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The complex Zr(9-BBN)(sub 4)[9-BBN=(mu-H)(sub 2)BC8H14}(sub 4) are synthesized via the reaction of K(9-BBN) with ZrCl(sub 4) in diethyl ether. The structure of the little compound is determined by X-ray and neutron single-crystal diffraction techniques.

A series of alkaline earth−transition metal heterobimetallic complexes {(DMF)xM(μ-CN)yM*(CN)4−y}∞ [M = Ba: M* = Ni 1, M* = Pd 2, M* = Pt 3; M = Sr: M* = Ni 4, M* = Pd 5, M* = Pt 6; x = 3 or 4; y = 3 or 4] was prepared. Single-crystal X-ray diffraction analysis revealed that {(DMF)4Ba(μ-CN)3Ni(CN)}∞1, {(DMF)4Sr(μ-CN)3Ni(CN)}∞4, {(DMF)4Sr(μ-CN)3Pd(CN)}∞5, and {(DMF)4Sr(μ-CN)3Pt(CN)}∞6 form isostructural one-dimensional "ladder" arrays through isocyanide linkages (M-NC-M*), while {(DMF)3Ba(μ-CN)4Pd}∞2, and {(DMF)3Ba(μ-CN)4Pt}∞3 are two-dimensional puckered sheet like arrays. These bimetallic complexes can serve as effective precursors for the synthesis of supported bimetallic catalysts. It has been established that Ba−Pd/SiO2 and Sr−Pd/SiO2 catalysts, prepared from 2 and 5 loaded onto a silica support, delivered specific reaction rates in the hydrodechlorination of mono- and dichloro benzene that were over an order of magnitude greater than that achieved with conventional Pd/SiO2. A series of six alkaline earth−transition metal heterobimetallic complexes has been prepared. On the basis of single-crystal X-ray diffraction analyses, some of these compounds are one-dimensional "ladder" structures such as {(DMF)4Ba(μ-CN)3Ni(CN)}∞, while others, {(DMF)4Ba(μ-CN)4Pd}∞ for example, are two-dimensional array structures. The alkaline earth palladium complexes can serve as precursors for the synthesis of highly active heterogeneous hydrodechlorination catalysts. [ABSTRACT FROM AUTHOR]

Abstract: Carbon-supported PtTi alloy nanoparticles with well-controlled particle size, dispersity, and composition uniformity, have been synthesized by thermal decomposition and reduction of Pt and Ti precursors at elevated temperatures. The synthesized alloy nanoparticles were characterized by X-ray diffraction, high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, and energy-dispersive spectroscopy. The catalytic activities of these alloys towards molecular oxygen electro-reduction were screened by the hydrodynamic RDE technique. Among the compositions tested, Pt75Ti25 displayed the highest catalytic activity and had a twofold improvement in catalytic performance as compared to a benchmark Pt/C catalyst. [Copyright &y& Elsevier]

Abstract: The gas phase hydrodechlorination (HDC) of chlorobenzene (CB), 1,2-dichlorobenzene (1,2-DCB) and 1,3-dichlorobenzene (1,3-DCB) has been investigated over Pd/SiO2 and a series of Ln-Pd/SiO2 prepared from the organometallic precursor{(DMF)10Ln2[Pd(CN)4]3}∞ where Ln=La, Ce, Sm, Eu, Gd and Yb; Pd loading=5%, w/w. Under identical reaction conditions, the following overall sequence of increasing initial fractional dechlorination has been established: Pd/SiO2

The complex Zr(9-BBN)4 [9-BBN = (µ-H)2BC8H14] has been synthesized via the reaction of K(9-BBN) with ZrCl4 in diethyl ether. The structure of the title compound has been determined by X-ray and neutron single-crystal diffraction techniques. Each 9-BBN ligand is coordinated to the Zr atom via two B-H-Zr bridges, and these metal-ligand bonding interactions are further augmented by three prominent C-H···Zr agostic interactions. Average molecular parameters derived from the neutron analysis: Zr-H = 2.051(8) Å, B-H = 1.286(7) Å, Zr···B = 2.409(6) Å, Zr-H-B = 87.7(4)°, H-Zr-H = 58.9(3)°. The Zr···H distances corresponding to the three C-H···Zr agostic interactions are 2.424(7), 2.663(8), and 2.551(7) Å. The fourth potential C-H···Zr interaction has a Zr···H distance [3.146(7) Å] that is too long to be considered in the agostic range. Single-crystal X-ray diffraction data were collected on an Enraf-Nonius Kappa CCD diffraction system, and neutron diffraction data were collected on the quasi-Laue diffractometer VIVALDI at the Institut Laue-Langevin; the final agreement factor for the neutron analysis is 6.52% for 2557 reflections with I > 2σ(I). [ABSTRACT FROM AUTHOR]

