The Gutmann
Acceptor (AN) and
Donor number (DN) are measures of the
strength of solvents as Lewis acids or bases.
The Acceptor Number is based on the
31P-NMR chemical shift of
triethylphosphine oxide in the solvent.
The Donor Number is based on the heat of reaction between the compound dissolved in CH
2ClCH
2Cl and
SbCl
5 is therefore a 'solute' rather than a 'solvent' scale.
Because SbCl
5 is decomposed by protic compounds, e.g. alcohols, the Donor Numbers for these
have to be determined by indirect methods.
The Acceptor Number is a measure of hydrogen bond acidity and correlated with other hydrogen bond acidity scales such as
→ Dimroth-Reichardt ET
(
→ ET vs AN) and
→ Swain Acity
(
→ Acity vs AN).
Correlation with
→ Kamlet-Taft α and
→ Catalán SA is weaker.
The Donor number is correlated with
→ Kamlet-Taft β
(
→ β vs DN).
See →
"The donor-acceptor approach to molecular interactions" by V. Gutmann
See →
Lewis donor strength for scales of Lewis bases.
| Name | Formula | AN | DN |
|---|
| bis(2-methoxyethyl) ether | C6H14O3 | 9.9 | - |
| 1,1-dichloroethane | C2H4Cl2 | 16.2 | - |
| morpholine | C4H9NO | 17.5 | - |
| 1-methylpyrrolidin-2-thione | C5H9NS | 17.7 | - |
| pyridinium dichromate | C10H12Cr2N2O7 | 18.3 | - |
| N,N-dimethylthioformamide | C3H7NS | 18.8 | - |
| 2-aminoethanol | C2H7NO | 33.7 | - |
| 3-methylphenol | C7H8O | 50.4 | - |
| 2,2,2-trifluoroethanol | C2H3F3O | 53.8 | - |
| 1,1,1,3,3,3-hexafluoro-2-propanol | C3H2F6O | 66.7 | - |
| antimony pentachloride | Cl5Sb | 100.0 | - |
| trifluoroacetic acid | C2HF3O2 | 105.3 | - |
| methanesulfonic acid | CH4O3S | 126.3 | - |
| trifluoromethanesulfonic acid | CHF3O3S | 129.1 | - |
| cyclohexane | C6H12 | - | 0.0 |
| hexane | C6H14 | 0.0 | 0.0 |
| heptane | C7H16 | 0.0 | 0.0 |
| tetrachloromethane | CCl4 | 8.6 | 0.0 |
| 1,2-dichloroethane | C2H4Cl2 | 16.7 | 0.0 |
| toluene | C7H8 | - | 0.1 |
| sulfuryl chloride | Cl2O2S | - | 0.1 |
| benzene | C6H6 | 8.2 | 0.1 |
| thionyl chloride | Cl2OS | - | 0.4 |
| acetyl chloride | C2H3ClO | - | 0.7 |
| 4,4,5,5-tetrachloro-1,3-dioxolan-2-one | C3Cl4O3 | - | 0.8 |
| dichloromethane | CH2Cl2 | 20.4 | 1.0 |
| carbon disulfide | CS2 | - | 2.0 |
| benzoyl fluoride | C7H5FO | - | 2.0 |
| 1,3-dichlorobenzene | C6H4Cl2 | - | 2.0 |
| benzoyl chloride | C7H5ClO | - | 2.3 |
| methyl trifluoroacetate | C3H3F3O2 | - | 2.7 |
| nitromethane | CH3NO2 | 20.5 | 2.7 |
| bromobenzene | C6H5Br | - | 3.0 |
| 1,2-dichlorobenzene | C6H4Cl2 | - | 3.0 |
| fluorobenzene | C6H5F | - | 3.0 |
| ethyl trichloroacetate | C4H5Cl3O2 | - | 3.1 |
| 4,5-dichloro-1,3-dioxolan-2-one | C3H2Cl2O3 | 16.7 | 3.2 |
| propanoyl chloride | C3H5ClO | - | 3.2 |
| chlorobenzene | C6H5Cl | - | 3.3 |
| iodobenzene | C6H5I | - | 4.0 |
| trichloromethane | CHCl3 | 23.1 | 4.0 |
| nitrobenzene | C6H5NO2 | 14.8 | 4.4 |
