Formal Co(0), Fe(0), and Mn(0) complexes with NHC and styrene ligation

Publication date: Available online 13 November 2019Source: Chinese Chemical LettersAuthor(s): Wenwei Chen, Qi Chen, Yingjie Ma, Xuebing Leng, Sheng-Di Bai, Liang DengAbstractThe limited knowledge on low-coordinate zero-valent transition-metal species has intrigued great synthetic efforts in developing ligand sets for their stabilization. While the combined ligand set of N-heterocyclic carbene (NHC) with vinylsilanes was the only known ligand system amenable to the stabilization of three-coordinate formal zero-valent cobalt, iron, and manganese complexes, the exploration on other ligands has proved that the ligand set of NHCs with styrene is equally effective in stabilizing three-coordinate formal zero-valent metal complexes in the form of (NHC)M(η2-CH2CHPh)2 (NHC = IPr, IMes; M = Co, Fe, Mn). These styrene complexes can be prepared by the one-pot reactions of MCl2 with styrene, NHC and KC8, and have been characterized by various spectroscopic methods. Preliminary reactivity study indicated that the interaction of [(IMes)Fe(η2-CH2CHPh)2] with DippN3 produces the iron(IV) bisimido complex [(IMes)Fe(NDipp)2] and styrene, which hints at the utility of these zero-valent metal styene complexes as synthons of the mono-coordinate species (NHC)M(0).Graphical AbstractThe use of styrene with N-heterocyclic carbene (NHC) as ligands allows the stabilization of three-coordinate formal cobalt(0), iron(0), and manganese(0) complexes in the form of (NHC)M(η2-CH2CHPh)2.
Source: Chinese Chemical Letters - Category: Chemistry Source Type: research