-Difluoroethene 734 705 .1
C2H2F2trans-1,2-Difluoroethene 688 .6 657 .9
C2H2O Ketene 825 .3 793 .6
C2H3ClO2Chloroacetic acid 765 .4 734 .5
C2H3Cl3O2,2,2-Trichloroethanol 729 .3 698 .9
C2H3F Fluoroethene 729 700 .1
C2H3FO2Fluoroacetic acid 765 .4 734 .5
C2H3F3O2,2,2-Trifluoroethanol 700 .2 669 .9
C2H3F3O Methyl trifluoromethyl ether 719 .2 690 .0
C2H3N Acetonitrile 779 .2 748
C2H3N Isocyanomethane 839 .1 806 .6
C2H3NO Methyl isocyanate 764 .4 732 .0
C2H3NS Methyl thiocyanate 796 .7 766 .1
C2H3NS Methyl isothiocyanate 799 .2 766 .7
C2H3N31H-1,2,3-Triazole 879 .3 847 .4
C2H3N31H-1,2,4-Triazole 886 .0 855 .9
C2H4Ethylene 680 .5 651 .5
C2H4F2O2,2-Difluoroethanol 727 .4 697 .0
C2H4F3N2,2,2-Trifluoroethylamine 846 .8 812 .9
C2H4N2Aminoacetonitrile 824 .9 791 .0
C2H4O Acetaldehyde 768 .5 736 .5
C2H4O Oxirane 774 .2 745 .3
C2H4O2Acetic acid 783 .7 752 .8
C2H4O2Methyl formate 782 .5 751 .5
C2H4S Thiirane 807 .4 777 .6
C2H5Br Bromoethane 696 .2 669 .7
Proton Affinities 10-177
Molecular formula
E paΔba G°
Name kJ/mol kJ/mol Notes
C2H5BrO2-Bromoethanol 766 .1 735 .7
C2H5Cl Chloroethane 693 .4 666 .9
C2H5ClO2-Chloroethanol 766 .1 735 .7
C2H5F Fluoroethane 683 .4 655 .8
C2H5FO2-Fluoroethanol 715 .6 685 .2
C2H5I Iodoethane 724 .8 698 .3
C2H5N Ethenamine 898 .9 866 .5
C2H5N Ethyleneimine 905 .5 872 .5
C2H5NO Acetamide 863 .6 832 .6
C2H5NO N-Methylformamide 851 .3 820 .3
C2H5NO2Nitroethane 765 .7 733 .2
C2H5NO2Ethyl nitrite 818 .9 786 .4
C2H5NO2Glycine 886 .5 852 .2
C2H5NO2Acetohydroxamic acid 854 .0 823 .0
C2H5NS Thioacetamide 884 .6 852 .8
C2H6Ethane 596 .3 569 .9
澳大利亚美食C2H6Hg Dimethyl mercury 771 .6 740 .8
C2H6N2Ethanimidamide 970 .7 938 .2
C2H6N2trans-Dimethyldiazene 865 .1 834 .4
C2H6N2O2-Aminoacetamide 882 .3
C2H6N2O2N-Methyl-N-nitromethanamine 828 .3 795 .8
C2H6O Ethanol 776 .4 746
C2H6O Dimethyl ether 792 764 .5
C2H6OS Dimethyl sulfoxide 884 .4 853 .7
C2H6O21,2-Ethanediol 815 .9 773 .6
C2H6S Ethanethiol 789 .6 758 .4
C2H6S Dimethyl sulfide 830 .9 801 .2
C2H6S2Dimethyl disulfide 815 .3 782 .8
C2H7N Ethylamine 912 .0 878
如何提高抗压能力
C2H7N Dimethylamine 929 .5 896 .5
C2H7NO Ethanolamine 930 .3 896 .8
C2H7O3P Dimethyl hydrogen phosphite 894 .8 862 .4
C2H7P Dimethylphosphine 912 .0 877 .9
C2H8N21,2-Ethanediamine 951 .6 912 .5
C2H8N21,1-Dimethylhydrazine 927 .1 894 .7
C2N2Cyanogen 674 .7 645 .8
C2O Dicarbon monoxide 774 .7 747 .0
C3Carbon trimer 767 .0 736 .3
C3F6O Perfluoroacetone 670 .4 639 .7
C3HN Cyanoacetylene 751 .2 720 .5
C3H2F6O1,1,1,3,3,3-Hexafluoro-2-propanol 686 .6 656 .2
C3H2N2Malononitrile 723 .0 694 .1
C3H32-Propynyl 741 708 .5
C3H3Cl3O1,1,1-Trichloro-2-propanone 768 .3 736 .3
C3H3F3O1,1,1-Trifluoroacetone 723 .9 692 .0
C3H3F3O2Methyl trifluoroacetate 740 .5 709 .6
C3H3N Acrylonitrile 784 .7 753 .7
C3H3NO Oxazole 876 .4 844 .5
C3H3NO Isoxazole 848 .6 816 .8
C3H3NO2-Oxopropanenitrile 746 .9 716 .2
C3H3NS Thiazole 904 872 .1
C3H3N31,3,5-Triazine 848 .8 819 .6
C3H4Allene 775 .3 745 .8
C3H4Propyne 748 .2 723 .0
C3H4Cyclopropene 818 .5 787 .8
C3H4ClN3-Chloropropanenitrile 773 .1 742 .4
C3H4N21H-Pyrazole 894 .1 860 .5
C3H4N2Imidazole 942 .8 909 .2
C3H4N2S2-Thiazolamine 930 .6 898 .7
C3H4O Acrolein 797 .0 765 .1
10-178 Proton Affinities
