Strong influence of magnetic field and non-uniform stress on elastic modulus and transition temperatures of twinned Ni-Fe(Co)-Ga alloy.

The magnetization value and electric resistivity of the single-crystalline sample of Ni50Fe19Co4Ga27 shape memory alloy were measured. The elastic modulus was determined by the Dynamic Mechanical Analysis (DMA). The characteristic temperatures of martensitic transformation (MT) of the alloy were estimated from the temperature dependences of magnetization, electric resistivity and elastic modulus. A significant disparity between MT temperatures resulting from DMA and those estimated from magnetic and resistivity measurements was discovered. It was argued that the discrepancy is caused by the non-uniform mechanical stressing of twinned single crystal by the DMA analyzer. Moreover, the DMA measurements revealed a significant decrease of the elastic modulus of twinned martensite under the applied magnetic field of 1.5 kOe. To explain this effect, the temperature-dependent Young's modulus of twinned crystal lattice was computed. The computations showed that the experimentally observed field-induced change of the elastic modulus is caused by the stress-assisted detwinning of the crystal lattice by the applied magnetic field.

Low-temperature diffusion in thin-film Pt-(Au-)-Co heterostructures: a structural and magnetic characterization.

Formation of functional thin films for nanoelectronics and magnetic data storage via thermally induced diffusion-driven structural phase transformations in multilayer stacks is a promising technology-relevant approach. Ferromagnetic thin films based on Co Pt alloys are considered as a material science platform for the development of various applications such as spin valves, spin orbit torque devices, and high-density data storage media. Here, we study diffusion processes in Pt-Co-based stacks with the focus on the effect of layers inversion (Pt/Co/substrate versus Co/Pt/substrate) and insertion of an intermediate Au layer on the structural transitions and magnetic properties. We demonstrate that the layer stacking has a pronounced effect on the diffusion rate at temperatures, where the diffusion is dominated by grain boundaries. We quantify effective diffusion coefficients, which characterize the diffusion rate of Co and Pt through the interface and grain boundaries, providing the possibility to control the homogenization rate of the Pt-Co-based heterostructures. The obtained values are in the range of 10-16-10-13cm2s-1for temperatures of 150 °C-350 °C. Heat treatment of the thin-film samples results in the coercivity enhancement, which is attributed to short-range chemical ordering effects. We show that introducing an additional Au intermediate layer leads to an increase of the coercive field of the annealed samples due to a modification of exchange coupling between the magnetic grains at the grain boundaries.

The metamorphosis of heterometallic trinuclear antiferromagnetic complexes into nano-sized superparamagnetic spinels.

Thermal decomposition of the trinuclear heterometallic oxoacetates [Fe(2)M(µ(3)-O)(CH(3)COO)(6)(H(2)O)(3)] has been used as a single-precursor method for synthesis of the spinel-structured ternary oxides MFe(2)O(4) (M = Mn(II), Co(II), and Ni(II)). This facile process occurring at 320 °C results in the formation of nanocrystalline, (7-20 nm) highly pure stoichiometric ferrites in quantitative yield. The magnetic properties of these nanoparticulate ferrites were studied in the 10-300 K temperature range, revealing superparamagnetic behaviour for the Ni and Mn particles and ferromagnetic behavior for the Co ones at room temperature. Their blocking temperatures follow the order: CoFe(2)O(4) > MnFe(2)O(4) > NiFe(2)O(4).

Synthesis, structure and magnetic properties of oligometallic systems derived from di- and trinuclear copper(II) amido-oximate complexes.

Three heterometallic complexes [M(H(2)O)(n)][Cu(3)L(2)(H(2)O)] (M = Mn(2+), Co(2+) or Ba(2+)) and one dinuclear compound (CuDien)(CuL{H(2)O}) were prepared by interaction of anionic compounds Cu(3)L(2)(2-) or CuL(2-) with the corresponding cations (H(4)L = 1,9-dicyano-1,9-bis(hydroximino)-3,7-diazanonane-2,8-dione; Dien = 1,5-diamino-3-azapentane). The complexes [M(H(2)O)(n)][Cu(3)L(2)(H(2)O)] have a polymeric structure, formed via oligomerization of Cu(3)L(2)(2-) units and additionally, in the case of the Ba-salt, by binding of Cu(3)L(2)(2-) units through Ba(2+). Antiferromagnetic interactions occur in all the complexes, while for [Co(H(2)O)(6)][Cu(3)L(2)(H(2)O)] there is evidence of some ferromagnetic ordering at low temperatures. The values of J are lower in magnitude than for similar, previously reported systems, which is attributed to the electron-withdrawing effect of the ligand cyano groups.

