Mixed occupancy: the crystal structure of scheelite-type LiLu[MoO].

Coarse colorless single crystals of lithium lutetium bis-[orthomolybdate(VI)], LiLu[MoO], were obtained as a by-product from a reaction aimed at lithium derivatives of lutetium molybdate. The title compound crystallizes in the scheelite structure type (tetra-gonal, space group 4/) with two formula units per unit cell. The Wyckoff position 4 (site symmetry ) comprises a mixed occupancy of Li and Lu cations in a 1:1 ratio.

Crystal structure of defect scheelite-type Nd[WO].

Neodymium(III) -oxidotungstate(VI) was synthesized as a side-product in an unsuccessful synthesis attempt at fluoride derivatives of neodymium tungstate in fused silica ampoules, using neodymium(III) oxide, neodymium(III) fluoride and tungsten trioxide. Violet, platelet-shaped single crystals of the title compound emerged of the bulk, which crystallize in the defect scheelite type with a trigonal dodeca-hedral coordination of oxide anions around the Nd cations and the hexa-valent tungsten cations situated in the centers of oxide tetra-hedra.

Blue Excitement: The Lanthanide(III) Chloride Oxidomolybdates(VI) LnCl[MoO] (Ln = La, Pr, and Nd) and Their Spectroscopic Properties.

The lanthanide(III) chloride oxidomolybdates(VI) with the empirical formula LnCl[MoO] (Ln = La, Pr, and Nd) were synthesized by solid-state reactions utilizing the respective lanthanide trichloride, lanthanide sesquioxide (where available), and molybdenum trioxide together with lithium chloride as a fluxing agent. The title compounds crystallize in hexagonal space group P6/ m ( a = 942-926 pm, c = 542-533 pm, Z = 2). Besides tetracapped trigonal prismatically coordinated Ln cations, noncondensed trigonal prismatic [MoO] entities are found in the crystal structure.

Black Current: Structure, Characterization, and Optoelectronic Properties of Ce Cl [MoO ].

The admixture of CeO , Ce, CeCl , and MoO with an excess of LiCl as flux in evacuated silica ampules leads to large black single crystals as well as a black microcrystalline powder of Ce Cl [MoO ] after tempering at 850 °C for three days. The title compound crystallizes in the hexagonal space group P6 /m (a=934.93(4), c=538.

Synthesis, crystal structure and spectroscopic properties of a novel yttrium(III) fluoride dimolybdate(VI): YFMo2O7.

Thermal treatment of a mixture of Y2O3, YF3 and MoO3 in a 1 : 1 : 6 molar ratio at 850 °C in evacuated silica ampoules yielded colorless, platelet-shaped single crystals of YFMo2O7. SiO2 was dissolved from the ampoule wall in small amounts, but could be removed from the crude product by treatment with hydrofluoric acid (20%). The title compound crystallizes monoclinically in the space group P2/c with two formula units per unit cell with the dimensions a = 4.

Tetra-yttrium difluoride disilicate orthosilicate, Y4F2[Si2O7][SiO4].

In the crystal structure of Y4F2[Si2O7][SiO4], three fundamental building blocks are present, viz. anionic disilicate and orthosilicate units ([Si2O7](6-) and [SiO4](4-)) and cationic [F2Y4](10+) entities. The latter are built up by two [FY3](8+) triangles sharing a common edge.

The defect scheelite-type lanthanum(III) ortho-oxidomolybdate(VI) La(0.667)[MoO(4)].

In scheelite-type La(0.667)[MoO(4)], one crystallographically unique position with site symmetry -4..

Filling gaps in the series of noninnocent hetero-1,3-diene chelate ligands: ruthenium complexes of redox-active α-azocarbonyl and α-azothiocarbonyl ligands RNNC(R')E, E = O or S.

The series of 4-center unsaturated chelate ligands A═B-C═D with redox activity to yield (-)A-B═C-D(-) in two steps has been complemented by two new combinations RNNC(R')E, E = O or S, R = R' = Ph. The ligands N-benzoyl-N'-phenyldiazene = L(O), and N-thiobenzoyl-N'-phenyldiazene = L(S), (obtained in situ) form structurally characterized compounds [(acac)(2)Ru(L)], 1 with L = L(O), and 3 with L = L(S), and [(bpy)(2)Ru(L)](PF(6)), 2(PF(6)) with L = L(O), and 4(PF(6)) with L = L(S) (acac(-) = 2,4-pentanedionato; bpy = 2,2'-bipyridine). According to spectroscopy and the N-N distances around 1.

Scheelite-type sodium neodymium(III) ortho-oxidomolybdate(VI), NaNd[MoO(4)](2).

Scheelite-type NaNd[MoO(4)](2) contains one crystallographic position (site symmetry [Formula: see text]) for the large cations, which is mixed-occupied by Na(+) and Nd(3+) cations in a 1:1 molar ratio. Thus, both are surrounded by eight O atoms in the shape of a trigonal dodeca-hedron. Furthermore, the structure consists of crystallographically unique [MoO(4)](2-) units (site symmetry [Formula: see text]) surrounded by eight sodium and neodymium cations, which are all vertex-attached.

2,3-Bis(1-methylimidazol-2-yl)quinoxaline (bmiq), a new ligand with decoupled electron transfer and metal coordination sites: the very different redox behaviour of isoelectronic complexes with [PtCl2] and [AuCl2]+.

