Controllable Synthesis of Lindqvist Alkoxopolyoxovanadate Clusters as Heterogeneous Catalysts for Sulfoxidation of Sulfides.

Six alkoxohexavanadate-based Cu- or Co-POVs [Cu(dpa)(acac)(HO)][VO(OMe)] (1), [Cu(phen)(acac)(MeOH)][VO(OMe)] (2), [Co(dpa)(acac)][VO(OMe)]·2MeOH (3), [Co(phen)(acac)][VO(OMe)] (4), [Cu(dpa)(acac)][VVO(OMe)] (5), and [Cu(dpa)(acac)(MeOH)][VVO(OMe)] (6) (POV = polyoxovanadate; dpa = 2,2'-dipyridine amine; phen = 1,10-phenanthroline; acac = acetylacetone anion) have been synthesized by controlling the reaction conditions and characterized by single-crystal X-ray diffraction and powder X-ray diffraction analyses, FT-IR spectroscopy, element analyses, and X-ray photoelectron spectroscopy. In compounds 1-4 and 6, Cu or Co complexes and alkoxohexavanadate anions are assembled through electrostatic interactions. Differently, in compound 5, seven-methoxo-substituted Lindqvist-type [VO(OMe)] are bridged to Cu complex via terminal O atoms by coordination bonds.

Sulfur-centred polyoxoniobate-based 3D organic-inorganic hybrid compound and its magnetic behavior.

The first sulfur-centered polyanion {SNb8V9.25O45.25} was isolated, which is covalently extended by cobalt complexes into a three-dimensional (3D) architecture.

Four alkoxohexavanadate-based Pd-polyoxovanadates as robust heterogeneous catalysts for oxidation of benzyl-alkanes.

Four alkoxohexavanadate-based Pd-POVs [Pd(dpa)(acac)]2[V6O13(OMe)6] (1), [Pd(dpa)(acac)]2[V6O11(OMe)8] (2), [Pd(dpa)(acac)]2[V6O11(OMe)8]·H2O (3), and [Pd(DMAP)2(acac)]2[V6O11(OMe)8]·H2O (4) (POV = polyoxovanadate; dpa = 2,2'-dipyridine amine; DMAP = 4-dimethylaminopyridine; acac = acetylacetone anion) have been synthesized and fully characterized by single crystal X-ray diffraction and powder X-ray diffraction analyses, Fourier transform infrared spectroscopy, element analyses, and X-ray photoelectron spectroscopy. In 1-4, Pd complexes and hexavanadate anions are assembled through electrostatic interactions. Interestingly, the [V6O11(OMe)8](2-) cores in 2 and 3 are a pair of isomers that can be isolated by controlling crystallization temperature.

Symmetry breaking of α-[H2W12O40](6-) depends on the transformation of isopolyoxotungstates.

Two enantiotopic 1D chain compounds, [Cu3(L1)3(H2O)2(H2W12O40)]·4H2O (1a,b; L1 = 2-(4,6-bis(pyridin-2-yl)pyridin-2-yl)pyridine), crystallizing in the chiral space group P212121 were prepared and spontaneously resolved in the absence of any chiral source. Interestingly, compounds 1a,b can be prepared from a [W7O24](6-) aqueous solution, [(n-C4H9)4N]4[W10O32], or Na10[H2W12O42], but when [H2W12O40](6-) aqueous solution was the starting material, the achiral compound [CuL1]2[H4W12O40]·5H2O (2) was obtained. When a terpyridine ligand (L2) having a coordination mode similar to that of L1 was used, the mesomeric dimer [Cu3(L2)3(H2O)(H2W12O40)]2·4H2O (3) was obtained from [W7O24](6-) aqueous solution or Na10[H2W12O42], but from [H2W12O40](6-) aqueous solution only compound [Cu2(L2)2Cl2]2[W10O32] (4) was isolated.

Cation-induced synthesis of new polyoxopalladates.

Seven polyoxopalladate compounds, [Pd(15)(SeO(3))(10)(μ(3)-O)(10)](10-), with Na(+) (1) and K(+) (2) as counterions, and Na(6)[M(II){Pd(12)(SeO(3))(8)(μ(4)-O)(8)}]·nH(2)O (M = Co (3), Zn (4), Ni (5), Cu (6), Mn (7); n = 7-9), have been prepared and characterized by SXRD, FT-IR, UV-vis, EA, TGA, and ESI-MS. These compounds comprise two distinct cluster configurations, {Pd(15)} and {M(II)Pd(12)}, which reveals the possibility of obtaining desired noble metal clusters with a certain nuclearity by using different cations as potential structural directing or template agents in synthesis. All compounds showed apparent absorptions in the visible light region, while 3 and 7 were found to show paramagnetic behavior typical of mononuclear Co(II) and Mn(II) complexes with zero-field splitting.

Transformation from [W6O19](2-) to [W6O22](8-) stabilized by Cu(II) complexation.

A rare [W6O22](8-) fragment has been first captured in aqueous solution of [W6O19](2-) by using a transition-metal complex and isolated as a new compound [Cu4(W6O22)(L1)2(H2O)2]·2H2O (1; L1 = 2-amino-4,6-bis(2-pyridyl)pyrimidine), indicating that [W6O19](2-) could also transform to [W6O22](8-) in aqueous solution besides the earlier proven ψ-metatungstates, [W10O32](4-), β-[(H2)W12O40](6-) and [W7O24](6-).

Lanthanide-organic cation frameworks with zeolite gismondine topology and large cavities from intersected channels templated by polyoxometalate counterions.

A family of organic-inorganic hybrid frameworks, {[Ln(H(2)O)(4)(pdc)](4)} [XMo(12)O(40)].2H(2)O (Ln = La, Ce, and Nd; X = Si and Ge; H(2)pdc = pyridine-2,6-dicarboxylate), have been prepared under hydrothermal conditions and characterized by single crystal X-ray diffraction analyses, elemental analyses, IR, and thermal gravimetric analyses. Single crystal X-ray diffraction reveals that all six compounds are isostructural, and each consists of a zeolite-like four-connected three-dimensional cationic framework {[Ln(H(2)O)(4)(pdc)](4)}(4+) and ball-shaped Keggin type [XMo(12)O(40)](4-) as templates.

A new two-dimensional supramolecule composed of mu-2,6-dimethylpyridine-3,5-dicarboxylato-kappa4O3,O3':O5,O5'-bis[chloro(1,10-phenanthroline-kappa2N,N')zinc(II)].

In the binuclear title molecule, [Zn(2)(C(9)H(7)NO(4))Cl(2)(C(12)H(8)N(2))(2)], the two metal centres are bridged by a 2,6-dimethylpyridine-3,5-dicarboxylate ligand. The binuclear unit is extended to form a two-dimensional supramolecular motif via pi-pi stacking interactions between neighbouring phenanthroline rings.

Structural diversity of silver(I) 4,6-dipyridyl-2-aminopyrimidine complexes: effect of counteranions and ligand isomerism.

Using two ligands, 4,6-bis(2-pyridyl)-2-aminopyrimidine (L1) with two N,N'-chelating sites and 4-(2-pyridyl)-6-(4-pyridyl)-2-aminopyrimidine (L2) (as the isomer of L1) containing one chelating site and one bridging unit, a series of novel Ag(I) complexes varying from zero- to two-dimensions have been prepared and their crystal structures determined via single-crystal X-ray diffraction. The two ligands are employed for the first time in coordination chemistry. The structures of compounds 1-3 are directed by the counteranions adopted in the reaction system: The reaction of L1 with AgNO3 yielded a dimer [Ag2L12](NO3)2 (1).