Synthesis, reactivity, structure and electronic properties of [N(CH3)4]C60·1.5thf: Fullerides with simple hexagonal packing

The preparation of [N(CH3)4] C60 ·1.5thf and characterisation of its electronic properties, using susceptibility, EPR and 13C MAS NMR measurements, is reported. X-Ray powder diffraction shows a simple hexagonal stacking sequence of close-packed C60 layers, with cations and solvent molecules located in the trigonal-prismatic sites. The electronic properties are consistent with narrow-band metallic behaviour at high temperature. A transition in susceptibility and EPR measurements is seen between 200 and 230 K. A similar synthesis affords a C60 2- compound with the same simple hexagonal fulleride packing

Influence of catalyst metal particles on the hydrogen sorption of single-walled carbon nanotube materials

The hydrogen sorption capacity of arc-synthesized single-walled carbon nanotubes (SWNTs) was studied using a specially built high-pressure rig coupled to a Toepler pump capable of directly measuring the desorbed volumes of gas. The samples studied were prepared using the arc-evaporation method and were as-produced SWNT material formed at the cathode (collar), as-produced SWNTs deposited in the soot and a purified sample of SWNTs. The three samples had similar diameter ranges, the major difference between them being the concentration of remaining metal particles from the Ni/Y/C catalyst used in the arc-synthesis. The effect of the presence of these residual catalyst metal particles has been analysed and seen to strongly influence the hydrogen storage capacity of the samples

A stable crystalline imino-N-heterocyclic carbene ligand and its corresponding palladium(II) and rhodium(I) complexes

The crystalline heteroditopic, acyclic, and nonenolizable imino-N-heterocyclic carbene chelating ligand 1-tert-butyl-3-(1-phenyliminophenylmethylene)imidazol-2-ylidene (designated as C boolean AND imine) has been isolated and structurally characterized. The metal complexes [Pd(C boolean AND imine)Cl-2], [Pd(allyl)(C boolean AND imine)]-PF6, [Rh(COD)(C boolean AND imine)]PF6, and [Rh(CO)(C boolean AND imine)(2)]Cl have been prepared either by Ag transfer or by reaction with the free carbene. The palladiumt(II) complexes have been tested for catalytic application in Suzuki type C-C cross-coupling reactions of aryl bromides and the rhodium(l) complexes for the catalytic hydroformylation of 1-octene. The metal complexes [Pd(C boolean AND imine)Cl-2], [Pd(allyl)(C boolean AND imine)]PF6, and [Rh(CO)(C boolean AND imine)(2)]Cl have been structurally characterized by single-crystal X-ray diffraction

Functionalization of single-walled carbon nanotubes via the Bingel reaction

Single-walled carbon nanotubes have been cyclopropanated under Bingel reaction conditions, and the functionalized nanotubes have been characterized by atomic force microscopy using "chemical tagging" techniques

Bimetallic nanoparticles aligned at the tips of carbon nanotubes

Cluster-derived bimetallic nanoparticles have been deposited onto multi-wall carbon nanotubes and shown to be generally homogeneously dispersed, of uniform small sizes, of the same composition as the starting mixed-metal clusters, and to have a tendency to align at the tips of the tubules

Synthesis of ring-substituted bis-eta5-cyclopentadienyl derivatives of the Group IV elements containing the bicyclic ligands eta5-C5H3(1,2-CH2-)n, n=4, 5, or 6

The synthesis of unsubstituted and substituted bicyclic eta5-cyclopentadienyl ligands and their Group IV metal complexes [M{eta5-C5H3(1,2-CH2–)n}2Cl2], where n=4, 5, 6 and M=Ti, Zr, Hf, is reported. An example of an ansa-bridged zirconium analogue is also described

Silver(I) complex of a new imino-N-heterocyclic carbene and ligand transfer to palladium(II) and rhodium(I)

A new imino-N-heterocyclic carbene ligand precursor [1-(2,4,6-Me3C6H2) imidazolium-3-{CH2C(t-Bu)=N(i-Pr)}] bromide has been synthesised and structurally characterised. The silver(I) complex [Ag(C(boolean AND)imine)(2)] AgBr2, where (C(boolean AND)imine) = 1-(2,4,6- Me3C6H2) imidazol-2-ylidene-3-{CH2C(t-Bu)=N(i- Pr)}, was readily prepared by reaction with Ag2O. Transfer of the ligand from silver(I) to palladium(II) and rhodium(I) by reaction with [PdCl2(MeCN)(2)] and [Rh(cod)(THF)(2)][BF4] led to the tautomerisation of the imine moiety to the enamine affording the structurally characterised complex [PdCl2(C(boolean AND)enamine)] and [ Rh( cod)(C(boolean AND)enamine)][BF4] respectively, where (C(boolean AND)enamine) = 1-(2,4,6-Me3C6H2) imidazol-2-ylidene-3-{CH=C(t-Bu) NH(i-Pr)}

Chemical and biochemical sensing with modified single walled carbon nanotubes

The nano dimensions, graphitic surface chemistry and electronic properties of single walled carbon nanotubes make such a material an ideal candidate for chemical or biochemical sensing. Carbon nanotubes can be nondestructively oxidized along their sidewalls or ends and subsequently covalently functionalized with colloidal particles or polyamine dendrimers via carboxylate chemistry. Proteins adsorb individually, strongly and noncovalently along nanotube lengths. These nanotube -protein conjugates are readily characterized at the molecular level by atomic force microscopy. Several metalloproteins and enzymes have been bound on both the sidewalls and termini of single walled carbon nanotubes. Though coupling can be controlled, to a degree, through variation of tube oxidative pre-activation chemistry, careful control experiments and observations made by atomic force microscopy suggest that immobilization is strong, physical and does not require covalent bonding. Importantly, in terms of possible device applications, protein attachment appears to occur with retention of native biological structure. Nanotube electrodes exhibit useful voltammetric properties with direct electrical communication possible between a redox-active biomolecule and the delocalized T system of its carbon nanotube support

MONO-ETA-CYCLOPENTADIENYL-BENZAMIDINATO CHLORO COMPOUNDS OF TITANIUM, ZIRCONIUM AND HAFNIUM

The new compounds {M(eta-C(5)R(5))[eta-CPh(NSiMe(3))(2)]]Cl-2} (where R = H, M = Ti, Zr, Hf or R = Me, M = Ti or Zr), are described. The crystal structures of {M(eta-C(5)R(5))([eta-CPh(NSiMe(3))(2)]Cl-2} (R = H, M = Zr or Hf) have been determined. The compound {Zr(eta-C5H5)[eta-CPh(NSiMe(3))(2)]Cl-2} acts as a co-catalyst for the polymerisation of ethylene and propene

A nonenolizable imino-N-heterocyclic carbene ligand and corresponding silver(I) metal complex

The nonenolizable imino-N-heterocyclic carbene ligand precursor [1-t-butylimidazolium-3-{C(Ph)=N(Ph)}] chloride has been synthesised. The corresponding silver (I) complex Ag(C boolean AND imine)Cl; where C boolean AND imine=[1-t-butylimidazolium-2-ylidene-3-{C(Ph)=N(Ph)}], was prepared by reaction with Ag2O. All of the compounds have been structurally characterized by single crystal X-ray diffraction. (c) 2005 Elsevier B.V. All rights reserved