Structure and Reactivity of a Methyl Zinc Bis(iminophosphorano)methanide Chelate Complex

Reaction of dimethyl zinc with bis{trimethylsilyliminodi(phenyl)phosphorano}methane, H 2 C(Ph 2 P NSiMe 3 ) 2 ( 1 ), in toluene gave the alkyl zinc complex [ZnMe{HC(Ph 2 P NSiMe 3 ) 2 - κ 2 N,N ‘ }] ( 2 ) via elimination of methane. The crystal structure of the complex confirms its monomeric nature and the bidentate coordination of the bis(iminophosphorano)methanide ligand to the zinc. AdNCO (Ad = adamantyl) reacted smoothly with 2 via a nucleophilic addition forming a new C−C bond in the novel tripodal alkyl zinc complex, [ZnMe{HC{C(O)N(Ad)}(Ph 2 P NSiMe 3 ) 2 - κ 3 N,N ‘,N" }], 3 . The methine carbon atom resonances (δ 28.4 for 2 and 52.9 for 3 ) were observed as triplets due to the coupling to two equivalent phosphorus atoms. The crystal structure of 3 shows a propeller type arrangement with the three nitrogen atoms of the monoanionic tridentate ligand bound to zinc.