ABSTRACT
Treatment of incomplete cubane-type clusters [(Cp*M){Re(L)}(2)(mu(3)-S)(mu(2)-S)(3)] (M = Ir (1a), Rh (1b); Cp* = eta(5)-C(5)Me(5); L = S(2)C(2)(SiMe(3))(2)) and [{(Pmb)Ru}{Re(L)}(2)(mu(3)-S)(mu(2)-S)(3)] (Pmb = eta(6)-C(6)Me(5)H) with 1 equiv of [Pt(PPh(3))(3)] gave tetranuclear tetra(sulfido) clusters having raft-type cores, [(Cp*M){Pt(PPh(3))(2)}{Re(L)}(2)(mu(3)-S)(4)] (M = Ir (3a), Rh) and [{(Pmb)Ru}{Pt(PPh(3))(2)}{Re(L)}(2)(mu(3)-S)(4)], which presents a sharp contrast to the reactions with [Pd(PPh(3))(4)] reported previously, affording the cubane-type clusters [(Cp*M){Pd(PPh(3))}{Re(L)}(2)(mu(3)-S)(4)] (M = Ir (2a), Rh) and [{(Pmb)Ru}{Pd(PPh(3))}{Re(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-Ph(2)PCH=CHPPh(2) (6), Ph(2)PCH(2)CH(2)PPh(2), Ph(2)PCH(2)CH(2)CH(2)PPh(2)). On the other hand, when 2 was allowed to react with Ph(2)PCH(2)PPh(2) (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 1a and 1b by treatment with dppm. It has also been found that further treatment of the cubane-type cluster 2a with excess [Pd(PPh(3))(4)] affords the heptanuclear tetra(sulfido) cluster [(Cp*Ir){Pd(PPh(3))}(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.
Subject(s)
Bridged-Ring Compounds/chemistry , Metals, Heavy/chemistry , Organometallic Compounds/chemistry , Sulfur/chemistry , Iridium/chemistry , Oxidation-Reduction , Palladium/chemistry , Platinum/chemistry , Rhenium/chemistry , Ruthenium/chemistryABSTRACT
Reactions of a dirhenium tetra(sulfido) complex [PPh(4)](2)[ReS(L)(mu-S)(2)ReS(L)] (L = S(2)C(2)(SiMe(3))(2)) with a series of group 8-11 metal complexes in MeCN at room temperature afforded either the cubane-type clusters [M(2)(ReL)(2)(mu(3)-S)(4)] (M = CpRu (2), PtMe(3), Cu(PPh(3)) (4); Cp = eta(5)-C(5)Me(5)) or the incomplete cubane-type clusters [M(ReL)(2)(mu(3)-S)(mu(2)-S)(3)] (M = (eta(6)-C(6)HMe(5))Ru (5), CpRh (6), CpIr (7)), depending on the nature of the metal complexes added. It has also been disclosed that the latter incomplete cubane-type clusters can serve as the good precursors to the trimetallic cubane-type clusters still poorly precedented. Thus, treatment of 5-7 with a range of metal complexes in THF at room temperature resulted in the formation of novel trimetallic cubane-type clusters, including the neutral clusters [[(eta(6)-C(6)HMe(5))Ru][W(CO)(3)](ReL)(2)(mu(3)-S)(4)], [(CpM)[W(CO)(3)](ReL)(2)(mu(3)-S)(4)] (M = Rh, Ir), [(Cp*Ir)[Mo(CO)(3)](ReL)(2)(mu(3)-S)(4)], [[(eta(6)-C(6)HMe(5))Ru][Pd(PPh(3))](ReL)(2)(mu(3)-S)(4)], and [(Cp*Ir)[Pd(PPh(3))](ReL)(2)(mu(3)-S)(4)] (13) along with the cationic clusters [(Cp*Ir)(CpRu)(ReL)(2)(mu(3)-S)(4)][PF(6)] (14) and [(Cp*Ir)[Rh(cod)](ReL)(2)(mu(3)-S)(4)][PF(6)] (cod = 1,5-cyclooctadiene). The X-ray analyses have been carried out for 2, 4, 7, 13, and the SbF(6) analogue of 14 (14') to confirm their bimetallic cubane-type, bimetallic incomplete cubane-type, or trimetallic cubane-type structures. Fluxional behavior of the incomplete cubane-type and trimetallic cubane-type clusters in solutions has been demonstrated by the variable-temperature (1)H NMR studies, which is ascribable to both the metal-metal bond migration in the cluster cores and the pseudorotation of the dithiolene ligand bonded to the square pyramidal Re centers, where the temperatures at which these processes proceed have been found to depend upon the nature of the metal centers included in the cluster cores.
