Hydrothermal synthesis and structural characterization of two new reduced phosphomolybdates based on an organoamine template and copper ion

Two new compounds, (H₂en)₃(H₂enMe)₄(H₃O){Cu^I[Mo^V ₆O₁₂(OH)₃(HPO₄)(PO₄)₃]₂}?·?6H₂O (1) and (H₂enMe)₄{Cu^ICu^II[Mo^V ₆O₁₂(OH)₃(PO₄)(HPO₄)₂(H₂PO₄)]₂}?·?3H₂O (2), were hydrothermally synthesized and characterized by elemental analysis, IR, TGA, and single-crystal X-ray diffraction analysis. Crystallographic analysis reveals that 1 is constructed from cluster anions {Cu^I[Mo^V ₆O₁₂(OH)₃(HPO₄)(PO₄)₃]₂}^15?, protonated organic amines, and water molecules. Each cluster is bridged through hydrogen bonds to form a 3-D supermolecular structure. For 2, {Cu^I[Mo^V ₆O₁₂(OH)₃(PO₄)(HPO₄)₂(H₂PO₄)]₂}^11? are connected by Cu^II cations to form an infinite chain. The formation of 1 and 2 reveals that organoamines influence the structures of the crystals.     

Self-assembly of reduced molybdophosphate-based supramolecular architectures and the study of their magnetic properties

Reduced molybdophosphate-based supramolecular compounds, such as (4,4′-H₂bipy)[Co(H₂O)₂]₂[Co(H₂PO₄)₂(HPO₄)₄(PO₄)₂(MoO₂)₁₂(OH)₆] · 17H₂O (1), [Co(2,2′-bipy)₂(H₂O)]₄[Co(H₂O)₂][Co(HPO₄)₆(PO₄)₂(MoO₂)₁₂(OH)₆] · 2H₂O (2), and [Co(2,2′-bipy)₂(H₂O)]₄[Co(H₂PO₄)(H₂O)₂]₂[Co(HPO₄)₆(PO₄)₂(MoO₂)₁₂(OH)₆] · 8H₂O (3) (4,4′-bipy=4,4′-bipyridine, 2,2′-bipy=2,2′-bipyridine), have been synthesized under hydrothermal conditions and characterized. Compound 1 exhibits a three-dimensional supramolecular twofold interpenetrating architecture built up of one-dimensional [P₄Mo₆]-based infinite covalent chains and free 4,4′-bipy molecules. Compound 2 also shows a three-dimensional supramolecular network constructed from one-dimensional covalent [P₄Mo₆]-based chains. Unlike compounds 1 and 2, compound 3 exhibits an interesting three-dimensional ‘honeycomb-like’ supramolecular network constructed by the stacking of [Co(2,2′-bipy)₂(H₂O)] units with one-dimensional channels, in which the [P₄Mo₆]-based polyoxometalate chains are located. The magnetic properties of compounds 2 and 3 are reported. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Self-assembly of four new extended architectures based on reduced polyoxometalate clusters and cadmium complexes

Four new [P₄Mo₆] cluster-based extended structures containing cadmium complexes, [Cd₃(4,4′-Hbpy)₂(4,4′-bpy)₂(H₂O)₈][Cd(H₂PO₄)₂(HPO₄)₄(PO₄)₂(MoO₂)₁₂(OH)₆]·7H₂O 1, (4,4′-Hbpy)₂[Cd(4,4′-bpy)₃(H₂O)₃][Cd(4,4′-bpy)(H₂O)]₂[Cd(H₂PO₄)₂(HPO₄)₄ (PO₄)₂(MoO₂)₁₂(OH)₆]·H₂O 2, [Cd₄(phen)₂(H₂O)₄][Cd(phen)(H₂O)]₂[Cd(HPO₄)₄ (HPO₄)₄(MoO₂)₁₂(OH)₆]·5H₂O 3 and [Cd₄(2,2′-bpy)₂(H₂O)₄][Cd(2,2′-bpy)(H₂O)]₂ [Cd(HPO₄)₄(HPO₄)₄(MoO₂)₁₂(OH)₆]·3H₂O 4 (4,4′-bpy=4,4′-bpyridine, phen=1,10-phenanthroline, 2,2′-bpy=2,2′-bpyridine), have been synthesized and characterized by elemental analysis, IR, TG and single crystal X-ray diffraction. The structure of compound 1 is constructed from the Cd[P₄Mo₆]₂ dimers linked by [Cd₃(4,4′-Hbpy)₂(4,4′-bpy)₂(H₂O)₈] subunits to generate a plane layer. Compound 2 consists of the positive 2D sheets that constructed from Cd[P₄Mo₆]₂ dimers linked by [Cd(4,4′-bpy)(H₂O)] complexes, then the 2D sheets are further linked up together to form a 3D supramolecular framework via extensive hydrogen-bonding interactions among the [P₄Mo₆] clusters, free 4,4′-bpy molecules, dissociated [Cd(4,4′-bpy)₃(H₂O)₃]²⁺ complexes and water molecules. Compounds 3 and 4 show new 2D layered structure, with Cd[P₄Mo₆]₂ building blocks connected by tetra-nuclear [Cd₄{(phen)₂/(2,2′-bpy)₂}(H₂O)₄] clusters and [Cd(phen/2,2′-bpy)(H₂O)] complexes. The fluorescent activities of compounds 3 and 4 are reported.     

