By reaction of diphenyltin(1V) chloride and triphenyltin(1V) hydroxide with esters of the 2mer captopyridine-5-carboxylic acid NH(CS)CHCHC (COOR )C'H (HTNME, R = methyl; HTNEE, R = ethyl; HTNIPE, R = isopropyl) the complexes Ph,Sn(L), Ph,SnCI(L) (L = TNME, TNEE and TNIPE) and Ph,Sn(TNEE), have been prepared and characterized by IR, NMR and Mossbauer spectroscopies. Moreover, the Ph,SnCl, /2-mercaptopyridine (HMP) system has been found to yield either the Ph,SnCI,(HMP), adduct or the Ph,SnCI(MP) complex.
The structures of Ph,SnCI(TNEE) and Ph,SnCI(MP) have been determined by X-ray single-crystal diffraction studies. The two structures are similar. Both ligands behave as bidentate chelating groups forming a four-membered ring with an identical small N-Sn-S bite angle of 63.7'. The tin atom is pentacoordinated, presenting a severely distorted trigonal bipyramidal geometry with apical CI-Sn-N angles of 155.0(2)0 [Ph,SnCI(TNEE)] and 155.7(7)' [Ph,SnCI(MP)] and equatorial C-Sn-C angles of 114.9(2)' and 125.0(3)" respectively. On the basis of '19Sn Mossbauer data, all the complexes should present analogous structures except Ph,Sn(TNEE), and Ph,SnCl,(HMP), , for which an octahedral coordination geometry with a trans arrangement of the phenyl groups can be proposed. The effect of dimethyl sulphoxide on Ph,SnCI(L) and Ph2SnCI,(HMP), is also discussed.