The hydrothermal syntheses and characterization of one- and two-dimensional structures constructed from metal-organic derivatives of polyoxometalates: [(Cu(bpy)2)(Cu(bpy)(H2O))(Mo5O15)(O3P(CH2)4PO3)].H2O and [(u2(tpypyz)(H2O)2)(Mo5O15)(O3PCH2CH2PO3)].5.5H2O [bpy = 2,2'-bipyridine,tpypyz = tetra(2-pyridyl)pyrazine

The hydrothermal reaction of CuSO(4).5H2O, Na2MoO(4).2H2O and 2,2'-bipyridine with the bridging diphosphonate ligand H2O3P(CH2)4PO3H2 yields the one-dimensional chain [(Cu(bpy)2)(Cu(bpy)(H2O)2)(Mo5O15)(O3P(CH2)4PO3)].H2O; the introduction of a second bridging component in the reaction of Cu(MeCO2)2.H2O, MoO3, H2O3PCH2CH2PO3H2 and tetra(2-pyridyl)pyrazine yields the network solid [(Cu2(tpypyz)(H2O)2)(Mo5O15)(O3PCH2CH2PO3)].5.5H2O.     

Solid state coordination chemistry of the copper(ii)-terpyridine/oxovanadium organophosphonate system: hydrothermal syntheses, structural characterization and magnetic properties

The hydrothermal reactions of CuSO4.5H2O, Na3VO4, 2,2':6':2'-terpyridine (terpy), and the appropriate organophosphonate ligand yield a series of materials of the Cu(ii)-terpy/oxovanadium organophosphonate family. The complexes exhibit distinct structures spanning one-, two- and three-dimensions and exhibiting diverse oxovanadium building blocks. Thus, [{Cu(terpy)}(V2O4)(O3PPh)(HO3PPh)2] (1) is one-dimensional and constructed from binuclear units of corner-sharing V(v) square pyramids. While [{Cu(terpy)}VO(O3PCH2PO3)] (2), [{Cu(terpy)}2(V4O10)(O3PCH2CH2PO3)] (3), and [{Cu(terpy)}(V2O4){O3P(CH2)3PO3}].2.5H(2)O (4.2.5H2O) are similarly one-dimensional, the V/O structural components consist of isolated V(iv) square pyramids, tetranuclear V(v) units of three tetrahedra and one square pyramid in a corner-sharing arrangement, and isolated V(v) tetrahedra and square pyramids, respectively. The second propylenediphosphonate derivative, [{Cu(terpy)}(V2O4){O3P(CH2)3PO3}] (5) is three-dimensional and exhibits isolated V(v) tetrahedra as the vanadate component. The two-dimensional structure of [{Cu(terpy)(H2O)}(V3O6){O3P(CH2)4PO3}] (6) is mixed valence with isolated V(iv) square pyramids and binuclear units of corner-sharing V(v) tetrahedra providing the V/O substructures.     

Anion-directed crystallization of coordination polymers: syntheses and characterization of Cu(4)(2-pzc)(4)(H(2)O)(8)(Mo(8)O(26)).2H(2)O and Cu(3)(2-pzc)(4)(H(2)O)(2)(V(10)O(28)H(4)).6.5H(2)O (2-pzc = 2-pyrazinecarboxylate)

Two new copper 2-pyrazinecarboxylate (2-pzc) coordination polymers incorporating [Mo(8)O(26)](4-) and [V(10)O(28)H(4)](2-) anions were synthesized and structurally characterized: Cu(4)(2-pzc)(4))(H(2)O)(8)(Mo(8)O(26)).2H(2)O (1) and Cu(3)(2-pzc)(4)(H(2)O)(2)(V(10)O(28)H(4)).6.5H(2)O (2). Crystal data: 1, monoclinic, space group P2(1)/n, a = 11.1547(5) A, b = 13.4149(6) A, c = 15.9633(7) A, beta = 90.816(1) degrees; 2, triclinic, space group P1, a = 10.5896(10) A, b = 10.7921(10) A, c = 13.5168(13) A, alpha = 104.689(2) degrees, beta = 99.103(2) degrees, gamma = 113.419(2) degrees. Compound 1 contains [Cu(2-pzc)(H(2)O)(2)] chains charge-balanced by [Mo(8)O(26)](4-) anions. In compound 2, layers of [Cu(3)(2-pzc)(4)(H(2)O)(2)] form cavities that are filled with [V(10)O(28)H(4)](2-) anions. The magnetic properties of both compounds are described.     