| 2-chloroethanol | C2H5ClO | - | 5.0 |
| styrene | C8H8 | - | 5.0 |
| 1,3-dimethylbenzene | C8H10 | - | 5.0 |
| nitroethane | C2H5NO2 | - | 5.0 |
| 1,4-dimethylbenzene | C8H10 | - | 5.0 |
| furan | C4H4O | - | 6.0 |
| ethylbenzene | C8H10 | - | 6.0 |
| cumene | C9H12 | - | 6.0 |
| ethoxybenzene | C8H10O | - | 8.0 |
| methoxybenzene | C7H8O | - | 9.0 |
| ethyl dichloroacetate | C4H6Cl2O2 | - | 9.4 |
| chloroacetonitrile | C2H2ClN | - | 10.0 |
| 1,3,5-trimethylbenzene | C9H12 | - | 10.0 |
| 2,2,4,4-tetramethyl-3-pentanone | C9H18O | - | 10.3 |
| acetic anhydride | C4H6O3 | - | 10.5 |
| methyl propanoate | C4H8O2 | - | 11.0 |
| phenol | C6H6O | - | 11.0 |
| 2,3-butanedione | C4H6O2 | - | 11.0 |
| 2,2,4-trimethylpentan-3-one | C8H16O | - | 11.3 |
| phosphorus oxychloride | Cl3OP | - | 11.7 |
| 2,2,5,5-tetramethylhexan-3-one | C10H20O | - | 11.8 |
| benzonitrile | C7H5N | 15.5 | 11.9 |
| 2-methyltetrahydrofuran | C5H10O | - | 12.0 |
| selenium oxychloride | H2Cl2OSe | - | 12.2 |
| methyl 2,2-dimethylpropanoate | C6H12O2 | - | 12.8 |
| ethyl chloroacetate | C4H7ClO2 | - | 13.0 |
| ethyl 2,2-dimethylpropanoate | C7H14O2 | - | 13.0 |
| isopropyl 2,2-dimethylpropanoate | C8H16O2 | - | 13.5 |
| isopropyl pivalate | C8H16O2 | - | 13.5 |
| acetonitrile | C2H3N | 18.9 | 14.1 |
| dioxane | C4H8O2 | 10.3 | 14.3 |
| 2,2-dimethylpentan-3-one | C7H14O | - | 14.6 |
| sulfolane | C4H8O2S | 19.2 | 14.8 |
| ethyl benzoate | C9H10O2 | - | 15.0 |
| 3-pentanone | C5H10O | - | 15.0 |
| 2,2,6,6-tetramethyl-4-heptanone | C11H22O | - | 15.0 |
| acetophenone | C8H8O | - | 15.0 |
| methyl benzoate | C8H8O2 | - | 15.0 |
| butyl acetate | C6H12O2 | - | 15.0 |
| 2-phenylacetonitrile | C8H7N | - | 15.1 |
| 4-methyl-2-oxo-1,3-dioxolane | C4H6O3 | 18.3 | 15.1 |
| 1,3,2-dioxathiolan-2-oxide | C2H4O3S | - | 15.3 |
| 2-methylpropanenitrile | C4H7N | - | 15.4 |
| bis(2-chloroethyl) ether | C4H8Cl2O | - | 16.0 |
| propyl acetate | C5H10O2 | - | 16.0 |
| 4-methyl-2-pentanone | C6H12O | - | 16.0 |
| benzophenone | C13H10O | - | 16.0 |
| diethyl carbonate | C5H10O3 | - | 16.0 |
| benzaldehyde | C7H6O | - | 16.0 |
| propanenitrile | C3H5N | - | 16.1 |
| 2-methylpentan-3-one | C6H12O | - | 16.2 |
| 2,4-dimethyl-3-pentanone | C7H14O | - | 16.2 |
| 2,6-dimethyl-4-heptanone | C9H18O | - | 16.4 |
| phenylphosphonic difluoride | C6H5F2OP | - | 16.4 |
| 1,3-dioxolan-2-one | C3H4O3 | - | 16.4 |
| ethyl 2-methylpropanoate | C6H12O2 | - | 16.4 |
| methyl acetate | C3H6O2 | 10.7 | 16.5 |
| N,N-dimethyltrifluoroacetamide | C4H6F3NO | - | 16.6 |
| butanenitrile | C4H7N | - | 16.6 |
| 2,2,2-trifluoro-N,N-dimethylacetamide | C4H6F3NO | - | 16.6 |
| ethyl butanoate | C6H12O2 | - | 16.8 |
| dimethylcyanamide | C3H6N2 | - | 17.0 |
| 3,3-dimethyl-2-butanone | C6H12O | - | 17.0 |
| ethyl formate | C3H6O2 | - | 17.0 |
