Adel Amer

STUDIES OF SOME HINDERED 2,2′-BITHIENYLS AND 3,3′-BRIDGED 2,2′-BITHIENYLS WITH SPECIAL REFERENCE TO THEIR UV SPECTRA AND OXIDATION POTENTIALS

Abstract Some hindered bithienyl derivatives have been synthesized by cross-coupling reaction of Grignard reagents using NiCl2(dppp)(dppp = Ph2PCH2CH2CH2PPh2) or by reductive dimerization in the presence of Zn/NiCl2(PPh3)2. Their UV spectra and oxidation potentials are discussed in terms of their coplanarity and of the inductive effect of the substituent.

On the Synthesis and Mass-Spectroscopical Identification of Certain Polyhalogenated Acetic Acids

Abstract Improved syntheses of bromochloroacetic acid 1, dibromochloroacetic acid 2, and bromodichloroacetic acid 3, are reported. The acids are identified by elemental analyses, 1H-NMR spectra, and their mass spectra.

Electrochromism and electrochemical characterization of soluble poly[3-alkylhetero(arylene)s]

Abstract Soluble conducting poly[3-alkyhetero(arylene)s] have been prepared electrochemically from 3-alkylheteroarylene monomers. Optical conditions for the electrochemical polymerization were in acetonitrile and tetrabutylammonium hexafluorophosphate (Bu 4 NPF 6 ) as the solvent and the electrolyte, respectively. Two oxidation potential values ( E ox ) were exhibited in the ranges 0.75–1.12 V and 1.86–2.02 V versus Ag/AgCl, respectively. On the other hand, the polymer oxidation potentials ( E pox ) in monomer-free solution were 1.34–1.42 V versus Ag/AgCl. The electrochemical data of these compounds are compared with those of poly(3-methylthiophene), polythiophene and their derivatives prepared under the same polymerization conditions. The conductivities of the electrochemically grown films were measured using thefour-probe technique before and after exposure to doping agents. The values for the conductivities (σ) of the “as-grown” films were in the order of ≈ 10 −2 –10 ω −1 cm −1 . The infrared (IR) and nuclear magnetic resonance (NMR) spectra of these polymers indicated that the bonding of the monomer units are mainly 2,5 linkages. Solubility tests of these polymers are also given. Thin films formed under constant current density of 1 mA cm −2 (galvanostatically) or cast by evaporation of the solvent on optically transparent electrodes (OTE) displayed electrochromic properties. The film colors are dark blue and brick red in the oxidized (doped) and in the neutral (undoped) states, respectively. The formal potential ( E 0 ′) and n values of the polymer films are reported. The E 0 ′ values of the films in the monomer-free solution were 0.73–0.96 V versus Ag/AgCl. These values were compared to the ( E prmpox ) values from the cyclic voltammetric technique for the same polymer films. The fluorescence spectra of the polymer solutions in different solvents showed an intense broad emission bond at ≈ 410–660 nm.

A CONVENIENT SYNTHESIS OF LONG-CHAIN 3-n-ALKYLTHIOPHENES AND 3-n- ALKYLFURANS

Abstract The syntheses of 3-substituted long-chain furans and thiophenes by a Wittig reaction are described. 1H-NMR and UV data of these compounds are reported.

PREPARATION OF 3-LONG-CHAIN SUBSTITUTED 5-MEMBERED HETEROARYLENES AND STUDIES OF THEIR LANGMUIR-BLODGETT FILM FORMATION

Abstract The synthesis of amphiphilic thiophene 1 and pyrrole 5 were achieved via Wittig and Friedel-Crafts reactions respectively. The ability of 1 and 5, as well as 3-heptadecylthiophene and poly(3-heptadecylthiophene), to form Langmuir-Blodgett films are discussed.

N-SUBSTITUTED AMINOTRIPHENYLPHOSPHONIUM TRIBROMIDES AS NOVEL BROMINATING AGENTS

Abstract A number of N-substituted aminotriphenylphosphonium tribromides were investigated for their brominating ability of substituted phenols. It was found that t-butylaminotriphenylphosphonium tribromide, I, exhibits a good and a rather high regiospecificity in comparison with the commonly used bromine.

The Composition of “Cu(II)-Poly(3-Methylthiophene) Conducting Polymer” Electrodes

Abstract The electrode material formed on the chemical polymerization of 3-methylthiophene using Cu(II) salts as catalysts had been previously reported to be a poly(3-methylthiophene) incorporating coordinately bound Cu(II). Further examination of the nature and composition of this material by FTIR, EPS, elemental analysis and cyclic voltammetry reported here shows that this material is actually a composity of Cu(I) and Cu(II) cyanide in a matrix containing poly(3-methylthiophene).