Small gas-phase dianions of Zn3O(4)(2-), Zn4O(5)(2-), CuZn2O(4)(2-), Si2GeO(6)(2-), Ti2O(5)(2-) and Ti3O(7)(2-)

We have searched for new species of small oxygen-containing gas-phase dianions produced in a secondary ion mass spectrometer by Cs+ ion bombardment of solid samples with simultaneous exposure of their surfaces to O2 gas. The targets were a pure zinc metal foil, a copper-contaminated zinc-based coin, two silicon-germanium samples (Si(1-x)Ge(x)(with x= 6.5% or 27%)) and a piece of titanium metal. The novel dianions Zn3O(4)(2-), Zn4O(5)(2-), CuZn2O(4)(2-), Si2GeO(6)(2-), Ti2O(5)(2-) and Ti3O(7)(2-) have been observed at half-integer m/z values in the negative ion mass spectra. The heptamer dianions Zn3O(4)(2-) and Ti2O(5)(2-) have been unambiguously identified by their isotopic abundances. Their flight times through the mass spectrometer are approximately 20 micros and approximately 17 micros, respectively. The geometrical structures of the two heptamer dianions Ti2O(5)(2-), and Zn3O(4)(2-) are investigated using ab initio methods, and the identified isomers are compared to those of the novel Ge2O(5)(2-) and the known Si2O(5)(2-) and Be3O(4)(2-) dianions.     

Cr[(H3N-(CH2)2-PO3)(Cl)(H2O)]: X-ray single-crystal structure and magnetism of a polar organic-inorganic hybrid chromium(II) organophosphonate

Cr[(H(3)N-(CH(2))(2)-PO(3))(Cl)(H(2)O)], a rare example of a polar organic-inorganic hybrid material containing Cr(2+), was prepared from CrCl(2), 2-aminoethylphosphonic acid, and urea in water and isolated as light-blue crystals. It crystallizes in the noncentrosymmetric monoclinic space group P2(1), with a = 5.249(1) A, b = 14.133(3) A, c = 5.275(1) A, and beta = 105.55(2) degrees. The inorganic layer of the hybrid network is formed by Cr(II) five-coordinated by three oxygen atoms from the phosphonates and one from the water molecule in a square pyramidal unit, whose apical position is occupied by the Cl(-) ion. Hydrogen bonds are established between the coordinating water molecule and the oxygen atoms of adjacent phosphonate ligands. The inorganic network is interspersed by ethylammonium groups, and the terminal ammonium moiety is linked to the apical Cl(-) ions through hydrogen bonds. Electrostatic interactions as well as hydrogen bonds and the coordinated chlorine atoms ensure the cohesion of the 3D structure. The lattice is polar (lack of inversion center), and this fact determines the magnetic behavior of the compound at low temperatures. The magnetic susceptibility data in the temperature range from 300 to 50 K show Curie-Weiss behavior, with C = 2.716 cm(3) K mol(-1) and the Weiss constant theta = -2.2 K. The corresponding effective magnetic moment of 4.7 mu(B) compares well with the expected value for Cr(2+) in d(4) high-spin configuration. A slight decrease of the chiT product versus T observed at temperatures below 50 K indicates nearest-neighbor antiferromagnetic exchange interactions. On cooling below T = 6 K, the magnetic susceptibility increases sharply up to a maximum at ca. 5 K and then decreases again. Below T = 6 K, hysteresis loops taken at different temperatures show that Cr[(H(3)N-(CH(2))(2)-PO(3))(Cl)(H(2)O)] behaves as a weak ferromagnet with the critical temperature T(N) at 5.5 K. The spin canting is responsible of the long-range magnetic ordering. The values of the coercive field, H(c), and of remnant magnetization, M(r), obtained from the hysteresis loop at T = 4.5 K (the lowest measured temperature) are 30 Oe and 0.08 mu(B), respectively.     

