Matrix Infrared Spectrum and Aromaticity of the Al2(CO)2 Molecule

• Published in: The journal of physical chemistry. A, Molecules, spectroscopy, kinetics, environment, & general theory Vol. 106; no. 48; pp. 11709 - 11713
• Main Authors: Kong, Qinyu, Chen, Mohua, Dong, Jian, Li, Zhenhua, Fan, Kangnian, Zhou, Mingfei
• Format: Journal Article
• Language: English
• Published: American Chemical Society 05.12.2002
• ISSN: 1089-5639; 1520-5215
• DOI: 10.1021/jp026351c

The reaction products between aluminum atoms and CO molecules in solid neon have been studied by matrix isolation infrared spectroscopy and quantum chemical calculations. Besides the previously reported AlCO and Al(CO)2 molecules, new absorption at 1727.9 cm-1 was also produced and assigned to a dibridged Al2(CO)2 molecule based on isotopic substitution experiments and theoretical frequency calculations. High level ab initio computations indicated that the Al2(CO)2 molecule has a singlet ground state with D 2 h symmetry. The molecule exhibits characteristics of aromaticity with two completely delocalized π electrons and an appreciable diatropic ring current.