pKa ValuesINDEXInorganic2Phenazine24 Phosphates3Pyridine25 Carboxylic acids4, 8Pyrazine26Aliphatic4, 8Aromatic7, 8Quinoline27Phenols9Quinazoline27Alcohols and oxygen acids10, 11Quinoxaline27Amino Acids12Special Nitrogen Compounds28Peptides13Hydroxylamines28Nitrogen Compounds14Hydrazines28Aliphatic amines15, 17, 19Semicarbazones28 Cyanoamines16Amidoximes28Anilines17, 18, 20Thiols29 Nucleosides21Carbon Acids30,31 Special Table Heterocycles22Indicators31Acridine23References32-34 Benzoquinoline24Cinnoline23Hydantoin24Imidazole24For complex chelating agents, see also reference 77.Note. This document was compiled by W.P. Jencks and has been added to by F.H. WestheimerACIDSCompound pK Ref.H3PO2 2.0, 2.23*28H2PO4–7.21*77 AgOH 3.964HPO4_12.32*77Al(OH)311.228H3PO3 2.028As(OH)39.2228H2PO3– 6.58*77H3AsO4 2.22, 7.0, 13.028H4P2O7 1.52*77H2AsO4– 6.98*77H3 P2O7– 2.36*77 HAsO4*11.53*77H2P2O7= 6.60*77As2O304H3AsO39.22*HP2O7=9.25*77H3BO39.23*28HReO4-1.2530H2B4O7 4.0034HSCN 4.0034H2SeO3 2.6, 8.3, 2.62*28 HB4O79.0034HSeO38.3277Be(OH)2 3.74H2SeO4Strong, 2.028 HBr-9.0031HOBr8.728HSeO4 2.0034 HOCl7.53, 7.4628, 33H3SiO310.034 HClO2 2.028H2SO3 1.9, 7.0, 1.76*28, 77 HClO3-1.0028H2SO4-3.0, 1.928 HClO4 (70%)-10.0031HSO37.21*77CH3SO3H-0.631HSO4– 1.99*77 HCN9.4034H2S2O4 1.929H2CO3 6.37, 6.35*, 3.5834, 32H2Se 3.89*77 HCO310.33*HSe–11.00*77H2CrO4-0.9830H2S7.00*77 HCrO4 6.50*2, 30HS–12.92*77 HOCN 3.9234HSbO211.034 HZ 3.17*, 0.59*77HTe 5.0034H2GeO38.59, 12.7234, 78H2Te 2.64, 11.034, 78 Ge(OH)48.68, 12.728H2TeO3 2.7, 8.028HI-10.031Te(OH)6 6.2, 8.828 HOI11.028H2VO4–8.9530 HIO30.828HVO4=14.430H4IO6– 6.0034H2CrO40.7477H5IO6 1.64, 1.55, 8.2734, 28HOCN 3.7377 HMnO4-2.2530HSCN0.8577 NH3OH* 5.98*H3PO2 1.0777 NH4*9.24*77H3PO4 2.12*77 HN3 4.72*77H2S2O30.60*, 1.72*77 HNO2 3.2928H3AuO313.3, 16.078 HNO3-1.328H3GaO310.32, 11.778N2H5+7.99*77H5IO6 3.29, 6.70, 15.078H2N2O27.0534(see above!)H2N2O2–11.034H4V6O17 1.9678H2OsO512.134H2NSO3H 1.080H2O15.7noneH3O+-1.7none* Indicates a thermodynamic value.Pb(OH)2 6.48 (10.92) 4 (78)PHOSPHATES AND PHOSPHONATES CF 3- 1.16, 3.9357CCl 3- 1.63, 4.8157Phosphates NH 3+CH 2- 2.35, 5.957CompoundpKRef.(–OOCCH 2)2NH +CH 2– --, 5.5757Phosphate 1.97, 6.82, 12.555CHCl 2- 1.14, 5.6157Glyceric acid 2-phosphate 3.6, 7.153CH 2CI- 1.40, 6.3057Enolpyruvic acid 3.5, 6.453CH 2Br- 1.14, 6.5257Methyl- 1.54, 6.3155(–OOCCH 22NH +(CH 2)2- --, 6.5457Ethyl- 1.60, 6.6255CH 2I- 1.30, 6.7257n-Propyl- 1.88,6.6755NH 3+CH 2CH 2- 2.45, 7.0057n-Butyl- 1.80, 6.8455Dimethyl- 1.2955C 6H 5CH=CH- 2.00, 7.157Di-n-propyl 1.5955HOCH 2- 1.91, 7.1557Di-n-butyl- 1.7255C 6H 5NH 2+(CH 2)3- 2.1, --57Glucose-3-0.84, 5.6756C 6H 5NH(CH 2)3---, 7.1757Glucose-4-0.84, 5.6756Br(CH 2)2- 2.25, 7.357α-glycero- 1.40, 6.4454CH 3(CH 2)5CH(COO –)---, 7.557β-glycero- 1.37, 6.3454C 6H 5CH 2- 2.3, 7.55573-phosphoglyceric acid 1.42, 3.4254NH 3+(CH 2)4)- 2.55, 7.55572-phosphoglyceric acid 1.42, 3.55, 7.1peroxymonophosphoric acid 4.0569NH 3+(CH 2)5- 2.6, 7.657diphosphoglyceric acid 7.40, 7.9954NH 3+(CH 2)10---, 8.0057glyceraldehyde- 2.10, 6.7554–OOC(CH 2)10---, 8.2557dioxyacetone- 1.77,6.4554(CH 3)3SiCH 2- 3.22, 8.7057hexose di- 1.52, 6.3154fructose-6-0.97, 6.1154C 6H 5CH 2- 3.3, 8.457glucose-6-0.94, 6.1154(C 6H 5)SC- 3.85, 9.0057glucose-1- 1.10, 6.1354adenylic acid 3.8?, 6.2?54Arylphosphonic acids inosinic acid 2.4?, 