摘要:
Acidification Of WS42- by HCl in MeCN in the presence of 2,2'-bipyridine (bpy) led to the discrete mononuclear compound W(O)(S2)2(bpy) (1) isolated at room temperature as crystals:monoclinic, space group C2/c, a = 25.670(8), b = 8.472(3), c = 12.466(4) angstrom, beta = 106.26(3)-degrees, V = 2603 angstrom3, Z = 8, R = 0.061. W(O)(S2)2(bpy) (2) was obtained by reaction of [Ni(bpy)2]Cl2 with WS42-, followed by crystallization at -30-degrees-C, monoclinic, space group P2(1)/n, a = 8.875(7), b = 12.205(6), c = 12.363(3) angstrom, beta = 90.12(5)-degrees, V = 1339(l) angstrom3, Z = 4, R = 0.062. Compounds 1 and 2 differ in their stackings. The alignment of the bpy ligands in 1 is parallel; in 2 the alignment is nearly perpendicular. Addition of 1,10-phenanthroline (phen) under the same conditions of acidity yielded W(O)(S2)2(phen) (3) isolated at room temperature as crystals: monoclinic, P2(1) a = 6.798(4), b = 14.807(5), c = 7.048(2) angstrom, beta = 92.25(3)-degrees, V = 709 angstrom3, Z = 2. The three complexes can all be described as a W-pentagonal bipyramid, with four sulfur atoms and a nitrogen atom forming the equatorial plane, the two axial positions being occupied by the remaining nitrogen atom of the bpy ligand and an oxo group. Formation of the W(O)(S2)2 core in solution is postulated through a redox process involving elemental sulfur produced in situ.