Assembly of triorganotin chloride with selenite ligands to macrocyclic, zigzag, helical, and linear structures: syntheses, characterizations, and crystal structures of [R3Sn(O2SeC6H4-4-Et)] n and [R3Sn(O2SeC6H4-2-Et)] n (R = Me, C6H5) complexes

Four new triorganotin(IV) complexes, [R3Sn(O2SeC6H4-4-Et)](4) (R = Me 1), [R3Sn(O2SeC6H4-4-Et)] (n) (R = Ph 2), [R3Sn(O2SeC6H4-2-Et)] (n) (R = Me 3; Ph 4) have been synthesized by the treatment of 4-ethylbenzeneseleninic acid, 2-ethylbenzeneseleninic acid, and the corresponding triorganotin(IV) chloride with sodium ethoxide in methanol. All of the complexes were characterized by elemental analysis, FT-IR, NMR (H-1, C-13, and Sn-119) spectroscopy, TGA, and X-ray crystallography. Crystal structures show that all of the complexes are generated by the bidentate oxygen atoms and the five-coordinated tin centers with trigonal bipyramid geometry. The structural analyses reveal that complex 1 has a centrosymmetric tetranuclear triorganotin selenite with 16-membered macrocycle, which is formed by trimethyltin and ligand alternate linking. A series of C-H center dot center dot center dot O and pi-pi stacking interactions in complex 1 play an important function in the supramolecular aggregation. Complex 3 has two 1D spring-like chiral helical chains and crystallizes in the monoclinic space group P2(1), which is chiral. Complex 2 and 4 are both 1D infinite neutral chain polymers and complex 2 forms a 2D supramolecular framework through intermolecular C-H center dot center dot center dot O interactions.