Synthesis and structures of the 1,3-diphospha-2-metallapentanes [LnM{P(Ph)C6H4PPh}][MLn= ZrCp″2(2), rac-SnR2(3), SnMe2, or BAr; Cp″=η-C5H3(SiMe3)2-1,3, R = CH(SiMe3)2, Ar = C6H2But3-2,4,6]; X-ray structures of complexes (2) and (3)

Abstract

Reactions of L_nMCl₂ with 1,2-C₆H₄(PPh)₂[Li(tmeda)]₂ yield the metallacycles [L_n[graphic omitted]Ph}][ML_n= ZrCp″₂(2), rac-SnR₂(3), meso-(4a) and rac-(4b) SnMe₂, and BAr (5); tmeda =(Me₂NCH₂)₂, p″=η-C₅H₃(SiMe₃)₂-1,3; R = CH(SiMe₃)₂, Ar = C₆H₂Bu^t₃-2,4,6], complex (2)[unlike (3)] having distinct P environments in the crystal, P(1) being planar and P(2) pyramidal and Zr–P(1) < Zr–P(2); in C₆D₅CD₃ solution, the low temperature PMPCC skeletal arrangement in (2) and (5) corresponds to that of crystalline (2), with exchange processes being evident at higher temperatures [also noted for (3)].