Syntheses, Structure Characterizations and Fluorescent Properties of Two Reduced Molybdenum (V) Phosphates Functionalized by Zinc Coordination Complexes

Two new materials built from reduced molybdenum (V) phosphates as building blocks and zinc coordination complexes as linkers, (H₃O)₂[Zn(2,2′-bpy)]₄[Zn(H₂O)]₂[Zn(HPO₄)₂ (PO₄)₆(MoO₂)₁₂(OH)₆] · 6H₂O (2,2′-bpy=2,2′-bpyridine) 1 and [Zn(phen)(H₂O)₂]₂[Zn(phen) (H₂O)]₂[Zn(H₂O)]₂[Zn(HPO₄)₄ (PO₄)₄(MoO₂)₁₂ (OH)₆] · 7H₂O (phen=1,10-phenanthroline) 2, have been synthesized and characterized by elemental analyses, IR, TG, and single crystal X-ray diffraction. Compound 1 is a new 3-D structure which constructed from Zn[P₄Mo₆]₂ dimers bonded together with [Zn(2,2′-bpy)] coordination complexes and [Zn(H₂O)] fragments. In compound 2, the Zn[P₄Mo₆]₂ dimeric units are linked by [Zn(phen)(H₂O)] coordination complexes and [Zn(H₂O)] fragments to form a new 2-D framework. The fluorescent activities of compounds 1 and 2 were reported. The crystal data for the two compounds are the following: 1, triclinic, P−1, a=13.036(3) ?, b=13.765(3) ?, c=14.459(3) ?, , Z=1; 2, triclinic, P−1, a=12.708(3) ?, b=14.016(3) ?, c=14.646(3) ?, , Z=1.Dedicated to Professor Michael T. Pope on the occasion of his retirement.     

Hydrothermal Synthesis and Structure of Two New Mo(V)-Oxide Phosphates

Two new members of Mo(V) phosphates were synthesized by hydrothermal methods. (enH₂)(enH)[NaMo₁₂O₂₄(OH)₆(HPO₄)₂(H₂PO₄)₆]·(en)₄·20H₂O(1)(en=H₂ NCH₂CH₂NH₂)[HAD-H₂]₂[HAD-H]₂[Zn₃Mo₁₂O₂₄(OH)₆(PO₄)₂(HPO₄)₆]·6H₂O (2) (HAD=H₂N(CH₂)₆NH₂). Compound 1 crystallized in the space group P2(1)/n, a=15.93120(10) Å, b=15.8946(2) Å, c=17.0665(2) Å, V=4316.02(8), =92.9060(10)°, Z=2. Compound 2 crystallized in the space group P(–1) with a=12.3726(3) Å, b=14.1948(3) Å, c=14.2310(4) Å, =72.7100(10), =65.0230(10), =69.5600(10)°, Z=2089.70(9) ų, and Z=1. The structure of 1 consists of sandwich-shaped cluster anion [Na{Mo^V ₆O₁₂(OH)₃(HPO₄)(H₂PO₄)₃}₂]^3– ({Na(Mo ^V ₆ ) ₂ }) held together via intermolecular hydrogen-bonding contacts. For the compound 2, the sandwich-shaped clusters Zn[Mo₆O₁₂(OH)₃(PO₄)(HPO₄)₃]₂ ({Zn(Mo ^V ₆ ) ₂} are linked by tetrahedrally-coordinated zinc into layers. Organic cations ([H₃N(CH₂)₆NH₃]²⁺ and [H₃N(CH₂)₆NH₂]⁺) are filled in the spaces between lamellas. The layers are held together by a hydrogen-bonded network, which involves the terminal phosphate P-OH groups, as well as organic cations and several waters of solvation.     

