A new dinuclear molybdenum(V)-sulfur complex containing citrate ligand: synthesis and characterization of K2.5Na2NH4[Mo2O2S2(cit)(2)].5H(2)O

The complex, K2.5Na2NH4[Mo2O2S2(cit)(2)]. 5H(2)O (1), was obtained by cryst allization from a solution of (NH4)(2)MoS4, potassium citrate (K(3)cit) and hydroxyl sodium in methanol and water under an atmosphere of pure nitrogen at ambient temperature. The crystals are triclinic, space group <P(1)over bar>, a = 7.376 (3)Angstrom, b = 14.620 (2) Angstrom, c = 14.661 (1) Angstr om, alpha = 71.10 (1)degrees, beta = 81.77 (1)degrees, gamma = 78.27(2)degr ees, R = 0.0584 for 2545 observed (I > 2 sigma (I)) reflections. Single cry stal structure analysis reveals that citrate ligand coordinated to molybden um atom through two carboxylato oxygens and one deprotonated hydroxyl oxyge n together with two bridging sulfur atoms and a terminal oxygen atom comple tes distorted coordination octahedron around each molybdenum atom. Principa l dimensions are: Mo = O-t, 1.707 Angstrom (av); Mo-S-b, 2.341 Angstrom (av ); Mo-O-(hydroxyl), 2.021 Angstrom (av); Mo-O(alpha-carboxyl), 2.1290 Angst rom (av) and Mo-O(beta-carboxyl), 2.268(av) Angstrom. IR spectrum is in agr eement with the structure.