Water/cyanobutadiyne complexes: an infrared matrix isolation and theoretical study

Abstract

The structures and energies of the 1 : 1 HC₅N : H₂O complexes in solid argon matrices have been investigated using FTIR spectroscopy and ab initio calculations, at the B3LYP/6-31G** and MP2/6-31G** levels of theory. Two types of 1 : 1 complexes are observed. The first one corresponds to the NH structure characterized by a hydrogen bond between H₂O and the nitrogen of HC₅N. The second corresponds to the OH form that involves a van der Waals interaction between the hydrogen of HC₅N and the oxygen of water. HC₅N can thus act either as an electrophile or as a nucleophile in complexes with water.