The hydrothermal synthesis of transition metal complex templated octamolybdates (original) (raw)
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[Cu( mim) 4] 2[α-Mo 8O 26] – A layer-type octamolybdate framework
Solid State Sciences, 2010
By reaction of (NH4)6Mo7O24·4H2O, Cu(NO3)2·2.5H2O and 1-methylimidazole (mim) under hydrothermal conditions the novel copper molybdate [Cu(mim)4]2[α-Mo8O26] is obtained in the form of blue, rectangular-shaped crystals. The title compound crystallizes with monoclinic lattice symmetry in the space group P21/n. The predominant structural feature of the title compound is a two-dimensional framework that is constituted by [α-Mo8O26]4−octamolybdate units as framework nods and
Crystals
A new organic-inorganic compound based on octamolybdate building blocks and copper(II) complexes of tetradentate N-donor ligands has been hydrothermally synthesized, namely [Cu(cyclam)] 2 [Mo 8 O 26 ]•1.5H 2 O (1), (cyclam: 1,4,8,11-tetraazacyclotetradecane). Compound 1 has been chemically (elemental and thermal analyses), spectroscopically (infrared spectroscopy), and structurally (single crystal and powder X-ray diffraction) characterized. The crystal packing of 1 shows a covalent framework structure formed by [Mo 8 O 26 ] n 4n− chains running along the 100 direction which are linked to each other through the coordination spheres of {Cu(cyclam)} 2+ complexes leading to a three-dimensional open network. This structural assembly generates voids that can be described as a succession of cavities communicated through narrow bottlenecks with approximate cross section of 4 × 7 Å 2 where the hydration water molecules are hosted. The robust open structure of 1 remains virtually unaltered upon thermal evacuation of guest solvent molecules at 130 • C, resulting in the anhydrous phase [Cu(cyclam)] 2 [Mo 8 O 26 ] (1a) with potentially accessible micropores as demonstrated by single-crystal X-ray diffraction measurements. Electron paramagnetic resonance spectroscopy analysis of 1 has also been assessed.
Inorganica Chimica Acta, 2000
The influences of ligand coordination modes on the oxide microstructures in the copper molybdate system were investigated. Rigid bridging ligands such as 4,4%-bypyridine (4,4%-bpy) and 2,4,6-tripyridyltriazine (tptz) afford polymeric cationic substructures with Cu(I) which provide scaffoldings for the entrainment and modification of the molybdenum oxide microstructure. These structural influences are manifested in [{Cu(4,4%-bpy)} 2 Mo 2 O 7 ] (MOXI-45) and [{Cu(tptz)} 2 Mo 6 O 19 ] (MOXI-46). In contrast, ligands such as pyridine (py) which do not effect the construction of polymeric substructures provide molecular building blocks which combine with the molybdenum oxide motifs in a less predictable fashion. Thus, [{Cu(py)} 4 Mo 8 O 26 ] (MOXI-47) is constructed from octamolybdate clusters linked by {Cu(py)} + 1 fragments into a virtual two-dimensional network. The interplay of ligand geometry and bonding mode and of metal coordination preferences plays an important role in the structure of [{Cu 2 (tpypz)(H 2 O) 2 }Mo 8 O 26 ] (MOXI-44), the unique example of a Cu(II)-containing material, with the binucleating tetrapyridylpyrazine ligand (tpypz) providing the organic building unit. The overall structure reflects the binucleating role of the ligand and the distorted octahedral geometry of the Cu(II) centers. The importance of hydrothermal techniques in effecting the syntheses of such composite materials is also discussed.
International Journal of Physical Sciences, 2015
A new one-dimensional coordination polymer formulated as [C2H10N2] [Mo3O10], 1, has been synthesized under hydrothermal conditions in the presence of ethylenediamine. The surface morphology of the assynthesized product reveals colorless rod-like single crystals of 1. The compound crystallizes in monoclinic space group P21/n with a = 8.08 Å, b =14.39 Å, c = 8.89 Å; β = 97.76°, V = 1033.65(12) Å3, Z = 4. The structure is a one-dimensional chain consisting of [Mo3O10] 2clusters of Mo (VI) octahedral interspersed by the amine molecules. In the infrared spectrum of the compound, the symmetric stretching vibrational mode of the -NH2 group is observed at 3278 cm -1 , while the band at 1604 cm -1 is assigned to scissoring mode of the –NH2 group. The peaks in the spectral range 1913 -2492 and 2962 cm -1 are attributed to -CH2 symmetric and asymmetric stretching vibrations respectively. The absorption bands at 1404 cm -1 is due to scissoring, while the one at 1149 cm -1 is attributable to twi...
