Kinetic and mechanistic investigations of hydrothermal transformations in zinc phosphates

The room-temperature crystallization of [C(6)N(2)H(18)][Zn(HPO(4))(H(2)PO(4))(2)], an organically templated zinc phosphate containing [Zn(2)(HPO(4))(2)(H(2)PO(4))(4)](4)(-) molecular anions, and its transformation to compounds containing either one- or two-dimensional inorganic components, [C(6)N(2)H(18)][Zn(3)(H(2)O)(4)(HPO(4))(4)], [C(4)N(2)H(12)][Zn(HPO(4))(2)(H(2)O)], or [C(3)N(2)H(6)][Zn(4)(OH)(PO(4))(3)], under hydrothermal conditions were studied in-situ using energy-dispersive X-ray diffraction. The ability to collect data during reactions in a large volume ( approximately 23 mL) Teflon-lined autoclave under real laboratory conditions has allowed for the elucidation of kinetic and mechanistic information. Kinetic data have been determined by monitoring changes in the integrated peak intensities of Bragg reflections and have been modeled using the Avrami-Erofe'ev expression. The crystallization of [C(6)N(2)H(18)][Zn(HPO(4))(H(2)PO(4))(2)] is a diffusion-controlled process, while nucleation is increasingly more important in determining the overall rate of the formation of [C(6)N(2)H(18)][Zn(3)(H(2)O)(4)(HPO(4))(4)], [C(4)N(2)H(12)][Zn(HPO(4))(2)(H(2)O)], and [C(3)N(2)H(6)][Zn(4)(OH)(PO(4))(3)]. The transformation of [C(6)N(2)H(18)][Zn(HPO(4))(H(2)PO(4))(2)] to [C(4)N(2)H(12)][Zn(HPO(4))(2)(H(2)O)] and [C(3)N(2)H(6)][Zn(4)(OH)(PO(4))(3)] occurs via a dissolution-reprecipitation mechanism, while the transformation to [C(6)N(2)H(18)][Zn(3)(H(2)O)(4)(HPO(4))(4)] may be the first observation of a direct topochemical conversion of one organically templated solid to another under hydrothermal conditions.     

Chirality transfer from guest chiral metal complexes to inorganic framework: the role of hydrogen bonding

The structure elucidation of a new zinc phosphate [Co(II)(en)(3)][Zn(4)(H(2)PO(4))(3)(HPO(4))(2)(PO(4))(2 H(2)O)(2)] (1) reveals that the racemic cobalt complex templates the zinc phosphate framework in such a way that the local C(2) point symmetry of the structural motif of the inorganic framework conforms with that of the cobalt complex pairing with it, in essence transferring its chirality to the inorganic host. An analysis of hydrogen bonding between the guest molecules and the inorganic host framework reveals that hydrogen bonding is responsible for the stereospecific structural arrangement. Upon examining previously reported chiral metal-complex-templated structures of metal phosphates, it is revealed that such hydrogen bonding is the common origin for inducing chirality transfer in metal-phosphate frameworks templated with chiral metal complexes. Crystal data of 1: orthorhombic, Pbcn (no. 60), a=10.4787(8) A, b=20.0091(14) A, c=14.9594(10) A, and Z=2.     

A novel organic-inorganic hybrid based on an 8-electron-reduced Keggin polymolybdate capped by tetrahedral, trigonal bipyramidal, and octahedral zinc: synthesis and crystal structure of (CH3NH3)(H2bipy)[Zn4(bipy)3(H2O)2MoV8MoVI4O36)(PO4)].4H2O

Hydrothermal reaction of H(3)PO(3), CH(3)NH(2), zinc(II) acetate, 4,4'-bipyridine (bipy), and (NH(4))(6)Mo(7)O(24).4H(2)O at 180 degrees C led to a novel organic-inorganic layered hybrid, [CH(3)NH(3)][H(2)bipy][Zn(4)(bipy)(3)(H(2)O)(2)Mo(V)(8)Mo(VI)O(36)(PO(4))].4H(2)O (1). Its structure was established by single-crystal X-ray diffraction. It crystallizes in the monoclinic space group P2(1)/c with cell parameters of a = 17.3032(2), b = 17.8113(3), and c = 23.4597 (4) A, beta = 106.410(1) degrees, V = 6935.6(2) A(3), and Z = 4. The structure of compound 1 features a novel 2D layer built from the 8e-reduced tetracapped Keggin [Zn(4)Mo(12)O(36)(PO(4))](3)(-) anions, which are further interconnected by bridging bipy ligands. The four zinc(II) ions are in tetrahedral, trigonal bipyramidal, and octahedral coordination geometries, respectively.     