6.4?542X-RC 6H 3PO 3H 2ADP 2 strong, 6.654X R ATP 3 strong, 6.654Cl 4-O 2N 1.12, 6.1457pyrophosphoric acid 0.9, 2.0, 6.6, 9.454Br 5-O 2N (a), 6.1457phosphopyruvic acid 3.5, 6.3854Cl 5-Cl (a), 6.6357creatine phosphate 2.7, 4.554Cl H 1.63, 6.9857arginine phosphate 2.8, 4.5, 9.6, 11.254Br H 1.64, 7.0057arginine 2.02, 9.0, 12.554Br 5-CH 3 1.81, 7.1557amino phosphate (-0.9), 2.8, 8.254Cl 4-NH 2--, 7.3357trimetaphosphate 2.0577CH 3O 4-O 2N 1.53, 6.9657CH 3O H 2.16, 7.7757PhosphonatesCH 3O 4-O 2N --, 8.2257H 2O 3P(CH 2)4PO 3H 2 <2, 2.75, 7.54, 8.3857HO 4-O 2N 1.22, 5.3957H 2O 3P(CH 2)3PO 3H 2 <2, 2.65, 7.34, 8.3557O 2N H 1.45, 6.7457H 2O 3PCH 2CH(CH 3)PO 3H 2 <2, 2.6, 7.00, 9.2757F H 1.64, 6.8057H 2O 3PCH 2PO 3H 2 <2, 2.57, 6.87, 10.3357I H 1.74, 7.0657Methyl- 2.3557NH 2H --, 7.2957Ethyl- 2.4357CH 3H 2.10, 7.6857n-propyl- 2.4557C 6H 5H (a), 8.1357isopropyl- 2.55, 7.7557HOOC H1.71, 9.1757n-butyl- 2.59, 8.1957isobutyl- 2.70, 8.4357**These values were obtained in 50% ethanol.s-butyl- 2.74, 8.4857(a) The compounds were not sufficiently soluble.t-butyl- 2.79, 8.8857For graphical plots of a large number of substituted phosphorus compounds see 83.neopentyl- 2.84, 8.65571,1 Dimethylpropyl- 2.88, 8.9657n-hexyl- 2.6, 7.957triphosphate8.90, 6.26, 2.3077n-dodecyl---, 8.2557tetrametaphosphate 2.7477CH 3(CH 2)5CH(COOH)- 1, --57fluorophosphate0.55, 4.856Acetic acids, substituted Phosphonates (Ref. 2)H- 4.76*20 X-H-H-NH3+-NH3+O2N- 1.68*20 X(CH2)PO3H2 2.357.1 1.85 5.35(CH3)3N+- 1.83*20 X(CH2)2PO3H2 2.457.85 2.457.00(CH3)2NH+- 1.95*20 X(CH2)4PO3H2 2.557.55CH3NH2+- 2.16*20 X(CH2)5PO3 H2 2.67.65NH3+- 2.31*20 X(CH2)6PO2H2 2.67.9CH3SO2- 2.36*20 X(CH2)10PO2H28.00NC- 2.43*20 Phosphines in acetonitrile, see ref. 89.C6H5SO2- 2.4420HO2C 2.83*20 CARBOXYLIC ACIDSAliphatic C6H5SO- 2.6620 Compound pK Ref.F- 2.6620 Acetoacetic 3.586Cl- 2.86*20 Acetopyruvic 2.61, 7.85 (enol)6Br- 2.8620 Aconitic, trans- 2.80, 4.466Cl2- 1.2920 Betaine 1.846F2- 1.2420 Citric 3.09, 4.75, 5.416Br3-0.6620 Crotonic 4.696Cl3-0.6520 Dihydroxyfumaric 1.146F3-0.23 (-0.26) (2)20 Dethylenediamine- 2.00, 2.676HONC4 3.0120 tetraacetic 6.16, 10.26F3C- 3.07*20 Formic 3.77*2N3- 3.0320 Fumaric 3.03, 4.546I- 3.1220 Glyceric 3.556C6H5O- 3.1220 Glycollic 3.826C2H5O2C- 3.3520 Glyoxylic 3.326C6H5S- 3.52*20 Homogentistic 4.406CH3O- 3.5320α-keto-β-methyl valeric 2.36NCS- 3.5820 Lactic 3.866CH3CO- 3.58*20 Maleic 1.93, 6.586Malic 3.40, 5.26C2H5O- 3.6020 Oxaloacetic (trans-enol) 2.566n-C3H7O 3.6520 +(cis-enol) 2.15, 4.066n-C4H9O 3.6620 Protocatechuic 4.486sec.-C4H9O- 3.6720 Pyruvic 2.506HS- 3.67*20Tartaric + 2.99, 4.406i-C3H7O- 3.69*20 + or - 2.89, 4.406CH3S- 3.72*20 meso 3.22, 4.856i-C3H7S- 3.72*20 Vinylacetic 4.426C6H5CH2S- 3.73*20C2H5S- 3.74*20n-C3H7S- 3.77*20n-C4H9S- 3.81*20HO- 3.83*20–O3S- 4.0520(C6H5)3CS- 4.30*20C6H5- 4.31*20CH2-CH- 4.35*20* Indicates thermodynamic values.Unsaturated acids (25°)CompoundpK poundpK ref.trans-CH 3-CH=CHCO 2H 4.69*20H-CH 2CH 2CO 2H 4.88*2cis-CH 3-CH=CHCO 2H 4.44*2H-CH=CHCO 2H 4.25*2C 6H 5-CH 2CH 2CO 2H4.66*2C 6H 5CH 2CH 2CO 2H 4.66*2trans-C 6H 5-CH=CHCO 2H 4.44*2C 6H 5CH=CHCO 2H** 4.44*2m-CH 3OC 6H 4CH 2CH 2CO 2H4.65*2C 6H 5CH 2CH 2CO 2H 4.66*2C 6H 5CH=CHCO 2H**4.442m-CH 3OC 6H 4CH=CHCO 2H 4.38*2m-ClC 6H 4CH=CHCO 2H**4.29*2m-ClC 6H 4CH 2CH 2CO 2H 4.58*2Unsaturated acids, Cis- and Trans-C