Jadwiga Sołoducho

Practical synthesis of bis-substituted tetrazines with two pendant 2-pyrrolyl or 2-thienyl groups, precursors of new conjugated polymers

Abstract Novel linear oligoheterocycles based on substituted tetrazines are described. The desired compounds have been accomplished by a variation of the original Pinner [Ann. Chem., 297 (1897) 221] synthesis in which the aromatic nitrile reacted with hydrazine in an aqueous solution to give bis(pyrrolyl)tetrazines or bis(phenyl)tetrazines. The bis(phenyl)tetrazines reacted with 3,4-ethylenedioxy-2-(trimethyltin)thiophene or 2-(trimethyltin)thiophene in the presence of Pd(PPh3)2Cl2 or Pd(PPh3)4 as catalyst to give the desired compounds. Quantum-chemical calculations were performed to assess the usefulness of the synthesized compounds for electropolymerization. Studies have indicated qualitative difference between bis-pyrrole tetrazine and bis-phenyl tetrazines regarding the electronic density rearrangement due to the loss of an electron.

Electropolymerization of 1,4‐bis(Pyrrol‐2‐yl)benzene in the Presence of the Easily Oxidized Electrolyte Sodium Tetraphenylborate

The low oxidation potential of 1,4-bis(pyrrol-2-yl)benzene (BPB) at 0.25 V vs. Ag/Ag + allows its electropolymerization in the presence of easily oxidized electrolytes, such as sodium tetraphenylborate (NaBPh 4 ). In contrast, the electropolymerization of pyrrole under the same conditions is unsuccessful due to electrolyte breakdown. The resulting conducting polymer, poly[1,4-bis(pyrrol-2-yl)phenylene tetraphenylborate], is highly electroactive with a low oxidation potential (E 1/2.p = 0.0 V vs. Ag/Ag + ) for formation of the conducting state. Electrochemical quartz crystal microbalance studies indicate that the BPh 4 - anions in the polymer film and electrolyte serve as the mobile dopant ions, moving into and out of the film, when the polymer is electrochemically switched between oxidized and reduced states.

Convenient synthesis of polybispyrrole system

This review on polybispyrrole chemistry summarizes the recent progress in the chemistry of most attractive conducting polymers. Some details of the unique synthesis of bis(pyrrole)arylenes, bis(pyrrole)carbazoles, bis(pyrrole)fluorenes, bis(pyrrole)naphthalenes and their oxidative polymerization and electronic structures are also discussed.

New route to the synthesis of the indolo[7,6-g]indole (“bis(pyrrolo)naphthalene”) system starting from 1,5-dihydroxynaphthalene

Abstract A short and convenient route for the synthesis of indolo[7,6-g]indole derivatives starting from dihydroxynaphthalene is described. 1,5-Dihydroxynaphthalene ( 1 ) after alkylation, nitration and reduction gave 4,8-diamino-1,5-dibutoxynaphthalene ( 4 ). After reaction with iodine, 4,8-diamino-1,5-disubstituted naphthalene gave the corresponding 3,7-diodonaphthalene ( 5 ) in nearly quantitative yields. Palladium-catalyzed reaction of this diiodonaphthalene derivative with (trimethylsilyl)acetylene (TMSA), followed by efficient CuI-mediated cyclization with simultaneous elimination of the TMS substituent, allowed an efficient preparation of 5,10-dibutoxyindolo[7,6-g]indole ( 8 ).

Synthetic routes to bis(pyrrolyl)arylenes. Experimental and molecular modeling studies

The synthesis and characterization of compounds derived from 9,9-dialkylfluorene and 1,4-dioxane[3,4-b]thiophene are described. The key step involves a modified Steglich reaction between 9,9-dialkyl-2,7-N,N′-diallyliminochlorofluorene or 2,5-N,N′-diallyliminochloroethylenedioxythiophene and tert-BuOK (Route 1). Route 2 for bis(pyrrol-2-yl)dioxanethiophene, involving the reaction between 1,4-dioxane[2,3-c]thiophene and a dioxolanepropanol, is also a useful and general strategy. Molecular modeling studies indicate relationships between the molecular parameters (structure, ionization potential, atomic charges) of the synthesized moieties and their polymerization properties.