| 2-propanone | C3H6O | 12.5 | 17.0 |
| ethyl propanoate | C5H10O2 | - | 17.1 |
| 3-methyl-2-butanone | C5H10O | - | 17.1 |
| ethyl acetate | C4H8O2 | 9.3 | 17.1 |
| dimethyl carbonate | C3H6O3 | - | 17.2 |
| N,N-dimethylcarbamoyl chloride | C3H6ClNO | - | 17.2 |
| 2-butanone | C4H8O | - | 17.4 |
| 2-pentanone | C5H10O | - | 17.5 |
| isopropyl acetate | C5H10O2 | - | 17.5 |
| cyclopentanone | C5H8O | - | 18.0 |
| dipropyl ether | C6H14O | - | 18.0 |
| cyclohexanone | C6H10O | - | 18.0 |
| oxolan-2-one | C4H6O2 | 17.3 | 18.0 |
| water | H2O | 54.8 | 18.0 |
| methyl propyl ether | C4H10O | - | 18.1 |
| phenylphosphonic dichloride | C6H5Cl2OP | - | 18.5 |
| dibutyl ether | C8H18O | - | 19.0 |
| dibenzyl ether | C14H14O | - | 19.0 |
| 1,2,3-propanetriol | C3H8O3 | - | 19.0 |
| diisopropyl ether | C6H14O | - | 19.0 |
| methanol | CH4O | 41.5 | 19.0 |
| formic acid | CH2O2 | 83.6 | 19.0 |
| diethyl ether | C4H10O | 3.9 | 19.2 |
| ethanol | C2H6O | 37.9 | 19.2 |
| butanol | C4H10O | 36.8 | 19.5 |
| propanol | C3H8O | 37.3 | 19.8 |
| ethanediol | C2H6O2 | - | 20.0 |
| tetrahydrofuran | C4H8O | 8.0 | 20.0 |
| 1,2-dimethoxyethane | C4H10O2 | 10.2 | 20.0 |
| acetic acid | C2H4O2 | 52.9 | 20.0 |
| N,N-dimethylbenzylamine | C9H13N | - | 21.0 |
| 2-propanol | C3H8O | 33.5 | 21.1 |
| 1,3-dioxolane | C3H6O2 | - | 21.2 |
| ethyl chloroformate | C3H5ClO2 | - | 21.3 |
| oxane | C5H10O | - | 22.0 |
| N,N-dimethylurethane | C5H11NO2 | - | 22.4 |
| diphenylphosphinic chloride | C12H10ClOP | - | 22.4 |
| trimethyl phosphate | C3H9O4P | 16.3 | 23.0 |
| 2-phenylethanol | C8H10O | 33.8 | 23.0 |
| benzyl alcohol | C7H8O | 36.8 | 23.0 |
| tributyl phosphate | C12H27O4P | 9.9 | 23.7 |
| 1,3,3-trimethyl-2-oxabicyclo[2.2.2]octane | C10H18O | - | 24.0 |
| formamide | CH3NO | 39.8 | 24.0 |
| pentanol | C5H12O | - | 25.0 |
| cyclohexanol | C6H12O | - | 25.0 |
| triethyl phosphate | C6H15O4P | - | 26.0 |
| N,N-dimethylformamide | C3H7NO | 16.0 | 26.6 |
| N,N-dimethylaniline | C8H11N | - | 27.0 |
| N-methylformamide | C2H5NO | 32.1 | 27.0 |
| 1-methylazepan-2-one | C7H13NO | - | 27.1 |
| N-methylpyrrolidone | C5H9NO | 13.3 | 27.3 |
| 1,3-dimethyl-2-imidazolidinone | C5H10N2O | - | 27.7 |
| N,N-dimethylacetamide | C4H9NO | 13.6 | 27.8 |
| trimethylurea | C4H10N2O | - | 29.3 |
| diethyl dimethylamidophosphate | C6H16NO3P | - | 29.5 |
| diethyl dimethylphosphoramidate | C6H16NO3P | - | 29.5 |
| 1,3-dimethylurea | C3H8N2O | - | 29.7 |
| dimethyl sulfoxide | C2H6OS | 19.3 | 29.8 |
| hexanol | C6H14O | - | 30.0 |
| dioctyl sulfoxide | C16H34OS | - | 30.3 |
| N,N-diethylformamide | C5H11NO | - | 30.9 |
| decanol | C10H22O | - | 31.0 |
| 2-chloroaniline | C6H6ClN | - | 31.0 |
| dibutyl sulfoxide | C8H18OS | - | 31.0 |
| N,N,N',N'-tetramethylurea | C5H12N2O | 9.2 | 31.0 |