C R 2H R 1CO 2H C C R 2R 1HCO 2H Cis-Acid Trans-Acid R 1R 2cis-acid trans-acid Ref.H-H- 4.25*4.25*2CH 3-H- 4.44*4.69*2Cl-H- 3.323.652C 6H 5-H- 3.88*4.44*2ClC 6H 4H- 3.91 4.4126-BrC 6H 4H- 4.02 4.412CH 3-CH 3- 4.305.022C 6H 5-H- 5.26***5.58***22,4,6-(CH 3)3C 6H 2-H-6.12***5.70***2C 6H 5-CH 3- 4.98***5.98***2Dicarboxylic acids, unsaturated*Maleic 1.92, 6.232Alicyclic Dicarboxylic acidsCitraconic (Dimethylmaleic acid)2.29, 6.152cis-Caronic(1,1-dimethylcyclopropane-23-dicarboxylic acid 2.34*, 8.31*2Acetylenedicarboxylic 1.73, 4.402∆1-tetrahydrophthalic 3.01, 5.3421,2-trans-cyclopropanedicarboxylic3.65*, 5.13*2Bromomaleic 1.45, 4.622trans-caronic 3.82*, 5.32*2Bromofumaric 1.46, 3.5721,2-cis-cyclopropane-dicarboxylic3.33*, 6.47*2Chlorofumaric 1.78, 3.812Fumaric 3.02,4.382Mesaconic (Dimethylfumaric acid)**trans3.09,4.752***in 40% acetone Phthalic 2.95, 5.412*thermodynamicItaconic (1-Propene-2-3-dicarboxylic acid)3.85, 5.452Chloromaleic 1.72, 3.862AliphaticAlicyclic Dicarboxylic acidsCompound pK Ref Compound pK Ref 1,2-trans-Cyclopropane-cis-Ethyleneoxide-dicarboxylic 3.65, 5.132dicarboxylic 1.94, 3.922 trans-Ethyleneoxide-1,3-cis-Cyclobutane-dicarboxylic 1.93, 3.252dicarboxylic 4.03, 5.3121,3-trans -Cyclobutanedi-1,2-cis-Cyclopentane-carboxylic 3.81, 5.282dicarboxylic 4.37, 6.5121,2-trans-Cyyclopentane-1,3-cis-Cyclopentanedicarboxylic 3.89, 5.912dicarboxylic 4.23, 5.5321,3-trans-Cyclopentane-1,2-cisCyclohexane-dicarboxylic 4.40, 5.452dicarboxylic 4.34, 6.7621,2-trans-Cyclohexane-1,3 -cis-Cyclohexane-dicarboxylic 4.18, 5.932dicarboxylic 4.10, 5.4621,3-trans-Cyclohexane-1,4-cis-Cyclohexanedicarboxylic 4.31, 5.732di-carboxylic 4.44, 5.7921,4-trans-Cyclohexane-dicarboxylic 4.18, 5.422Dicarboxylic acids*oxalic 1.23, 4.192Succinic 4.19, 5.482 Malonic 2.83, 5.692 O-O’-Dimethyl- 3.77, 5.942 Methyl- 3.05, 5.762 (high melting)Ethyl- 2.99, 5.832 O-O’-Dimethyl- 3.94, 6.202n-propyl 3.00, 5.842 (low melting)i-propyl- 2.94, 5.882 O,O’-Diethyl- 3.63, 6.462 Dimethyl- 3.17, 6.062 (high melting)Methylethyl- 2.86, 6.412 O,O’-Diethyl- 3.51, 6.602Diethyl- 2.21, 7.292 (low melting)Ethyl-n-propyl- 2.15, 7.432Tetramethyl- 3.50, 7.282Di-n-propyl- 2.07, 7.512Glutaric 4.34, 5.422Adipic 4.42, 5.412B-Methyl 4.25, 6.222Pimelic 4.48, 5.422B-Ethyl 4.29, 6.332Suberic 4.52, 5.402B-n-Propyl 4.31, 6.392Azelaic 4.55, 5.412B,B-Dimethyl- 3.70, 6.292DL-1:2-Dichlorosuccinic 1.68, 3.1820 B,B-Methylethyl- 3.62, 6.702meso-1:2-Dichlorosuccinic 1.74, 3.2420 B,B-Diethyl- 3.62, 7.122DL-1:2-Dibromosuccinic 1.48, ----20 B,B-Di-n-propyl 3.69, 7.312meso-1:2-Dibromosuccinic 1.42, 2.9720D-Tartaric 3.03, 4.4520DL-1:2-Dimethylsuccinic 3.93, 6.0020DL-Tartaric 3.03, ----20meso-1:2-Dimethylsuccinic 3.77, 5.3620 meso-Tartaric 3.29, 4.9220*All are thermodynamic valuesAliphatic HO- 6.332Br- 6.082 Bicyclo[2.2.2]octane-1-carboxylic acids, 4-substitutedLysergic acid, etc.H- 6.752ergometrine 6.8, --2 C2H5O2C- 6.312Dihydroergometrine7.4, --2β-dihydrolysergol8.2, --2 NC- 5.902Lysergic acid7.8, 3.32C6H5O- 3.53* 3.95* 4.52*α-dihydrolysergic8.3, 3.62CH3- 3.91* 4.24* 4.34* ergometrinine7.3, --2(CH3)2CH- 4.35*α-dihydrolysergol8.3, --2(CH3)3N+- 1.37 3.45 3.436-methylergoline8.85, --2NC- 3.60* 3.55* isolysergic acid8.4, 3.42HO2C* 2.95* 3.54 3.51γ-dihydrolysergic8.6, 3.62F3C- 3.79HO- 2.98* 4.08* 4.58*I- 2.85* 