Dichlorobis(4-methylpentan-2-onato-C4,O)tin(IV) and bis(4-methylpentan-2-onato-C4,O)(2-thioxo-1,3-dithiole-4,5-dithiolato-S,S')tin(IV) at 150 K.

The structures of the ketotins determined here, [SnCl(2)(C(6)H(11)O)(2)] and [Sn(C(3)S(5))(C(6)H(11)O)(2)], respectively, along with that previously reported for [MeC(O)CH(2)CMe(2)](2)SnI(2), are compared with the structures of the analogous estertins [MeOC(O)CH(2)CH(2)](2)SnX(2). Pairwise comparison of the mean ketotin [estertin] Sn-X and Sn-O distances as Sn-X 2.4422 (4) [2.4054 (7) A], 2.4970 (4) [2.471 (2) A] and 2.8463 (4) [2.7788 (8) A] and Sn-O 2.4926 (12) [2.528 (1) A], 2.6110 (11) [2.629 (7) A] and 2.435 (3) [2.525 (4) A] (for X = Cl, S and I, respectively) clearly demonstrates the superior donor ability of the ketotin O atom in chelate formation.