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.

Magnetic switch of permeability for polyelectrolyte microcapsules embedded with Co@Au nanoparticles.

We explored using a magnetic field to modulate the permeability of polyelectrolyte microcapsules prepared by layer-by-layer self-assembly. Ferromagnetic gold-coated cobalt (Co@Au) nanoparticles (3 nm diameter) were embedded inside the capsule walls. The final 5 mum diameter microcapsules had wall structures consisting of 4 bilayers of poly(sodium styrene sulfonate)/poly(allylamine hydrochloride) (PSS/PAH), 1 layer of Co@Au, and 5 bilayers of PSS/PAH. External alternating magnetic fields of 100-300 Hz and 1200 Oe were applied to rotate the embedded Co@Au nanoparticles, which subsequently disturbed and distorted the capsule wall and drastically increased its permeability to macromolecules like FITC-labeled dextran. The capsule permeability change was estimated by taking the capsule interior and exterior fluorescent intensity ratio using confocal laser scanning microscopy. Capsules with 1 layer of Co@Au nanoparticles and 10 polyelectrolyte bilayers are optimal for magnetically controlling permeability. A theoretical explanation was proposed for the permeability control mechanisms. "Switching on" of these microcapsules using a magnetic field makes this method a good candidate for controlled drug delivery in biomedical applications.

Solid state coordination chemistry of metal oxides: structural consequences of fluoride incorporation into the oxovanadium-copper-bisterpy-{O3P(CH2)nPO3}4- system, n= 1-5 (bisterpy = 2,2':4',4":2",2"'-quaterpyridyl-6', 6"-di-2-pyridine).

Hydrothermal reactions of a vanadate source, an appropriate Cu(II) source, bisterpy and an organodiphosphonate, H2O3P(CH2)nPO3H2(n= 1-5), in the presence of HF, yielded a family of materials of the type oxyfluorovanadium/copper-bisterpy/organodiphosphonate. Under similar reaction conditions, variations in diphosphonate tether length n provided the one-dimensional [{Cu2(bisterpy)}V2F2O2{HO3PCH2PO3}{O3PCH2PO3}](1) and [{Cu2(bisterpy)}V2F4O4{HO3P(CH2)2PO3H}](3), the two-dimensional [{Cu2(bisterpy)}V2F2O2(H2O)2{HO3P(CH2)2PO3}2] x 2H2O (2 x 2H2O), [{Cu2(bisterpy)(H2O2}V2F2O2{O3P(CH2)3PO3}{HO3P(CH2)3PO3H}(4) and [{Cu2(bisterpy)}V4F4O4(OH)(H2O){HO3P(CH2)5PO3}{O3P(CH2)5PO3}] x H2O (9 x H2O) and the three-dimensional [{Cu2(bisterpy)}3V8F6O17{HO3P(CH2)3PO3}4]0.8H2O (5 x 0.8H2O), [{Cu2(bisterpy)}V4F2O6{O3P(CH2)4PO3}2](8) and [{Cu2(bisterpy)(H2O)}2V8F4O8(OH)4{HO3P(CH2)5PO3H}2{O3P(CH2)5PO)}3] x 4.8H2O (10 x 4.8H2O). In addition, two members of the oxovanadium/Cu2(bisterpy)/organodiphosphonate family [{Cu2(bisterpy)}V2O4{HO3P(CH2)3PO3}2](6) and [{Cu2(bisterpy)}3V4O8(OH)2{O3P(CH2)3PO3}2{HO3P(CH2)3PO3}2] x 5H2O (7 x 5H2O) cocrystallized from the reaction mixture which provided 5. The overall architectures reveal embedded substructures based on V/P/O(F) clusters, chains, networks, and frameworks. In contrast to the oxovanadium/Cu2(bisterpy)/ organodiphosphonate family, several of the materials of this study also exhibit the direct condensation of vanadium polyhedra to produce binuclear and/or tetranuclear building units.

Solid-state coordination chemistry of the oxomolybdate-organodiphosphonate/nickel-organoimine system: structural influences of the secondary metal coordination cation and diphosphonate tether lengths.

