Abstract: A series of novel double helicates, {A[Mo2VIO4LnIII(H2O)6(C4H2O6)2]·4H2O}n (Ln = Sm, Eu, Gd, Ho, Yb, Y; C4H2O6 = L-tartaric acid； A = NH4 or H3O), have been synthesized from the reactions of chiral ligands L-tartaric acid with molybdates as well as lanthanide cations. The architectures of these compounds are one dimensional enantiopure novel right- or left-handed double helical one-dimensional chains, which are somehow like DNA in general configurations. By the hydrothermal reaction method, some molybdenum oxide units such as {MoO4}, {Mo2O7}, {Mo8O26} are linked up by transition metal/organic ligand fragments to novel zero-, one-, two- or three-dimensional structures. Most of these compounds have voids, which are occupied by some suitable crystallization molecules. These compounds are: [Cu(4,4’-bpy)]2MoO4·2H2O, [Cu(4,4’-bpy)]2Mo2O7 and [Cu(4,4’-bpy)(Hnic)(H2O)]2Mo8O26. Compound [Gd(H2O)3]3[GdMo12O42]·3H2O is the first product in the herterometallate chemistry containing lanthanide cations that is synthesized by the hydrothermal reaction. The compound is built up by Silverton-type [GdMo12O42]9- anions linking up nine coordinated Gd3+ cations. It is the first example for introducing a paramagnetic lanthanide cation into the Silverton-type anionic center, which provides a very interesting example for the further synthesis of such kind compound/polymer. One-dimensional polymer, [Cu2(C8H6N2)2(C7H6N2)]2[Mo8O26], which consists of β-[Mo8O26]4- anions linked by quinoxaline and its oxidized product benzimidazole ligands coordinating binuclear copper(I) fragments, provides the first example that the isolated copper(I) complex under hydrothermal conditions “captures” the reduction product of original starting organonitrogen ligand to form a copper(I)-β-octamolybdate complex.

Key words: polyoxomolybdate, hydrothermal synthesis, crystal structure