Samarium complexes supported by the diamine bis(phenol) proligand H2(tBu2O2NN′)=Me2N(CH2)2N{CH2-(2-OH-3,5-tBu2-C6H2)2} were prepared and structurally characterized. [Sm(tBu2O2NN′)]2(μ-Cl)2 (1) was obtained from reaction of SmCl3 with K2(tBu2O2NN′) in THF, DME or pyridine. The reaction of 1 with LiNEt2 gave a zwitterionic bimetallic complex of Sm and Li, [Sm(tBu2O2NN′)2Li] (2) that formed upon ligand redistribution and did not allow the isolation of the expected diethylamido derivative. Analogously treatment of Sm{N(SiMe3)2}3 with H2tBu2O2NN′ led to a zwitterionic samarium complex [Sm(tBu2O2NN′)(tBu2O2N(H)N′)] (3) that also displays a 2ligand:1Sm ratio. In 3 the samarium is formally an ate centre and the tripodal nitrogen of one of the ligands is protonated. The reaction of 1 with Li[2-(CH2NMe2)C6H4] proceeded through chloride metathesis to give [Sm(tBu2O2NN′)(κ2-{2-(CH2NMe2)-C6H4})] (4).

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Two synthetic pathways to N-(2-formyl-1-methylimidazol-4-yl)-2,2-dimethylpropanamide from 1-methyl-2-carboxaldehyde are described. The reagent serves as a useful synthon for reductive amination reactions with primary and secondary amines in the presence of sodium cyanoborohydride to yield a series of ligands with second coordination sphere functional groups. Protocols for the syntheses of related imidazole synthons functionalized in the 4-position with amino acids, Schiff bases, and other amides are also reported.

Reactions of UI3(THF)4, UCl4 and ThCl4 with 1equiv. of tris(3,5-dimethylpyrazolyl)methane (Tpm∗) in THF led to the formation of the complexes [U(Tpm∗)I3(THF)] (1), [U(Tpm∗)Cl4] (2) and [Th(Tpm∗)Cl4] (3) in good yields. The NMR spectra indicated symmetrical structures in solution, with equivalent pyrazolyl groups of the Tpm∗ ligand. The X-ray crystal structures of the three complexes were determined and in all cases the metallic centre is seven-coordinated, presenting distorted capped octahedral coordination geometry with near C3v symmetry. In 1, the tridentate pyrazolylmethane ligand and the three iodine atoms define the two staggered triangular faces of the octahedron, respectively, and the latter is capped by the THF oxygen. In 2 and 3, the coordination geometry is similar, with three chlorine atoms defining a triangular face capped by the fourth chlorine.

Based on the design principle of high reflective (HR) membrane of multilayer medium. The HR membrane appropriate for the chemical oxygen-iodine laser (COIL) with Si/SiO2 as high low refractive index materials, was designed on the silicon substrate, using TFCale3.4 simulation design software. We get the reflectivity of COIL over 99.999% at the output wavelength of 1315nm, above 99.2% at the harmonic of 632.8 nm in theory. The thermal deformation of Si-based reflector under the irradiation of Gaussian beam are calculated, using heat conduction equations and axial thermal deformation formula.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

A series of iron(III) complexes based on the tetradentate ligand 4-((1-methyl-1H-imidazol-2-yl)methyl)-1-thia-4,7-diazacyclononane (L) has been synthesized, and their solution properties investigated. Addition of FeCl(3) to methanol solutions of L yields [LFeCl(2)]FeCl(4) as a dark red solid. X-ray crystallographic analysis reveals a pseudo-octahedral environment around iron(III) with the three nitrogen donors of L coordinated facially. Ion exchange reactions with NaPF(6) in methanol facilitate chloride exchange resulting in a different diastereomer for the [LFeCl(2)](+) cation. X-ray analysis of [LFeCl(2)]PF(6) finds meridional coordination of the three nitrogen donors of L. Electrochemical studies of [LFeCl(2)](+) in acetonitrile display a single Fe(III)/(II) reduction potential at -280 mV versus ferrocenium/ferrocene. In methanol, a broad cathodic wave is observed because of partial exchange of one chloride for methoxide with half-potentials of -170 mV and -440 mV for [LFeCl(2)](+/0) and [LFeCl(OCH(3))](+/0), respectively. The equilibrium constants for chloride exchange are 7 × 10(-4) M(-1) for Fe(III) and 2 × 10(-8) M(-1) for Fe(II). In aqueous solutions chloride exchange yields three accessible complexes as a function of pH. Strongly acidic conditions yield the aqua complex [LFeCl(OH(2))](2+) with a measured pK(a) of 3.8 ± 0.1. Under mildly acidic conditions, the μ-OH complex [(LFeCl)(2)(OH)](3+) with a pK(a) of 6.1 ± 0.3 is obtained. The μ-oxo complex [(LFeCl)(2)(O)](2+) is favored under basic conditions. The diiron Fe(III)/Fe(III) complexes [(LFeCl)(2)(OH)](3+) and [(LFeCl)(2)(O)](2+) can be reduced by one electron to the mixed valence Fe(III)/Fe(II) derivatives at -170 mV and -390 mV, respectively. From pH dependent voltammetric studies, the pK(a) of the mixed valent μ-OH complex [(LFeCl)(2)(OH)](2+) is calculated at 10.3.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Supramolecular assembly of N,N′-(thiodiethane-2,1-diyl)bis(1-methyl-1H-imidazole-2-carboxamide) and Ag(I) yields a solid with discreet Ag2S2 centers stacked in columns via π-interactions with hydrogen-bonds to triflate in cavities between four neighboring columns.