Journal of Materials Science, 2007
The hydrothermal syntheses, single-crystal X-ray structures and magnetic properties of [Co(C 4 O 4)(H 2 O) 2 ] (1), [Co 3 (OH) 2 (C 4 O 4) 2 ] Á 3H 2 O (2) and [Fe(OH) 2 (C 4 O 4)] (3) are described. Pale yellow cubes of 1 and brown red crystals of 2 were obtained from the reaction of Co(OH) 2 and squaric acid at 200°C. Brown needle of 3 were obtained similarly from Fe(SO 4) Á 7H 2 O, squaric acid and NaOH. 1 consists of a cubic sodalite arrangement with empty cavities where the Co atoms are connected by l 4-squarate and two trans-water molecules each, while 2 and 3 contain metal-hydroxide double-chains of edge-sharing octahedral, brucite-type for 2 and goethite for 3, connected by l 6-squarate. 2 contains water molecules in the channels which can be removed and re-inserted repeatedly without loss of crystallinity. All three compounds possess 3D frameworks made up of coordination and hydrogen bonds. 1 behaves as a paramagnet while 2 and 3 are antiferromagnets and 2 transforms to a ferromagnet reversibly upon dehydration and rehydration. The structures of two one-dimensional polymers employing 2,5-pyridinedicarboxylate, [Co 2 (H 2 O) 6 (2,5-pydc) 2 ] Á 2H 2 O (4) and Cu (2,5-pydc) 2 (5), are also reported.
The first examples of benzidinium cations templated low-dimensional molybdates
Inorganica Chimica Acta, 2005
For the first time, use of benzidine as a structure-directing agent has resulted in the crystallization of two novel organic/inorganic hybrid molybdates under hydrothermal condition (180°C and autogenous pressure). The presence of monoprotonated benzidinium ions in aqueous molybdate solution appears to engineer two new hybrid solids: one-dimensional chains in [H 2 NC 12 H 8 NH 3 ] 2 Mo 2 O 7 , 1 (a = 5.9686, b = 7.0761 and c = 14.3293 Å , a = 77.17°, b = 85.25°and c = 88.56°; P 1 and Z = 2) and two-dimensional step-wise layered molybdate [H 2 NC 12 H 8 NH 3 ] 2 Mo 5 O 16 , 2 (a = 5.6843, b = 14.3024 and c = 19.4787Å , a = 108.1°, b = 98.4°and c = 90.0°; P 1, Z = 2). 1 is an unusual solid wherein the anionic chains are charge compensated by counter cations which also act as ligands to the metal and 2 is a new layered molybdate built of MoO 5 square pyramids and MoO 6 octahedra.
Synthesis, solid state characterization and thermal behaviour of some t-butylammonium polymolybdates
Thermochimica Acta, 1992
A series of coordination polymers of Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) have been synthesized from sebacoyl bis(isonicotinoylhydrazone) (SEBI) ligand and metal salts. The coordination polymers have been characterized using elemental analyses, magnetic susceptibility measurements, spectral (electronic and infrared) studies, powder XRD and thermal analyses. The IR spectral data suggest that sebacoyl bis(isonicotinoylhydrazone) behaves as an octadentate chelating ligand. On the basis of electronic spectral studies and magnetic moment values, an octahedral geometry has been assigned to Mn(II), Co(II), Ni(II) and Cu(II) coordination polymers while tetrahedral geometry to Zn(II) coordination polymer. The thermogravimetric analyses of parent ligand and its metal chelates have shown remarkable differences in mode of thermal decomposition and their thermal stabilities.
Transition Metal Chemistry, 1999
The hydrothermal reaction of MoO3, V, Na2WO4· 2H2O, [N(CH2CH2)3N](1,4-diazabicyclo[2.2.2] octane), and H2O at 160°C for 90h gave dark-brown crystals of [HN(CH2CH2)3N]2[HMoVMoVI5O19]·[N(CH2CH2)3N], (1), in 40% yield. Complex (1) is the first one-electron reduced mixed-valence hexamolybdate to be crystallized and structurally characterized. The crystal structure of (1) consists of discrete [HMoVMoVI5O19]2− anions, [HN-(CH2CH2)3N]+ cations, and neutral [N(CH2CH2)3N] molecules of crystallization.