3.86* Hydroxycyclohexanecarboxylic acids Cl- 2.94* 3.83* 3.99* Cyclohexanecarboxylic 4.902(CH3)3Si- 4.24* 4.27* cis-1,2 4.802C2H5O- 4.21* 4.17* 4.45* cis-1,3 4.602i-C3H7O- 4.24* 4.15* 4.68* cis-1,4 4.842n-C5H11O- 4.55* trans-1,2 4.682C6H5- 3.46*trans-1,3 4.822CH3CH2- 3.77 4.35* trans-1,4 4.682(CH3)3C- 3.46 4.28 4.40*–HO3P- 3.78 4.03 3.95 Aromaticbenzene-CO3H 4.20*2–O3S- 4.15 4.11 Anthracene-1-COOH 3.692H2N- 4.98 4.79 4.92 Anthracene-9-COOH 3.652(CH3)2N-8.42 5.10 5.03 naphthalene-2-COOH 4.172–HO3As- 4.22 Naphthalene-1-COOH 3.692–O2C- 5.41** 4.60 4.82CH3NH- 5.3 5.10 5.04 Substituted benzoic acids (ref. 2)COOH*thermodynamicfor complex chelating agents, see also ref. 84.see also page 9a for more carboxylic acids. Benzoic acid o m pOrtho-substituted benzoic acidsH- 4.20* 4.21*Benzoic acid pK Ref.O2N- 2.17* 3.45* 3.442-CH3- 3.91**2CH3CO-2-t-C4H9- 3.462CH3SO2- 3.64* 3.52*2,6-(CH3)2- 3.212CH3S-2,3,4,6-(CH3)4- 4.002HS-2,3,5,6-(CH3)4- 3.522Br- 2.85* 3.81* 4.00*2-C2H5- 3.772F- 3.27* 3.87* 4.14*CH3O- 4.09* 4.09* 4.47*2-C6H5- 3.46**2n-C3H7O- 4.24* 4.20* 4.46*2,4,6-(CH3)3- 3.432n-C4H9O- 4.25* 4.53*2,3,4,5-(CH3)4- 4.222 Benzene Polycarboxylic acids Ref. 2Acid Position of carboxyl pK I pK II pK III pK IV pK V pK VI Benzoic1 4.17*Phthalic1,2 2.98* 5.28*Isophthalic1,3 3.46* 4.46*Terephthalic1,4 3.51* 4.82*Hemimellitic1,2,3 2.80* 4.20* 5.87*Trimellitic1,2,4 2.52* 3.84* 5.20*8Trimesic 1,3,5 3.12* 3.89* 4.70*Mellophanic 1,2,3,4 2.06* 3.25* 4.73* 6.21*Prehnitic 1,2,3,5 2.38* 3.51* 4.44* 5.81*Pyromellitic1,2,4,5 1.92* 2.87* 4.49* 5.63*Benzenepentacarboxylic 1,2,3,4,5 1.80* 2.73* 3.97* 5.25* 6.46*Mellitic1.2,3,4,5,61.40*2.19*3.31*4.78*5.89*6.96**ionic strength 0.032-Methoxyethyliminodiacetic 2.2, 8.96**thermodynamic2-Methylthioethyliminodiacetic 2.1, 8.91oxalic acid* 1.25, 4.14N-n-propylaminoacetic 2.25, 10.03Carboxylic Acids Ref. 77N-2-sulfoethyliminodiacetic 1.92, 2.28, 8.16Aminomalonic acid* 3.32, 9.83α-Bromobutyric acid 2.97N-Butylaminoacetic acid 2.29, 10.07N-(carbamoylmethyl)-imino-diacetic acid2.30, 6.602-carboxyethyliminodiacetic acid2.06,3.69, 9.66Cyanomethyliminodiacetic 3.06, 4.34β-carboxymethylaminopropionic 3.61, 9.46α,β-diaminopropionic acid 1.23, 6.69α,α-diaminobutyric 1.85, 8.24, 10.44Diethylaminoacetic 2.04, 10.47Di-(carboxymethyl)-aminomethyl phosphonic acid 2.00, 2.25, 5.57, 10.76Dimethylaminoacetic 2.08, 9.80N-ethylaminoacetic 2.30, 10.10α,β-dimercaptosuccinic 2.40, 3.46, 9.44, 11.82Gluconic* 3.86β-hydroxybutyric 4.39Ethylenediamine-N,N-diacetic 5.58, 11.05α-hydroxybutyric 3.65β-hydroxypropionic 3.73N-2-hydroxyethyliminodiacetic 2.2, 8.73Iminodiacetic* 2.98, 9.893-hydroxypropyliminodiacetic 2.06, 9.24β-iodopropionic* 4.04Iminodipropionic 4.11, 9.61N-isopropylaminoacetic 2.36, 10.06Isobutyric* 4.86α-mercaptobutyric 3.53Mandelic acid 3.41N-methylaminoacetic 2.24, 10.012-MercaptoethyliminodiaceticNitrilotriacetic 3.03, 3.07, 10.