Synthesis and Structure Characterization of Some Triorganotin Esters of Heteroaromatic Carboxylic Acid and Crystal Structure of Triphenyltin Esters of 6-Hydroxynicotinic Acid and 5-Chloro-6-hydroxynicotinic Acid

Reactions of (R₃Sn)₂O (R=Ph, 2-ClC₆H₄CH₂, 2-FC₆H₄CH₂, 4-CNC₆H₄CH₂) with 6-hydroxynicotinic acid and 5-chloro-6-hydroxynicotinic acid in 1:2 stoichiometry yielded eight triorganotin compounds. These compounds have been characterized by elemental analysis, IR and ¹H NMR spectroscopy. The crystal structures of triphenyltin esters of 6-hydroxynicotinic acid (1) and 5-chloro-6-hydroxynicotinic acid (2) were determined by single crystal X-ray diffraction. In these two compounds the tin atoms are rendered five-coordinate in a trigonal bipyramidal structure by coordination though the three phenyl carbon atoms and two oxygen atoms, one from carboxylate and other from the phenolic hydroxide. The resulting structures are two one-dimensional linear polymers through an interaction between the O atoms of phenolic hydroxide and tin atoms of an adjacent molecule.