[V10O28(C6H7NH)6].2(C6H7NH).2(ClO4).2-H2O, M(r) = 1945.4, monoclinic, P2(1)/c, a = 12.580 (2), b = 26.262 (5), c = 11.340 (4) angstrom, beta = 108.11 (2)-degrees, V = 3561 (2) angstrom3, Z = 2, D(m) = 1.8 (1) (by flotation in CHBr3-CCl4), D(x) = 1.81 Mg m-3, lambda(Mo Kalpha) = 0.71069 angstrom, mu=1.38 mm-1, F(000) = 1960, T = 298 K, R = 0.025 for 1789 observed reflections. The formula unit consists of the decavanadate anion, two perchlorate anions, eight 3-methylpyridinium cations and two water molecules and is centrosymmetric. The polyanion is similar to other known decavanadates. The perchlorate ions are disordered.
