Investigation on coordination modes of organotin(IV) complexes with 6-thiopurine and related ligands

The organotin(IV) complexes R2Sn(tpu)2 · L [L = 2MeOH, R = Me (1); L = 0: R = n-Bu (2), Ph (3), PhCH2 (4)], R3Sn(Hthpu) [R = Me (5), n-Bu (6), Ph (7), PhCH2 (8)] and (R2SnCl)2 (dtpu) · L [L = H2O, R = Me (9); L = 0: R = n-Bu (10), Ph (11), PhCH2 (12)] have been synthesized, where tpu, Hthpu and dtpu are the anions of 6-thiopurine (Htpu), 2-thio-6-hydroxypurine (H2thpu) and 2,6-dithiopurine (H2dtpu), respectively. All the complexes 1–12 have been characterized by elemental, IR, 1H, 13C and 119Sn NMR spectra analyses. And complexes 1, 2, 7 and 9 have also been determined by X-ray crystallography, complexes 1 and 2 are both six-coordinated with R2Sn coordinated to the thiol/thione S and heterocyclic N atoms but the coordination modes differed. As for complex 7 and 9, the geometries of Sn atoms are distorted trigonal bipyramidal. Moreover, the packing of complexes 1, 2, 7 and 9 are stabilized by the hydrogen bonding and weak interactions.