Synthesis And Characterization Of 5-Coordinate Tungsten Hydride Anions: [((Bu3sinh)-Bu-T)((Bu3sin)-Bu-T=)(2)Hwr]M

Treatment of ((Bu3SiNH)-Bu-t)((Bu3SiN)-Bu-t=)(2)WH (1-H) with small alkyl anions (RM) afforded tungsten alkyl hydride anions [((Bu3SiNH)-Bu-t)((Bu3SiN)-Bu-t=)(2)HWR)]M (3-(R) M: R=CH3, M=Li; R=Bu-n, M=Li; R=(neo)Pe, M=Li; R=CH2Ph (Bn), M=K (two isomers); R=CCH, M=Na; R=CH=CH2 (Vy), M=Li). The saturated alkyl anions 3-(R) M (3-(R)M: R=CH3, M=Li; R=nBu, M=Li; R=neoPe, M=Li; R=CH2Ph (Bn), M=K) degraded via apparent 1,2-RH-elimination to produce the known [((Bu3SiN)-Bu-t=)(3)WH] M (2-HM), but the acetylide (3-(C2H)Na) and vinyl (3-(Vy)Li) anions converted to their hydrogenated isomers, [((Bu3SiN)-Bu-t=)(3)WVy]Na (2-VyNa) and [((Bu3SiN)-Bu-t=)(3)WEt]Li (2-EtLi), respectively. The structure of 3-(Bu-n) Li is reported, and a discussion of tungsten-hydride coupling constants in (Bu3SiX)-Bu-t-ligated (X=O, NH, N) systems is given.