The first examples of benzidinium cations templated low-dimensional molybdates (original) (raw)
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Annales de chimie Science des Matériaux, 2007
NH 4)(Mo 5. .5)(O 17 , H 2 O) is prepared at 200°C from MoO 3 and a mixture of ammonium carbamate and ammonium bicarbonate in water. (NH 4)(Mo 5. .5)(O 17 , H 2 O), isostructural with K 0.13 V 0.13 Mo 0.87 O 3 , is hexagonal, P6 3 /m, a = 10.549(5) Å, c = 3.729(2) Å. The structure determination, TGA experiments, chemical analyses and density measurements (d meas. = 3.83, d calc. = 3.86) are consistent with the existence of one vacancy for 12 molybdenum sites. Charge compensation is ensured by the substitution of oxygen atoms by water molecules. The localisation of the water molecules is proposed from Fourier map syntheses. Résumé-Synthèse et étude structurale du molybdate hexagonal lacunaire (NH 4)(Mo 5. .5)(O 17 ,H 2 O) ; (NH 4)(Mo 5. .5)(O 17 ,H 2 O), préparé à 200°C à partir de MoO 3 dans une solution aqueuse de carbamate et bicarbonate d'ammonium, présente une structure Reprints-R. BENCHRIFA; CNRST,
Formation of molybdate organic-hybrids and exfoliated molybdate nanosheets
FlatChem, 2017
Novel synthetic approaches for the effective construction of MoO x-organic hybrid structures and MoO x nanosheets (NSs) have been developed. A solvothermal (ST) treatment of molybdenum trioxide utilizing dodecylamine (DDA) as an intercalating agent leads to the formation of MoO x-DDA hybrid structures. Layer spacing as a function of organic molecule lengths can be controlled by changing the surfactants located between the nanosheets. Maintaining the integrity of the parent crystal, hexagonal-shaped molybdenum oxide NSs up to four micrometers in lateral size separate following sonication of the hybrid structures. Formation of MoO xoleylamine (OAm) highly oriented nanosheets with plasmonic behavior were also achieved using a rapid ST treatment of molybdenum trioxide in the presence of OAm surfactant. The effects of time and temperature on the formation, morphology, and crystal structure of well-ordered nanosheets were explored. These synthesized hybrid nanostructures and NSs are expected to show great potential for a variety of applications including rechargeable batteries, catalysis, and nanodevices.
The hydrothermal synthesis of transition metal complex templated octamolybdates
European journal of …, 2007
The hydrothermal reaction of an aqueous ammonium heptamolybdate solution with cobalt or copper metal salts in the presence of imidazole (imi) or pyrazole (pz) in the temperature range 120-180°C and at autogenous pressure yields four fully oxidized metal-complex-templated octamolybdates, namely [{Cu I (imi) 2 } 4 (imi) 2 Mo 8 O 26 ]•4H 2 O (1), (Himi) 2-[{Cu II (imi) 2 } 2 Mo 8 O 27 ] (2), [{Co II (pz) 4 } 2 (pz) 2 Mo 8 O 26 ] (3), and [{Cu II (pz) 4 } 2 Mo 8 O 26 ]•2H 2 O (4). The single-phase nature of the solids was established by single-crystal and powder Xray diffraction, thermal analysis, and spectroscopic techniques. Compounds 1, 3, and 4 are neutral composite solids-1 is a discrete molecular unit while 3 and 4 are 2D sheets. Compound 2 consists of anionic chains with imidazolium
Inorganica Chimica Acta, 1984
13.858(4), b = 11.018(3), c = 14.005(8) A, 0 = 91.35(5/O, V = 2138(l) A3, D,, = 2.46, D, =2.47Mg m-', ~(MoKcY) = 23.07 cm-l, R = 0.064 and WR = 0.068 for 5090 observed reflexions.
