Synthesis and Crystal Structure of Tetraimidazolium Dinicotinatooctamolybdate

The title compound, [C3H5N2]4[(C6H5NO2)2(Mo8O26)] 1, was synthesized by the reaction of H2MoO4, nicotinic acid and imidazole in aqueous solution. Single-crystal X-ray analysis has revealed that compound 1 (C24H30Mo8N10O30) crystallizes in the monoclinic system, space group P21/n, Mr = 1706.10, a = 12.529(1), b = 12.796(1), c = 14.038(1) A。, u = 100.2(1)°, V = 2215.3(2) A。3, Z = 2, Dc = 2.558 g/cm3, F(000) = 1640, μ = 2.299 mm-1, the final R = 0.0527 and wR = 0.0964 for 3064 observed reflections with I > 2(I). X-ray crystal structure analysis suggests that compound 1 consists of centrosymmetric dinicotinatooctamolybdate anion and four protonated imidazole cations, which are linked into a three-dimensional framework through hydrogen bonding.