Synthesis and crystal structure of macrocyclic di-n-butyltin(IV) complex with 2-mercapto-4-methyl-5-thiazoleacetic acid, {[n-Bu2Sn(O2CCH2C4H3NS)SS(C4H3NSCH2CO2)Sn n-Bu2]O}2

A novel macrocyclic di-n-butyltin(IV) complex 1 was synthesized by the reaction of di-n-butyltin(IV) oxide and 2-mercapto-4-methyl-5-thiazoleacetic acid. Characterization of the complex 1 was achieved using elemental analysis, IR, 1H, 13C and 119Sn NMR spectra and X-ray diffraction. X-ray data of the complex 1 revealed that it is an unusual macrocycle containing the bridging-S–S-linkages and tetranuclear ladder based on a planar four-membered Sn2O2 ring. In the so-called ladder structure, there are two distinct tin environments, the endocyclic tin atom is best described as five-coordinate and the exocyclic tin atom as six-coordinate.