The new, potentially ambidentate heterocyclic ligand 2,3-bis(1-methylimidazol-2-yl)quinoxaline (bmiq) was obtained from 2,3-bis(1-methylimidazol-2-yl)glyoxal and 1,2-diaminobenzene. Its coordination to PtCl(2) and to the isoelectronic [AuCl(2)](+) in [AuCl(2)(bmiq)](AuCl(4)) occurs via the imine N donors of the imidazolyl groups, leading to the formation of seven-membered chelate rings with boat conformation. According to the spectroelectrochemistry (UV-vis-NIR, EPR), the reversible electron addition to the [PtCl(2)(bmiq)] and the free ligand takes place in the (non-coordinated) quinoxaline part of the molecule, similarly as for related complexes of dipyrido[3,2-a:2',3'-c]phenazines (dppz), 2,3-bis(2-pyridyl)quinoxalines (bpq) and 2,3-bis(dialkylphosphino)quinoxalines (QuinoxP).

Combining two non-innocent ligands in isomeric complexes [Pt(pap)(m)Q(n)](0) (pap = phenylazopyridine, Q = 3,5-di-tert-butyl-benzoquinone.

Isomeric complexes of platinum, which contain two non-innocent ligands are reported. The built-in coordination asymmetry in the ligands makes it possible to separate two different positional isomers. Results from X-ray crystallography is used to invoke the popular structure oxidation state correlation in these complexes.

A five-center redox system: molecular coupling of two noninnocent imino-o-benzoquinonato-ruthenium functions through a pi acceptor bridge.

Combining the concepts of noninnocent behavior of metal/ligand entities and the coupling of redox-active moieties via an electronically mediating bridge led to the synthesis and the structural, electrochemical, and spectroscopic characterization of [Cl(Q)Ru(mu-tppz)Ru(Q)Cl](n) where Q(o) is 4,6-di-tert-butyl-N-phenyl-o-iminobenzoquinone and tppz(o) is 2,3,5,6-tetrakis(2-pyridyl)pyrazine, the available oxidation states being Ru(II,III,IV), Q(o,*-,2-), and tppz(o,*-,2-). One-electron transfer steps between the n = (2-) and (4+) states were studied by cyclic voltammetry and by EPR, UV-vis-NIR spectroelectrochemistry for the structurally characterized anti isomer of [Cl(Q)Ru(mu-tppz)Ru(Q)Cl](PF(6))(2), 2(PF(6))(2), the only configuration obtained. The combined investigations reveal that 2(2+) is best described as [Cl(Q(*-))Ru(III)(mu-tppz(o))Ru(III)(Q(*-))Cl](2+) with antiferromagnetic coupling between the ruthenium(III) and the iminosemiquinone components at each end.

Benzo-1,3,2-diazaphospholide and benzo-1,3,2-diazaphospholium: an isoelectronic aromatic anion-cation pair.

Isoelectronic benzo-1,3,2-diazaphospholium cations and benzo-1,3,2-diazaphospholide anions were prepared from the same phosphazane precursor; both species display according to computational studies similar aromaticity as the neutral benzo-1,3,2-diazaphosphole but are chemically more stable due to their ionic nature.

Carboxyl-functionalized task-specific ionic liquids for solubilizing metal oxides.

Imidazolium, pyridinium, pyrrolidinium, piperidinium, morpholinium, and quaternary ammonium bis(trifluoromethylsulfonyl)imide salts were functionalized with a carboxyl group. These ionic liquids are useful for the selective dissolution of metal oxides and hydroxides. Although these hydrophobic ionic liquids are immiscible with water at room temperature, several of them form a single phase with water at elevated temperatures.

YF[MoO4] and YCl[MoO4]: two halide derivatives of yttrium ortho-oxomolybdate: syntheses, structures, and luminescence properties.

The halide derivatives of yttrium ortho-oxomolybdate YX[MoO 4] (X = F, Cl) both crystallize in the monoclinic system with four formula units per unit cell. YF[MoO 4] exhibits a primitive cell setting (space group P21/ c; a = 519.62(2) pm, b = 1225.

Metal-induced tautomerization of p- to o-quinone compounds: experimental evidence from CuI and ReI complexes of azophenine and DFT studies.

Azophenine (7,8-diphenyl-2,5-bis(phenylamino)-p-quinonediimine, L(p)) reacts with [Cu(PPh3)4](BF4) or [Re(CO)(5)Cl] to yield the (Ph3P)(2)Cu(+) or [(OC)(3)ClRe] complex of the tautomeric form 7,8-diphenyl-4,5-bis(phenylamino)-o-quinonediimine, L(o), as evident from structure determinations and from very intense metal-to-ligand charge transfer (MLCT) transitions in the visible region. Time-dependent DFT (TD-DFT) calculations on model complexes [(N intersection N)Re(CO)(3)Cl] confirm the spectroscopic results, showing considerably higher oscillator strengths of the MLCT transition for the o-quinonediimine complexes in comparison to compounds with N intersection N=1,4-dialkyl-1,4-diazabutadiene. The complexes are additionally stabilized through hydrogen bonding between two now ortho-positioned NHPh substituents and one fluoride of the BF(4) (-) anion (Cu complex) or the chloride ligand (Re complex).

A Fully Characterized Complex Ion with Unreduced TCNQ as Fourfold Bridging Ligand: [(μ -TCNQ){fac-Re(CO) (bpy)} ].

Innocent behavior of a typical non-innocent ligand has been observed for the first structurally characterized discrete metal complex with tetranucleating TCNQ. The coordination of four [Re(CO) (bpy)] units (see picture: C: black, N: green, O: blue, Re: red) facilitates the reduction of the already excellent π-acceptor molecule TCNQ by a further 0.74 V! TCNQ=7,7,8,8-tetracyano-p-quinodimethane, bpy=2,2'-bipyridine.