Trimethylsilylchalcogenolates of Co(II) and Mn(II): from mononuclear coordination complexes to clusters containing -ESiMe3 moieties (E = S, Se).

The Co(II) and Mn(II) complexes (tmeda)Co(ESiMe(3))(2) (E = S, 1a; E = Se, 1b), (3,5-Me(2)C(5)H(3)N)(2)Co(ESiMe(3))(2) (E = S, 2a; E = Se, 2b), [Li(tmeda)](2)[(tmeda)Mn(5)(mu-ESiMe(3))(2)(ESiMe(3))(4)(mu(4)-E)(mu(3)-E)(2)] (E = S, 3a; E = Se, 3b), [Li(tmeda)](2)[Mn(SSiMe(3))(4)] (4), [Li(tmeda)]4[Mn(4)(SeSiMe(3))(4)(mu(3)-Se)(4)] (5), and [Li(tmeda)](4)[Mn(Se(4))(3)] (6) (tmeda = N,N,N',N'-tetramethylethylenediamine) have been isolated from reactions of Li[ESiMe(3)] and the chloride salts of these metals. The treatment of (tmeda)CoCl(2) with two equivalents of Li[ESiMe(3)] (E = S, Se) yields 1a and 1b, respectively, whereas similar reactions with MnCl(2) yield the polynuclear complexes 3a (E = S) and 3b (E = Se). The selective preparation of the mononuclear complex 4 is achieved by increasing the reaction ratios of Li[SSiMe(3)] to MnCl(2) to 4:1. Single crystal X-ray analysis of complexes 1-5, confirms the presence of the trimethylsilylchalcogenolate moieties and distorted tetrahedral geometry around the metal centers in each of these complexes. The structure of the tris(tetraselenide) complex [Li(tmeda)](4)[Mn(Se(4))(3)] (6), isolated in small quantities from the preparation of 5, is also described.