H. Bräunling

Synthesis of polyarenemethines, a new class of conducting polymers

Abstract Two synthetic routes to form black insoluble and infusable polymers containing polyarenemethine structures are described. The highest conductivity obtained by doping with iodine was 10 −4 S/cm. Syntheses and structures are discussed.

Polyarylmethines; synthesis and physical properties

Abstract Polyarylmethines are predicted theoretically to exhibit low bandgaps. Though few syntheses have been reported, there is no practical evidence for the low bandgaps, because all materials reported till now proofed to be doped. We report a new synthetic way yielding soluble, doped polymers or oligomers which can be examinated by UV - VIS - IR - spectroscopy. Our experiments show that doped polyarylmethines in solution are very sensitive to the pH and that doping and undoping shows some similarities to polyaniline

Neuartige basische liganden für die homogenkatalytische methanolcarbonylierung: Teil XX. kinetische untersuchungen der methanolcarbonylierung zu acetaldehyd unter verwendung eines ether-phosphan-modifizierten cobaltkatalysators

Abstract Methanol is hydrocarbonylated to acetaldehyde by means of a catalytic system consisting of CoI2 and [C4H7O2-CH2- P(Ph)-CH2-]2, (C4H7O2 = 1,4-dioxanyl) with synthesis gas. The rate of this reaction in terms of the decrease of the molar fraction of methanol can be expressed by the following equation: The activation energy and the standard activation entropy are 48 kJ mol−1 and −216 J mol−1 K−1, respectively. Whereas excess ligand (CoI2/ ligand = 1 2 ) and admixture of water results in a drastic decrease in the reaction rate, addition of iodide in the form of LiI has no effect on it. The conversions reach approximately 90%. For the industrial application of this process in a continuously working plant, converions of 20 – 30% would be advantageous. In this latter range the selectivities with respect to acetaldehyde including its dimethylacetal (‘total aldehyde’) are higher than 80%. At 270 bar, MeOH/ligand/CoI2 = 800/1/1 and 190 °C, a space-time yield of 6.1 kg of total aldehyde per m3 of MeOH per minute is achieved.

Poly(arenemethylidenes) — Low gap compounds with intriguing chemical and physical properties

Abstract A new class of conducting polymers, polyarenemethylidenes (PAM), are chemically prepared by polycondensation of heterocyclic dicarbinoles in coatings. The materials show high third-order non-linear optical coefficients χ(3) in the order of 10−9 esu and charge carrier mobilities up to 10 cm2/Vs.

Polydiheteroarylenemethines — A new class of conducting polymers

Abstract A new class of conducting polymers, polydiheteroarylenemethines, are chemically prepared by polycondensation of heterocyclic dicarbinoles. It is shown that this method is especially useful for preparation of coatings and electrical conducting composites with conductivities up to 10 −2 S/cm and high third order nonlinear optical susceptibility.

15N CPMAS NMR study of the structure and reactions of polypyrrylenemethine and polyfurylenepyrrylenemethine

Abstract The chemical structure and reactions of the recently prepared conducting polymers polypyrrylenemethine (PPM) (H. Braunling and R. Becker, Ger. Offen. Patent Applic. No. 3 710 657 (Mar. 31, 1987)) and polyfurylenepyrrylenemethine (PFPM) have been studied using high-resolution solid-state 15 N CPMAS NMR spectroscopy of the 15 N-labeled compounds. The results show the presence of azomethine nitrogen atoms which can be protonated with acids and deprotonated again with bases as free base porphyrins. Thus, these polymers have to be regarded, at least partially, as polymer analogs of the corresponding free base porphyrins.

Polyheteroarylmethines, Syntheses and Physical Properties

Selfcondensation of 2-pyrrolealdehyde with phosphoroxichloride gives a product with a polypyrrylmethine like structure. Structure and reactivity of the methinegroup are investigated by 15N-CPMAS and 13C-CPMAS technique.