A New Route to Light Emitting Organic Materials Based on Triazine Derivatives

Novel light-emitting organic materials comprising conjugated oligomers chemically attached via a flexible spacer to an electron–or hole-conducting core were synthesized by Stille cross-coupling methodology and designed for tunable charge injection and optical properties. The hyperbranched structures have been characterized by 1H NMR, 13C NMR, and UV-VIS spectroscopy. The obtained structures show good stability in common organic solvents such as CHCl3, toluene, and CH2Cl2 and exhibit excellent thermal stability. A preliminary electroluminescence properties were also investigated. This class of materials will help to balance charge injection and transport and to spread out the charge recombination zone, thereby significantly improving the device efficiency and lifetime of unpolarized and polarized OLEDs.

Electrochemical Nanosized Biosensors: Perspectives and Future of Biocatalysts

Electrochemical biological sensor device unite the sensitivity of classic instrumental techniques with the inseparable selectivity of the biological agent. The bio-element of the sensing device identifies the analyte following in a biocatalytic way and definitely generates an electrical response recorded by a transducing element. The signal is proportional to concentration of the analyzed substance. Certain of developed modern biosensors are commercial available and are regularly applied in clinical, environmental, or industrial arrangements. The enzymatic electrode is often the principal element of electrochemical biosensors. The choice of suitable composition of agents, in example: biocatalyst, mediators, semiconducting elements, supports, for design of enzymatic sensors directs an electrode activity according to electron transport rate, its stability, and vitality. Presented article underlined also the variety of technologies for creation of sensors basing on carbon nanotubes and their application in detecting of a numerous of biological molecules.

Comparative Study of Alternating Low-band-Gap Benzothiadiazole Co-oligomers

The benzothiadiazole – arylene alternating conjugated oligomers have been designed and synthesized via Suzuki coupling reaction. The structures and properties of the conjugated oligomers were characterized by 1HNMR, 13CNMR, UV–vis absorption spectroscopy, photoluminescence (PL) spectroscopy. The luminescent measurements demonstrate that polybenzothiadiazoles are good chromophores able to form thin films by Langmuir-Blodgett (LB) technique, making them suitable for further applications. Also the electrical properties of obtained films confirm the good potential of these novel aryl-based π-conjugated polymers for the development of various electrical and electrochemical solid-state devices.

CONVENIENT SYNTHESIS AND PHYSICOCHEMICAL PROFILE OF NEW DERIVATIVES OF PYRIMIDINE

A synthesis of linear oligoheterocycles based on the substituted pyrimidines are described. The desired compounds have been accomplished by the variation of the original Pinner synthesis in which the aliphatic nitrile reacted with hydrogen chloride to give imino ester. These compound reacted with ammonia gas to give amidine. Chalcones in reaction with amidines give bis(phenyl)pyrimidines. The bis(phenyl)pyrimidines reacted with 3,4- ethylenedioxy-2-trimethyltinthiophene or 2-trimethyltinthiophene in the presence of Pd(PPh3)2Cl2 or Pd(PPh3)4 as catalyst to give designed compounds. In this work are presented also some electrochemical measurements using Langmuir - Blodgett technique in mono- and binary systems.

HERBICIDALLY ACTIVE DERIVATIVES OF AMINOMETHYLENEBIS-PHOSPHONIC ACID-MODE OF ACTION AND STRUCTURE-ACTIVITY RELATIONSHIP

Abstract: (N-pyridylamino)methylenebisphosphonates exhibit strong herbicidal activity which may be reversed by supplementation of the growth media with aromatic amino acids. They appeare to be the inhibitors of aromatic amino acids biosynthesis acting as inhibitors of DAHP synthase the first enzyme of shikimate pathway. Over 40 analogues of these acids were synthesized in order to determine the structure-activity relationship.