Three 1-D molybdenum(V) phosphates with copper/nickel coordination cations

Three 1-D reduced molybdenum(V) phosphates, [Ni(OH)₂][Na₂(H₂O)₃]₂{Ni[(MoO₂)₆(OH)₃(HPO₄)₃(PO₄)]₂}?·?2C₆H₁₄N₂?·?2H₃O?·?5H₂O (1), [Ni(H₂O)₂][K(H₂O)₅]₂{Ni[(MoO₂)₆(OH)₃(HPO₄)₃(PO₄)]₂}?·?2C₆H₁₄N₂?·?2H₃O?·?4H₂O (2), and [Cu(H₂O)₂][Na(H₂O)₅]₂{Cu[(MoO₂)₆(OH)₃(HPO₄)₃(PO₄)]₂}?·?2C₆H₁₄N₂?·?2H₃O?·?4H₂O (3), have been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction. The crystallographic analysis reveals that 1 is based on {Ni[Mo₆O₁₂(OH)₃(HPO₄)₃(PO₄)]₂} clusters connected through {[Ni(OH)₂][Na₂(H₂O)₃]₂} pentanuclear mixed-metal cluster units to yield unusual 1-D chains along the c-axis, which further form 3-D supramolecular networks via hydrogen-bonding. Compounds 2 and 3 are heterogeneous isostructural compounds. Both are built from M[Mo₆P₄]₂ (M?=?Ni or Cu) blocks as the structural motif combined with [MO₄(H₂O)₂] (M?=?Ni or Cu) octahedra to form 1-D chains, where M[Mo₆P₄]₂ (M?=?Ni or Cu) is bonded by [M′(H₂O)₅] (M′?=?K or Na). Furthermore, bulk carbon paste electrode modified with 1 (1-CPE) displays good electrocatalytic activity toward reduction of nitrite or bromate.     

Cubane Tellurido Clusters [Zn(NH3)4]3[Mo4Te4(CN)12] and [Cd(NH3)4]3[W4Te4(CN)12]: Syntheses and Crystal Structures

Single crystals of [Zn(NH₃)₄]₃[Mo₄Te₄(CN)₁₂] (I) and [Cd(NH₃)₄]₃[W₄Te₄(CN)₁₂] (II) were obtained by applying solutions of K₇[Mo₄Te₄(CN)₁₂] · 11H₂O and K₆[W₄Te₄(CN)₁₂] · 5H₂O in aqueous ammonia over solutions of ZnCl₂ and Cd(NO₃)₂ in glycerol and were characterized by X-ray diffraction analysis. The IR spectra and thermal properties of compounds I and II were examined.     

Two New Ferrous Molybdophosphates as Temperature-Dependent Hydrothermal Reaction Products

Two new ferrous molybdophosphates, (H₂enMe)₇Fe^II[Mo₁₂^V(HPO₄)₂(PO₄)₆(OH)₆O₂₄]·7H₂O 1 and (H₂enMe)₆Fe^II[Mo₁₂^V(HPO₄)₄(PO₄)₄(OH)₆O₂₄]·4H₂O 2 (enMe = 1,2-propanediamine), have been synthesized from an identical starting mixture through hydrothermal reactions using temperature as the only independent variable, and thoroughly characterized by IR, TG, single crystal X-ray diffraction and cyclic voltammetry. The structures of both 1 and 2 are built from the building blocks of the formula, {Fe^II[Mo₆P₄O₃₁]₂}, consisting of a network of MO₆ (M = Fe, Mo) octahedra and PO₄ tetrahedra linked through their vertices as anions, and protonated 1,2-propanediamine as cations, respectively. The most important aspect is that the non-hydrogen atomic ratio of Mo, Fe, P, O in the anions of 1 and 2 is the same, but the protonation of the PO₄ groups is different in 1 and 2. Less protonation of the PO₄ groups in 1 obtained at high temperature results in the anion carrying more charges and gives rise to more H₂enMe cations per [Fe^II(P₈Mo₁₂^V)] unit compared with that in 2 obtained at low temperature, and as a consequence, different interpenetrating hydrogen-bonded network structures are formed in the two different compounds in terms of packing efficiency and the system energy minimization.     

