C-C AND C-O BOND CONFORMATIONS IN 1,2-DIMETHOXYETHANE, BIS-(2-METHOXYETHYL)ETHER AND POLY(ETHYLENEOXIDE) - DEPENDENCE ON SOLVENT AND TEMPERATURE

Data from (3)J(HCCH) and (3)J(HCOC) couplings in 1,2-dimethoxyethane a nd bis-(2-methoxyethyl)ether, plus (3)J(HCCH) in poly(ethylene oxide), have been obtained in five solvents by iterative fitting. The resulti ng proportions of gauche rotamers are higher than previous estimates, and higher still after allowance is made for the pentane effect. They fit well with gas phase electron diffraction data, with current gas ph ase theoretical calculations and with standard RIS parameters for the polymer, but less well with calculations for the liquid state. The inf luence of solvent arises more from variations in its H-bond donor prop erties than in its dielectric. Copyright (C) 1996 Elsevier Science Ltd .