The hydrothermal reactions of a molybdate source, a nickel(II) salt, tetra-2-pyridylpyrazine (tpyprz), and organodiphosphonic acids H(2)O(3)P(CH(2))(n)()PO(3)H(2) (n = 1-5) of varying tether lengths yielded a series of organic-inorganic hybrid materials of the nickel-molybdophosphonate family. A persistent characteristic of the structural chemistry is the presence of the [Mo(5)O(15)(O(3)PR)(2)](4)(-) cluster as a molecular building block, as noted for the one-dimensional materials [[Ni(2)(tpyprz)(2)]Mo(5)O(15)[O(3)P(CH(2))(4)PO(3)]]x6.65H(2)O (6x6.65H(2)O) and [[Ni(2)(tpyprz)(2)]Mo(5)O(15)[O(3)P(CH(2))(5)PO(3)]]x3.75H(2)O (8x3.75H(2)O), the two-dimensional phases [[Ni(4)(tpyprz)(3)][Mo(5)O(15)(O(3)PCH(2)CH(2)PO(3))](2)]x23H(2)O (3x23H(2)O) and [[Ni(3)(tpyprz)(2)(H(2)O)(2)](Mo(5)O(15))(Mo(2)O(4)F(2))[O(3)P(CH(2))(3)PO(3)](2)]x8H(2)O (5x8H(2)O), and the three-dimensional structures [[Ni(2)(tpyprz)(H(2)O)(3)]Mo(5)O(15)[O(3)P(CH(2))(3)PO(3))]]xH(2)O (4xH(2)O) and [[Ni(2)(tpyprz)(H(2)O)(2)]Mo(5)O(15) [O(3)P(CH(2))(4)PO(3)]]x2.25H(2)O (7x2.25H(2)O). In the case of methylenediphosphonic acid, the inability of this ligand to tether adjacent pentanuclear clusters precludes the formation of the common molybdophosphonate building block, manifesting in contrast a second structural motif, the trinuclear [(Mo(3)O(8))(x)(O(3)PCH(2)PO(3))(y)] subunit of [[Ni(tpyprz)(H(2)O)(2)](Mo(3)O(8))(2) (O(3)PCH(2)PO(3))(2)] (1) which had been previously observed in the corresponding methylenediphosphonate phases of the copper-molybdophosphonate family. Methylenediphosphonic acid also provides a second phase, [Ni(2)(tpyprz)(2)][Mo(7)O(21)(O(3)PCH(2)PO(3))]x3.5H(2)O (9x5H(2)O), which contains a new heptamolybdate cluster [Mo(7)O(21)(O(3)PCH(2)PO(3))](4)(-) and a cationic linear chain [Ni(tpyprz)](n)(4n+) substructure. The structural chemistry of the nickel-molybdophosphonate series contrasts with that of the corresponding copper-molybdophosphonate materials, reflecting in general the different coordination preferences of Ni(II) and Cu(II). Consequently, while the Cu(II)-organic complex building block of the copper family is invariably the binuclear [Cu(2)(tpyprz)](4+) subunit, the Ni(II) chemistry with tpyprz exhibits a distinct tendency toward catenation to provide [Ni(3)(tpyprz)(2)](6+), [Ni(4)(tpyprz)(3)](8+), and [Ni(tpyprz)](n)(4n+) building blocks as well as the common [Ni(2)(tpyprz)](4+) moiety. This results in a distinct structural chemistry for the nickel(II)-molybdophosphonate series with the exception of the methylenediphosphonate derivative 1 which is isostructural with the corresponding copper compound [[Cu(2)(tpyprz)(H(2)O)(2)](Mo(3)O(8))(2)(O(3)PCH(2)PO(3))] (2). The structural chemistry of the nickel(II) series also reflects variability in the number of attachment sites at the molybdophosphonate clusters, in the extent of aqua ligation to the Ni(II) tpyprz subunit, and in the participation of phosphate oxygen atoms as well as molybdate oxo groups in linking to the nickel sites.

Functionalized metal oxide clusters: synthesis, characterization, crystal structures, and magnetic properties of a novel series of fully reduced heteropolyoxovanadium cationic clusters decorated with organic ligands--[MVIV6O6[(OCH2CH2)2N(CH2CH2OH)]6]X (M = Li, X = Cl x LiCl; M = Na, X = Cl x H2O; M = Mg, X = 2Br x H2O; M = Mn, Fe, X = 2Cl; M = Co, Ni, X = 2Cl x H2O).

