Tin(IV) Polymers: Part 2. Synthesis and Structure of Tri(p-substituted Benzyl)tin(IV) Pyridinecarboxylates and Crystal Structure of [(4-FC6H4CH2)3SnOCO(4-C5H4N)]∞ and [(4-NCC6H4CH2)3SnOCO(4-C5H4N)·2CH3CN]∞

Reactions of bis[tri(p-substituted benzyl)tin] oxide with pyridinecarboxylic acid in 1:2 stoichiometry yielded compounds of the type (4-XC6H4CH2)3SnO2CPy (X=F, Cl, NC; Py=3-pyridinyl, 4-pyridinyl). These compounds have been characterized by elemental analyses, IR and 1H NMR spectroscopy. The crystal structures of tri(4-fluorbenzyl)tin 4-pyridinecarboxylate (2) and tri(4-cyanobenzyl)tin 4-pyridinecarboxylate (4) were determined by single crystal X-ray diffraction. In compounds 2 and 4, the tin atoms are rendered five-coordinated in a trigonal bipyramidal structure by coordinating with intermolecular pyridine N atoms of carboxylate groups. The resulting structures are two one-dimensional linear polymers containing Sn–O bond length of 2.140(4) Å and 2.150(4) Å and Sn–N bond lengths of 2.537(6) Å and 2.522(4) Å.