CHARACTERIZATION OF ORGANIC ELECTROLYTE SYSTEMS BY NUCLEAR-MAGNETIC-RESONANCE AND MOLECULAR-ORBITAL SIMULATION - EQUILIBRIUM-CONSTANT AND NET CHARGE-DISTRIBUTION IN SOLVATION STATE

Solvation states of single solvent electrolyte systems of ethylene car bonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC), ehylm ethyl carbonate (EMC) and diethyl carbonate (DEC) with LiPF6 were char acterized by C-13-NMR solvation shift and molecular orbital (MO) simul ation. Dissociation constants and solvation constants were estimated b y parameter fitting to solvation shift using a simple equilibrium mode l, The solvation shifts Delta delta were observed not only at a lower field but also at a higher field due to change of net charge Delta rho in solvent molecules by Li+ attachment. This particular feature of so lvation shifts was demonstrated in the molecular orbital simulation as driven by the change of net charge using a 1:1 (Li+:solvent) solvatio n model. (C) 1997 Elsevier Science S.A.