Organic-inorganic hybrids based on novel bimolecular [Si2W22Cu2O78(H2O)]12- polyoxometalates and the polynuclear complex cations [Cu(ac)(phen)(H2O)]n n+ (n=2, 3)

The reaction of a monosubstituted Keggin polyoxometalate (POM) generated in situ with copper-phenanthroline complexes in excess ammonium or rubidium acetate led to the formation of the hybrid metal organic-inorganic compounds A7[Cu2(ac)2(phen)2(H2O)2][Cu3(ac)3(phen)3(H2O)3][Si2W22Cu2O78(H2O)].approximately 18 H2O (A=NH4+ (1), Rb+ (2); ac=acetate; phen=1,10-phenanthroline). These compounds are constructed from inorganic and metalorganic interpenetrated sublattices containing the novel bimolecular Keggin POM, [Si2W22Cu2O78(H2O)]12-, and Cu-ac-phen complexes, [Cu(ac)(phen)(H2O)]n n+ (n=2, 3). The packing of compound 1 can be viewed as a stacking of open-framework layers parallel to the xy plane built of hydrogen-bonded POMs, and zigzag columns of pi-stacked Cu-ac-phen complex cations running along the [111] direction. Magnetic and EPR results are discussed with respect to the crystal structure of the compounds. DFT calculations on [Cu(ac)(phen)(H2O)]n n+ cationic complexes have been performed, to check the influence of packing in the complex geometry and determine the magnetic exchange pathways.     

Solid state coordination chemistry: construction of 2D networks and 3D frameworks from phosphomolybdate clusters and binuclear Cu(II) complexes. The syntheses and structures of [(Cu2(tpypyz)(H2O)2)(Mo5O15)(HOPO3)2].nH2O [n = 2, 3; tpypyz = tetra(2-pyridyl)pyrazine

The hydrothermal reaction of MoO3, Cu(C2H3O2)2.H2O, tpypyz, H3PO4 and H2O yields a 2D material, [(Cu2(tpypyz)(H2O)2)(Mo5O15)(HOPO3)2].2H2O (1.2H2O), constructed from (Mo5O15(HOPO3)2)4- clusters linked through (Cu2(tpypyz)(H2O)2)2+ components; in contrast, use of Cu2O in the synthesis in place of Cu(C2H3O2)2.H2O yields a 3D material [(Cu2(tpypyz)(H2O)2)(Mo5O15)(HOPO3)2].3H2O (2.3H2O), constructed from the same building blocks as 1.2H2O.     

Hydrothermal synthesis, crystal structure, conductivity, and thermal decomposition of [Cu(4,4'-bipy)(H2O)(Mo3O10)].H2O

The hydrothermal reaction of (NH(4))(6)Mo(7)O(24).4H(2)O, CuCl(2).2H(2)O, and 4,4'-bipyridine yields bipyridine-ligated copper-trimolybdate monohydrate [Cu(4,4'-bipy)(H(2)O)(Mo(3)O(10))].H(2)O in the monoclinic system with space group of C(2/c) and cell parameters of a = 15.335(2) A, b = 15.535(2) A, c = 15.106(2) A, beta = 101.162(2) degrees, V = 3530.7(9) A(3), and Z = 8. Its structure consists of one-dimensional infinite ([Mo3O10]2-)( infinity ) chains linked through [Cu2(H2O)2(4,4'-bipy)] units. The Mo-O chain contains distorted [MoO(6)] octahedra connected through corner-sharing oxygen atoms into infinite chains along the c direction and each chain is located in the channel formed by four adjacent crossing chains of [Cu(4,4'-bipy)(H2O)](n)(2n+). The crystal shows weak conductivity through Mo-O chain along the c direction and insulating property along either a or b direction. Furthermore, a crystalline bimetallic oxide, CuMo3O10, forms when the title compound undergoes thermal treatment in N(2) atmosphere after the complete removal of the ligands.     

