Structural study of di- and triorganotin(IV) dicarboxylates containing one double bond

Tri- and diorganotin(IV) dicarboxylates derived from trans-glutaconic acid and acetone 1,3-dicarboxylic acid were prepared. Their structure was studied using NMR, IR, and MS data. All of these compounds (except for compound 2a) are polymeric in the solid state and depolymerise upon dissolving in deuteriochloroform to give monomeric particles with four-coordinated central tin atoms. X-ray crystallography was used to characterize (E)-bis(tributylstannyl) pent-2-enedioate (1a). This compound crystallizes in a monoclinic space group system. The supramolecular organization of 1a can be described as layered polymeric sheets constructed of forty-membered rings that are interconnected on four different sites to the third dimension. Each layer assembled of the forty-membered rings, is made up of six triorganotin fragments and six trans-glutaconic acids, where four of them are incorporated in the core of the ring and other two are bidentate bridging and participating in the ring system by three atoms of CO₂ group only.