Organic Moiety-Regulated Photocatalytic Performance of Phosphomolybdate Hybrids for Hexavalent Chromium Reduction

Visible-light-driven photocatalytic Cr(VI) reduction is a promising pathway to moderate environmental pollution, in which the development of photocatalysts is pivotal. Herein, three hourglass-type phosphomolybdate-based hybrids with the formula of: (H₂bpe)₃[Zn(H₂PO₄)][Zn(bpe)(H₂O)₂]H{Zn[P₄Mo₆O₃₁H₆]₂} ⋅ 6H₂O ( 1 ) Na₆[H₂bz]₂[ZnNa₄(H₂O)₅]{Zn [P₄Mo₆O₃₁H₃]₂} ⋅ 2H₂O ( 2 ) and (H₂mbpy) {[Zn(mbpy)(H₂O)]₂[Zn(H₂O)]₂}{Zn[P₄Mo₆O₃₁H₆]₂} ⋅ 10H₂O ( 3 ) (bpe=trans-1,2-bi(4-pyridyl)-ethylene; bz=4,4′-diaminobiphenyl; mbpy=4,4’-dimethyl-2,2’bipyridine) were synthesized under the guidance of the functional organic moiety modification strategy. Structural analysis showed that hybrids 1 – 3 have similar 2D layer-like spatial arrangements constructed by {Zn[P₄Mo₆]₂} clusters and organic components with different conjugated degree. With excellent redox properties and wide visible-light absorption capacities, hybrids 1 – 3 display favourable photocatalytic activity for Cr(VI) reduction with 79%, 70% and 64% reduction rates, which are superior to that of only inorganic {Zn[P₄Mo₆]₂} itself (21%). The investigation of organic components on photocatalytic performance of hybrids 1 – 3 suggested that the organic counter cations (bpe, bz and mbpy) can effectively affect the visible-light absorption, as well as the recombination of photogenerated carriers stemmed from {Zn[P₄Mo₆]₂} clusters, further promoting their photocatalytic performances towards Cr(VI) reduction. This work provides an experimental basis for the design of functionalized photocatalysts via the modification of organic species.     

Structural characterizations and magnetic properties of three new reduced molybdenum phosphates

Three new molybdophosphates, [Co(dien)₂]·(H₃dien)₆·{[CoMo₁₂O₂₄(OH)₆(HPO₄)₂(PO₄)₆][Co(Hdien)]₂[CoMo₁₂O₂₄(OH)₆(PO₄)₈]}·(dien)·4H₃O·5H₂O (1), (H₃dien)₄[MMo₁₂O₂₄(OH)₆(HPO₄)₄(PO₄)₄]·10H₂O [M=Co for (2), Ni for (3); dien=diethylenetriamine], have been synthesized by employing hydrothermal method and characterized by single crystal X-ray diffraction. Compound 1 is built up of Co[P₄Mo₆]₂ units as the structural motif covalently linked by [Co(Hdien)] complex subunits to yield an unusual 1-D chain. Compounds 2 and 3 are isomorphic and both display covalent discrete M[P₄Mo₆]₂ cluster structures which are linked by the hydrogen bonds to form 3-D supramolecular networks. Both 1 and 2 display antiferromagnetic interaction and these three compounds all exhibit intensive photoluminescence.     

Synthesis, Characterization and Crystal Structure of a New Cobalt Phosphomolybdate that Contains [(Mo16O32)Co16(H2O)18(PO4)6(HPO4)18] Wheels

A new compound, [Co(H₂O)₆][{Co₂(H₂O)₆}{Co(H₂PO₄)₂}{(PO₄)₆(HPO₄)₁₈(Mo₁₆O₃₂)Co₁₆(H₂O)₁₈}] · 23H₂O (1), has been prepared under mild hydrothermal conditions and structurally characterized by elemental analyses, i.r. spectrum, XPS spectrum and single-crystal X-ray diffraction. Compound (1) consists of [(Mo₁₆O₃₂)Co₁₆- (H₂O)₁₈(PO₄)₆(HPO₄)₁₈] wheel-shape clusters as the structural motif, which are covalently linked by [Co₂(H₂O)₆] and [Co(H₂PO₄)₂] fragments to form a two-dimensional layer framework. It is the first time that such wheels have been linked by both mononuclear and dimeric Co^II octahedra. Electronic supplementary material Electronic supplementary material is available for this article at and accessible for authorised users.     