Low-lying electronic states of M(3)O(9)(-) and M(3)O(9)(2-) (M = Mo, W)

Multiple low-lying electronic states of M(3)O(9)(-) and M(3)O(9)(2-) (M = Mo, W) arise from the occupation of the near-degenerate low-lying virtual orbitals in the neutral clusters. We used density functional theory (DFT) and coupled cluster theory (CCSD(T)) with correlation consistent basis sets to study the structures and energetics of the electronic states of these anions. The adiabatic and vertical electron detachment energies (ADEs and VDEs) of the anionic clusters were calculated with 27 exchange-correlation functionals including one local spin density approximation functional, 13 generalized gradient approximation (GGA) functionals, and 13 hybrid GGA functionals, as well as the CCSD(T) method. For M(3)O(9)(-), CCSD(T) and nearly all of the DFT exchange-correlation functionals studied predict the (2)A(1) state arising from the Jahn-Teller distortion due to singly occupying the degenerate e' orbital to be lower in energy than the (2)A(1)' state arising from singly occupying the nondegenerate a(1)' orbital. For W(3)O(9)(-), the (2)A(1) state was predicted to have essentially the same energy as the (2)A(1)' state at the CCSD(T) level with core-valence correlation corrections included and to be higher in energy or essentially isoenergetic with most DFT methods. The calculated VDEs from the CCSD(T) method are in reasonable agreement with the experimental values for both electronic states if estimates for the corrections due to basis set incompleteness are included. For M(3)O(9)(2-), the singlet state arising from doubly occupying the nondegenerate a(1)' orbital was predicted to be the most stable state for both M = Mo and W. However, whereas M(3)O(9)(2-) was predicted to be less stable than M(3)O(9)(-), W(3)O(9)(2-) was predicted to be more stable than W(3)O(9)(-).     

PbCu3(OH)(NO3)(SeO3)3·1/2H2O und Pb2Cu3O2(NO3)2(SeO3)2: Synthese und Kristallstrukturuntersuchung

Crystals of PbCu₃(OH)(NO₃)(SeO₃)₃·1/2H₂O [a=7.761(3)Å,b=9.478(4)Å,c=9.514(4)Å, =66.94(2)°, =69.83(2)°, =81.83(2)°, space group P ,Z=2] and Pb₂Cu₃O₂(NO₃)₂(SeO₃)₂ [a=5.884(2)Å,b=12.186(3)Å,c=19.371(4)Å, space group Cmc2₁,Z=4] were synthesized under hydrothermal conditions. Their crystal structures were refined with three-dimensional X-ray data toR _w=0.033 resp. 0.055. In PbCu₃(OH)(NO₃)(SeO₃)₃·1/2H₂O the Cu atoms are [4+1] and [4+2] coordinated and via SeO₃ groups a three-dimensional atomic arrangement is built up. In Pb₂Cu₃O₂(NO₃)₂(SeO₃)₂ there are sheets, which are connected only via Pb-O bonds ranging from 2.98 Å to 3.16 Å.

     

Two new hybrid organic/inorganic copper(II)-oxovanadate(V) diphosphonates: [Cu2(phen)2(O3PCH2PO3)(V2O5)(H2O)] x H2O and [Cu2(phen)2(O3P(CH2)3PO3)(V2O5)] x C3H8. Synthesis, structure, and magnetic properties

Two new hybrid organic/inorganic copper oxovanadium diphosphonates [Cu2(phen)2(O3PCH2PO3)(V2O5)(H2O)] x H2O (1) and [(Cu2(phen)2(O3P(CH2)3PO3)(V2O5)] x C3H8 (2) have been obtained by hydrothermal synthesis. The compounds are monoclinic, and they crystallize in the space group P2(1)/n with cell parameters of a = 11.788(2) A, b = 17.887(3) A, c = 14.158(2) A, and beta = 93.99(0) degrees and in the space group C2/c with cell parameters of a = 11.025(1) A, b = 18.664(2) A, c = 15.054(2) A, and beta = 90.06(0) degrees, respectively. Both compounds present two-dimensional frameworks built up from infinite chains of corner-sharing vanadium tetrahedra and diphosphonate groups connected by copper tetramers for (1) and copper dimers for (2). The remarkable feature of (2) is the encapsulation of propane molecules, stabilized by strong hydrogen bonding between the layers. The magnetic properties of the compounds have been investigated showing antiferromagnetic coupling with Tmax = 64 K for (1) and Curie-like paramagnetic behavior for (2).     

Increase in intrinsic anion conductance upon inhibition of the electroneutral Cl(-)/HCO(3)(-) exchanger: effect of CO(2)/HCO(3)(-).

