Structural chemistry of organotin carboxylates: VII. Synthesis of triorganostannate esters of dicarboxylic acids. Crystal structure of dicyclohexylammonium 2,6-pyridinedicarboxylatotributylstannate

Abstract

The dicyclohexylammonnium 2,6-pyridinedicarboxylatotriorganostannates, [(c-C 6H 11) 2NH 2]-[R 3Sn((O 2C) 2C 5H 3N)], (R = n-C 4H 9, C 4H 9, C 6H 5) have been prepared from di-c-hexylamine, 2,6-pyridinedi-carboxylic acid and bis(tributyltin)oxide (R = n-C 4H 9) or triphenyltin hydroxide (R = C 6H 5). On the basis of Mössbauer quandrupole splittings the tin atoms are assigned five-coordinate geometries. An X-ray analysis of the R = n-butyl compound shows that the structure is polymeric with neighbouring tri-organotin centres being linked by dicarboxylate ligands. Each carboxylate moiety is involved in coordination to a Sn atom via one O atom only which has the result that the Sn atoms are five-coordinate and exist in trigonal bipyramidal geometries with the O atoms in axial positions; Sn–O(1) 2.31(1), Sn–O(3′) 2.26(1) Å and O(1)−Sn−O(3′) 173.2(6)°. The pyridine N atom is not involved in coordination to tin