Two distinct manganese molybdenum(V) phosphates directed by different organic amines

By employing different organic amines as structure-directing agents, two new distinct 3D porous inorganic frameworks based on molybdenum(V) phosphates and Mn^II, (H₂en)₂{[Mn(H₂O)]₂[MnMo₁₂O₂₄(OH)₆(H₂PO₄)₂(HPO₄)₄(PO₄)₂]}·7H₂O (en = ethylenediamine) (1) and (H₃dien)₂{[Mn(H₃O)₂][Mn₃Mo₁₂O₂₄(OH)₆(HPO₄)₂(PO₄)₆]}·5H₂O (dien = diethylenetriamine) (2), have been hydrothermally synthesized, and characterized by routine physical methods. In compound 1, Mn^II all adopt octahedral coordination mode and each sandwich cluster Mn[Mo₆P₄O₃₁]₂ (abbreviated as Mn[Mo₆P₄]₂) acts as an octa-dentate ligand linking eight Mn^II, which result in a 3D inorganic (4, 8)-connected framework with the (4⁶)(4¹⁰·6¹²·8⁶) topology. Compound 2 shows a 3D (4, 10)-connected framework with the (3¹·4⁴·6¹)(3⁴·4⁹·5⁷·6¹⁷·7⁴·8⁴) topology, in which Mn^II ions exhibit both tetrahedral and octahedral coordination modes, and each Mn[Mo₆P₄]₂ links ten Mn^II. Interestingly, there exist channels along the a and b axes in 1, while along the a and c axes in 2. The differences between the two compounds should be ascribed to the distinctions of the organic amines. Primary de-/rehydration behaviors and electrochemistry properties have also been studied for the two compounds.     

A novel chain-like molybdenum phosphate: hydrothermal synthesis,crystal structure and characterization of [NH3(CH2CH2)2NH3]3[NH3(CH2CH2)2NH2]-Na5[Mo6O12(OH)3(PO4)(HPO4)3]2·4H2O

A novel organic/inorganic hybrid molybdenum phosphate, [NH₃(CH₂CH₂)₂NH₃]₃[NH₃(CH₂CH₂)₂NH₂]Na₅-[Mo₆O₁₂(OH)₃(PO₄)(HPO₄)₃]₂·4H₂O (1), involving molybdenum presented in V oxidation, has been hydrothermally prepared and characterized by elemental analysis, i.r., u.v.–vis., x.p.s., t.g. and single crystal X-ray diffraction. The structure of the title compound (1) may be considered to consist of two [Mo₆O₁₂(OH)₃(PO₄)(HPO₄)₃] units bonded together with NaO₆ octahedra, forming dimers. Further, these dimers connect with each other through four Na⁺ cations as bridges, giving rise to novel one-dimensional chain-like skeleton. Piperazines exist among inorganic chains acting as charge balancing cations.     

Novel Three-Dimensional Coordination Polymers Based on [Mo6Se8(CN)6]7− Anions and Mn2+ Cations

Three novel coordination polymers K₅[MnMo₆Se₈(CN)₆] · 8H₂O (1), (Me₄N)₄[{Mn(H₂O)₂}_1.5Mo₆Se₈(CN)₆] · 4H₂O (2), and K₃[{Mn₂(H₂O)₄}Mo₆Se₈(CN)₆] · 7H₂O (3) have been synthesized by layering of a methanol solution of [Mn(salen)]CH₃COO (salen–N,N′-bis(salicylidene)ethylenediamine) on an aqueous solution of K₇[Mo₆Se₈(CN)₆] · 8H₂O. The compounds have been characterized by single-crystal X-ray diffraction analysis. All structures are based on negatively charged porous polymer frameworks where CN groups of [Mo₆Se₈(CN)₆]⁷⁻ cluster complexes are coordinated to Mn²⁺ cations. Cavities in the frameworks are filled by additional cations and solvate water molecules.     