| dioctyl methylphosphonate | C17H37O3P | - | 31.2 |
| 3-methyl-1-butanol | C5H12O | - | 32.0 |
| octanol | C8H18O | - | 32.0 |
| quinoline | C9H7N | - | 32.0 |
| N,N-diethylacetamide | C6H13NO | 13.6 | 32.2 |
| N-methylaniline | C7H9N | - | 33.0 |
| 1,3-dimethyltetrahydropyrimidin-2(1H)-one | C6H12N2O | - | 33.0 |
| pyridine | C5H5N | 14.2 | 33.1 |
| trioctylphosphine oxide | C24H51OP | - | 33.8 |
| 4-methylpyridine | C6H7N | - | 34.0 |
| pyridine N-oxide | C5H5NO | - | 34.4 |
| aniline | C6H7N | - | 35.0 |
| tert-butyl acetate | C6H12O2 | - | 35.9 |
| 4-methylpyridine N-oxide | C6H7NO | - | 36.3 |
| N-(dimethylamino-ethoxyphosphoryl)-N-methylmethanamine | C6H17N2O2P | - | 36.4 |
| hexaethylphosphoramide | C12H30N3OP | - | 36.6 |
| 2-methyl-1-propanol | C4H10O | - | 37.0 |
| N-bis(dimethylamino)phosphoryl-N-ethylethanamine | C8H22N3OP | - | 37.8 |
| N-(dimethylamino-pyrrolidin-1-ylphosphoryl)-N-methylmethanamine | C8H20N3OP | - | 38.0 |
| 2-methyl-2-propanol | C4H10O | 27.1 | 38.0 |
| hexamethylphosphoramide | C6H18N3OP | 10.6 | 38.8 |
| 3-methylpyridine | C6H7N | - | 39.0 |
| dimethyl sulfide | C2H6S | - | 40.0 |
| piperidine | C5H11N | - | 40.0 |
| bis(diethylamino)-pyrrolidinophosphine oxide | C12H28N3OP | - | 40.2 |
| bis(ethylamino)-(dimethylamino)phosphine oxide | C6H18N3OP | - | 40.6 |
| 1-di(piperidin-1-yl)phosphorylpiperidine | C15H30N3OP | - | 40.9 |
| diethyl sulfide | C4H10S | - | 41.0 |
| N-(azetidin-1-yl-dimethylaminophosphoryl)-N-methylmethanamine | C7H18N3OP | - | 41.1 |
| bis(dimethylamino)-(ethylamino)phosphine oxide | C6H18N3OP | - | 41.2 |
| butanamine | C4H11N | - | 42.0 |
| N,N,1,3-tetramethyl-1,3,2-diazaphospholidin-2-amine 2-oxide | C6H16N3OP | - | 42.1 |
| dimethylamino-di(azetidin-1-yl)phosphine oxide | C8H18N3OP | - | 42.3 |
| ethylamino-dipyrrolidinophosphine oxide | C10H22N3OP | - | 42.6 |
| tri(azetidin-1-yl)phosphine oxide | C9H18N3OP | - | 43.0 |
| hydrazine | H4N2 | - | 44.0 |
| 2-methyl-2-butanol | C5H12O | - | 44.0 |
| N-dipyrrolidin-1-ylphosphoryl-N-methylmethanamine | C10H22N3OP | - | 45.4 |
| tripyrrolidinophosphine oxide | C12H24N3OP | - | 47.2 |
| N-bis(ethylamino)phosphorylethanamine | C6H18N3OP | - | 47.3 |
| N-(aziridin-1-yl-dimethylaminophosphoryl)-N-methylmethanamine | C6H16N3OP | - | 48.6 |
| N-[bis(aziridin-1-yl)phosphoryl]-N-methylmethanamine | C6H14N3OP | - | 49.1 |
| tributylamine | C12H27N | - | 50.0 |
| triethylenephosphoramide | C6H12N3OP | - | 50.0 |
| diethylamine | C4H11N | 9.4 | 50.0 |
| N,N-dioctyloctan-1-amine oxide | C24H51NO | - | 52.3 |
| ethylamine | C2H7N | - | 55.0 |
| 1,2-diaminoethane | C2H8N2 | 20.9 | 55.0 |
| bis(pyrrolidino)diethylaminophosphine oxide | C12H26N3OP | - | 55.2 |
| 2-methyl-2-propanamine | C4H11N | - | 57.0 |
| ammonia | H3N | - | 59.0 |
| triethylamine | C6H15N | 1.4 | 61.0 |
