Hydrothermal Syntheses And Characterizations Of Metal Cluster Polymers And Coordination Polymers

As the applications of hydrothermal technique on the syntheses, various organic-inorganic hybrid materials of particular properties emerges constantly and much attention has been caused on the performances studies of various materials. The metal-oxygen clusters have been employed to constructed novel molecules-based function materials owing to their particular physical chemistry properties. We synthesized some metal-oxygen clusters, the cluster-polymers based on molybdenum-vanadium and molybdenum-phosphorous oxygen clusters, and the coordination polymers of rare earth with organic ligands. On the bases of X-ray structural analyses, some compounds have been characterized by IR, XPS, EPR spectra. The thermal analyses and magnetic properties of some compounds have also been studied, which would take a role in the explorations of structures and functions for the compounds.I Molybdenum-vanadium oxygen clustersCompounds 1 and 2, H3{[(VVO4)MoVI8VIV4(VIVO)2O36][Cu(en)2]4} (MoO4)2 6H2O (M = V and P), two polymers of cluster with new types, have beensynthesized by hydrothermal technique, which have three-dimensional network structures based on the molybdenum-vanadium cluster of bicapped Keggin structure linked by the transition metal complex ion [Cu(en)2]2+ bridges. Compounds 1 and 2 belong to the isostructural polymers of cluster, which are firstly constructed from the molybdenum-vanadium cluster with bicapped Keggin structure by us. The X-ray single crystal analysis, elemental analysis, IR, XPS, EPR, and TG etc., have been performed on the compounds. The magnetic behavior of compound 1 was measured, and the data between 70 K and 230 K is coincident with the Curie-Weiss law, Curie Constant c = 2.655 emu-mor'-K and Weiss Constant θ = - 17.99 K. The anti-ferromagnetic interaction is existed between the metal ions of this compound.Compound 3, H3[Co(en)3]2[(VVO4)MoVI8VIV4(VIVO)2O36] 5H2O, is a new discrete cluster compound with bi-capped Keggin structure molybdenum-vanadium oxygen cluster, and [Co(en)3]2+ complex ion act as the balanced cations, the discrete molybdenum-vanadium oxygen cluster with bi-capped Keggin structure based on only vanadium center is less reported up to now. Compound 4, H3[(VVO4)MoVI8VV4(VIVO)2O36] 8H2O, possess one-dimensional chain structure with the bi-capped Keggin cluster units linked through the bridged oxygen atoms. In this compound, only the bi-capped vanadium atoms are reduced and other Mo or V atoms have not been reduced, and this leads to the formation of cluster anion with lower charges which are less reported. H[Ni(en)2]2{[Ni(en)2] [(VVO4)Mo8V4(VIVO)4O36]}(dien) 2H2O (5), dien represents diethylenetriamine), belongs to the polymer of cluster with one-dimensional chain structure based on bi-capped Keggin cluster units linked through the bridged [Ni(en)2]2+ groups. The X-ray single crystal analysis, elemental analysis, IR, XPS, EPR, and TG etc., havebeen performed on these compounds. The magnetic behavior of compound 5 was also measured, and the data indicates the existence of stronger antiferromagnetic coupling of eleven Mo(V) and V(IV) ions. So the only magnetically active ions would be Ni(II) ions which is consistent with the result of EPR spectra. II Molybdenum-phosphorous oxygen clustersFour polymers of cluster (compounds 6-9) with one- and two-dimensional extended structures were synthesized under different pH values based on [P2MO5O23]6- cluster unit linked by bridged [Cu(en)2]2+ groups, and compound 10 was also synthesized which possesses three-dimensional network structures based on the [P2MO5O23]6" cluster anions connected by hydrated K+ ions.In 6, [Cu(en)2]{Cu(en)2}0.5(H2O)}{H3[P2Mo5023]3[Cu(en)2]6}4H2O, a cluster polymer, the [P2MO5O23]6- building units were linked firstly by single-bridge, single-bridge and double-bridge [Cu(en)2]2+ groups alternatively to form the one-dimensional chains, which were further connected together through the weaker interactions (Cu6 ...O distance , about 2.9 A) generating a two-dimensional structure network. The difference between compound 7 and 6 i...