Blue shifted hydrogen bond in CH/D3CN…HCCL3 complexes

Behera, Bedabyas

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https://hdl.handle.net/2142/100649 Copy

Description

Title

Blue shifted hydrogen bond in CH/D3CN…HCCL3 complexes

Author(s)

Behera, Bedabyas

Contributor(s)

Das, Puspendu Kumar

Issue Date

2018-06-22

Keyword(s)

Fundamental interest

Abstract

H-bonded complexes between CHCl3 and CH/D3CN have been identified by FTIR spectroscopy in the gas phase at room temperature. With increasing partial pressure of the components, The C-H stretching fundamental shifts to the blue which has been identified as due to C-H...N interaction. The C-H stretching frequency of CHCl3 with CH3CN and CD3CN are shifted by +8.7 and +8.6 cm−1 ,respectively. By using quantum chemical calculations at the MP2/6-311++G∗∗ level, we predict the geometry, electronic structural parameters, binding energy, and spectral shift in the H-bonded complexes. The potential energy scans of the above complexes as a function of C...N distance shows that the H-bonding interaction is predominantly due to contribution of two opposing forces i.e.,electrostatic attraction between H and N which leads to the C-H bond elongation with consequent red-shift and the electronic and nuclear repulsion between the C and N which results in C-H bond contraction and blue-shift of the C-H stretching frequency. The net effect of these two opposing forces at the equilibrium complex geometry dictates the nature of the shift although the influence of the surrounding atoms bonded to the atoms that are directly involved in the H-bonding cannot be fully underestimated. The total interaction energy (- 14.23 kJ/mol) is characterized by Morokuma energy decomposition analysis where the binding in CH/D3CN...CHCl3 is dominated by electrostatic attraction (-25.86 kJ/mol). The attraction, however, is considerably suppressed by exchange repulsion (+19.54 kJ/mol). Other components like polarization (-5.44 kJ/mol) and charge transfer (-5.06 kJ/mol) make significant contribution to the interaction energy.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Language

eng

Permalink

http://hdl.handle.net/2142/100649

DOI

10.15278/isms.2018.FD05

Copyright and License Information

Copyright 2018 Bedabyas Behera

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