Synthesis, structure, and antibacterial properties of ternary rare-earth complexes with o-methylbenzoic Acid and 1,10-phenanthroline

Ternary rare-earth complexes with o-methylbenzoic acid (o-MBA) and 1,10-phenanthroline (Phen) Ln(2)(o-MBA)(6)(Phen)(2) center dot nH(2)O(n = 0, 1) (Ln = La, Pr, Y, Yb) were synthesized and characterized by elemental analysis, IR, X-ray diffraction, and TG-DTG means. The complex La-2(o-MBA)(6)(Phen)(2) center dot H2O (I) is composed of two species of binuclear molecules in which the La3+ ion is coordinated with two nitrogen atoms of Phen and seven oxygen atoms of carboxylate groups. The carboxylate groups were bonded to La3+ in three modes: chelating-bidentate, bridging-bidentate, and chelating-bridging tridentate. The La3+ ion adopted a vigorous distorted monocapped square antiprism geometry. Complex I belongs to the triclinic crystal system, P space group, lattice parameters: a = 13.058(3), b = 12.7584(11), c = 20.773(4) , alpha = 101.18(3)A degrees, beta = 93.88(3)A degrees, gamma = 115.82(3)A degrees, V = 3283.0(11)(3), Z = 2, rho(calcd) = 1.484 mg/m(3), M (r) = 1467.06, F(000) = 1476, mu = 1.350 mm(-1). The structure was refined to R (l) = 0.0631 and wR (2) = 0.1504. The antibacterial activity test indicates that these complexes exhibit better antibacterial ability against Escherichia coli and Staphylococcus aureus than the corresponding rare-earth chloride or o-MBA.