نتایج جستجو برای: phenylene
تعداد نتایج: 2124 فیلتر نتایج به سال:
[structure: see text]. Flash vacuum pyrolysis (FVP) of linear [3]phenylene affords its angular counterpart and the same mixture of polycyclic aromatic hydrocarbon isomers as that observed on FVP of angular [3]phenylene. A mechanism, supported by a 13C labeling study, is proposed to explain these results.
Single-molecule study of phenylenevinylene oligomers revealed distinct spectral forms due to different conjugation lengths which are determined by torsional defects. Large spectral jumps between different spectral forms were ascribed to torsional flips of a single phenylene ring. These spectral changes reflect the dynamic nature of electron delocalization in oligophenylenevinylenes and enable e...
background: hair dye poisoning, with main toxic component paraphenylene diamine, is a medical emergency. it is on increasing trend in developing countries due to wide availability and low cost of hair dyes. it carries a high mortality and does not have any specific antidote. case report: twenty three years old patient presented with breathelessness along with difficulty in speaking for one hou...
A new parameter, related to and easily determined from the structure of a benzenoid system and that of a phenylene – the number of inlets (r) – is introduced. The connectivity (Randi}) index of both benzenoid systems and phenylenes is then shown to depend solely on the number of vertices and on r. A simple relation is established between the connectivity index of a phenylene and of the correspo...
The feasibility of using π-conjugated polymers as next-generation electronic materials is extensively studied; however, their charge mobilities are lower than those of inorganic materials. Here we demonstrate a new design principle for increasing the intramolecular charge mobility of π-conjugated polymers by covering the π-conjugated chain with macrocycles and regularly localizing π-molecular o...
in this paper, new (2e, 2'e)-3, 3'-(((3- hydroxypropane-1, 2-diyl) bis (oxy)) bis (2, 1-phenylene)) bis (1-phenylprop-2-en-1-one) (2a) was prepared in good yield by condensation reaction of acetophenone with bisaldehyde (1a) in ethanolic naoh solutions at room temperature. the (2e, 2'e)-3, 3'-(((3- hydroxypropane-1, 2-diyl) bis (oxy)) bis (2, 1-phenylene)) bis (1-phenylprop-2-en-1-one) (2a) was...
A family of dinuclear neutral thiolate gold complexes of the type RPh2PAuS(C6H4)nSAuPPh2R (n = 2, 3), RPh2PAuS(C6H4)S(C6H4)SAuPPh2R, RPh2PAuSCH2(C6H4)2CH2SAuPPh2R where R represents a pyridine or a phenylene ring, has been prepared and fully characterized. X-ray crystallographic studies showed the presence of aurophilic interactions for those species bearing two phenylene spacers between the go...
The ability of m-phenylene to ferromagnetically couple spin-containing substituents that are substantially twisted out of conjugation is investigated. The "bis(TMM)" strategy is employed, in which two triplet TMM biradicals are linked through m-phenylene to produce relatively stable, organic tetraradicals that are characterized by EPR spectroscopy. Under conditions of moderate twisting (4), fer...
Trigonal molecules compartmentalise the pores of a honeycomb network of 3,4:9,10-tetracarboxylic diimide (PTCDI) and 1,3,5-triazine-2,4,6-triamine (melamine). Extending the 1,3,5-tri(phenylene-ethynylene)benzene core by a phenyl group allows for a well-defined accommodation of the molecule into two symmetry equivalent positions in the pore. The corresponding styryl or phenylene-ethynylene deriv...
The synthesis of phenylene-ethynylene rods and their use as rigid spacers is described. Alternation of a Sonogashira reaction and silyl group cleavage was used to obtain rigid spacers with even and odd numbers of phenylene units. Preliminary applications of these rods in divalent systems are shown. Inhibition studies with Pseudomonas Aeruginosa lectin LecA showed that the rigid spacer proved gr...
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