The electroneutral Cl(-)/HCO(3)(-) exchange, present at the apical membrane of rabbit gallbladder epithelium, apparently is converted into a stilbene- and dipyridamole-sensitive, nonrectifying, approximately 5-pS anion channel after the exchange is directly inhibited (inhibitors tested: hydrochlorothiazide (HCTZ), phlorizin, phenylglyoxal and diphenylamine-2-carboxylic acid (DPC)). In intact tissue, in the absence of CO(2)/HCO(3)(-) in the media, the opening of these channels causes an approximately 7-mV depolarization of the apical membrane. This has been shown to be a constant index of the total Cl(-) conductance (G(Cl)) activated. The effect of exogenous and endogenous CO(2)/HCO(3)(-) on the depolarization has now been investigated in the intact tissue by conventional microelectrodes. The anion exchange has been measured radiochemically. The presence of exogenous or endogenous CO(2)/HCO(3)(-) reduces the depolarization induced by HCTZ, phlorizin and DPC from approximately 7 to 3 mV, but 10(-4) mol/l acetazolamide restores the full depolarization. Response time, S(0.5) and Hill number are unchanged in each case. The way of bicarbonate replacement is irrelevant. The depolarization generated by phenylglyoxal, which covalently binds to the transport site of the exchanger and prevents HCO(3)(-) binding, is unaffected by CO(2)/HCO(3)(-) presence. HCO(3)(-) binding to the transport site is suggested to partially hinder the conversion of the exchanger into the channel.     

Modeling the Formation of Molybdenum Oxides from Alkoxides: Crystal Structures of [Mo(4)O(4)Cl(4)(&mgr;(2)-OEt)(4)(HOEt)(2)(&mgr;(3)-O)(2)] and [PPN](+)[Et(3)NH](+)[Cl(2)(O)Mo(&mgr;(2)-O)(2)Mo(O)Cl(2)](2)(-)

The reactions of the binuclear oxomolybdenum(V) complex [Cl(2)(O)Mo(&mgr;-OEt)(2)(&mgr;-HOEt)Mo(O)Cl(2)] (1) with Me(3)Si(allyl) and SbF(3) produce the compounds [Mo(6)O(6)Cl(6)(&mgr;(3)-O)(2)(&mgr;(2)-OEt)(6)(&mgr;(2)-Cl)(2)] (2) and [Mo(8)O(8)Cl(6)(&mgr;(3)-O)(4)(OH)(2)(&mgr;(2)-OH)(4)(&mgr;(2)-OEt)(4)(HOEt)(4)] (3), respectively. Treatment of 1 with the Lewis base PMe(3) affords the tetrameric complex [Mo(4)O(4)Cl(4)(&mgr;(2)-OEt)(4)(HOEt)(2)(&mgr;(3)-O)(2)] (4), which represents another link in the chain of clusters produced by the reactions of 1 and simulating the build-up of polymeric molybdenum oxides by sol-gel methods. The crystal structure of 4 has been determined [C(12)H(32)Cl(4)Mo(4)O(12), triclinic, P&onemacr;, a = 7.376(2) ?, b = 8.807(3) ?, c = 11.467(4) ?, alpha = 109.61(1) degrees, beta = 92.12(3) degrees, gamma = 103.75(2) degrees, Z = 1]. By contrast, reaction of 1 with the nitrogen base NEt(3), followed by treatment with [PPN]Cl.2H(2)O ([PPN](+) = [Ph(3)P=N=PPh(3)](+)), gives the complex [PPN](+)[Et(3)NH](+)[Cl(2)(O)Mo(&mgr;(2)-O)(2)Mo(O)Cl(2)](2)(-) (6) in 90% yield. Its crystal structure [C(36)H(30)Cl(4)MoNOP(2), triclinic, Pna2(1), a = 21.470(6) ?, b = 16.765(2) ?, c = 9.6155(14) ?, alpha = 90 degrees, beta = 90 degrees, gamma = 90 degrees, Z = 16] includes the anion [Cl(2)(O)Mo(&mgr;(2)-O)(2)Mo(O)Cl(2)](2)(-), which is a charged derivative of the species forming the gels in sol-gel processes starting from chloromolybdenum ethoxides. Furthermore, compound 1 is found to be catalytically active in esterification and dehydration reactions of alcohols.     

