Electrosynthesis of poly(<Emphasis Type="Italic">p</Emphasis>-phenylene) and poly(<Emphasis Type="Italic">p</Emphasis>-phenylene/pyrrole) films under controlled humidity

Poly(p-phenylene/pyrrole) (PPP-PPY) films were electrochemically synthesised on transparent indium-tin-oxide-covered glass (ITO) electrodes. The presence of two monomers, p-phenylene and pyrrole, in the polymerisation medium facilitated the synthesis process, yielding electroactive, uniform and stable films. In order to obtain materials with improved quality, PPP, PPY and PPP-PPY films were prepared in a mild, dry atmosphere. The morphological, electrochemical and optical properties were compared for different films obtained by varying the number of cycles with and without controlling humidity.     

Electrochemical preparation of poly(<Emphasis Type="Italic">p</Emphasis>-phenylene) thin films

We report the electrochemical preparation of poly(p-phenylene) (PPP) thin films with a polymerization degree of approximately 20 using biphenyl as starting material. The PPP films are prepared directly on a tin oxide electrode, presenting a positive charge carrier mobility of 5×10⁻⁷ cm² V⁻¹ s⁻¹.     

Catalytic hydrogenation of persubstituted <Emphasis Type=Italic>p</Emphasis>-nitrosophenols

Catalytic hydrogenation of dialkyl 2-hydroxy-4,6-dimethyl-5-nitrosobenzene-1,3-dicarboxylates over Pd/C gave the corresponding previously unknown dialkyl 5-amino-2-hydroxy-4,6-dimethylbenzene-1,3-dicarboxylates. The first-order rate constants for the hydrogenation process were found to be linearly related to steric constants of the alkyl groups.     

X-ray crystal structures of <Emphasis Type=Italic>p</Emphasis>-halogenated 6,6-diphenylfulvenes

Crystal structures of a series of p-halogenated 6,6-diphenylfulvenes 2–5 are reported and comparatively discussed including the known structure of the non-halogenate parent compound 1. The molecular structures show twisted conformations of the plane aryl and fulvene subunits against each other, rather unaffected by the different halogen substituents. The packing structures exclusively involve C–H···X (X = F, Cl, π) contacts while Hal···Hal and π-stacking interactions do not occur.     

Reaction of methylpheophorbides <Emphasis Type=Italic>d</Emphasis> and <Emphasis Type=Italic>b</Emphasis> with amines

A series of formyl analogs of chlorin e₆ 13-amides were synthesized in high yields by reaction under mild conditions of primary and secondary amines with methylpheophorides b and d. In contrast with the secondary 13-amides, tertiary 13-amides were found as two isomers differing in the orientation of the amide plane relative to the plane of the chlorin ring. Methylpheophorbides b and d were more reactive toward the amines than methylpheophorbide a.     

<Emphasis Type=Italic>bis</Emphasis>-Cardenolides

Twelve new bis-cardenolides were synthesized by reaction of natural cardenolides with diamines to form imines and ammonium salts. Anomalous physicochemical properties consisting of resistance to hydrolysis and increased polarity were observed for the bis-ketoimines.     

Comparative characteristics of water-soluble proteins from <Emphasis Type=Italic>Larix sibirica</Emphasis>, <Emphasis Type=Italic>Picea obovata</Emphasis>, and <Emphasis Type=Italic>Abies sibirica</Emphasis> bud meristem

The amount of water-soluble proteins in bud meristem of Larix sibirica L., Picea obovata L., and Abies sibirica L. was shown to increase by 2-3 times in autumn during development of low-temperature resistance. The fractional composition of water-soluble proteins of the studied species and the amino-acid composition of groups of water-soluble proteins with different molecular weight (MW) were similar. Nitrogen accumulated as aspartic acid, glycine, and alanine in high- and medium-molecular-weight proteins. The peptides (MW < 5 kDa) typically had a high content of hydrophobic proline and hydrophilic tyrosine.