Oligo p-phenylene

Fig. 12. Cyclic voltammograms (corrected with respect to background currents) for the reduction of defined oligo-p-phenylene-vinylenes (THF, NaBPlu)...

Electrochemical data for the solid state are rare, but one example comprises reduction potential measurements of oligo(p-phenylene-vinylenes) with a convergence limit of —2.18 V vs. Fc/Fc+ for long chains. In contrast to the solution measurements, all solid-state voltammograms exhibit a strong hysteresis [240]. 

When neither solvent nor supporting salt can provide oxygen (e.g. in a system CH2CI2/BU4NBF4) and a strong proton donor is present in the solution, the oxidation of diphenylsulfide yields oligo(p-phenylene)sulfides (Scheme 28) [122],... 

Recently, polyphilic compounds have been reported, where an Rp-chain and a carbosilane chain were attached at opposite sides of a terphenyl or oligo (p-phenylene ethinylene) core [42], Compound 188 with the longest oligo (p-phenylene ethinylene) core shows two hexagonal columnar phases separated by a thermoreversible continuous (second order) phase transition with critical behavior upon approaching the transition temperature. Based on XRD data it was... 

Thermochromic photoluminescent liquid crystals have been reported recently as well as the mechanochromic photoluminescent liquid crystals. Weder and coworkers reported on oligo(p-phenylene vinylene) derivative 6 showing thermochromic... 

Indelli, M. T., Chiorboli, C., Flamigni, L., De Cola, L., Scandola, E, Photoinduced electron transfer across oligo-p-phenylene bridges. Distance and conformational effects in Ru0I) Rh0II) dyads. Inorg. Chem. 2007, 46, 5630-5641. 

Sakai, N., Brennan, K.C., Weiss, L.A. and Matile, S. (1997) Toward biomimetic ion channels formed by rigid-rod molecules Length-dependent ion-transport activity of substituted oligo-(p-phenylene)s. Journal of the American Chemical Society, 119, 8726-7. 

Rigid push-pull oligo(p-phenylene) rods Depolarization of bilayer membranes with negative membrane potential. Journal of the American Chemical Society, 121, 7961-2. 

Fig. 7 Schematic representation of the formation of a helical columnar structure by hierarchical self-assembly of a chiral oligo(p-phenylene vinylene) 10 bearing ureido-s-triazine units in M-dodecane. (Reproduced with permission from [51]. Copyright 2005 American Chemical Society)...

Photoexcitation of OPVn in Solution. The photoexcitations of oligo(p-phenylene vinylene)s (OPVns, n = 2-7) [106] can be summarised as follows. The singlet excited state OPVn(5i) decays radiatively or non-radiatively to the ground state and via intersystem crossing to the OPVn(Ti) triplet state. The singlet excited state lifetimes t have been determined for OPV3 (r =... 

Formally, such an electron transfer could be considered as a hole transfer in which a positive charge is transferred from the fullerene to the oligo(p-phenylene vinylene). 

Ether-linked p-dialkynylarenes underwent alkyne cyclotrimerization to form monodisperse oligo-p-phenylenes containing dihydrobenzo[c]furans <02OL745>. 

Oligo(p-phenylene sulfide)s with reactive end groups have recently been prepared by an oxidative polymerization method [126]. Polymers with chloro, bromo, iodo, and carboxyl end groups were obtained. 

The redox properties of oligo-p-phenylenes change when sterically relevant methyl groups exist in the central rings. Thus, in comparison with the unsubstituted oligomers in... 

Anodic oxidation of diphenyl disulfides in CH2CI2/BU4NBF4 solution in the presence of trifluoroacetic acid yields oligo (p-phenylene) sulfides [41]. Under these conditions the oxidation proceeds via a one-electron transfer, and it is believed that in acidic medium nucleophilic reactions involving the initial cationic product are suppressed. A sulfonium cation formed by reaction of a cation radical with the starting material is suggested as an intermediate ... 

Heidenhain, S.B. et al., Perfluorinated oligo(p-phenylene)s Efficient n-type semicon-... 

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