Formation of a spiral-shaped inorganic-organic hybrid chain, [Cu(II)(2,2'-bipy)(H(2)O)(2)Al(OH)(6)Mo(6)O(18)](n)()(n)()(-): influence of intra- and interchain supramolecular interactions

A novel chainlike coordination polymer [Cu(II)(2,2'-bipy)(H(2)O)(2)Al(OH)(6)Mo(6)O(18)](n)()(n)()(-), formed from a heteropolyanion [Al(OH)(6)Mo(6)O(18)](3)(-) as a building unit and a copper(II) complex fragment, [Cu(II)(2,2'-bipy)(H(2)O)(2)](2+), as a linker, provides the first example of an extended structure based on an Anderson type of polyanion and a transition metal complex with organic ligand. The intra- and interchain O-H.O hydrogen-bonding interactions are seemingly responsible for the spiral shape of this chain. Crystal data: triclinic space group Ponemacr;, a = 11.2253(18) A, b = 14.5194(17) A, c = 15.2672(10) A, alpha = 112.191(8) degrees, beta = 106.693(9) degrees, gamma = 93.916(13) degrees, and Z = 2.     

Further evidence for the tetraoxoiodate(V) anion,IO(4)(3-): hydrothermal syntheses and structures of Ba[(MoO(2))(6)(IO(4))(2)O(4)] x H(2)O and Ba(3)[(MoO(2))(2)(IO(6))(2)] x 2H(2)O

The hydrothermal reaction of MoO(3) with BaH(3)IO(6) at 180 degrees C for 3 days results in the formation of Ba[(MoO(2))(6)(IO(4))(2)O(4)] x H(2)O (1). Under similar conditions, the reaction of Ba(OH)(2) x 8H(2)O with MoO(3) and Ba(IO(4))(2) x 6H(2)O yields Ba(3)[(MoO(2))(2)(IO(6))(2)] x 2H(2)O (2). The structure of 1, determined by single-crystal X-ray diffraction, consists of corner- and edge-sharing distorted MoO(6) octahedra that create two-dimensional slabs. Contained within this molybdenum oxide framework are approximately C(2v) tetraoxoiodate(V) anions, IO(4)(3-), that are involved in bonding with five Mo(VI) centers. The two equatorial oxygen atoms of the IO(4)(3-) anion chelate a single Mo(VI) center, whereas the axial atoms are mu(3)-oxo groups and complete the octahedra of four MoO(6) units. The coordination of the tetraoxoiodate(V) anion to these five highly electropositive centers is probably responsible for stabilizing the substantial anionic charge of this anion. The Ba(2+) cations separate the layers from one another and form long ionic contacts with neighboring oxygen atoms and a water molecule. Compound 2 also contains distorted MoO(6) octahedra. However, these solely edge-share with octahedral hexaoxoiodate(VII), IO(6)(5-), anions to form zigzagging one-dimensional, (1)(infinity)[(MoO(2))(IO(6))](3-), chains that are polar. These chains are separated from one another by Ba(2+) cations that are coordinated by additional water molecules. Bond valence sums for the iodine atoms in 1 and 2 are 5.01 and 7.03, respectively. Crystallographic data: 1, monoclinic, space group C2/c, a = 13.584(1) A, b = 7.3977(7) A, c = 20.736(2) A, beta = 108.244(2) degrees, Z = 4; 2, orthorhombic, space group Fdd2, a = 13.356(7) A, b = 45.54(2) A, c = 4.867(3) A, Z = 8.     

Polyoxometalate-supported transition metal complexes and their charge complementarity: synthesis and characterization of [M(OH)6Mo6O18[Cu(Phen)(H2O)2]2][M(OH)6Mo6O18[Cu(Phen)(H2O)Cl]2].5H2O (M = Al(+, Cr3+)