-2.14, 8.17, 10.792-PhosphonoethyliminodiaceticMethyliminodiacetic 2.81, 10.181.95,2.45, 6.54, 10.46*ThermodynamicPHENOLSCompound pK pound pK Ref. Chromotropic acid 5.36, 15.66Resorcinol--, 9.15 (30o)50o-Methoxyphenol--, 9.9350p-Methoxyphenol--, 10.1650 o-Hydroxybenz-3-Hydroxyanthran-aldehyde7.9550ilic acid10.09, 5.20512-Amino-4,5 dimethyl-2-Aminophenolphenol hydrochloride10.4 5.2851hydrochloride9.99, 4.86514,5-dihydroxybenzene-1,3 disulphonic acid7.6612.6eKojic acid9.4077Phenol o m p Phenol o m pH-9.95*9.94*O2N-7.23*8.35*7.14* (CH3)3N+-7.4288OCH- 6.798.007.66CH3SO2-9.337.83NC-8.61**7.95CH3CO-9.198.05CH3O2C-8.47*C2H5O2C-8.50*n-C4H9O2C-8.47*C3H5CH2O2C-8.41*I-9.17*Br-8.42*9.11*9.34*Cl-8.48*9.02*9.38*F-8.81*9.28*9.95*CH3S-9.539.53HO-9.489.449.96HOCH2-9.92*9.83*9.82*CH3-10.28*10.08 10.19*C2H5-10.29.910.0CH3O-9.939.6510.20H2N-9.719.8710.30-O2C-9.94*9.39*-O3S-9.299.03--O3P-10.29.9--O3As8.37 C6H5-9.939.599.51NO- 6.35**2-Chloro-4-Nitro- 5.42792-Nitro-4-Chloro- 6.4679* Thermodynamic**Reference 52ALCOHOLS and other OXYGEN ACIDSAlcoholsCompound pK pound pK Ref. Choline13.96C3F7•CH(C2F5)•OH 10.4865 Chloral hydrate9.66, 11.061(C3F7)2CH•OH10.5265 Trifluoroethanol12.562Carbonium ionsCF3CH2OH11.4, 12.4363CF3CH(OH)CH311.863Triphenylmethanols in H2SO4 HC1O4 HNO3refCF3CH2(CH3)3OH12.43104,4,4-Trimethoxy.82. .82 .8066C3F7CH2OH11.4**634,4’-Dimethoxy-1.24-1.14-1.1166(C3F7)2CHOH10.6**634-Methoxy-3.40-3.59-3.4166HCCCH2OH13.55644-Methyl-5.41-5.6766C(CH2OH))414.1644-Trideuteriomethyl- 5.43 5.6766HOCH2CHOHCH2OH 4.4643,3’,3”-Trimethyl- 6.35-5.9566HOCH2CH2OH14.7764Unsubstituted triphenyl-CH3CCH2OH14.8264methanol- 6.63-6.89 6.6066CH3OH15.54644,4;,4;-Trichloro- 7.74-8.0166 CH2=CHCH2OH15.52644-Nitro-9.15-9.7666 H2O15.7464CCl3CH2OH 11.8***CH3CH2OH1664CF3CH2OH 11.3***Substituent effects for ionization of RCH2OHRCCl-312.24,11.8064,65CF3-12.3764CHF2CH2-12.7464Hydroxamic acidsCHCl2-12.8964Furo-8.4572CHEC-13.5564Glycine7.4072H2Cl-14.3164Hippuro-8.8072CH3CCH2-14.864iso Nicotin7.8572HOCH215.164p-Methylbenz-8.9072H-15.564Nicotin-8.3072CH2=CH-15.564Nicotin-methiodide 6.4672CH3-(extrap)(15.9)64m-Nitrobenz-8.0772CF3C(CH3)2OH11.664Picolin8.5072HOCH2CF2CH2OH1164Pyrimidine-2-carbox-7.8872Primary alcohols=R•CH2•OH and Salicyl-7.4372Secondary alcohols in 50% alcohol Tropo-9.0972C2F511.3565C4F911.3565C5F1111.3765C7F1511.3565Other oxygen acidsCHF212.0065Trimethylamine-n-oxide 4.618CF2Cl11.6365Dimethylglyoxime12.8477CHF2CF211.3465(50% dioxane)CHF2 • (CF2)211.3565O-methyl ether12.9277CF3 • CH212.765Tropolone12a77CF3 • (CH2)212.965 α-Bromotropolone 6.95a77CF3 • CHMe • OH11.2865Acetald hydrate13.4891C3F7 • CHMe • OH11.3865Formald hydrate13.2991C3F7CHEt • OH11.3765C3F7CHPr • OH11.3765C3F7 • CH(CF3) • OH10.4665a50% dioxane***50 aquaeous ethanolOTHER OXYGEN ACIDSHydroxamic acids Aceto-9.4068Compound pK Ref.n-Butyro-9.4868Pyridine oxidesn-Butyro-9.00684-Aminopyridine 1-oxide 3.6967p-Methoxybenzo-9.19684-Dimethylaminopyridine 1-oxide3.8867N-Hydroxyphthalimide 7.00, 6.1071, 72Salicylo 7.32684-Dimethylaminopyridine 1-oxide3.8867Benzo-8.8868p-Chlorobenzo-9.59684-Dimethylamino-1-methoxypyridinium perchlorate >1167α-Naphtho-~7.768Propiono-9.46682-Methylaminopyridine 1-oxide 2.61672-Amino-1-methoxypyridinium perchlorate12.467Oximes4-Hydroxypyridine 1-oxide 2.4567Benzophenone oxime 11.3184-Methoxypyridine 1-oxide 2.0567Diethyl ketoxime 12.6181-Methoxypyridi-4-one 2.5767Isonitrosoacetylacetone (INAA) 7.4762-Hydroxypyridine 1-oxide -0.8675-Methyl-1,2,3-cyclohexanetrione-1,3-dioxime8.3762-Ethoxypyridine 1-oxide 1.18671-Methoxypyrid-2-one -1.3Acetophenone oxime 11.48184-Methylaminopyridine 1-oxide 3.8567Acetoxime 11.42184-Amino-1-methoxypyridinium perchlorate>1167Isonitrosoacetone (INA) 8.376Salicyclaldoxime (SA)9.2762-Aminopyridine 