Phenyl group

Abstract: The effect of a 4-carboxyphenyl or a 4-nitrophenyl thin film at the surface of a glassy carbon electrode on their electrochemical responses in the presence of various electroactive probes has been investigated. The grafting of a substituted phenyl group to a glassy carbon electrode was achieved by electrochemical reduction of the corresponding substituted phenyldiazonium derivative in acetonitrile. The blocking properties of the film depend primarily on electrostatic and electrolyte/solvent effects. Permselectivity for the 4-carboxyphenyl film can be achieved by controlling the dissociation of the carboxy group. The substituted phenyl layer is much more compact and less permeable in contact with a nonaqueous solvent than with an aqueous solvent presumably because the layer is poorly solvated. Electrochemical impedance measurements indicate that the kinetics of electron transfer are slowed down when the time used to modify the glassy carbon electrode is increased. Cyclic voltammetry and X-ray photoelectron...

Abstract: Two donor-π-acceptor (D-π-A) dyes are synthesized for application in dye- sensitized solar cells (DSSC). These D-π-A sensitizers use triphenylamine as donor, oligothiophene as both donor and π-bridge, and benzothiadiazole (BTDA)/cyanoacrylic acid as acceptor that can be anchored to the TiO2 sur- face. Tuning of the optical and electrochemical properties is observed by the insertion of a phenyl ring between the BTDA and cyanoacrylic acid acceptor units. Density functional theory (DFT) calculations of these sensitizers provide further insight into the molecular geometry and the impact of the additional phenyl group on the photophysical and photovoltaic performance. These dyes are investigated as sensitizers in liquid-electrolyte-based dye-sensitized solar cells. The insertion of an additional phenyl ring shows significant influence on the solar cells’ performance leading to an over 6.5 times higher efficiency (η = 8.21%) in DSSCs compared to the sensitizer without phenyl unit (η = 1.24%). Photophysical investigations reveal that the insertion of the phenyl ring blocks the back electron transfer of the charge separated state, thus slowing down recombination processes by over 5 times, while maintaining efficient electron injection from the excited dye into the TiO2-photoanode.

Abstract: Substituted heteroaromatic compounds of formula (I) and in particular substituted quinolines and quinazolines, are protein tyrosine kinase inhibitors. The compounds are described as are methods for their preparation, pharmaceutical compositions including such compounds and their use in medicine, for example in the treatment of cancer and psoriasis, or a salt or solvate thereof; wherein X is N or CH; Y is a group W(CH2), (CH2)W, or W, in which W is O, S(O)m wherein m is 0, 1 or 2, or NRa wherein Ra is hydrogen or a C?1-8? alkyl group; R?1? represents a phenyl group or a 5- or 6-membered heterocyclic ring containing 1 to 4 heteroatoms selected from N, O or S(O)?m?, wherein m is as defined above, with the provisos that the ring does not contain two adjacent O or S(O)m atoms and that where the ring contains only N as heteroatom(s) the ring is C-linked to the quinazoline or quinoline ring, R?1? being optionally substituted by one or more R3 groups; P = 0 to 3; U, R2, R3 are as defined in the application.

Abstract: A series of photophysical measurements and semiempirical calculations were carried out with 1,4-bis(phenylethynyl)benzene in search of evidence on the effects of phenyl group rotation and chromophore aggregation of oligo- and poly(phenyleneethynylene)s. It is suggested that planarization gives rise to relatively modest shifts of ca. 20−30 nm, which preserve the vibronic structure of the monomer and retain a high emission quantum yield. In contrast, it is proposed that aggregation gives rise to larger shifts and loss of vibronic structure.

Abstract: Dyes of formula (1) or (2) wherein R1, R1', R2 and R2' are each independently of the others hydrogen, C1-C4alkyl, halogen or nitro, R3, R3', R4 and R4' are each independently of the others C1-C4alkyl unsubstituted or substituted by OH, C1-C4alkoxy, halogen, CN or phenyl, R5 is hydrogen or C1-C4alkyl, R6 is unsubstituted or amino-substituted C5-C12alkyl; or unsubstituted or amino-substituted C5-C8cycloalkyl; or phenyl-substituted C1-C4alkyl; or wherein R5 and R6 together with the nitrogen atom linking them from a piperazine ring, which is substituted, at the nitrogen atom that is not bonded to the phenyl group, by C1-C4-alkyl or phenyl, the alkyl and phenyl radicals mentioned as substituents of the nitrogen atom of the piperazine ring being unsubstituted or substituted by amino, X1, X2, X3 and X4 are each independently of the others hydrogen, C1-C4alkyl, C1-C4alkoxy or halogen, Y1 is a bridging member of formula (I) or -NH-(CH2)6-NH-, and X- is an anion, as wels as methods of dyeing or printing textile materials, leather, paper or glass fibres with those dyes, are described.