Two Anderson-type heteropolyanion-supported copper phenanthroline complexes, [Al(OH)6Mo6O18[Cu(phen)(H2O)2]2]1+ (1c) and [Al(OH)6Mo6O18[Cu(phen)(H2O)Cl]2]1- (1a) complement their charges in one of the title compounds [Al(OH)6Mo6O18[Cu(phen)(H2O)2]2][Al(OH)6Mo6O18[Cu(phen)(H2O)Cl]2].5H2O [1c][1a].5 H2O 1. Similar charge complementarity exists in the chromium analogue, [Cr(OH)6Mo6O18[Cu(phen)(H2O)2]2][Cr(OH)6Mo6O18[Cu(phen)(H2O)Cl]2].5 H2O [2c][2a].5 H2O 2. The chloride coordination to copper centers of 1a and 2a makes the charge difference. In both compounds, the geometries around copper centers are distorted square pyramidal and those around aluminum/chromium centers are distorted octahedral. Three lattice waters, from the formation of intermolecular O-H.....O hydrogen bonds, have been shown to self-assemble into an "acyclic water trimer" in the crystals of both 1 and 2. The title compounds have been synthesized in a simple one pot aqueous wet-synthesis consisting of aluminum/chromium chloride, sodium molybdate, copper nitrate, phenanthroline, and hydrochloric acid, and characterized by elemental analyses, EDAX, IR, diffuse reflectance, EPR, TGA, and single-crystal X-ray diffraction. Both compounds crystallize in the triclinic space group P. Crystal data for 1: a = 10.7618(6), b = 15.0238(8), c = 15.6648(8) angstroms, alpha = 65.4570(10), beta = 83.4420(10), gamma = 71.3230(10), V = 2182.1(2) angstroms3. Crystal data for 2: a = 10.8867(5), b = 15.2504(7), c = 15.7022(7) angstroms, alpha = 64.9850(10), beta = 83.0430(10), gamma = 71.1570(10), V = 2235.47(18) angstroms3. In the electronic reflectance spectra, compounds 1 and 2 exhibit a broad d-d band at approximately 700 nm, which is a considerable shift with respect to the value of 650-660 nm for a square-pyramidal [Cu(phen)2L] complex, indicating the coordination of [M(OH)6Mo6O18]3- POM anions (as a ligand) to the monophenanthroline copper complexes to form POM-supported copper complexes 1c, 1a, 2c, and 2a. The ESR spectrum of compound 1 shows a typical axial signal for a Cu2+ (d9) system, and that of compound 2, containing both chromium(III) and copper(II) ions, may reveal a zero-field-splitting of the central Cr3+ ion of the Anderson anion, [Cr(OH)6Mo6O18]3-, with an intense peak for the Cu2+ ion.     

Cu(2)[o-Br-C(6)H(3)(CO(2))(2)](2)(H(2)O)(2).(DMF)(8)(H(2)O)(2): a framework deliberately designed to have the NbO structure type.

The synthesis of an NbO-type metal-organic framework was achieved by design: o-Br-BDC (BDC = benzenedicarboxylate) was used to direct the formation of Cu2(CO2)4 paddle wheel units at 90 degrees to each other and thus yield the target network. The compound was formulated as Cu2[o-Br-BDC]2(H2O)2.(DMF)8(H2O)2 (MOF-101) and characterized by single-crystal X-ray diffraction [cubic, space group Imm (No. 229) with a = 21.607(3) A, V = 10088(2) A3, Z = 6], which fully confirmed the presence of the expected structure. Despite having very large apertures and voids, MOF-101 has a noninterpenetrated structure, an intriguing observation that is discussed in the context of dual structures.     

Langmuir-Blodgett films of a Mo-blue nanoring [Mo(142)O(429)H(10)(H(2)O)(49)(CH(3)CO(2))(5)(CH(3)CH(2)CO(2))](30)(-) (Mo(142)) by the semiamphiphilic method

Langmuir monolayers and LB films of the ring-shaped mixed-valence polyoxomolybdate [Mo142O429H10(H2O)49(CH3CO2)5(CH3CH2CO2)](30-) (Mo142) dissolved in the aqueous subphase have been successfully fabricated by using the adsorption properties of a DODA monolayer. Infrared and ultraviolet-visible spectroscopy of the LB films indicates that Mo142 and DODA molecules are incorporated within these LB films. X-ray reflectivity experiments indicate that the LB films exhibit a well-defined lamellar structure formed by bilayers of DODA molecules alternating with monolayers of Mo142. Using behenic acid-modified hydrophobic quartz substrate is critical for the formation of the well-defined lamellar structure. From the values of the periodicity obtained by these experiments it is clear that the Mo142 clusters lie flat along the charged organic layers. AFM images also showed the flat and homogeneous films on the quartz substrates treated with behenic acid. Cyclic voltammograms of Mo142-LB films deposited on ITO substrates showed quasi-reversible oxidation/reduction waves with positive shift of the potential compared to the case of solution.