1-oxide 2.67671,2,3-Cyclohexanetrionetrioxime 8.0762-Dimethylaminopyridine 1-oxide2.27675-Methyl-1,2,3-cyclohexane-trionetrioxime8.0762-Methylamino-1-methoxypyridinium toluene-p-sulphonate >11674-Benzyloxypyridine 1-oxide 1.9967Oxygen acids1-Benzyloxypyrid-4-one 2.5867sulfinic acids 2-Methoxypyridine 1-oxide 1.2367p-Toluene- 1.99731-Benzyloxypyrid-2-one -1.767p-Chlorobenzene-73p-Nitrobenzene-73Pyridine 1-oxides p-Bromobenzene- 1.8973RpK Ref.m-Nitrobenzene- 1.88734-CH 3 1.2947Benzene-1.84,2.16733-CH 3 1.0847Peroxyacids3,4-(CH)4 1.0147Peroxymonosulfuric 9.4693-COOC 4H 90.0347Acetic 8.2704-NO 2-1.747n-Butyric 8.2703-NH 2 1.4747Formic 7.170H0.7947Propionic 8.1703-COOH 0.0947peroxydiphosphoric 5.18, 7.8854-COOH-0.4847peroxymonophosphoric 4.8590Peroxides ROOH (Ref. 70)H CH 3C 2H 5iso-C 3H 7tert-C 4H 9iso-C 4H 911.611.511.812.112.812.8Oximesref. 93Pyridine-2-aldoxime heptiodide 8.00benzoquinoline mon- 6.25Pyridine-4-aldoxime methiodide 8.503-pyridine-1,2-ethanedione-2-oxime methiodide7.20Pyridine-4-aldoxime pentiodide 8.504-Pyridine-1,2-ethanedione-2-oxime methiodide7.1O-Methyltyrosine ethyl ester 7.3122 octopine 13, 1.368.776Pyridine-2-aldoxime methiodide8.0Phenylglyoxald-8.3 2.40Pyridine-4-aldoxime dodeciodide8.5Phenylalanine 1.839.136 Pyridine-3-alkoxime methiodide9.22-Pyrrolidoone-5-carboxylic acid (glucamicacid) 3.32Hydroxamic acids ref. 93Serine 2.219.156 D-Lysine-7.93Threonine 2.6310.436 N-phenylnicotino-8.00N-Trimethyl tyrosine9.7521 Chloroaceto-8.40Tyrosine 10.07, 2.209.11 Formo-8.65Urocanic acid 5.8 3.5p-Chlorophenoxyaceto-8.75Valine 2.329.626 p-Hydroxybenzo-8.93β-Alanine 3.6010.196 p-Methoxybenzo-9.00γ-Aminobutyric acid 4.2310.436 N-Phenylbenzo-9.15Arginine 12.48 2.179.046 o-Aminobenzo-9.17Asparagine 2.028.86 L-Tyrosine9.20Azaserine8.556 L-Lysine7.9Canavanine7.40, 9.2511.50 (?)6 p-Nitrobenzo-8.0Creatine 2.6711.026 p-Aminobenzo-9.3Cysteine 10.78 1.718.336 L-Lacti-9.33,4-DihydroxyphenylalaninePropiono-9.49.88, 2.368.686 Phthalo-9.411.68Indole-3-aceto-9.5Glutamine 2.179.136 Cyclohexano-9.7Histamine 5.09.76 Hexano-9.7β-Hydroxyglutamic 2.099.206acid 4.18Amino Acids Hydroxyproline 1.929.736 Compound pK Ref.Leucine 2.369.606-COOH-NH3Methionine 2.289.21 Alanine 2.359.6961-Methylhistidine 6.48, 1.698.856α-Aminobutyric acid 2.559.60Norleucine 2.399.766α-Aminoisobutyric 2.3610.216Norvaline 2.369.766 Argininosuccinic >12, 1.629.586Ornithine 1.718.6962.70, 4.2610.76 Aspartic acid 2.09,3.869.826Proline 1.9910.606 Canaline10.3, 9.2011.6 (?)6Sarcosine 2.2310.016 Creatinine4.849.26Taurine 1.58.746 Cystine 1.657.856Thiolhistidine <1.5, 11.42.269.856 1.848.476 Diidotyrosine 6.48, 2.127.826Tryptophan 2.389.396 Glutamic acid 2.19, 4.259.676Tyrosine ethyl ester 7.339.8022 Glycine 2.349.66PeptidesHistidine 6.0, 1.829.176Anserine 7.0 2.659.56 Carnosine 6.83--9.516Hydroxylsine 2.138.626Cystinyldiglycine 3.12 6.3669.67 3.12 6.95 Isoleucine 2.369.686Glycylglycine 3.06 8.13 Lysine 2.188.956Gly-gly-gly 3.267.912310.53Glycylproline 2.848.556 O-Methyl tyrosine9.2721Aspartyl histi- 2.457.98dine 6.82 3.02Gly-gly-gly-gly 3.057.7523 Diglycylcystine 2.717.946Lysyl-lysine (L,L) 3.017.536 Glutathione 9.12 2.128.66610.0511.013.53Compound-COOH-NH2-NH2-NH2-NH2Ref. Gly•Ala (L) or (D) 3.178.2327 Ala•Gly (L) or (D) 3.168.2427 Gly•Ala•Ala (LL) 3.388.1027 Gly•Ala•Ala (LD) 3.308.1727 