The syntheses of mononuclear complexes cis-Mo(V)OXL (X = Cl, Br, OMe, OEt, OPh, SPh, NCS, OSiMe(3)) and two binuclear complexes Mo(2)(V)O(3)L(2) of the title ligand LH(2) are reported. Two forms of MoOCIL, with cis oxo and chloro ligands, were crystallized, one in space group P2(1)/n, with a 10.440(2) Angstrom, b = 14.260(2) Angstrom, 12.041(2) Angstrom, beta = 102.76(2)degrees, V = 1748(1) Angstrom(3), and Z = 4, and the other in P2(1)/n, with a = 13.564(4) Angstrom, b = 7.172(2) Angstrom, c = 18.242(6) Angstrom, beta = 95.19(1)degrees, V = 1767(2) Angstrom(3), and Z = 4. MoO(OSiMe(3))L crystallizes in space group P2(1)/c, with a = 15.923(3) Angstrom, b = 11.141(2) Angstrom, c = 14.186(2) Angstrom, beta = 112.64(2)degrees, V = 2323(1) Angstrom(3), and Z = 4, while MoO(NCS)L crystallizes in Pna2(1), with a = 22.471(2) Angstrom, b = 12.136(2) Angstrom, c = 7.138(1) Angstrom, V = 1947(1) Angstrom(3), and Z = 4. The four structures reveal two possible conformations for ligand L : one with trans S atoms (cis,trans-MoOCIL and -MoO(OSiMe(3))L) and one with cis S atoms (cis,cis-MoOCIL and -MoO(NCS)L). The cis, cis isomers are converted to the cis,trans forms under reflux in MeCN at 80 degrees C. Only the cis,trans forms could be isolated for bulkier ligands X (OPh, SPh, OSiMe(3)). A short H3C ... X interaction is present in the cis,cis forms : C ... Cl = 3.07 Angstrom and C ... N = 2.93 Angstrom, for X = Cl and NCS, respectively. Infrared and electronic spectral data provide unambiguous identification of the stereochemistry of ligand L in mononuclear complexes MoOXL. Effective removal of ligand X = OR from cis,cis-MoO(OR)L (R = Me, Et) led to two binuclear complexes (Mo(V)OL)(2)(mu-O) of C-i and C-1 point symmetries. C-i-(MoOL)(2)(mu-O). thf crystallizes in space group P2(1)/c, with a = 8.5650(5) Angstrom, b = 15.1862(9) Angstrom, c = 16.8038(9) Angstrom, beta = 100.183(1)Alpha, V = 2157.1(8) Angstrom(3), and Z = 2, while C-1-(MoOL)(2)(mu-O). CH2Cl2 crystallizes in space group P2(1)/c, with a = 12.5250(5) Angstrom, b = 24.673(1) Angstrom, c = 12.7253(6) Angstrom, beta = 108.070(4)degrees, V = 3738.6(3) Angstrom(3), and Z = 4. C-i-(MoOL)(2)(mu-O). thf features two cis,trans-Mo(V)OXL centers with X = mu-O, while C-1-(MoOL)(2)(mu-O). CH2Cl2 contains a cis,trapls and a cis,cis center. In the latter, the Mo-O-Mo link is asymmetric, allowing relief of steric crowding on the cis,cis side of the molecule.