Amine-templated linear vanadium sulfates with different chain structures

Amine-templated vanadium sulfates of the formula [HN(CH(2))(6)NH][(V(IV)O)(2)(OH)(2)(SO(4))(2)].H(2)O, I, [H(3)N(CH(2))(2)NH(3)][V(III)(OH)(SO(4))(2)].H(2)O, II, and [H(2)N(CH(2))(4)NH(2)][(V(IV)O)(H(2)O)(SO(4))(2)], III, have been prepared under hydrothermal conditions. These vanadium sulfates add to the new emerging family of organically templated metal sulfates. Compound I has a linear chain structure consisting of V(2)O(8) square-pyramid dimers connected by corner-sharing SO(4) tetrahedra, creating four-membered rings along the chain. Both II and III possess simple linear chain topologies formed by VO(6) octahedra and SO(4) tetrahedra, with II having the tancoite chain structure. Compound I crystallizes in the triclinic space group P1 (No. 2) with a = 7.4852(4) A, b = 9.5373(5) A, c = 11.9177(6) A, alpha = 77.22 degrees, beta = 76.47(2) degrees, gamma = 80.86 degrees, Z = 2. Compound II: monoclinic, space group P2(1)/c (No. 14), a = 6.942(2) A, b = 10.317(3) A, c = 15.102(6) A, beta = 90.64(4) degrees, Z = 4. Compound III: triclinic, space group P1 (No. 2) with a = 6.2558(10) A, b = 7.0663(14) A, c = 15.592(4) A, alpha = 90.46(2) degrees, beta = 90.47(2) degrees, gamma = 115.68(2) degrees, Z = 2. Magnetic susceptibility measurements reveal weak antiferromagnetic interactions in I and III and ferromagnetic interactions in II.     

Ionic liquid of choline chloride/malonic acid as a solvent in the synthesis of open-framework iron oxalatophosphates

Two new iron(III) oxalatophosphates, Cs2Fe(C2O4)(0.5)(HPO4)2 (1) and CsFe(C2O4)(0.5)(H2PO4)(HPO4) (2), have been synthesized by using a low melting point eutectic mixture of choline chloride and malonic acid as a solvent and characterized by single-crystal X-ray diffraction and magnetic susceptibility. Crystal data are as follows: compound 1, monoclinic, P2(1)/c (No. 14), a = 8.5085(4) A, b = 12.7251(6) A, c = 9.8961(4) A, beta = 107.117(1) degrees , V = 1024.01(8) A(3), Z = 4, and R(1) = 0.0264; compound 2, monoclinic, P2(1)/n (No. 14), a = 8.0038(3) A, b = 10.2923(3) A, c = 11.4755(4) A, beta = 100.507(1) degrees , V = 929.47(5) A(3), Z = 4, and R(1) = 0.0311. The structure of 1 comprises FeO6 octahedra connected by HPO4(2-) tetrahedra and bisbidentate oxalate anions to form a 3D framework containing intersecting 12-ring channels, with the charge-compensating Cs+ cations being located at the intersections of these channels. The structure of 2 consists of 2D layers of octahedral FeO6, tetrahedral H2PO4- and HPO4(2-) moieties, and bisbidentate oxalate ligands with the Cs+ cations between the layers. They are the first examples for the use of ionic liquid as a solvent in the synthesis of metal oxalatophosphates.     

Synthesis, characterization and magnetic properties of four new organically templated metal sulfates [C5H14N2][M(II)(H2O)6](SO4)2, (M(II) = Mn, Fe, Co, Ni)

A series of novel organically templated metal sulfates, [C(5)H(14)N(2)][M(II)(H(2)O)(6)](SO(4))(2) with (M(II) = Mn (1), Fe (2), Co (3) and Ni (4)), have been successfully synthesized by slow evaporation and characterized by single-crystal X-ray diffraction as well as with infrared spectroscopy, thermogravimetric analysis and magnetic measurements. All compounds were prepared using a racemic source of the 2-methylpiperazine and they crystallized in the monoclinic systems, P2(1)/n for (1, 3) and P2(1)/c for (2,4). Crystal data are as follows: [C(5)H(14)N(2)][Mn(H(2)O)(6)](SO(4))(2), a = 6.6385(10) ?, b = 11.0448(2) ?, c = 12.6418(2) ?, β = 101.903(10)°, V = 906.98(3) ?(3), Z = 2; [C(5)H(14)N(2)][Fe(H(2)O)(6)](SO(4))(2), a = 10.9273(2) ?, b = 7.8620(10) ?, c = 11.7845(3) ?, β = 116.733(10)°, V = 904.20(3) ?(3), Z = 2; [C(5)H(14)N(2)][Co(H(2)O)(6)](SO(4))(2), a = 6.5710(2) ?, b = 10.9078(3) ?, c = 12.5518(3) ?, β = 101.547(2)°, V = 881.44(4) ?(3), Z = 2; [C(5)H(14)N(2)][Ni(H(2)O)(6)](SO(4))(2), a = 10.8328(2) ?, b = 7.8443(10) ?, c = 11.6790(2) ?, β = 116.826(10)°, V = 885.63(2) ?(3), Z = 2. The three-dimensional structure networks for these compounds consist of isolated [M(II)(H(2)O)(6)](2+) and [C(5)H(14)N(2)](2+) cations and (SO(4))(2-) anions linked by hydrogen-bonds only. The use of racemic 2-methylpiperazine results in crystallographic disorder of the amines and creation of inversion centers. The magnetic measurements indicate that the Mn complex (1) is paramagnetic, while compounds 2, 3 and 4, (M(II) = Fe, Co, Ni respectively) exhibit single ion anisotropy.     

