SYNTHESIS AND REACTIONS OF A STANNANETHIONE DERIVED FROM A KINETICALLY STABILIZED DIARYLSTANNYLENE

Stannanethione Tbt(Tip)Sn=S (Tbt = 2,4,6-tris[bis(trimethylsilyl)methy l]phenyl; Tip = 2,4,6-triisopropylphenyl), containing a novel tin-sulf ur double bond, was synthesized by the reactions of the corresponding kinetically stabilized diarylstannylene Tbt(Tip)Sn: with styrene episu lfide or elemental sulfur. An absorption maximum due to the n-pi tran sition of the tin-sulfur double bond appeared at 473 nm in hexane. It reacted with thiocumulenes such as carbon disulfide and phenyl isothio cyanate and with styrene oxide and mesitonitrile oxide to give the cor responding cycloadducts. The structure of the [2 + 2] cycloadduct of a stannanethione with carbon disulfide was determined by X-ray structur al analysis. In contrast to Tbt(Tip)Sn=S, the less hindered stannaneth ione Tbt(Mes)Sn=S (Mes = mesityl) dimerized at room temperature to aff ord the corresponding 1,3,2,4-dithiadistannetane.