Infrared and ab initio study of acetylene–acetone complex in solid argon and nitrogen matrices

The infrared absorption spectrum of the hydrogen-bonded acetylene–acetone complex has been investigated in solid argon and nitrogen matrices. Formation of the 1:1 acetylene–acetone complex was evidenced by the shifts in the vibrational frequencies of the modes involving the acetylene and acetone submolecules. The structure of the adduct, energies and the vibrational frequencies were computed at the B3LYP and MP2 level using 6-31++G∗∗ basis sets. The computed vibrational frequencies of 1:1 acetylene–acetone complex agree well with the experimental frequencies. The computed vibrational frequencies indicated a primary C–H⋯O hydrogen-bonded interaction between the hydrogen of acetylene and carbonyl oxygen in acetone. Structures, interaction energies, and vibrational frequencies have also been computed for 2:1 acetylene–acetone and acetylene–acetone–water complexes. AIM analysis was also performed to understand the nature of the interactions in these complexes.