A new organic-inorganic hybrid layered molybdenum(V) cobalt phosphate constructed from [H24(Mo16O32)Co16(PO4)24(OH)4(C5H4N)2(H2O)6](4-) wheels and 4,4'-bipyridine linkers

A new layered molybdenum cobalt phosphate, Na(2)[Co(H(2)O)(6)][(Mo(16)O(32))Co(16)(PO(4))(4) (HPO(4))(16)(H(2)PO(4))(4)(OH)(4)(C(10)H(8)N(2))(4)(C(5)H(4)N)(2)(H(2)O)(6)]·4H(2)O (1), has been hydrothermally synthesized and structurally characterized. 1 crystallizes in the monoclinic space group P2(1)/n with a = 15.6825(18) ?, b = 39.503(4) ?, c = 17.2763(17) ?, β = 93.791(2)°, V = 10679.4(18) ?(3), and Z = 2. A polyoxoanion of 1 exhibits an unusual organic-inorganic hybrid wheel-type cluster, in which two pyridine ligands link to the surface Co(II) atoms of a [H(24)(Mo(16)O(32))Co(16)(PO(4))(24)(OH)(4)(H(2)O)(6)] (namely, {Mo(16)Co(16)P(24)}) wheel via the Co-N bonds. Furthermore, each {Mo(16)Co(16)P(24)} wheel is connected to four adjacent wheels by four pairs of 4,4'-bipyridine linkers, forming a 2D layered network. The susceptibility measurement shows the existence of dominant antiferromagnetic interactions in 1.     

New amine-templated zinc phosphates with a temperature-induced increase of structural dimensionality

Three new amine-templated zinc phosphates, [C4N2H14][Zn(HPO4)2].H2O, AU-I, [C4N2H14][Zn2(H(0.5)PO4)2(H2PO4)], AU-II, and [C4N2H14][Zn5(H2O)(PO4)4], AU-III, are prepared by hydrothermal synthesis using an organic amine, N,N'-dimethylethylendiamine CH3NHCH2CH2NHCH3, as structure-directing agent. The three materials are prepared from the same reaction mixture, 1Zn(CH3CO2)2:3.05H3PO4:2.25CH3NHCH2CH2NHCH3:138H2O (pH = 5.1), AU-I at RT, AU-II at 60 degrees C, and AU-III at 170 degrees C. The materials are built from corner-sharing ZnO4 and PO4 tetrahedra forming chains, layers, or framework structures for AU-I to III, respectively, and are linked together by hydrogen bonds via the diprotonated amine ions. The complete hydrogen-bond scheme is resolved for these new compounds and reveals some interesting phenomena, for example, a hydrogen shared between two phosphate groups in AU-II, thereby forming H(0.5)PO4 groups. Furthermore, the water molecules are different; that is, in AU-I they act as hydrogen-bond donor and acceptor, whereas they act as ligand in AU-III with coordination to Zn. The structures of the compounds are determined by single-crystal X-ray diffraction analysis. AU-I, [C4N2H14][Zn(HPO4)2].H2O, crystallizes in the triclinic space group P-1, a = 8.215(2), b = 8.810(3), c = 8.861(3) A, alpha = 88.001(4) degrees , beta = 89.818(5) degrees , and gamma = 89.773(5) degrees , Z = 2. AU-II, [C4N2H14][Zn2(H(0.5)PO4)2(H2PO4)], is monoclinic, P2/n, a = 11.7877(4), b = 5.2093(2), c = 12.2031(4) A, beta = 98.198(1) degrees , Z = 2. AU-III, [C4N2H14][Zn5(H2O)(PO4)4], crystallizes in the orthorhombic space group Pna2(1) with lattice parameters, a = 20.723(2), b = 5.2095(6), c = 17.874(2) A, Z = 4. The phase stability investigated by systematic hydrothermal synthesis is presented, and the materials are further characterized by 31P solid-state MAS NMR, for example, by determination of 31P chemical shift anisotropies for AU-III, while the thermal behavior is investigated by thermogravimetry (TG).     

Proton control of oxidation and spin state in a series of iron tripodal imidazole complexes