A novel series of fully reduced heteropolyoxovanadium(IV) compounds, [MVIV6O6[(OCH2CH2)2N(CH2CH2OH)]6]X (1, M = Li, X = Cl x LiCl; 2, M = Na, X = Cl x H2O; 3, M = Mg, X = 2Br x H2O; 4, M = Mn, X = 2Cl; 5, M = Fe, X = 2Cl; 6, M = Co, X = 2Cl x H2O; 7, M = Ni, X = 2Cl x H2O), have been synthesized and characterized by FT-IR and UV-vis spectroscopies, thermogravimetric analysis, elemental analysis, manganometric titration, temperature-dependent magnetic susceptibility measurements, bond valence sum calculations, X-ray powder diffraction, and single-crystal X-ray diffraction analyses. The structures of the crystals are comprised of discrete units of fully reduced cluster cations, [MVIV6O6[(OCH2CH2)2N(CH2CH2OH)]6]n+, counterions (chloride or bromide), and water of crystallization (in the case of 2, 3, 6, 7). In each case the cluster ion is composed of a fully reduced cyclic [MV6N6O18] (M = Li, Na, Mg, Mn, Fe, Co, Ni) framework decorated with six triethanolamine ligands. Two arms of each triethanolamine ligand are coordinated to the metallacycle, and the third arm projects outward from the hexagonal ring. The [MV6N6O18] core adopts the Anderson-type structure. The cyclic core is comprised of a ring of six edge-sharing [VO5N] octahedra linked to a central [MO6] unit. The hexametalate ring contains six d1 ions [VIV] and shows remarkable flexibility to encapsulate a variety of metal centers Mn+ (Mn+ = Li+, Na+, Mg2+, Mn2+, Fe2+, Co2+, Ni2+) with different (dn) spins. The compounds show good thermal stability and exhibit interesting magnetic properties that make these magnetic clusters promising building blocks for constructing supramolecular structures and extended structure magnetic solids. Crystal data for 1; C36H78Cl2N6Li2O24V6, trigonal space group R, a = 13.7185(3) angstroms, c = 24.8899(8) angstroms, Z = 3. Crystal data for 2: C36H80ClN6NaO25V6, triclinic space group P, a = 11.1817(5) angstroms, b = 12.1612(5) angstroms, c = 21.5979(10) angstroms, alpha = 75.8210(10), beta = 78.8270(10), gamma = 71.1400(10), Z = 2. Crystal data for 4: C36H78Cl2N6MnO24V6, monoclinic, space group P2(1), a =11.2208(5) angstroms, b = 21.5041(9) angstroms, c = 11.8126(5), beta = 111.2680, Z= 2. Crystal data for 5: C36H78Cl2N6FeO24V6, monoclinic, space group P2(1), a = 11.3057(7) angstroms, b = 21.4372(13) angstroms, c = 11.8167(7) angstroms, beta = 111.4170, Z = 2.

Solid state coordination chemistry: structural consequences of variations in tether length in the oxovanadium-copper-bisterpy-[O3P(CH2)nPO3]4- system, n= 1-6 (bisterpy = 2,2':4',4'':2'',2'''-quarterpyridyl-6',6''-di-2-pyridine).

Hydrothermal reactions of Na3VO4, an appropriate Cu(II) source, bisterpy and an organodiphosphonate, H2O3P(CH2)nPO3H2 (n = 1-6) yielded a family of materials of the type [Cu2(bisterpy)]4+/VxOy(n-)/[O3P(CH2)nPO3]4-. This family of bimetallic oxides is characterized by an unusual structural diversity. The oxides [[Cu2(bisterpy)]V2O4[O3PCH2PO3H]2] (1), [[Cu2(bisterpy)(H2O)]VO2[O3P(CH2)3PO3][HO3P(CH2)3PO3H2]] (4) and [[Cu2(bisterpy)]V2O4[O3P(CH2)6PO3H]2].2H2O (7.2H2O) are one-dimensional, while [[Cu2(bisterpy)(H2O)2]V2O4[O3P(CH2)2PO3][HO3P(CH2)2PO3H]2] (2), [[Cu2(bisterpy)]V4O8[O3P(CH23PO3]2].4H2O (3.4H2O) and [[Cu2(bisterpy)]V2O4(OH)2[O3P(CH2)4PO3]].4H2O (5.4H2O) are two-dimensional. The V(IV) oxide [[Cu2(bisterpy)]V4O4[O3P(CH2)5PO3H]4].7.3H2O (6.7.3H2O) provides a relatively unusual example of a three-dimensional bimetallic oxide phosphonate. The structures reveal a variety of V/P/O substructures as building blocks.

