Syntheses and Crystal Structures of two Ring-like {Mo18} Cluster Compounds

Sodium molybdate was reduced to produce ring-like compounds in the presence of carboxylic acids. Compound 1: Na8(H2O)28(H3O)+{Na(DMSO)2[MoVI10MoV8O52(OH)4(CH3C- OO)2]}11H2O (C8H103O102Na9S2Mo18, Mr = 3829.85), where the {Mo18} ring is built up by two acetic acids connecting two {Mo9} building blocks and the 1-D chain of 1 is formed through the coordinated sodium cations. Crystal data: triclinic, space group P, a = 11.3228(2), b = 15.4170(2), c = 16.7209(3) ? a = 113.006(1), b = 108.455(1), g = 92.430(1), V = 2501.98(7) 3, Z = 1, Dc = 2.542 g/cm3, F(000) = 1854, (MoKa) = 2.381 mm-1, T = 293(2) K, final R = 0.0532 and wR = 0.1203 for 7291 observed reflections with I > 2(I) from 8775 independent reflections. Compound 2: Na8(H2O)22(H3O)+{Na(DMSO)2[MoVI10MoV8O52(OH)4(C2H5COO)2]}10H2O (C10H93O94Na9- S2Mo18, Mr = 3715.79). Crystal data: monoclinic, space group C2/m, a = 18.044(1), b = 25.944(2), c = 10.4087(6) ? b = 106.613(2), V = 4669.3(5) 3, Z = 2, Dc = 2.643 g/cm3, F(000) = 3584, (MoKa) = 2.542 mm-1, T = 293(2) K, final R = 0.0536 and wR = 0.1621 for 4617 observed reflections with I > 2(I) from 5398 independent reflections. Similar to 1, the {Mo18} ring is built up by two {Mo9} building blocks that are connected up by two propanoic acids and these {Mo18} rings are further linked into a two-dimensional layer through the coordinated sodium cations.