SYNTHESIS, STRUCTURE, AND CHARACTERIZATION OF N-LIGATED W(6)S(8)L(6) CLUSTER COMPLEXES

The synthesis and structure determination of two N-ligated W(6)S(8)L(6) (L = pyridine or 4-tert-butylpyridine) complexes are presented. Described herein is the preparation of W6S8(C5H5N)(6) (1) from the reaction of W6Cl12, NaSH, and NaOBu in refluxing pyridine and the preparation of W6S8(C9H13N)(6) . 6C(6)H(6) (2) from the reaction of W6Cl12, KSH, KOBu, and 4-tert-butylpyridine in DMF (followed by recrystallization from benzene). Thin, orange plate-shaped crystals of W6S8(C5H5N)(6) (1) were isolated after working up the product from the above reaction in pyridine at 210 degrees C. They crystallize in the space group P (1) over bar (No. 2) with lattice constants a = 9.404(2) Angstrom, b = 10.725(5) Angstrom 11.905(6) Angstrom, alpha = 114.43(3)degrees, beta = 90.52(3)degrees, gamma = 109.07(3)degrees, V = 1018.6(7) Angstrom(3), and Z = 1, with R (R(w)) = 0.0525 (0.0686). Large, dark red-brown crystals of W6S8(C9H13N)(6) . 6C(6)H(6) (2) were prepared by a method similar to that for 1, but under less rigorous conditions, This method leads to the isolation of W6S8(C9H13N)(6) . 6C(6)H(6) (2), which crystallizes in the Space group R (3) over bar (No. 148) with lattice constants a = 20.208(3) Angstrom, c = 20.843(3) Angstrom, V = 7371(2) Angstrom(3), and Z = 3, with R (R(w)) = 0.0413 (0.0482). Both 1 and 2 contain the neutral, substitution-resistant W6S8 cluster core consisting of an octahedral arrangement of tungsten atoms with face-capping sulfur atoms. The coordination environment of each tungsten atom is completed by a single pyridine (or 4-tert-butylpyridine) ligand in the exo position. All of the W-W and W-S distances in these clusters fall within the ranges 2.652-2.667 Angstrom (for W-W) and 2.430-2.478 Angstrom (for W-S), which are comparable to those found in related tungsten sulfide cluster complexes.