On the interaction of cyanoformaldehyde with HNO, HF, HCl, H2O, and CH3OH: A preference for orthogonal structures

5 years ago

On the interaction of cyanoformaldehyde with HNO, HF, HCl, H2O, and CH3OH: A preference for orthogonal structures

The potential energy surfaces of the complexes of cyanoformaldehyde, (formyl cyanide, HCOCN), with HNO, HF, HCl, H2O, and CH3OH have been investigated theoretically at the MP2 and CCSD(T) levels using several extended basis sets. Twenty-two low-lying minima have been detected, seven for HCOCN-HNO, three for each of the HCOCN-HF and HCOCN-HCl dimers, four for HCOCN-H2O and five for the HCOCN-CH3OH complex. The two most stable HCOCN-HNO complexes have non-planar structures as do the most stable arrangements of HCOCN-H2O and HCOCN-CH3OH. The vibrational frequency shifts typical for formyl groups engaged in hydrogen bonding, red shifts of CO stretches and blue shifts of CH stretches, occur in most of the dimers. Similarly, in almost all HCOCN-HNO complexes, the NH stretching frequencies are also blue-shifted. However, in case of the two most stable HCOCN-HNO complexes, red shifts of harmonic NH stretches are calculated. Inclusion of anharmonic contributions reduces these red shifts substantially and in one case converts the red shift to a blue shift. Conventional red shifts of XH (X=F, Cl, O) stretching frequencies and blue shifts for formyl CH stretches are calculated for the complexes with HF, HCl, H2O, and CH3OH.

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DOI: S2210271X17304292