eta~6-Triphosphabenzene,eta~5-Triphosphacyclohexadienyl,and eta~5-Diphosphacyclopentadienyl Complexes of Group 8 and 9 Metals:Heterocycle Transformations at the Metal Center

摘要

The reactivity of a 1,3,5-triphosphabenzene,P_3C_3Bu~t_3,and a triphosphacyclohexadienyl anion,[MeP_3C_3Bu~t_3]~-,toward a range of group 8 and 9 halide complexes has been investigated.The anion reacts with FeCl2 to give the known tetraphosphaferrocene [Fe(eta~5-l,3-P_3C_3Bu~t_3)_2] and an unusual heterocage complex,[(eta~5-l,3-P_3C_3Bu~t_3)Fe{P2(PMe)_2(CBut)_3}],via phosphinidene elimination and intramolecular phosphinidene transfer reactions,respectively.The reactions of P_3C_3Bu~t_3 or [MeP_3C_3Bu~t_3]~-with [Cp*Ru(NCMe)_3] [PF_6] have afforded [Cp*Ru(eta~6-P_3C_3Bu~t_3)] [PFe] and the first example of a triphosphacyclohexadienyl-transition metal complex,[Cp*Ru{eta~5-(MeP)P_3C_3Bu~t_3}].The latter can also be prepared by treating [Cp*Ru(eta~6-P_3C_3Bu~t_3)] [PF6] with MeLi.Similarly,the reaction of [Cp*Ru(eta~6-P_3C_3Bu~t_3)] [PFe] with LiAlH_4 has yielded the 2-H-triphosphacyclohexadienyl complex [Cp*Ru-{eta~5-P_3C_3Bu~t_3(CHBu~t)}].Treatment of [Rh(COD)Cl]_2 with P_3C_3Bu~t_3 in the presence of Na[BAr~f_4],Ar~f= C_6H_3(CF_3)_2-3,5,gave the complex [(COD)Rh(eta~6-P_3C_3Bu~t_3)] [BAr~f_4],which when reacted with either water or ethanol afforded the 1,1-addition products [(COD)Rh{eta~5-[(H)-(RO)P]P_3C_3Bu~t_3}][BAr~f_4],R = H or Et.The mechanisms of the various heterocycle transformation reactions are discussed,and the X-ray crystal structures of all new complexes are reported.