Seven co-ordinate macrocyclic tetrathioether complexes of molybdenum(II) and tungsten(II)

Treatment of [{Mo(mu-Br)Br(CO)(4)}(2)] with 3,3,7,7,11,11,15,15,octamethyl-1,5,9,13-tetrathiacyclohexadecane (Me(8)[16]aneS(4)) in CH2Cl2 gave the crystallographically characterised, seven-co-ordinate, ionic complex [MoBr(Co)(2)(Me(8)[16]aneS(4))][MoBr3(CO)(4)] 1. Reaction of 2 equivalents of [MI(2)(CO)(3)(NCMe)(2)] (M = Mo or W) with 1 equivalent of Me(8)[16]aneS(4) afforded the analogous iodo-complex [MoI(CO)(2)(Me(8)[16]aneS(4))][MoI3(CO)(4)] 2 and the crystallographically characterised complexes [WI(CO)(2)(Me(8)[16]aineS(4))][WI3(CO)(4)] 3 and [WI(CO)(3)(Me(8)[16]aneS(4))][WI3(CO)(4)] 4. The cations in complexes 1 and 3 have distorted capped-trigonal-prismatic geometries whereas that in 4 has a geometry lying between capped octahedral and capped trigonal prismatic. The anions of all three complexes have capped octahedral geometries. Treatment of 2 equivalents of [MI(2)(CO)(3)(NCMe)(2)] with 1 equivalent of 1,5,9,13-tetrathiacyclohexadecane ([16]aneS(4)), 1,4,8,11-tetrathiacyclotetradecane ([14]aneS(4)) or 1,4,7,10-tetrathiacyclododecane ([12]aneS(4)) yielded the bimetallic thioether-bridged complexes [M(2)I(4)(CO)(6)([n]aneS(4)-S,S',S '',S '')] (n = 16, M = Mo; n = 14, M = Mo or W; n = 12, M = Mo), and the ionic complexes [WI(CO)(2)([n]aneS(4))][WI3(CO)(4)] (n = 16 or 21). The relationship between the various products of these reactions are discussed. Reaction of [16]aneS(4) with [MoCl3(thf)(3)] (thf = tetrahydrofuran) gave a polymeric complex of empirical formula [Mo3Cl9([16]aneS(4))(2)] plus the dinuclear, ionic complex [Mo2Cl5([16]aneS(4)-S,S')(2)]Cl.