Syntheses, characterizations and crystal structures of new organoantimony(V) complexes with heterocyclic (S, N) ligand

Eight new organoantimony(V) complexes with 1-phenyl-1H-tetrazole-5-thiol [L1H] and 2,5-dimercapto-4-phenyl-1,3,4-thiodiazole [L2H] of the type RnSbL5 − n (L = L1: n = 4, R = n-Bu 1, Ph 2, n = 3, R = Me 3, Ph 4; L = L2: n = 4, R = n-Bu 5, Ph 6, n = 3, R = Me 7, Ph 8) have been synthesized. All the complexes 1–8 have been characterized by elemental, FT-IR, 1H and 13C NMR analyses. Among them complexes 2, 6 and 8 have also been confirmed by X-ray crystallography. The structure analyses show that the antimony atoms in complexes 2 and 6 display a trigonal bipyramid geometry, while it displays a distorted capped trigonal prism in complex 8 with two intramolecular Sb⋯N weak interactions. Furthermore, the supramolecular structure of 2 has been found to consist of one-dimensional linear molecular chain built up by intermolecular C–H⋯N weak hydrogen bonds, while a macrocyclic dimer has been found in complex 6 linked by intermolecular C–H⋯S weak hydrogen bonds with head-to-tail arrangement. Interestingly, one-dimensional helical chain is recognized in complex 8, which is connected by intermolecular C–H⋯S weak hydrogen bonds.