[MCpBz(CO)(3)](2) (M = Mo 3, W 4; CpBz = pentabenzylcyclopentadienyl) complexes were prepared by reaction of Li[MCpBz(CO)(3)] [M = Mo (1), W (2)] with Fe-III. [MoCpBz(CO)(2)](2) (5) can be prepared by thermal elimination of CO from 3 and also by reaction of 1 with C3H5Br. The steric bulk of the CpBz ligands causes all the dimers to exist either in the solid state or in solution as the trans isomers. The hydrido complexes [MH(CpBz)(CO)(3)] [M = Mo (6), W (7)] were prepared by reactions of 1 and 2 with H+. Cyclic voltammetry and controlled potential coulometry of 5 in CH2Cl2, thf and CH3CN were performed and mechanisms for the redox behaviour are proposed. (c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007.

The reaction of titanium trisamidotriazacyclononane, [Ti{N(Ph)SiMe2}3tacn] (1), with C60 led to the synthesis of [Ti{N(Ph)SiMe2}3tacn]C60 (2) in high yield. Treatment of 2 with PhCH2Br led to the formation of [Ti{N(Ph)SiMe2}3tacn]Br and the radical PhCH2C60 (3). The reaction of CH3I with 1 gives two products. One is [Ti{N(Ph)SiMe2}3tacn]I (4), which results from the oxidation of 1 by an I radical. The other product, 5, resulting from a multistep reaction scheme that involves redox and nucleophilic reactions, presents an imido ligand formed by ligand rearrangement upon C-N bond cleavage. In solution, an exchange process that corresponds to a reversible 1,3-silyl shift between two Ti-bonded N atoms leads to isomers 5a and 5b. This equilibrium transforms an imido (TiNPh) into an amido ligand (Ti{NPh}SiMe2CH2Ph) with concomitant generation of an anionic moiety in the originally neutral triazacyclononane ring. In solution, either 5a or 5b displays additional fluxional processes that consist of its corresponding racemization processes.

New half-sandwich molybdenum complexes [Mo(CpBZ)Cl-2(O)] (1), [{Mo(CpBZ)(O)(2)}(2)(mu-O)] (5), and [Mo(CpBZ)Cl-2](2) (6) (CpBz = C-5(CH2Ph)(5)), the tungsten derivative [W(CpBZ)Cl(O)(2)] (3), and a high yield synthesis of [Mo(CpBz)Cl(O)(2)] (2) are described. The molecular structures and cyclic voltammetry measurements of 1 and 2 and a comparative study of various molybdenum dioxo complexes as olefin epoxidation catalyst precursors are also presented. The performance of [Mo(CpPr4i)Cl(O)(2)] (9) as cyclooctene epoxidation catalyst using TBHP as oxidant was determined and compared with other [MoCP'Cl(O)(2)] complexes (Cp' = C,H, (7), C5Me5 (8), CpBz (2)) to assess the activity dependence on the ring substituents. Under the same experimental conditions, bimetallic compounds [{MoCp'(O)(2)}(2)(mu-O)] (Cp' = CpBz (5), Cp* (10), CpBu3t (11), CpPr4i (12)) have been tested and [CpMoO2](2)O was checked in aqueous solution, with H2O2 and TBHP as oxidant. Finally, [Mo(CpBz)(CO)(3)CH3] (4) was used as a catalyst precursor for cyclooctene epoxidation in the presence of TBHP. The analogy between the behaviors displayed by this complex and complex 2 is discussed.

[M(CpBz)(CO)(3)CH3] (M = Mo, 2a, W, 2b; CpBz = C-5(CH2Ph)(5)) have been prepared and reacted with PCl5 and PhI - Cl-2. Depending on the metal and on the chlorinating reagent used [Mo(CpBz)(eta(2)-COCH3)Cl-3], 3, [W(CpBz)Cl-4], 4, [Mo(CpBz)(CO)(3)Cl], 5 and [Mo(CpBz)Cl-4], 6 have been obtained. The molecular structures of all compounds are reported and two conformations have been characterised for the benzyl substituents. In complexes 2a, 2b and 5 one phenyl ring bends towards the metals while in 3 and 4 the five phenyls point opposite to the metals. (C) 2004 Elsevier B.V. All rights reserved.

The solubilities and properties (density, viscosity, conductivity and pH) of solution in the system of Na2CrO4-NaHCO3-H2O were studied at 25°C and 40°C by isothermal method. And density of the equilibrium liquid phase has been calculated. The results are in agreement with the experiments.

The reaction process of sodium chromate with carbon dioxide and ammoniawas studied. The effect of ammonia to sodium chromate molar ratio, concentration of sodiumchromate and temperature on conversion rate was investigated. The results show that ratioof ammonia to sodium chromate of 2, concentration of sodium chromate of 40%, temperatureat 30℃ are proper conditions. The solubility of the Na+, NHk4+ CrO42-－H2O system wasdetermined at 25℃ and 35℃. The crystals of double-salt NaNH4CrO4·2H2O, (NH4)2CrO4and NaHCO3 may coexist in the solid phase. (NH4)2CrO4 in the reacted solution can beseparated as NaNH4CrO4·2H2O crystal by salting-out with Na2CrO4.