Synthesis of Diorganotin Esters of 5-Bromonicotinic Acid: X-ray Crystal Structure of Polymeric 5-Bromonicotinatodiorganotin

Abstract

Two types of diorganotins [R2Sn(OCOC5H3N-3-Br-5)2] n and {[R2Sn(OH2)(OCOC5H3N-3-Br-5)2]2} n (R= Me, n-Bu, Ph, n-Oc), are prepared from 5-Br-omonicotinic acid and diorganotin oxides. All the compounds, 1–8, are characterized by elemental analysis as well as IR and 1H-NMR spectroscopy. The crystal structures of [R2Sn(OCOC5H3N-3-Br-5)2] n (2) and {[R2Sn(OH2)(OCOC5H3N-3-Br-5)2]2} n (8) were determined by single crystal X-ray diffraction. In compound 2, each carboxylate moiety of 5-Br-omonicotinic acid is involved in coordination to one Sn atom via two O-atoms, and the N-atom of one pyridine-ring coordinates to the neighboring Sn atom which leads to a polymeric chain. And the N-atom of the other pyridine-ring is dissociative. In compound 8, the compound proves to be dinuclear macrocyclic compounds with 5-Br-omonicotinic acid bridging the adjacent tin atoms with a 12-member ring. The hydrogen bonds ( $$\hbox{N}\ldots\hbox{H}-\hbox{O}$$ ) are observed in the compound 8. These intermolecular hydrogen bonds form another ring, and lead to a polymeric chain in the lattice at the same time.