Crystal structure of hexaaqua-cobalt di(pyridine-2,5-dicarboxylato)-diaqua-cobalt tetrahydrate, Co(H2O)6Co(C7H3NO4)2(H2O)2·4(H2O), C14H30Co2N2O20

Abstract

C14H30Co2N2O20, triclinic, P1 (no. 2), a = 7.264(2) A, b = 8.647(3) A, c = 11.460(3) A, 5 = 70.204(5)° , 4 = 85.143(5)° , 3 = 70.168(5)° ,V = 636.7 A , Z = 1, Rgt(F) = 0.0274, wRref(F ) = 0.0773, T = 293 K. Source of material All reagentswere commercially available and of analytical grade. 2,5-pyridinedicarboxylic acid (0.084 g, 0.5 mmol) was dissolved in the mixed solution of 10 ml CH3CH2OH and10 ml H2O forming solution A, CoCl2·6H2O (0.234 g, 1 mmol) and LaCl3 (0.1 g, 0.4 mmol) were dissolved in 20 ml H2O forming solution B. Solution A was slowly added to solution B, and the mixture was adjusted to pH = 5.1 using 5 mol/L NaOH solution. The mixture was stirred and heated for one hour. The resulting solution was filtered and the filtrate evaporated at room temperature. Several weeks later, red block crystals of (I) were obtained. Experimental details TheH atoms bonded towater were located in a difference synthesis and refined with distance restrains of O–H = 0.83A and H–H = 1.37(2)A and Uiso(H) = 1.2Ueq(O). The remaining H atoms were positioned geometrically, with C–H distances of 0.93A, and were refined in a riding model with Uiso(H) = 1.2Ueq(C).