Synthesis and structure determination of three new heterometallic molybdenum complexes are presented -one with cobalt and two with nickel, thereof two with β-diketonate ligands and one with aminoalcohol ligands. Cobalt acetylacetonate in reaction with MoO(OMe) 4 provided Co 2 Mo 2 O 2 (acac) 2 (OMe) (1) and MoO(acac)(OMe) 3 (4). Nickel acetylacetonate in reaction with MoO(OMe) 4 provided access to Ni 2 Mo 2 O 2 (acac) 2 (OMe) and 4. Ni(OR N ) 2 (R N = CHMeCH 2 NMe 2 ) in reaction with MoO(OMe) 4 yielded Ni 2 Mo 2 O 2 (OR N ) 2 (OMe) 10 (3). The two new oxo-molybdenum complexes undergo ether elimination upon storage and the corresponding dioxocomplexes, [MoO 2 (acac)(OMe)] 2 (5) and [MoO 2 (OR N )(OMe)] 2 (6), were also isolated. Compounds 3 and 4 could also be obtained by interaction between stoichiometric amounts of Hacac with MoO(OMe) 4 and MoO 2 (OMe) 2 respectively. The local structure around the nickel atom in compound 2, in solution, and compound 3, in solid state and toluene/hexane solution, has been determined by means of EXAFS. The complexes are intended as single-source precursors;
Reactions of mono(dinitrogen) complexes of molybdenum. Isolation and characterization of hydrazido(2-) and mono- and dihydride complexes. Crystal structure of MoBrPhP(CH2CH2PPh2)2.cntdot.1/2C5H12
Inorganic Chemistry, 1990
The reactions of a series of mono(dinitr0gen) complexes of molybdenum Mo(N2)(dpepp)(L2) [where dpepp = PhP(CH2CH2PPh2)2 and L2 = 2 PMe2Ph (l), Me2PCH2PMe2 (dmpm) (2), l,2-(Me2As)2C6H4 (diars) (3), Ph2PCH2PPh2 (dppm) (4), Ph2PCH2CH2PPh2 (dppe) (5)] with acids are reported. Reactions of 1 with excess HX (X = Br, CI) in the solid state or HX (2 mol) in toluene led to the isolation of the hydrazido(2-) complexes [MoX(NNH2)(q2-dpepp)(PMe2Ph)JX [6 (X = CI) and 7 (X = Br)] in which dpepp is bidentate. Similar results were obtained with CF,SO,H. Heating a toluene solution of 7 led to the loss of one PMe2Ph and reincorporation of the pendant phosphine to form mer-[MoBr(NNHz)(dpepp)(PMe2Ph)]Br. Complexes 6 and 7 yielded ammonia and hydrazine when treated with HCI and HBr. The pendant phosphine can be protonated (HBr) and alkylated. Complex 1 reacted with HBr (1 mol) to initially (0.25 h) produce an equimolar mixture of 1 and 7. These two complexes reacted (15 h) to give an almost quantitative yield of Mo(H)Br(dpepp)(PMe2Ph) (10). With HBr (1 mol), 10 produced Mo(H),Br,(dpepp)(PMe,Ph). Solid 2 reacted with excess HX (X = Br, CI, SOJF,) to produce the unstable hydrazido(2-) dication [M~(NNH~)(dpepp)(dmpm)]~+ without loss of a ligand. In solution the stability of the dication increased with decreasing basicity of the anion: CI < Br < S03CF3. [Mo(NNH2)(dpepp)(dmpm)] [SO3CF3I2 was isolated. Decomposition of the dication in solution led to loss of N2 and formation of a pair of isomeric eight-coordinate dihydrides, [M~(H)~Cl(dpepp)(dmpm)] [HCI,] (16). Reaction of 2 with HBr (1 mol) in benzene led to the isolation of [M~(H)~Br(dpepp)(dmpm)]Br (13, single isomer), MoBr(dpepp)(dmpm) (14), and Mo(H)Br(dpepp)(dmpm) (15, single isomer). A similar reaction with HCI produced Mo(H)-Cl(dpepp)(dmpm) (17) as a pair of isomers. Complex 14 crystallizes with 0.5 mol of pentane in the monoclinic space group P2,/c with a = 12.452 (2) A, b = 15.738 (2) A, c = 21.677 (3) A, 0 = 98.94 (I)O, and Z = 4. Complexes 3-5 gave evidence of hydrazido(2-) formation upon treatment with acid, but in solution N2 was rapidly evolved and hydrides were formed. Structural assignments of new complexes are based upon 3'P and 'H NMR spectral data. Dpepp is shown to adopt both fac and mer configurations. The protonation of metal-N, complexes is discussed.
[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