New Mixed-Metal Carbonyl Tellurido Clusters from Solvothermal Synthesis

Mixed-metal carbonyl telluride clusters ( P ~ ~ P ) ~ [ F ~ ~ M T ~ ~ ( C O ) I I ] (M = Mo, (l), W, (2)) and Na(EtN)?[Fe3W2Te~(TeMe)(C0)12].2H20 (3) have been synthesized methanothemally at 80 "C using mixtures of Fe3(C0)12, M(CO)6 (M = Mo, W), and Na2Te2 with PhPBr, or Et4NCl.H20, in a sealed Pyrex tube. Compound 1 crystallizes in the monoclinic space group C2Ic with a = 20.379(4) A, b = 14.724(3) A, c = 39.298(6) A, B = 95.22(1)", V = 11742(7) A3, and Z = 8. In the anionic [Fe2Mo(Tez)(Te)(C0)11l2cluster of 1, a [Fe2(Te2)(Te)(CO)sl21 unit isjoined to an Mo(C0)5 moiety by its Tez2ligand. Compound 3 crystallizes in the triclinic space group P1 with a = 12.636(3) A, b = 13.385(4) A, c = 20.804(7) A, a = 73.30(3)", /3 = 87.24(3)", y = 65.40(2)", V = 3054(4) A3, and Z = 2. In the [Fe3W2(Te2)3(Te)2(TeMe)(C0)l2l3anion of 3, a W-W unit is connected to the rest of the cluster through telluride ligands to form an unsymmetrical cagelike structure. 125Te NMR spectral data for 1-3 and (Ph4P)2[Fez(Tez)(Te)(C0)6] have been obtained in DMSO-& Clusters 1, 2, and (Ph4P)2[Fe2(Te2)(Te)(CO)6] display three-line spectra, while seven singlets are observed for 3, corresponding to seven different environments for the tellurium atoms in 3.