Reaction of iron salts with three tripodal imidazole ligands, H(3)(1), H(3)(2), H(3)(3), formed from the condensation of tris(2-aminoethyl)amine (tren) with 3 equiv of an imidazole carboxaldehyde yielded eight new cationic iron(III) and iron(II), [FeH(3)L](3+or2+), and neutral iron(III), FeL, complexes. All complexes were characterized by EA(CHN), IR, UV, M?ssbauer, mass spectral techniques and cyclic voltammetry. Structures of three of the complexes, Fe(2).3H(2)O (C(18)H(27)FeN(10)O(3), a = b = c = 20.2707(5), cubic, I3d, Z = 16), Fe(3).4.5H(2)O (C(18)H(30)FeN(10)O(4.5), a = 20.9986(10), b = 11.7098(5), c = 19.9405(9), beta = 109.141(1), monoclinic, P2(1)/c), Z = 8), and [FeH(3)(3)](ClO(4))(2).H(2)O (C(18)H(26)Cl(2)FeN(10)O(9), a = 9.4848(4), b = 23.2354(9), c = 12.2048(5), beta = 111.147(1) degrees, monoclinic, P2(1)/n, Z = 4) were determined at 100 K. The structures are similar to one another and feature an octahedral iron with facial coordination of imidazoles and imine nitrogen atoms. The iron(III) complexes of the deprotonated ligands, Fe(1), Fe(2), and Fe(3), are low-spin while the protonated iron(III) cationic complexes, [FeH(3)(1)](ClO(4))(3) and [FeH(3)(2)](ClO(4))(3), are high-spin and spin-crossover, respectively. The iron(II) cationic complexes, [FeH(3)(1)]S(4)O(6), [FeH(3)(2)](ClO(4))(2), [FeH(3)(3)](ClO(4))(2), and [FeH(3)(3)][B(C(6)H(5))(4)](2) exhibit spin-crossover behavior. Cyclic voltammetric measurements on the series of complexes show that complete deprotonation of the ligands produces a negative shift in the Fe(III)/Fe(II) reduction potential of 981 mV on average. Deprotonation in air of either cationic iron(II) or iron(III) complexes, [FeH(3)L](3+or2+), yields the neutral iron(III) complex, FeL. The process is reversible for Fe(3), where protonation of Fe(3) yields [FeH(3)(3)](2+).     

Exploration of composition space in templated uranium sulfates

The phase stability of organically templated uranium sulfates in the [UO(2)(CH(3)CO(2))(2).2H(2)O/homopiperazine/H(2)SO(4)] and [UO(2)(CH(3)CO(2))(2).2H(2)O/N,N-dimethylethylenediamine/H(2)SO(4)] systems has been studied using composition space. Two new compounds were formed in each system; [N(2)C(5)H(14)](2)[UO(2)(SO(4))(3)] (USO-17) and [N(2)C(5)H(14)][UO(2)(H(2)O)(SO(4))(2)] (USO-18) contain homopiperazine, and [N(2)C(4)H(14)][UO(2)(SO(4))(2)] (USO-19) and [N(2)C(4)H(14)][(UO(2))(2)(H(2)O)(SO(4))(3)].H(2)O (USO-20) contain N,N-dimethylethylenediamine. The relative stability of the products from each system is dependent upon the reactant mole fractions in the initial reaction gel. Crystal data: USO-17, a = 14.4975(3) A, b = 11.9109(3) A, c = 13.0157(3) A, beta = 110.475(1) degrees, monoclinic, C2/c (No. 15), Z = 4; for USO-18, a = 7.6955(2) A, b = 11.7717(3) A, c = 14.7038(4) A, orthorhombic, P22(1)2(1) (No. 18), Z = 4; for USO-19, a = 9.3322(1) A, b = 9.7743(2) A, c = 13.8897(3) A, orthorhombic, P2(1)2(1)2(1) (No. 19), Z = 4; and for USO-20, a = 11.2460(2) A, b = 10.5387(2) A, c = 17.0432(3) A, beta = 92.9884(6) degrees, monoclinic, P2(1)/c (No. 14), Z = 4.     

Solid state coordination chemistry: one-, two-, and three-dimensional materials constructed from molybdophosphonate subunits linked through binuclear copper tetra-2-pyridylpyrazine groups