Solid state coordination chemistry of oxomolybdenum organoarsonate materials.

The oxomolybdenum-arsonate system was investigated under hydrothermal conditions in the presence of charge-compensating copper(II)-organonitrogen complex cations as secondary building blocks. A series of materials of the Mo/O/As/Cu/ligand family has been prepared and structurally characterized. The architectures of the products reflect the identity of the arsonate component and the organonitrogen ligand, as well as the reaction conditions. The structural versatility of this emerging class of compounds is manifested by the one-dimensional structures of [[Cu(o-phen)(H(2)O)(2)](2)Mo(6)O(18)(O(3)AsOH)(2)] (1), [[Cu(terpy)](2)Mo(4)O(13)H(AsO(4))(2)].2H(2)O (2.2H(2)O), [[Cu(2,2'-bpy)(H(2)O)](2)Mo(6)O(18)(O(3)AsC(6)H(5))(2)].2H(2)O (4.2H(2)O), and [[Cu(o-phen)(H(2)O)](2)[Mo(6)O(18)(O(3)AsC(6)H(5))(2)]].4H(2)O (5.4H(2)O), by the two-dimensional materials [[Cu(2)(tpyprz)(H(2)O)(2)]Mo(6)O(18)(O(3)AsOH)(2)].2H(2)O (3.2H(2)O), [[Cu(terpy)](2)Mo(6)O(18)(O(3)AsC(6)H(5))(2)].H(2)O (6.H(2)O), and [[Cu(2)(tpyprz)]Mo(6)O(18)(O(3)AsC(6)H(5))(2)].2H(2)O (7.2H(2)O), and the molecular clusters [[Cu(2,2'-bpy)(2)](2)Mo(12)O(34)(O(3)AsC(6)H(5))(4)].2.35H(2)O (8.2.35H(2)O) and [Cu(o-phen)(H(2)O)(3)][Cu(o-phen)(2)Mo(12)O(34) (O(3)AsC(6)H(5))(4)].3H(2)O (9.3H(2)O).

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.

A building block approach to the synthesis of organic-inorganic oxide materials: the hydrothermal synthesis and network structure of [[Ni4(tpypyz)3][Mo5O15(O3PCH2CH2PO3)]2] x 23H2O (tpypyz = tetra-2-pyridylpyrazine).

The hydrothermal reaction of MoO3, [Ni(CH3CO2)2] x 4H2O, tpypyz, ethylenediphosphonic acid and water yields the 2D material [[Ni4(tpypyz)3][Mo5O15(O3PCH2CH2PO3)]2] x 23H2O (1 x 23H2O), constructed from [Mo5O15(O3PCH2CH2PO3)]4- clusters linked in one-dimension through the ethylene tethers of the diphosphonate component; these molybdodiphosphonate chains are in turn linked into a 2D network through the tetranuclear secondary metal-ligand subunit [Ni4(tpypyz)3]8+.

[Re(III)Cl(3)] core complexes with bifunctional single amino acid chelates.

The reactions of the Re(V) starting material [ReO(PPh(3))(2)Cl(3)] with ligands of the type XN(Y)Z [X = Y = 2-pyridylmethyl, Z = -CH(2)CO(2)Et (L(1)Et), -CH(2)CH(2)CO(2)Et (L(2)Et), -CH(2)CH(2)CH(2)CH(2)CH(NHCO(2)Bu(t))CO(2)H (L(3)H); X = 2-pyridylmethyl, Y = 2-(1-methylimidazolyl)methyl, Z = -CH(2)CO(2)Et (L(4)Et)] yielded the Re(III) trichloride complexes of the type [ReCl(3)(L(n)R)]. The complexes are mononuclear, paramagnetic species with a facial geometry of the chloride ligands. The nitrogen donors of the tridentate L(n)()R ligands complete the distorted octahedral coordination spheres of the complexes. Crystal data: [ReCl(3)(L(1)Et)] (1), monoclinic, C2/m, a = 16.088(3) A, b = 9.980(2) A, c = 12.829(2) A, beta = 91.384(3) degrees, Z = 4, D(calc) = 1.967 g/cm(-)(3); [ReCl(3)(L(4)Et)] (4), monoclinic, C2/c, a = 22.880(1) A, b = 7.4926(4) A, c = 22.560(1) A, beta = 94.186(1) degrees, Z = 8, D(calc) = 2.001 g/cm(-3).