一个新颖镍配位阳离子修饰的还原型钼磷酸盐：Ni[Mo6O12(OH)3(PO4)(HPO4)3]2][Ni(H2O)2][Ni(H2O)(bipy)2]4·5H2O

水热合成并通过红外、热重、单晶X-射线衍射表征了一个新颖镍配位阳离子修饰的还原型钼磷酸盐,Ni[Mo₆O₁₂(OH)₃(PO₄)(HPO₄)₃]₂][Ni(H₂O)₂][Ni(H₂O)(bipy)₂]₄·5H₂O。单晶X-射线衍射研究表明,两个{Mo₆P₄}簇单元通过一个镍离子连接形成一个Ni[Mo₆P₄]₂二聚结构单元,其进一步和其他的镍配位阳离子连接成钼磷酸盐一维链状结构。在H₂O₂存在下的液－固体系中,使用该化合物催化氧化苯甲醛的探针反应结果表明,该化合物具有较高的催化氧化活性。     

Bis(iminodiethylenedi­ammonium) di‐μ5‐hydrogen­phosphato‐penta­molybdate(VI) tetra­hydrate

The crystal structure of the title compound, (C₄H₁₅N₃)₂[Mo₅O₁₅(HPO₄)₂]·4H₂O, is made up of [Mo₅O₁₅(HPO₄)₂]⁴⁻ clusters, iminodiethylenediammonium cations and solvent water mol­ecules. The [Mo₅O₁₅(HPO₄)₂]⁴⁻ cluster, with approximate C₂ symmetry, can be considered as a ring formed by five distorted edge‐ and corner‐sharing MoO₆ octa­hedra, capped on both poles by a hydro­phosphate tetra­hedron. There exist N—H⋯O, O—H⋯N and C—H⋯O hydrogen bonds between the organic ammonium groups and the clusters, with inter­atomic N⋯O distances ranging from 2.675 (3) to 2.999 (3) Å, and C⋯O distances ranging from 3.139 (5) to 3.460 (5) Å.     

Molybdenum Bisphosphonates with Cr(III) or Mn(III) Ions

The synthesis of Mo^VI bisphosphonates (BPs) complexes in the presence of a heterometallic element has been studied. Two different BPs have been used, the alendronate ligand, [O₃PC(C₃H₆NH₃)(O)PO₃]^4? (Ale) and a new BP derivative with a pyridine ring linked to the amino group, [O₃PC(C₃H₆NH₂CH₂C₅H₄N)(O)PO₃]^4? (AlePy). Three compounds have been isolated, a tetranuclear Mo^VI complex with Cr^III ions, (NH₄)₅[(Mo₂O₆)₂(O₃PC(C₃H₆NH₃)(O)PO₃)₂Cr]·11H₂O (Mo₄(Ale)₂Cr), its Mn^III analogue, (NH₄)_4.5Na_0.5[(Mo₂O₆)₂(O₃PC(C₃H₆NH₃)(O)PO₃)₂Mn]·9H₂O (Mo₄(Ale)₂Mn), and a cocrystal of two polyoxomolybdates, (NH₄)₁₀Na₃[(Mo₂O₆)₂(O₃PC(C₃H₆NH₂CH₂C₅H₄N)(O)PO₃)₂Cr]₂[CrMo₆(OH)₆O₁₈]·37H₂O ([Mo₄(AlePy)₂Cr]₂[CrMo₆]). In this latter compound an Anderson-type POM [CrMo₆(OH)₆O₁₈]^3? is sandwiched between two tetranuclear Mo^VI complexes with AlePy ligands. The protonated triply bridging oxygen atoms bound to the central Cr^III ion of the Anderson anion develop strong hydrogen bonding interactions with the oxygen atoms of the bisphosphonate complexes. The UV–Vis spectra confirm the coexistence in solution of both POMs. Cyclic voltammetry experiments have been performed, showing the reduction of the Mo centers. In strong contrast with the reported Mo^VI BP systems, the presence of trivalent cations in close proximity to the Mo^VI centers dramatically impact the potential solid-state photochromic properties of these compounds.     

