DFT-MD Studies on Gas Phase [CO2(H2O)n]- Clusters (n = 0 – 8)

Research output: Conference PapersRGC 33 - Other conference paper

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Detail(s)

Original languageEnglish
Publication statusPresented - 17 Oct 2020

Conference

Title27th Symposium on Chemistry Postgraduate Research in Hong Kong
LocationOnline
PlaceHong Kong
Period17 October 2020

Abstract

The carbon dioxide radical anion (CO2-) was a key intermediate in electrochemical activation of CO2 1. Spectroscopic studies of CO2- in gas-phase hydrated clusters, [CO2(H2O)n]-, have reported a size-dependent blueshift of the symmetric C-O stretch of the anion with increasing cluster size in their corresponding IR spectra2. However, the origin of this blueshift remained elusive. In this work, [CO2(H2O)n]- clusters up to n=8 were simulated using density functional theory molecular dynamics (DFT-MD) using revPBE functional at 100K in an NVT ensemble with the CP2K package. After equilibration, dipole moment of structures at each timestep were computed, which were then autocorrelated and Fourier transformed to obtain the theoretical IR spectra. The simulation revealed two types of structures, namely, internally-solvated structures with hydrogen bonding at C atom, and externally-solvated structures, which does not have such interactions. The size-dependent blueshift was reproduced in internally-solvated structures, which have more apparent symmetric C-O stretch in their theoretical IR spectra than their externally-solvated counterparts.

Citation Format(s)

DFT-MD Studies on Gas Phase [CO2(H2O)n]- Clusters (n = 0 – 8). / Lam, Zachary; Tang, Wai Kit; Siu, Chi-Kit.
2020. 27th Symposium on Chemistry Postgraduate Research in Hong Kong, Hong Kong.

Research output: Conference PapersRGC 33 - Other conference paper