Inorganic Chemistry, Vol.49, No.15, 6889-6896, 2010
Core Conversion Reactions of the Cubane-Type Metal-Sulfido Clusters: Shape Shift, Contraction, and Expansion of the MM' Re2S4 Cubanes (M = Ir, Rh, Ru; M' = Pt, Pd)
Treatment of incomplete cubane-type clusters [(Cp*M){Re(L)}(2)(mu(2)-S)(3)] (M = Ir (1a), Rh (1b); Cp* C5Me5; L = S2C2(SiMe3)(2)) and [{(Pmb)Ru}{Re(L)}(2)(mu(3)-S)(mu(2)-S)(3)] (Pmb = eta(6)-C6Me5H) with 1 equiv of [Pt(PPh3)(3)] gave tetranuclear tetra(sulfido) clusters having raft-type cores, [(Cp*M){Pt(PPh3)(2)}{Re(L)}(2)(mu(3)-S)(4)] (M = Ir (3a), Rh) and [{(Pmb)Ru}{Pt(PPh3)(2)}{Re(L)}(2)(mu(3)-S)(4)], which presents a sharp contrast to the reactions with [Pd(PPh3)(4)] reported previously, affording the cubane-type clusters [(Cp*M){Pd(PPh3)}{Re(L)}(2)(mu(3)-S)(4)] (M = Ir (2a), Rh) and [{(Pmb)Pu}-{Pd(PPh3)}{Pe(L)}(2)(mu(3)-S)(4)]. The reactions of 2a with diphosphines P2 resulted in the conversion of its cubane-type core into the analogous raft-type frameworks, forming [(Cp*Ir){Pd(P2)}{Re(L)}(2)(mu(3)-S)(4)] (P2 = cis-Ph2PCH=CHPPh2 (6), Ph2PCH2CH2PPh2, Ph2PCH2CH2CH2PPh2). On the other hand, when 2 was allowed to react with Ph2PCH2PPh2 (dppm) as P2, the trinuclear tri(sulfido) cluster [(Cp*Ir){Re(L}(2)(mu(3)-S)(2)(mu(2)-S)(mu(2)-dppm)] (9a) was obtained. Alternatively, this cluster 9a and its Rh analogue 9b were derived from the incomplete cubane-type clusters la and 1b by treatment with dppm. It has also been found that further treatment of the cubane-type cluster 2a with excess [Pd(PPh3)(4)] affords the heptanucleartetra(sulfido) cluster [(Cp*Ir){Pd(PPh3)}(4)Re-2(mu(3)-L)(2)(mu(3)-S)(4)] (10). The detailed structures have been determined by the X-ray analyses for 3a, 6, 9a, and 10.