The hydrothermal reactions of MoO(3), an appropriate Cu(II) source, tetra-2-pyridylpyrazine (tpypyz), and phosphoric acid and/or an organophosphonate yielded a series of organic-inorganic hybrid materials of the copper-molybdophosphonate family. A common feature of the structures is the entrainment within the extended architectures of chemically robust [Mo(5)O(15)(O(3)PR)(2)](4)(-) clusters as molecular building blocks. The cluster is a characteristic feature of the one-dimensional materials [[Cu(2)(tpypyz)(H(2)O)(3)]Mo(5)O(15)(HPO(4))(O(3)PCH(2)CO(2)H)].H(2)O (1.H(2)O) and [[Cu(2)(tpypyz)(H(2)O)]Mo(5)O(15)(O(3)PC(6)H(5))(2)].2H(2)O (2.2H(2)O), the two-dimensional network [[Cu(2)(tpypyz)(H(2)O)(3)]Mo(5)O(15)(HPO(4))(2)].2H(2)O (5.2H(2)O) and the three-dimensional frameworks [[Cu(2)(tpypyz)(H(2)O)(2)]Mo(5)O(15)[O(3)P(CH(2))(n)()PO(3)]].xH(2)O [n = 3, x = 2.25 (6.2.25H(2)O); n = 4, x = 0.33 (7.0.33H(2)O)]. In the case of methylenediphosphonate as the phosphorus component, the unique chelating nature of the ligand precludes formation of the pentamolybdate core, resulting in the chain structures [[Cu(2)(tpypyz)(H(2)O)]Mo(3)O(8) (HO(3)PCH(2)PO(3))(2)].8H(2)O (3.8H(2)O) and [[Cu(2)(tpypyz)(H(2)O)](2)(Mo(3)O(8))(2)(O(3)PCH(2)PO(3))(3)].16.9H(2)O (4.16.9H(2)O). For structures 1-7, the secondary metal-ligand building block is the binuclear [Cu(2)(tpypyz)(H(2)O)(x)](4+) cluster. There is considerable structural versatility as a result of the variability in the number of attachment sites at the phosphomolybdate clusters, the coordination geometry of the Cu(II), which may be four-, five-, or six-coordinate, the extent of aqua ligation, and the participation of phosphate oxygen atoms as well as molybdate oxo groups in bonding to the copper sites. Crystal data: 1.H(2)O, C(26)H(28)N(6)Cu(2)Mo(5)O(28)P(2), monoclinic C2/c, a = 42.497(2) A, b = 10.7421(4) A, c = 20.5617(8) A, beta = 117.178(1) degrees, V = 8350.1(5) A(3), Z = 8; 2.2H(2)O, C(36)H(32)N(6)Cu(2)Mo(5)O(24)P(2), monoclinic P2(1)/c, a = 11.2478(7) A, b = 19.513(1) A, c = 21.063(1) A, beta = 93.608(1) degrees, V = 4613.7(5) A(3), Z = 4; 3.8H(2)O, C(26)H(40)N(6)Cu(2)Mo(3)O(29)P(4), monoclinic C2/c, a = 32.580(2) A, b = 17.8676(9) A, c = 15.9612(8) A, beta = 104.430(1) degrees, V = 8993.3(8) A(3), Z = 8; 4.16.9H(2)O, C(51)H(71.75)Cu(4)Mo(6)N(12)O(51)P(6), monoclinic P2(1)/c, a = 27.929(3) A, b = 12.892(2) A, c = 22.763(3) A, beta = 90.367(2) degrees, V = 8195.7(2) A(3), Z = 4;( )()5.2H(2)O, C(24)H(28)N(6)Cu(2)Mo(5)O(28)P(2), monoclinic P2(1)/n, a = 11.3222(4) A, b = 18.7673(7) A, c = 19.4124(7) A, beta = 98.819(1) degrees, V = 4076.1(3) A(3), Z = 4; 6.2.25H(2)O, C(27)H(28.5)N(6)Cu(2)Mo(5)O(24.25)P(2), monoclinic C2/c, a = 12.8366(5) A, b = 18.4221(8) A, c = 34.326(1) A, beta = 100.546(1) degrees, V = 7980.1(6) A(3), Z = 8; 7.(1)/(3)H(2)O, C(28)H(28.7)N(6)Cu(2)Mo(5)O(23.3)P(2), monoclinic C2/c, a = 12.577(1) A, b = 18.336(1) A, c = 36.476(3) A, beta = 91.929(2) degrees, V = 8407.3 A(3), Z = 8.     

Synthesis and characterization of a new bisphosphonic acid and several metal hybrids derivatives

Commercial bis-(4-bromophenyl)-ether, [BrC(6)H(4)](2)-O, has been used to prepare 4-[4'-(diethoxyphosphoryl)phenoxy]phenyl-phosphonic acid diethyl ester, [(CH(3)CH(2))(2)O(3)P-C(6)H(4)](2)-O, (I) following a slight modification of the Michaelis-Arbuzov reaction. The acid hydrolysis of I gave 4-(4'-phosphonophenoxy)phenyl phosphonic acid, [H(2)O(3)P-C(6)H(4)](2)-O (II), and both compounds have been characterized by (1)H NMR and (13)C NMR. The crystal structure of II has been determined by single-crystal X-ray diffraction. II crystallizes in an orthorhombic unit cell, space group Pbcn, with a = 7.822(3) A, b = 5.821(2) A, c = 28.982(9) A, and V = 1319.7(7) A(3). The final R factor was R1 = 0.0614. The structure is layered, being held together through a hydrogen bonding network. II has been used as precursor in the syntheses of new metal (Mn, Fe, Co, Ni, Cu, and Zn) bisphosphonates. The syntheses were carried out using a fixed metal/bisphosphonic acid molar ratio of 2.1:1 and the influence of the pH in the reactions has been studied. Nine new compounds have been isolated: Mn(2)(O(3)PC(6)H(4)OC(6)H(4)PO(3)).1.5H(2)O (III), Mn(5)(OH)(2)(O(3)PC(6)H(4)OC(6)H(4)PO(3))(2).2H(2)O (IV), Fe(HO(3)PC(6)H(4)OC(6)H(4)PO(3)).0.5H(2)O (V), Co(2)(O(3)PC(6)H(4)OC(6)H(4)PO(3)).2H(2)O (VI), Ni(2)(O(3)PC(6)H(4)OC(6)H(4)PO(3)).3H(2)O (VII), Ni(2)(O(3)PC(6)H(4)OC(6)H(4)PO(3)).2H(2)O (VIII), Cu(2)(O(3)PC(6)H(4)OC(6)H(4)PO(3)) (IX), Zn(2)(O(3)PC(6)H(4)OC(6)H(4)PO(3)) (X), and Zn(HO(3)PC(6)H(4)OC(6)H(4)PO(3)H) (XI). Compound IX crystallizes in an orthorhombic unit cell, space group Pbcn, and unit cell parameters a = 8.1012(5) A, b = 5.3109(3) A, c = 29.2595(5) A, and V = 1258.8(1) A(3). Its structure has been solved by ab initio powder diffraction and refined by the Rietveld method to R(F) = 0.042. IX has a pillared layer framework with highly distorted CuO(5) groups sharing edges to give isolated dimers. XI was indexed in a monoclinic unit cell, space group P112(1), with parameters a = 9.4991(9) A, b = 5.0445(5) A, c = 29.131(2) A, gamma = 91.945(7) degrees, and V = 1395.1(3) A(3). Its structure has been refined by the Rietveld method, R(F) = 0.054, since it is isostructural with the known compound, Zn[HO(3)P(C(6)H(4))(2)PO(3)H]. All solids were also characterized by thermal analysis and IR and UV-Vis spectroscopies.     

