Wydział Chemii

K. S. Rutkowski

S. M. Melikova

D. A. Smirnov

Paweł Rodziewicz

Aleksander Koll

2002

Journal of Molecular Structure

614

305-313

10.1016/S0022-2860(02)00265-X

Naukowa

Angielski

Artykuł

FTIR spectra of acetylene have been studied in liquefied Ar, Kr, N₂, CO and CO₂ in the range ∼1000–9000 cm⁻¹. Width, position and absolute integral intensity of a set of fundamental and combination bands were determined. In the case of ν₃ band an effect of vibrational resonance interaction of Fermi-type has been taken into account and the position of non-perturbed ν₃⁰ and (ν₂+ν₄+ν₅)⁰ bands were evaluated in the solutions studied. Liquid to crystal state phase transition experiments, performed in Kr solutions, show reversible growth of self-associates when going to lower temperatures of C₂H₂ doped solid Kr. The ν₃(Σ_u⁺) C–H stretch band exhibits weak side shoulders in the case of CO and CO₂ solvents. New combination bands, attributed to ν₂(C₂H₂)+ν₃(CO₂), ν₃(C₂H₂)+ν₃(CO₂) and ν₁(C₂H₂)+ν₃(CO₂) simultaneous transitions due to vibrational excitation of both the interacting partners have been revealed in the region of ∼4000–6000 cm⁻¹. Detecting the ν₃(C₂H₂)+ν₃(CO₂) combination band, which is forbidden in the frame of dipole approximation, suggests an appreciable role of mutual polarization due to dipole–quadrupole polarizability of molecular partners. The observed spectroscopic features are compared with the results of theoretical DFT/B3LYP and ab initio MP2 calculations utilizing the 6-311++G(3df,3pd) basis set, which predict weak heterodimer formation, with linear H–CC–H⋯CO and slipped parallel
H-C C-HO-C-Ostructures being favored.

C2H2, Weak interactions, Vibrational spectra, Simultaneous transitions, Noble gas solutions

http://doi.org/10.1016/S0022-2860(02)00265-X

http://www.elsevier.com