Exploring the microscopic solvation of doubly charged anions: symmetric or asymmetric solvation in the CO2-(CH2)(4)-CO22-center dot(H2O)(2) dicarboxylate dianion cluster?

TY - JOUR

T1 - Exploring the microscopic solvation of doubly charged anions: symmetric or asymmetric solvation in the CO2-(CH2)(4)-CO22-center dot(H2O)(2) dicarboxylate dianion cluster?

AU - Dessent, C E H

AU - Rigby, C

PY - 2003/3/7

Y1 - 2003/3/7

N2 - optimised geometries and absolute energies of CO2-(CH2)(4)-CO22- . (H2O)(n), = 0, 1, 2, were determined using 2 density functional methods. The n = I global minimum was found to contain a bifurcated hydrogen-bond, with the n = 2 minimum containing two such bonds. Vertical detachment energies (VDEs) obtained for the n = 1,2 global minima at the MP2/6-31+G*//B3LYP/6-31+G* level agree well with experiment, and suggest that the two waters solvate the carboxylate groups separately in CO2-(CH2)(4)-CO2 . (H2O)(2). However, a number of different isomers were 2 identified for both clusters with several isomers producing similar VDEs, indicating that the measured VDEs may contain contributions from multiple isomers. Calculations are presented illustrating that IR predissociation spectra would allow the direct identification of these isomers. (C) 2003 Elsevier Science B.V. All rights reserved.

AB - optimised geometries and absolute energies of CO2-(CH2)(4)-CO22- . (H2O)(n), = 0, 1, 2, were determined using 2 density functional methods. The n = I global minimum was found to contain a bifurcated hydrogen-bond, with the n = 2 minimum containing two such bonds. Vertical detachment energies (VDEs) obtained for the n = 1,2 global minima at the MP2/6-31+G*//B3LYP/6-31+G* level agree well with experiment, and suggest that the two waters solvate the carboxylate groups separately in CO2-(CH2)(4)-CO2 . (H2O)(2). However, a number of different isomers were 2 identified for both clusters with several isomers producing similar VDEs, indicating that the measured VDEs may contain contributions from multiple isomers. Calculations are presented illustrating that IR predissociation spectra would allow the direct identification of these isomers. (C) 2003 Elsevier Science B.V. All rights reserved.

KW - DENSITY-FUNCTIONAL THEORY

KW - WATER CLUSTERS

KW - PHOTOELECTRON-SPECTROSCOPY

KW - THEORETICAL INVESTIGATIONS

KW - AB-INITIO

KW - GAS-PHASE

KW - SPECTRA

KW - IONS

KW - STABILIZATION

KW - ENERGETICS

U2 - 10.1016/S0009-2614(03)00070-8

DO - 10.1016/S0009-2614(03)00070-8

M3 - Article

SN - 0009-2614

VL - 370

SP - 52

EP - 61

JO - Chemical Physics Letters

JF - Chemical Physics Letters

IS - 1-2

ER -