Synthetic Strategies To Obtain V-P-O Open Frameworks Containing Organic Species as Structural Directing Agents. Crystal Structure of the V(IV)-Fe(III) Bimetallic Phosphate [H(3)N(CH(2))(2)NH(3)](2)[H(3)N(CH(2))(2)NH(2)][Fe(III)(H(2)O)(2)(V(IV)O)(8)(OH)(4)(HPO(4))(4)(PO(4))(4)].4H(2)O

A general synthetic approach to rationalize the solution preparative chemistry of oxovanadium phosphates containing organic species as structural directing agents is presented. Careful attention is payed to the hydrolysis and condensation processes involving the ionic species in solution, and a simple restatement of the partial charge model (PCM) has been used in order to organize the experimental results. The structure of a new V(IV)-Fe(III) bimetallic oxovanadium phosphate, [H(3)N(CH(2))(2)NH(3)](2)[H(3)N(CH(2))(2)NH(2)] [Fe(III)(H(2)O)(2)(V(IV)O)(8)(OH)(4)(HPO(4))(4)(PO(4))(4)].4H(2)O, has been determined by X-ray single crystal diffraction methods. This compound crystallizes in the monoclinic system, space group P2(1)/n and the cell dimensions are as follows: a = 14.383(3) ?, b = 10.150(2) ?, c = 18.355(4) ?, and beta = 90.39(3) degrees (Z = 2). The existence of a complex intercrossing channel system, including a very large channel of 18.4 ? of diameter (in which both water molecules and ethylenediamine species are located), is the more interesting feature of this structure. Thermal decomposition, including the dehydration/rehydration process, has been studied by thermal analysis and variable temperature X-ray powder diffraction techniques. A complementary SEM study of the different intermediate decomposition products is presented.     

Hydrothermal Synthesis, Structure, and Solid State (19)F NMR Study of ULM-17: (H(3)O)(2)[V(4)(HPO(4))(PO(4))(3)O(6)F](2)[NC(7)H(14)](6)

(H(3)O)(2)[V(4)(HPO(4))(PO(4))(3)O(6)F](2)[NC(7)H(14)](6) (labeled ULM-17) has been hydrothermally synthesized (150 degrees, 24 h, autogeneous pressure). It is monoclinic (space group P2(1)/c (No. 14)) with a = 21.4747(6) ?, b = 17.7223(5) ?, c = 20.1616(6) ?, beta = 94.329(1) degrees, and Z = 4. The structure consists in the hexagonal close packing of discrete hydronium cations, protonated quinuclidine and molecular anions [V(4)(HPO(4))(PO(4))(3)O(6)F](4)(-) (1) The structure presents two kinds of octameric anions built up from the tetrahedral arrangement of V(V)O(5)F octahedra sharing edges and vertices, capped by phosphorus tetrahedra. The stability of the solid is ensured via strong hydrogen bonds between the oxygens of the polyanions and the hydrogens of both hydronium and quinuclidinium cations. The particuliar location of fluorine at the center of the molecular anion 4-fold coordinated by V(V) was studied by solid state NMR.     

Synthesis of a single four-ring (S4R) molecular zinc phosphate and its assembly to an extended polymeric structure: a single-crystal and in-situ MAS NMR investigation

A reaction of ZnO, HCl, H(3)PO(4), and 2-pyridylpiperazine in THF/H(2)O mixture at 75 degrees C for 72 h produces a new zinc phosphate, [(C(5)NH(5))(C(4)N(2)H(10))][Zn(H(2)PO(4))(2)(HPO(4))], I. Zinc phosphate I consists of single four-ring (S4R) units with terminal phosphoryl groups hanging from the Zn center. On reaction with zinc acetate dihydrate in the presence of water at 100 degrees C, I gave another new zinc phosphate, [(C(5)NH(5))(C(4)N(2)H(10))][Zn(2)(H(2)PO(4))(HPO(4))(PO(4))] x 2H(2)O, II. II has a layer structure with apertures formed by 4- and 8-T atoms (T = Zn, P). An examination of the two structures reveals that I and II are related, II being formed by the direct addition of Zn(2+) ions to I. Room-temperature (31)P MAS NMR studies show the presence of different phosphorus species in both compounds. An in-situ (31)P MAS NMR investigation on the formation of II from I in the presence of Zn(2+) ions and water reveals the transformation to be facile. What is noteworthy in this study is that the structural integrity of the S4Rs has been maintained during the formation of II. Donor-acceptor hydrogen bond interactions and pi-pi interactions involving the pyridyl groups also appear to play subtle roles in both phosphates. This study, the first attempt of its kind, combines the principles of supramolecular organic chemistry with inorganic building units and contributes to our understanding of the formation of framework solids.     

