Kovacic s method

Kovacic s method was improved by Arnautov and Kobryanskii (2000) using an oxidative poly condensation route. The PPP obtained had a higher molecular weight (Sun et al. 2005). 

Polymerization of benzene by a catalyst-oxidant system (Kovacic s method)... 

Fig. 7. Direct syntheses of poly(p-phenylene) (a) Kovacic s doublecatalyst method, (b) single-catalyst method, (c) Wurtz-Fittig method, (d) Ullmann method, (e) Grignard method, and (f) diazonium method.

The attempts to synthesize PPP may be classified as either direct or indirect methods. In the first case, the monomers that are connected already contain the phenylene moiety that will become the repeating unit of the final polymer. In the second case, a precursor polymer is first synthesized from which PPP is then released, e.g., by thermal treatment. The most prominent examples are Kovacic s direct route [9] and the ICl re-... 

There is one paper in the literature for which the critical assessment of regiochemical control in the direct synthesis of PPPs does not apply. In 1978 and subsequent years, Yamamoto reported on the reaction between di-haloaromatic compounds and Mg metal in the presence of various low valency Ni catalysts [27,28]. When 1,4-dibromobenzene (2), 1 equiv of Mg, and dichloro-Ni(bi-pyridyl) in refluxing tetrahydrofuran is used, an exclusively para-linked, low molecular weight PPP (IR) is obtained (Fig. 8.1). The superiority of this very mild coupling process over other direct methods becomes immediately apparent if Yamamoto s material is visually compared with, e.g., Kovacic s. Whereas the former material is slightly yellow, the latter is black. 

Malnasi-Csizmadia, A., Pearson, D. S., Kovacs, M., Woolley, R. J., Geeves, M. A., and Bagshaw, C. R. (2001). Kinetic resolution of a conformational transition and the ATP hydrolysis step using relaxation methods with a Dictyostelium myosin ii mutant containing a single tryptophan residue. Biochemistry 40, 12727-12737. 

Martel, P., Kovacs, T., Voss, R. and Megraw, S. (2003) Evaluation of caged freshwater mussels as an alternative method for environmental effects monitoring (EEM) studies. Environ. 

Picer M, Kovac T, Britvic S, Picer N (2001) The chemical and biogenotoxic characterization of organic xenobiotics in aquatic sediment materials. 1. The application and comparison of chemically non-specific and biogenotoxic methods. Chemosphere 44, 1673-1683. 

The formation of symmetrical C-C bonds by the oxidative homocoupling of benzene and its electron-rich derivatives to yield poly(p-phenylene)s was achieved in the pioneering studies of Scholl [13, 14] during the early 1920s, followed by Kovacic (1960) [15-17], by applying various Lewis acid/oxidant combinations. The formation of each new C-C bond leads to the elimination of two protons, which are expelled as two HCl molecules (Scheme 13.1). The intramolecular adaptations of these oxidative methods have been applied towards the synthesis... 

A. Derecskei-Kovacs, D. E. Woon and D. S. Marynick Nonempirical wave functions for very large molecules. II. The PRDDO/M/FCP method, Int. J. Quantum Chem. 61 67-76 (1997). 

M. Mach, A. Zawisza, B. Lewandowski, S. Jarosz, in Proven Carbohydrate Methods, vol. I, P. Kovac (Ed.), Taylor Francis, Oxford, pp. 387-411, and references therein. 

Jadamec, J. R. Bauman, R. Anderson, C. R Jakubielski, S. A. Sutton, N. D. Kovacs, M. J. Method for detecting bacteria in a sample using a metabolizable fluorescent conjugate and measuring fluorescence emission intensity ratio. U.S. Patent 5968762,1999. 

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