title: The long-sought seventeen-electron radical [(C6Me6)Cr(CO)3](+): isolation, crystal structure and substitution reaction.
abstract: A highly air-sensitive seventeen-electron half-sandwich radical, [(C6Me6)Cr(CO)3](+), which has been long sought over 40 years, was isolated and structurally characterized. EPR spectroscopy and theoretical calculations indicate that the spin density mainly resides on the chromium atom. The radical can undergo a substitution reaction with PPh3 to form a more stable cation, [(C6Me6)Cr(CO)2(PPh3)](+). This work provides a direct observation of the radical process for CO-substitution reactions found in (arene)M(CO)3 (M = Cr, Mo, or W) systems, and suggests that other stable radicals of the type [(arene)M(CO)3](+) are accessible.
authors.affiliation: State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China. xpwang@nju.edu.cn.
authors.forename: Wenqing
authors.initials: W
authors.lastname: Wang
authors.forename: Xingyong
authors.initials: X
authors.lastname: Wang
authors.forename: Zaichao
authors.initials: Z
authors.lastname: Zhang
authors.forename: Ningning
authors.initials: N
authors.lastname: Yuan
authors.forename: Xinping
authors.initials: X
authors.lastname: Wang