Examines the cyclic organohydroborate complexes of zirconium monocyclopentadienyl. Reaction of compounds with hydride ion abstracting; Characterization of compounds by single-crystal x-ray diffraction analysis; Discussion on the properties of metallohydroborate systems.

The catalytic activity/selectivity of a 5% w/w Pd/SiO2 catalyst prepared by Pd(NO3)2 impregnation has been compared with that delivered by 5% w/w Pd/SiO2 and Pd&z.sbnd;Yb/SiO2 prepared from Pd(C2H3O2)2 and {(DMF)10Yb2[Pd(CN)4]3}∞ precursors, respectively; phenol hydrogenation (T=423 K) was used as a test reaction. The activated catalysts have been characterized by HRTEM/EDX; differences in activity are related to the TEM derived Pd particle size distribution. Incorporation of Yb resulted in an appreciable enhancement of both phenol conversion and the overall yield of cyclohexanone, an effect that is attributed to electron donation from Yb to the active Pd centers. [Copyright &y& Elsevier]

Presents the preparation of the complexes {(DMF)[sub 10]Ho[sub 2][Ni(CN)[sub 4]][sub 3]}[sub infinity] and {(DMF)[sub 10-]Gd[sub 2][Ni(CN)[sub 4]][sub 3]}[sub infinity] through an improved synthetic route. Absorption band of the complexes; Comparison of the shift to higher wavenumber for isocyanide linkages in the complexes; Reduction of the reaction time from 1-2 weeks to within 15-30 minutes.

Abstract: The catalytic oxygen electroreduction properties of platinum alloyed with base metals were screened using a high throughput combinatorial method. Candidate catalysts were identified by comparing the activity–stability–composition relationships between the platinum alloys and a pure platinum standard. Among the alloys studied, PtCo, PtNi, PtZn, and PtCu displayed the highest catalytic activities towards molecular oxygen electroreduction, but suffered from poor chemical stability in acid electrolytes. Alloys based on PtW, PtTi, and PtSe offered modest catalytic activity improvements and good chemical stabilities. In addition to the high throughput discovery, various synthesis technologies were studied to engineer alloy particles on the nanoscale. A good correlation in catalytic activity was found between thin film and carefully engineered powder catalysts. [Copyright &y& Elsevier]

9-BBN hydroborate complexes Ti{(mu-H)2BC8H14}3(THF)2 (1), Ti{(mu-H)2BC8H14}3(OEt2) (2), and [K(OEt2)4]-[Ti{(mu-H)2BC8H14}4] (4) were formed from the reaction of TiCl4 with K[H2BC8H14] in diethyl ether or THF. Ti{(mu-H)2BC8H14}3(PhNH2) (3) was isolated from the reaction of 2 with aniline in diethyl ether. In the formation of these complexes, Ti(IV) is reduced to Ti(III). The coordinated diethyl ether in 2 can be displaced by the stronger bases THF and aniline, to form 1 and 3, respectively. All of the compounds were characterized by single-crystal X-ray diffraction analysis. In complex 1, which contains two coordinated THF ligands, the titanium possesses a 17 electron configuration and there is no evidence for agostic interaction. Complexes 2 and 3 contain only one coordinated ether or aniline ligand, and the titanium possesses a 15 electron configuration. In these compounds, a C-H hydrogen on an alpha carbon on the BC8H14 unit of a 9-BBN hydroborate ligand forms an agostic interaction with the titanium. Criteria for assessing the existence of agostic interactions are discussed. As the potassium salt, the anion of complex 4 is more stable than the complexes 1-3. Organometallic anions of the type [ML4]- for titanium(III) are rare.