Coordination compounds based on the cluster anion [Re4Te4(CN)12]4− and Zn2+ cation

Three new coordination compounds [{Zn(H₂O)₂} {Zn(H₂O)₄} Re₄Te₄(CN)₁₂] (1), [Zn(en)₂(NH₃)₂][{Zn(en)(NH₃)₂} Re₄Te₄(CN)₁₂]·H₂O (2), and [{Zn₂(dien)₃} Re₄Te₄(CN)₁₂]· ·₆H₂O (3) (dien is diethylenetriamine) were prepared by reactions of aqueous solutions of the tetrahedral cluster rhenium tellurocyanide complex K₄[Re₄Te₄(CN)₁₂]· 5H₂O with zinc dichloride in the presence of ammonia, ethylenediamine, and diethylenetriamine, respectively. Complex 1 has a three-dimensional structure with two types of the Zn atoms; complex 2 is ionic with the polymeric chain anion; complex 3 has a molecular structure. The structures of complexes 1–3 were determined by single-crystal X-ray diffraction analysis. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 718–721, April, 2006.     

Synthesis and characterization of two new inorganic–organic hybrid cobalt molybdenum(V) phosphates

Two new inorganic–organic hybrid cobalt phosphomolybdates (Hdien)₂[Co(dien)]₂[Co(dien)(H₂O)]₂[CoMo₁₂O₂₄(HPO₄)₂(H₂PO₄)₂(PO₄)₄(OH)₆]?···?5H₂O (1) and (H₂dien)₂[Co(dien)]₂[Co(H₂O)₂]₂[CoMo₁₂O₂₄(HPO₄)₄(PO₄)₄(OH)₆]?···?7H₂O (2) (dien?=?diethylenetriamine), involving molybdenum in the V oxidation state and covalently bonded transition metal complexes, have been prepared under mild hydrothermal conditions and structurally characterized by elemental analyses, IR spectra, TG analyses, and single-crystal X-ray diffraction. Compound 1 exhibits a one-dimensional (1D) chain framework, in which dien molecules adopt two kinds of coordination modes. Compound 2 shows a two-dimensional (2D) layer framework with three types of unusual tunnels. To the best of our knowledge, it is the first time [Co(dien)] units are directly incorporated into 1D and 2D skeletons of reduced molybdenum phosphates. The electrochemical properties of the two compounds were studied via the method of bulk-modified carbon paste electrodes. Furthermore, the magnetic properties of compound 2 are reported.     

New Perspectives in Polyoxometalate Chemistry by isolation of compounds containing very large moieties as transferable building blocks: (NMe4)5[As2Mo8V4AsO40] · 3H2O, (NH4)21[H3Mo57V6(NO)6O183(H2O)18] · 65 H2O, (NH2Me2)18(NH4)6[Mo57V6(NO)6O183(H2O)18] · 14 H2O,and (NH4)12[Mo36(NO)4O108(H2O)16] · 33 H2O

The compounds (NMe₄)₅[As₂Mo₈V₄AsO₄₀] · 3 H₂O 2a , (NH₄)₂₁[H₃Mo₅₇V₆(NO)₆O₁₈₃(H₂O)₁₈] · 65 H₂O 3a , (NH₂Me₂)₁₈(NH₄)₆[Mo₅₇V₆(NO)₆O₁₈₃(H₂O)₁₈] · 14 H₂O 3b and (NH₄)₁₂[Mo₃₆(NO)₄O₁₀₈(H₂O)₁₆] · 33 H₂O 4a ( 3a and 4a were not correctly reported in the literature regarding to their composition, structures and the oxidation states of the metal centres) which contain large isolated anionic species, have been prepared (among them 3a, 3b , and 4a in rather high yield) and characterized by complete crystal structure analysis as well as IR/Raman, UV/VIS/NIR, ESR spectroscopy and magnetic susceptibility measurements, redox titrations, bond valence sum calculations, elemental analyses and thermogravimetric studies. Perspectives for polyoxometalate chemistry referring to the synthesis of “extremely” large nanoscaled species are discussed, together with the occurrence of a large transferable {Mo₁₇} building block in the compounds 3a, 3b and 4a which also exists in the corresponding iron compound Na₃(NH₄)₁₂[H₁₅Mo₅₇Fe₆(NO)₆O₁₈₃(H₂O)₁₈] · 76 H₂O 7a .