Observation of Carbon–Carbon Coupling Reaction in Neutral Transition-Metal Carbonyls
Chong Wang, Qinming Li, Xiangtao Kong, Huijun Zheng, Tiantong Wang, Ya Zhao, Gang Li, Hua Xie, Jiayue Yang, Guorong Wu, Weiqing Zhang, Dongxu Dai, Mingfei Zhou, Xueming Yang, Ling Jiang
Abstract
Neutral titanium-metal carbonyl complexes with the chemical formula Ti(CO)n (n = 4–7) are produced in the gas phase by the reactions of titanium atoms with carbon monoxide in a pulsed laser vaporization–supersonic expansion source. Their infrared absorption spectra in the carbonyl stretching frequency region are measured by infrared plus vacuum ultraviolet (IR+VUV) two-color ionization spectroscopy based on a tunable VUV free electron laser. Infrared spectroscopy in conjunction with quantum chemical calculations confirm that all of these complexes have unexpected titanium ketenylidene OTiCCO(CO)n−2 structures. Bonding analysis indicates that the OTiCCO core structure can be described by the bonding interactions between a TiO+ cation in the doublet ground state and a doublet ground state of CCO–. The results reveal that the C–O bond breaking and C–C bond formation proceed efficiently in the reactions between laser-vaporized titanium atoms and carbon monoxide.