COMPOUNDS OF GERMANIUM AND TIN .14. REARRANGEMENT OF BIS(2,4,6-TRI-TERT-BUTYLPHENYL)STANNYLENE - SYNTHESIS AND STRUCTURE OF A DONOR-FREE ALKYLARYLSTANNYLENE-TUNGSTEN COMPLEX

Bis(2,4,6-tri-tert-butylphenyl)stannylene R(2)Sn(2), rearranges in sol ution to the sterically less crowded alkylarylstannylene RR'Sn (3), R' = CH2-C(CH3)(2)-3,5-tBu(2)C(6)H(3). Treatment of 3 with [(OC)(5)W(THF )] yields the donor-free tungsten stannylene complex [(OC)(5)W = SnRR' ] (4). The molecular structure of 4 reveals a three-coordinate tin ato m in a strictly planar environment and an acute CSnC angle of 91.5 deg rees. Trapping reactions of 3 with selenium, 2,3-dimethylbutadiene, an d 3,5-di-tert-butyl-artho-benzoquinone furnish the 1,3-diselenadistann etane and the [4 + 1]-cycloaddition products, respectively.