10.1021/jp306446d.s001
Janice A. Steckel
Janice A.
Steckel
Ab Initio Calculations
of the Interaction between
CO<sub>2</sub> and the Acetate Ion
American Chemical Society
2012
distortion
CT
charge transfer
NPA
Ab Initio Calculations
DMA
Acetate IonA series
ab initio geometries
CO 2
binding energies
functional
CCSD
B 3LYP approach
ab initio calculations
CHELPG
DFT methods
complex
AC
VV
kcal
2012-11-29 00:00:00
Dataset
https://acs.figshare.com/articles/dataset/Ab_Initio_Calculations_of_the_Interaction_between_CO_sub_2_sub_and_the_Acetate_Ion/2464756
A series of ab initio calculations designed to investigate
the
interaction of CO<sub>2</sub> with acetate are presented. The lowest
energy structure, AC–CO<sub>2</sub>-η<sup>2</sup>, is
predicted by CCSD(T)/aVTZ to be bound by −10.6 kcal/mol. Six
of the bound complexes have binding energies on the order of −8
kcal/mol, but analysis shows that the η<sup>1</sup>-CT complex
is fundamentally different from the others. The η<sup>1</sup>-CT complex is characterized by geometric distortion, large polarization
and induction effects and charge transfer whereas the other five complexes
have little geometric distortion and negligible charge transfer. The
amount of charge that is transferred from the anion to the CO<sub>2</sub> in the η<sup>1</sup>-CT complex is estimated to be
about half an electron by NPA, DMA, CHELPG, and Mulliken analyses,
whereas the EDA-ALMO-CTA (B3LYP) approach predicts a charge transfer
of 75 me<sup>–</sup>. However, the transfer of this small amount
of charge leads to an energy lowering of −56 kcal/mol, without
which the complex would not be bound. The RI-MP2 geometries closely
approximate those resulting from the CCSD optimizations, and the optimized
second-order opposite spin (O2) method performs well for all the complexes
except for the η<sup>1</sup>-CT complex. DFT methods do not
reproduce all the ab initio geometries, binding energies and/or energy
ordering of these complexes although the range-separated hybrid meta-GGA
(M11) and nonlocal (VV10 and vdwDF10) functionals are shown to yield
results significantly better than other functionals considered for
this system. The fact that there is such variation among DFT methods
has implications for DFT-based ab initio molecular dynamics simulations
and for the parametrization of classical force fields based on DFT
calculations.