Ala•Ala•OH (DD) 3.308.1427 Ala•Ala•OH (LD) 3.128.3027 H•Ala•Ala•Ala•OH (3L) 3.398.0327 H•Ala•Ala•Ala•OH (LLD) 3.378.0527 H•Ala-Ala-Ala•OH (LDL) 3.318.1327 H•Ala-Ala-Ala•OH (DLL) 3.378.0627 H-Ala-Ala-Ala•OH (3D) 3.398.0627 H•Ala-Ala-Ala-Ala•OH (4L) 3.427.9427 H•Ala-Ala-Ala-Ala•OH (LLDL) 3.247.9327 H•Ala-Ala-Ala-Ala•OH (LDLL) 3.227.9927 H•Ala-Ala-Ala-Ala•OH (DLLL) 3.427.9927 H•Lys-Ala•OH (LL) 3.227.6210.7027 H•Lys-Ala•OH (LD) 3.007.7410.6327 H•Ala-Lys-Ala•OH (3L) 3.157.6510.3027 H•Ala-Lys-Ala•OH (LDL) 3.337.9710.3627 H•Ala-Lys-Ala•OH (LLD) 3.297.8410.4927 H•Ala-Lys-Ala-Ala•OH (4L) 3.588.0110.5827 H•Ala-Lys-Ala•OH (LDLL) 3.328.0110.3727 H•Ala-Lys-Ala-Ala-Ala•OH (5L) 3.537.7510.3527 H•Ala-Lys-Ala-Ala-Ala•OH (LDLLL) 3.307.8510.2927 H•Lys-Lys•OH (LL) 3.017.5310.0511.0127 H•Lys-Lys•OH (LD) 2.857.539.9210.9827 H•Lys-Lys•OH (3L) 3.087.349.8010.5411.3227 H•Lys-Lys-Lys•OH (LDL) 2.917.299.7910.5411.4227 H•Lys-Lys-Lys•OH (LDD) 2.947.149.6010.3811.0927 Compound pK ref.Glutathione 3.59, 8.75, 9.6577Glycylserine8.2377Glycylleucine8.1377Leucylglycine7.9677Glycylisoleucine7.9677Leucylglycylglycine7.6677Glycylphenylalanine8.2877Glycyltyrosine8.2277Benzylglutamic acid 3.49, 4.9977Glycyltryptophane8.0477Glutathione, oxidized 3.15, 4.03, 8.57, 9.5477Alanylalanine (LL) 3.308.1492Alanylalanine (LD) 3.128.3092Lysylalanine (LL) 3.227.6210.7092Lysylalanine (LD) 3.007.7410.6392Leucyltyrosine (LL) 3.467.8410.0992Leucyltyrosine (DL) 3.128.3810.3592Lysyllysine (LD) 2.857.539.9292NITROGEN COMPOUNDSAliphatic Amines pK ref.Ammonia9.211n-Propyl-10.531 Primary Amines Trimethylsilymethyl-10.961β-Alanine ester9.131CH3ONH2 4.6012 Allylamine-9.692Allyl-9.491 Benzyl9.341γ-Amino-n-butyric acid ester 9.711n-Butyl-10.591sec-Butyl-10.561t-Butyl-10.551Cyclohexyl-10.641 Cyclohexylmethyl-10.491β-difluoroethyl-7.521 Ethanol-9.501Ethyl10.631 Ethylenedi-9.98, 7.521, 77Glycine ester7.751 Hydrazine8.101Hydroxyl- 5.971 Isopropyl-10.631Methoxy- 4.601 Methyl-10.621neo-Pentyl-10.211 Phenylamyl-10.492δ-Phenylbutyl10.402β-Phenylethyl-9.831γ-Phenylpropyl-10.201Triethylenedi-8.8*?X XNH3+XCH2NH3+X(CH2)2NH3+X(CH2)3NH3+X(CH2)4NH3+X(CH2)5NH3+ref. H-9.25*10.64*10.67*10.58*10.61*10.63*2 HF2C-7.52RO2C-7.759.139.7110.15*10.372 HO- 5.96*9.50*C6H5- 4.58*9.37*9.83*10.20*10.39*10.49*2 H2N-8.12*9.98*10.65*10.84*11.05*2 H2C=CH-9.69CH3-10.64*10.67*10.58*10.61*10.63*10.64*2 X-H-NH3+-CO2–-SO3–-PO3–2X-NH3+9.25*-.88110.25X(CH2)2NH3+10.649.77 5.7510.8X(CH2)2NH3+10.6710.199.2010.8X(CH2)4NH3+10.619.3110.7710.6510.9X(CH2)5NH3+10.639.7410.7510.9511.0X(CH2)8NH3+10.6510.10X(CH2)10NH3+10.6411.3511.25X(CH2)3NH3+10.588.5910.4310.05Secondary amines Di-n-butyl-11.251 Dimethyl-10.641Diisobutyl-10.501Di-n-propyl-11.001α-Ethylpyrroline7.432 Diisopropyl-11.051α-Benzylpyrroline-7.082t-Butylcyclohexyl-11.2312-Methylpiperidine10.992α-Cyclohexylpyrroline7.952α-Cyclohexylpyrrolidine10.802α-(p-Tolyl)pyrroline7.592α-(p-Tolyl)pyrrolidine10.012α-Ethylpyrrolidine10.432N,O-dimethylhydroxylamine 4.7512α-Benzylpyrrolidine10.362Acetanilide+0.614N-methylhydroxylamine 5.9612*thermodynamic valueDiethyl-10.981Aliphatic Amines Methyl-β-diethylamino-ethyl-sulfide 1,2-Iminoethane 7.9871,2-Dimethyl-∆2-pyrroline 11.942cis-2,3-Iminobutane 8.7271-methyl-2-n-butyl-∆2-pyrroline 11.901,2-Imino-2-methylpropane 8.6171-Ethyl-2-methyl-∆2-pyrroline 11.9221,2-Iminobutane 