Condensation Reaction of Dimethyltin(IV) Oxide with 2-(2,3-Dichloroanilino)benzoic Acid Synthesis and Study of a Novel Dimeric Tetraorganodistannoxane

Abstract

The novel symmetric dimeric tetraorganodistannoxane [(Me2Sn)4(DCPA)2)O2(OH)2] (2) and [(Me2Sn)4(DCPA)2)O2(OC2H5)2] (3) where HDCPA is 2-(2,3-dichloroanilino)benzoic acid (1) have been prepared. The crystal structure of 3 has been determined by X-ray crystallography. Three distannoxane rings are present to the centrosymmetric dimeric tetraorganodistannoxane by virtue of μ3-oxo form the central R4Sn2O2 core with a planar Sn2O2 ring, resulting in a ladder type structural motif. Five-coordinated tin atoms are present in the distannoxane dimer. The ligands act as monodentate agents, thus rendering the tin atom five-coordinated. Significant π → π stacking interactions and intramolecular hydrogen bonds stabilize the structure 3. The polar imino hydrogen atom participates in intramolecular hydrogen bonds. The formation of the dimeric distannoxanes 2 and 3 represent a ladder-type carboxylates in which the insertion of a μ2-OH or a μ2-OC2H5 group occurs. This unusual result can be interpreted in terms of a competition between the strength different donors, in which the –OH or the –OC2H5 groups show higher donor capacity than the carboxylato group of DCPA.