Synthesis, crystal structure, and solid-state NMR spectroscopy of a new open-framework aluminophosphate (NH(4))(2)Al(4)(PO(4))(4)(HPO(4))xH(2)O

A new three-dimensional open-framework aluminophosphate (NH(4))(2)Al(4)(PO(4))(4)(HPO(4)).H(2)O (denoted AlPO-CJ19) with an Al/P ratio of 4/5 has been synthesized, using pyridine as the solvent and 2-aminopyridine as the structure-directing agent, under solvothermal conditions. The structure was determined by single-crystal X-ray diffraction and further characterized by solid-state NMR techniques. The alternation of the Al-centered polyhedra (including AlO(4), AlO(5), and AlO(6)) and the P-centered tetrahedra (including PO(4) and PO(3)OH) results in an interrupted open-framework structure with an eight-membered ring channel along the [100] direction. This is the first aluminophosphate containing three kinds of Al coordinations (AlO(4), AlO(5), and AlO(6)) with all oxygen vertexes connected to framework P atoms. (27)Al MAS NMR, (31)P MAS NMR, and (1)H --> (31)P CPMAS NMR characterizations show that the solid-state NMR techniques are an effective complement to XRD analysis for structure elucidation. Furthermore, all of the possible coordinations of Al and P in the aluminophosphates with an Al/P ratio of 4/5 are summarized. Crystal data: (NH(4))(2)Al(4)(PO(4))(4)(HPO(4))xH(2)O, monoclinic P2(1) (No. 4), a = 5.0568(3) A, b = 21.6211(18) A, c = 8.1724(4) A, beta = 91.361(4) degrees , V = 893.27(10) A(3), Z = 2, R(1) = 0.0456 (I > 2 sigma(I)), and wR(2) = 0.1051 (all data).     

New titanium and nickel gallophosphates with layered structures

Two new transition-metal gallophosphates, (H(2)C(4)H(10)N(2))(3)[(Ti(2.5)(H(2)O)(4)Ga(5.5)(PO(4))(10)].2H(2)O (TGP-1) and [H(3.5)(C(4)H(13)N(3))(2)][(Ni(0.5)(OH)(4)Ga(5.5)(PO(4))(3)(HPO(4))(4)].2H(2)O (NGP-1), have been synthesized under mild hydrothermal conditions and characterized by single-crystal X-ray diffraction, thermogravimetric analysis, electron paramagnetic resonance, electron probe microanalysis, and magnetic susceptibility data. TGP-1 exhibits a unique two-dimensional structure consisting of tetrahedral and octahedral metals centers and is the foremost paramagnetic TiGaPO material ever prepared. NGP-1 as well represents the first NiGaPO compound and adopts a layer structure that is constructed from hexameric M-O clusters of trigonal bipyramids and octahedra. In both compounds, the transition metals incorporate with gallium into octahedral sites only, while the four- and five-coordinated metals centers are only Ga(3+) ions. The unique sites for Ti(3+) and Ni(2+) ions have been initially elucidated from single-crystal structure refinements and further confirmed by bond-valence-sum calculations, EPR, and magnetic susceptibility studies. Crystal data: TGP-1, monoclinic, P2(1)/c; a = 25.692(2) A, b = 9.6552(8) A, c = 9.8418(8) A, beta = 96.737(2)(o) , V = 2424.5(3) A(3), and Z = 2; NGP-1, monoclinic, C2/c, a = 20.8363(12) A, b = 11.9546(7) A, c = 16.4577(9) A, beta = 117.285(1)(o) , V = 3643.3(1) A(3), Z = 4.     

Novel metal-organic frameworks with specific topology from new tripodal ligands: 1,3,5-tris(1-imidazolyl)benzene and 1,3-bis(1-imidazolyl)-5-(imidazol-1-ylmethyl)benzene