8.2971-n-Butyl-2-methyl-∆2-pyrroline 11.902trans-2,3-Iminobutane 8.6971,2-Dimethyl-∆2-tetrahydropyridine11.572Secondary Amines N-Ethyl derivative of: 1,2-Imino-ethane7.937Allylmethyl-10.111Benzylethyl-9.681Trans-2,3-Iminobutane 9.477Morpholine 8.361Trimethylhydroxylamine 3.6512N-Benzoylpiperazine 7.781Dimethylethyl-9.991Di-sec-butyl-11.011Triethyl-10.651N-Methylmethoxyamine 4.751Dimethyl-n-butyl-10.021Pyrolidine 11.271Dimethyl-isopropyl-10.3011-Tosylpiperazine 7.39Dimethyl-t-butyl-10.521Benzylmethyl-9.581Tri-n-butyl-10.891Piperidine 11.221Diallylmethyl-8.791N-Carbethoxypiperazin 8.2811-n-Propylpiperidine 10.482Dietrimethylsilylmethyl-11.40110.110.15Diallyl-9.2919.8--5N-Methylhydroxyl- 5.9611,2-Dimethylpyrrolidine 10.262Trimethyleneimine 11.2911-Methyl-2-n-butylpyrrolidin 10.242Cis-2,6-dimethyl-piperidine 10.9231-Ethyl-2-methylpyrrolidine 10.6421-n-Butyl-2-methylpyrrolidine 10.4321-Ethyl-2-methylpyrrolidine 10.7021,2-Iminobutane 8.187Tertiary amines cis-2,3-Iminobutane 8.567Trimethyl-9.761N-dimethylhydroxylamine 5.2012Dimethyldiethyl-10.291Allyldimethyl 8.781Dimethyl-n-propyl-9.9911,2-Dimethylpiperidine 10.262Dimethyl-isobutyl-9.9111-Ethyl-2-methyl-∆2-tetrahydropyridine11.572Dimethyl-sec-butyl-10.401Tri-n-propyl-10.651Triallyl-8.311N-Allylpiperidine 9.6921-Diethylamino-hexane-thiol-(6)Cyanoamines2-Amino-2-cyanopropane 5.39N-piperidine-CH 2CN 4.558β-Isopropylaminopropionitrile 8.09Et 2NCN -2.08β-Diethylaminopropionitrile 7.69Et 2N(CH 2)2CN 7.658Et 2NCH 2CN 4.558Et 2N(CH 2)4CN 10.088Et 2N(CH 2)3CN 9.298Et 2NC(CH 3)2CN 9.138Et 2N(CH 2)5CN 10.468EtN(CH 2CN)2-0.68HN(CH 2CN)20.28EtN(CH 2CH 2CN)2 4.558HN(CH 2CH 2CN)2 5.268H 2NCH 2CN 5.348N(CH 2CH 2CN)3 1.18N-Amphetamine-(CH 2)2-CN 7.238N-piperidine-C(CH 3)2CN 9.228N-Norcodeine-(CH 2)2CN 5.688N-Methamphetamine-(CH 2)2CN 6.958Dimethylcyanimide 1.29Methyl cyanamide 1.29Diethylcyanimide 1.29Ethyl cyanamide 1.29Aminoacetonitrile 5.39Cyanamide 1.19Diethylaminoacetonitrile 4.59Dimethylaminoacetonitrile 4.29β-Aminopropionitrile7.79CF3CH2NHCH3 6.0510β-Dimethylaminopropionitrile7.09Phenylethylaminesβ,β"-Dicyanodiethylamine 5.292-phenylethylamine9.7811 For complex chelating agents of aliphatic amines,see also ref. 77.N-methyl-2-(3,4-dihydroxyphenyl)-ethylamine8.7811N-methyl-2-phenyl10.3111 Fluoro-substituted aminesEpinephrine8.5511 CF3CH2NH2 5.710Arterenol8.5511 CF3CH2N(CH3)2 4.7510R2R1CHCH2NHR4R3ref. 11R1R2R3R4pKH H H H9.78H H OH H8.90H OH OH H8.81OH H OH H8.67H OH H H9.22OH OH H H8.93OH OH OH H8.58H H H CH310.31H H OH CH39.31H OH OH CH28.62OH H OH CH38.89H OH H CH39.36OH OH H CH38.78OH OH OH CH38.55Ring amines and imines (in 80% methyl cellosolve) (ref. 2)Pentamethylene9.99Cyclotridecyl9.63 Hexamethylene10.00Cyclotetradecyl9.54 Heptamethylene9.77Cyclopentadecyl9.54 Octamethylene9.39Cycloheptadecyl9.57 Nonamethylene9.14Cyclooctadecyl9.54 Decamethylene9.04Undecamethylene9.14Amines otherDodecamethylene9.31Dimeoone 5.2318 Tridecamethylene9.35Phthalimide8.3018 Tetradecamethylene9.35Nitrourea 4.5718 Hexadecamethylene9.29Nitrourethane 3.2818 Heptadecamethylene9.27Diphenylthiocarbazone 4.56 Cyclohexyl9.82β,β,β"-Triaminotriethylamine Cycloheptyl9.998.42, 9.44, 10.1387 CyclooctylCyclononyl9.95Anilines Ref. 2Cyclodecyl9.85MonosubstitutedCycloundecyl9.71Substituent o m p Cyclododecyl9.62H- 4.62* 4.64* 4.58*。
