Materials Literature
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Abstract A series of hyperbranched poly(arylene ether phosphine oxide)s (HB PAEPOs) were prepared via an A 2 + B 3 polymerization scheme with tris(4‐fluorophenyl)phosphine oxide as B 3 , and a variety of bisphenols as A 2 . The effects of the reactivity of the A 2 monomer, the A:B ratio, the addition mode, the solvent…
Abstract We describe non‐radiative energy‐transfer experiments to measure the rates of polymer interdiffusion in P(MMA‐ co ‐BA) latex films formed in the presence of poly(vinyl alcohol) (PVOH). PVOH had relatively little effect on the initial efficiency of energy transfer, even when the amount of PVOH was large enough…
The TetL antiporter from the Bacillus subtilis inner membrane is a tetracycline-divalent cation efflux protein that is energized by the electrochemical proton gradient across the membrane. In this study, we expressed tetL in Escherichia coli and investigated the oligomeric state of TetL in the membrane and in detergen…
Abstract The first structural determination of dinuclear compounds with μ 1,5 ‐dicyanamide [dca, N(CN) 2 − ] as bridging ligand has been achieved with the products of formula [Ni(µ 1,5 ‐dca)(dca)(dpt)] 2 ( 1 ) and [Ni(µ 1,5 ‐dca)(dca)(medpt)] 2 ( 2 ) [dpt = bis(3‐aminopropyl)amine and medpt = bis(3‐aminopropyl)methyla…
Stable configurations and full symmetry groups of double wall carbon nanotubes are determined. These are used to calculate phonon bands for commensurate tubes. In particular, the modes with rigid walls are analysed and weak interlayer interaction is confirmed. Taking infra-red measurements is found to be a suitable me…
We suggest an analytical theory to describe angular magnetoresistance oscillations recently discovered in the quasi-one-dimensional conductor (TMTSF)2PF6 [see Phys. Rev. B 57, 7423 (1998)]] and define the positions of the oscillation minima. The origin of these oscillations is related to interference effects resulting…
Abstract The dioxomolybdenum( VI ) complex [MoO 2 Cl 2 (L‐L)], containing the bidentate 1,4‐diazabutadiene ligand RN=C(Ph)−C(Ph)=NR [R = (CH 2 ) 3 Si(OEt) 3 ], was immobilised in the ordered mesoporous silica MCM‐41 by carrying out a grafting reaction in dichloromethane. The grafted material (3.3 wt.‐% Mo) was tested…
We describe the preparation of six diketones based on the frameworks of five bis-naphthoporphyrins and one perinaphthoporphyrin. All diketones derive from meso-tetraarylporphyrins having incorporated two carbonyl groups, each one connected to one beta-pyrrole carbon and one ortho carbon atom from a meso-aryl group. Th…
Abstract Reaction of α‐Na 12 (As 2 W 15 O 56 ) with Fe II in 1 M NaCl solution followed by air oxidation yields αααα‐H 2 Na 14 [(NaOH 2 ) 2 Fe III 2 (As 2 W 15 O 56 ) 2 ] (Na 2 ), the arsenic analogue of the divacant lacunary sandwich, αααα‐H 2 Na 14 [(NaOH 2 ) 2 Fe III 2 (P 2 W 15 O 56 ) 2 ] (Na 1 ). This complex (Na…
The synthesis and characterization of nanoparticle-cored dendrimers (NCDs), consisting of a metal core capped by arylpolyethers terminated with ester or carboxylate groups, are reported. These NCDs, comprising nanometer-sized gold clusters at the core and organic dendrons radially connected to the gold core by gold-su…
The three-dimensional (3D) structure of the huge quasicrystal approximant nu-AlFeCr (space group P6(3)/m, a = 40.687 and c = 12.546 A) was solved by electron crystallography. High-resolution transmission-electron-microscopy (HREM) images and selected-area electron diffraction patterns from 13 different zone axes were…
A series of tris(2-pyridylmethyl)amines including one and two asymmetric centers were synthesized in a stereo-controlled fashion as potential ligands of lanthanide cations. The reaction of chiral pyridylethyl methanesulfonates and bis(pyridylmethyl)amines occurred via an S(N)2 mechanism with complete inversion of asym…
Individual multiwalled carbon nanotubes were mounted on tungsten support tips in a scanning electron microscope equipped with a nanomanipulator. It was possible to select the diameter of the nanotube to align the nanotube with respect to the tip axis and to tune the contact length of the nanotube and the support tip.…
Self-trapped hole (STH) induced by ArF laser irradiation in silica glass $(a\ensuremath{-}{\mathrm{SiO}}_{2})$ was investigated by the electron-spin resonance method. In order to observe the relation between the yield of STH and structural disorder of the glass, samples with different fictive temperatures ${T}_{f},$ w…
This paper describes the synthesis and characterization of a new series of sterically nondemanding, dicationic porphyrins that exhibit novel DNA-binding interactions. Cationic porphyrins continue to be the focus of a great deal of effort because of the promise they have for use in photodynamic, antiviral, and anticanc…
Results from a novel approach which uses protein crystallography for the screening of a low affinity inhibitor fragment library are analyzed by comparing the X-ray structures with bound fragments to the structures with the corresponding full length inhibitors. The screen for new phospho-tyrosine mimics binding to the…
Abstract The 30–100 nm primary particles of mesoporous silica have been conveniently synthesized from a highly dilute aqueous solution of CnTAMX–sodium silicate.
We present the experimental and theoretical evidence that a new Sm X phase made of asymmetric bent-shaped molecules has a layered, nontilted, optically uniaxial and polarly ordered structure with random direction of the layer polarization. The randomness results from the sign degeneracy of the difference in polarizati…
Well-ordered mesostructured/mesoporous silica nanofibers have been synthesized in a quiescent dilute aqueous cationic surfactant/silica precursor reaction mixture under strong acidic conditions. These nanofibers have diameters ranging from 50 to 300 nm and lengths up to millimeters. Transmission electron microscopy (T…
A novel cross-linked siloxane-based solid polymer network has been synthesized by the hydrosilylation of polymethylhydrosiloxane (PMHS) partly substituted with oligo(ethylene glycol) methyl ether side groups and a α,ω-diallyl poly(ethylene glycol) cross-linking reagent. The ionic conductivities of the networks doped w…