Skip to Content
Merck
  • Measuring the relative hydrogen-bonding strengths of alcohols in aprotic organic solvents.

Measuring the relative hydrogen-bonding strengths of alcohols in aprotic organic solvents.

Chemphyschem : a European journal of chemical physics and physical chemistry (2014-11-25)
Malcolm E Tessensohn, Melvyn Lee, Hajime Hirao, Richard D Webster
ABSTRACT

Voltammetric experiments with 9,10-anthraquinone and 1,4-benzoquinone performed under controlled moisture conditions indicate that the hydrogen-bond strengths of alcohols in aprotic organic solvents can be differentiated by the electrochemical parameter ΔEp (red) =|Ep (red(1)) -Ep (red(2)) |, which is the potential separation between the two one-electron reduction processes. This electrochemical parameter is inversely related to the strength of the interactions and can be used to differentiate between primary, secondary, tertiary alcohols, and even diols, as it is sensitive to both their steric and electronic properties. The results are highly reproducible across two solvents with substantially different hydrogen-bonding properties (CH3 CN and CH2 Cl2 ) and are supported by density functional theory calculations. This indicates that the numerous solvent-alcohol interactions are less significant than the quinone-alcohol hydrogen-bonding interactions. The utility of ΔEp (red) was illustrated by comparisons between 1) 3,3,3-trifluoro-n-propanol and 1,3-difluoroisopropanol and 2) ethylene glycol and 2,2,2-trifluoroethanol.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
Acetonitrile solution, contains 0.05 % (v/v) trifluoroacetic acid
Sigma-Aldrich
Acetonitrile solution, contains 0.1 % (v/v) trifluoroacetic acid, suitable for HPLC
Supelco
Ethanol solution, certified reference material, 2000 μg/mL in methanol
Sigma-Aldrich
Acetonitrile solution, contains 0.1 % (v/v) formic acid, suitable for HPLC
Sigma-Aldrich
Isopropyl alcohol, ≥99.7%, FCC, FG
Supelco
1-Butanol, suitable for HPLC, 99.8%
Sigma-Aldrich
2-Methyl-1-propanol, BioUltra, for molecular biology, ≥99.5% (GC)
Sigma-Aldrich
Ethanol Fixative 80% v/v, suitable for fixing solution (blood films)
Sigma-Aldrich
Acetonitrile solution, contains 10.0% acetone, 0.05% formic acid, 40.0% 2-propanol
Supelco
Melting point standard 283-286°C, analytical standard
Supelco
1,4-Benzoquinone, Pharmaceutical Secondary Standard; Certified Reference Material
Sigma-Aldrich
Acetonitrile solution, contains 0.05 % (w/v) ammonium formate, 5 % (v/v) water, 0.1 % (v/v) formic acid, suitable for HPLC
Sigma-Aldrich
1-Butanol, suitable for HPLC
Sigma-Aldrich
Ethylene glycol, JIS special grade, ≥99.5%
Sigma-Aldrich
1-Butanol, SAJ first grade, ≥99.0%
Sigma-Aldrich
Ethanol, JIS special grade, 94.8-95.8%
Sigma-Aldrich
1-Butanol, JIS special grade, ≥99.0%
Sigma-Aldrich
Ethylene glycol, SAJ first grade, ≥99.0%
Sigma-Aldrich
2-Methyl-1-propanol, SAJ first grade, ≥99.0%
Sigma-Aldrich
2-Butanol, JIS special grade, ≥99.0%
Sigma-Aldrich
2-Methyl-1-propanol, JIS special grade, ≥99.0%
Supelco
Ethylene glycol solution, NMR reference standard, 80% in DMSO-d6 (99.9 atom % D), NMR tube size 5 mm × 8 in.
Sigma-Aldrich
Ethanol, 94.8-95.8%
Supelco
p-Benzoquinone, for spectrophotometric det. of amines, ≥99.5% (HPLC)
Supelco
2,2,2-Trifluoroethanol, analytical standard, for NMR spectroscopy
Sigma-Aldrich
1-Butanol, suitable for HPLC, ≥99.7%
Sigma-Aldrich
1-Butanol, ACS reagent, ≥99.4%
Sigma-Aldrich
1-Butanol, puriss. p.a., ACS reagent, reag. ISO, reag. Ph. Eur., ≥99.5% (GC)
Sigma-Aldrich
1-Butanol, for molecular biology, ≥99%
Sigma-Aldrich
2-Methyl-1-propanol, suitable for HPLC, 99.5%