Reactions of two new tripodal ligands 1,3,5-tris(1-imidazolyl)benzene (4) and 1,3-bis(1-imidazolyl)-5-(imidazol-1-ylmethyl)benzene (5) with metal [Ag(I), Cu(II), Zn(II), Ni(II)] salts lead to the formation of novel two-dimensional (2D) metal-organic frameworks [Ag(2)(4)(2)][p-C(6)H(4)(COO)(2)].H(2)O (6), [Ag(4)]ClO(4) (7), [Cu(4)(2)(H(2)O)(2)](CH(3)COO)(2).2H(2)O (8), [Zn(4)(2)(H(2)O)(2)](NO(3))(2) (9), [Ni(4)(2)(N(3))(2)].2H(2)O (10), and [Ag(5)]ClO(4) (11). All the structures were established by single-crystal X-ray diffraction analysis. Crystal data for 6: monoclinic, C2/c, a = 23.766(3) A, b = 12.0475(10) A, c = 13.5160(13) A, beta = 117.827(3) degrees, Z = 4. For compound 7: orthorhombic, P2(1)2(1)2(1), a = 7.2495(4) A, b = 12.0763(7) A, c = 19.2196(13) A, Z = 4. For compound 8: monoclinic, P2(1)/n, a = 8.2969(5) A, b = 12.2834(5) A, c = 17.4667(12) A, beta = 96.5740(10) degrees, Z = 2. For compound 9: monoclinic, P2(1)/n, a =10.5699(3) A, b = 11.5037(3) A, c = 13.5194(4) A, beta = 110.2779(10) degrees, Z = 2. For compound 10: monoclinic, P2(1)/n, a = 9.8033(3) A, b = 12.1369(5) A, c = 13.5215(5) A, beta = 107.3280(10) degrees, Z = 2. For compound 11: monoclinic C2/c, a = 18.947(2) A, b = 9.7593(10) A, c = 19.761(2) A, beta = 97.967(2) degrees, Z = 8. Both complexes 6 and 7 are noninterpenetrating frameworks based on the (6, 3) nets, and 8, 9 and 10 are based on the (4, 4) nets while complex 11 has a twofold parallel interpenetrated network with 4.8(2) topology. It is interesting that, in complexes 6,7, and 11 with three-coordinated planar silver(I) atoms, each ligand 4 or 5 connects three metal atoms, while in the case of complexes 8, 9, and 10 with six-coordinated octahedral metal atoms, each ligand 4 only links two metal atoms, and another imidazole nitrogen atom of 4 did not participate in the coordination with the metal atoms in these complexes. The results show that the nature of organic ligand and geometric needs of metal atoms have great influence on the structure of metal-organic frameworks.     

New hydrothermal synthesis and structure of Th2(PO4)2(HPO4).H2O: the first structurally characterized thorium Hydrogenphosphate

Th(2)(PO(4))(2)(HPO(4)).H(2)O was synthesized under wet hydrothermal conditions starting from a mixture of H(3)PO(3) and Th(NO(3))(4).5H(2)O. The crystal structure was solved by powder X-ray diffraction data. The unit cell parameters are a = 6.7023(8) Angstroms, b = 7.0150(8) Angstroms, c = 11.184(1) Angstroms, beta = 107.242(4) degrees, space group P2(1), and Z = 2. The structure consists of layers of both thorium atoms and PO(4) groups, alternating with a layer formed by HPO(4) entities and water molecules. By thermal treatment, this compound turns into Th(4)(PO(4))(4)P(2)O(7), a ceramic already described in the field of the immobilization of tetravalent actinides.     

Macrocyclic copper(II) and zinc(II) complexes incorporating phosphate esters

Slow evaporation of solutions prepared by adding either Cu(ClO(4))(2).6H(2)O or Zn(ClO(4))(2).6H(2)O to solutions containing appropriate proportions of Me(3)tacn (1,4,7-trimethyl-1,4,7-triazacyclononane) and sodium phenyl phosphate (Na(2)PhOPO(3)) gave dark blue crystals of [Cu(3)(Me(3)tacn)(3)(PhOPO(3))(2)](ClO(4))(2).(1)/(2)H(2)O (1) and colorless crystals of [Zn(2)(Me(3)tacn)(2)(H(2)O)(4)(PhOPO(3))](ClO(4))(2).H(2)O (2), respectively. Blue crystals of [Cu(tacn)(2)](BNPP)(2) (3) formed in an aqueous solution of [Cu(tacn)Cl(2)], bis(p-nitrophenyl phosphate) (BNPP), and HEPES buffer (pH 7.4). Compound 1 crystallizes in the triclinic space group P1 (No. 2) with a = 9.8053(2) A, b = 12.9068(2) A, c = 22.1132(2) A, alpha = 98.636(1) degrees, beta = 99.546(1) degrees, gamma = 101.1733(8) degrees, and Z = 2 and exhibits trinuclear Cu(II) clusters in which square pyramidal metal centers are capped by two phosphate esters located above and below the plane of the metal centers. The trinuclear cluster is asymmetric having Cu...Cu distances of 4.14, 4.55, and 5.04 A. Compound 2 crystallizes in the monoclinic space group P2(1)/c (No. 14) with a = 13.6248(2) A, b = 11.6002(2) A, c = 25.9681(4) A, beta = 102.0072(9) degrees, and Z = 4 and contains a dinuclear Zn(II) complex formed by linking two units of [Zn(Me(3)tacn)(OH(2))(2)](2+) by a single phosphate ester. Compound 3 crystallizes in the monoclinic space group C2/c (No. 15) with a = 24.7105(5) A, b = 12.8627(3) A, c = 14.0079(3) A, beta = 106.600(1) degrees, and Z = 4 and consists of mononuclear [Cu(tacn)(2)](2+) cations whose charge is balanced by the BNPP(-) anions.