Surface plasmon resonance study of the interaction of a beta-cyclodextrin polymer and hydrophobically modified poly(N-isopropylacrylamide)

Surface plasmon resonance (SPR) technique is used to follow, both in real time and in situ, the association between a physically adsorbed polymer of beta-cyclodextrin (pbetaCD) and different hydrophobically modified poly(N-isopropylacrylamide) (PNIPAM) copolymers containing either adamantyl or dodecyl groups. This association is due to the complex formation between the hydrophobic groups and the betaCD cavities. Therefore, the adsorbed amount of PNIPAM onto the pbetaCD layer depends on the substituent and on its substitution level. The association and dissociation rate constants are evaluated from the kinetics of PNIPAM adsorption. An estimation of the association constants leads to values higher than 10(4) M(-1), reflecting the strong interaction between these polymers.     

Chemical instabilities during oxidation of 1,4-naphthalenediol in a homogeneous medium: II. Thermodynamic analysis and mathematical modeling

A possible mechanism of 1,4-naphthalenediol oxidation in the oscillatory regime has been considered, and a mathematical model describing the kinetics has been developed. Based on a thermodynamic Lyapunov function, it has been shown that the source of chemical instabilities is in the existence of autocatalytic steps and dynamic feedbacks. Qualitative analysis and numerical solution of the set of differential equations that model the reaction kinetics have been performed. The character of the stationary state and the possibility of bifurcations have been determined. The mathematical model satisfactorily describes the processes occurring in the system.     

Synthesis of unsaturated esters of pyridine- and quinolinedicarboxylic acids

The divinyl, diallyl, and dipropargyl esters of pyridine-2,4-, pyridine-2,6-, and quinoline-2,4-dicarboxylic acids and the divinyl and dipropargyl esters of pyridine-2,5-dicarboxylic acid have been synthesized.     

Five-membered-ring-substituted 1-methyl-1H-indeno[1,2-b]pyridines

1-Methyl-1H-indeno[1,2-b]pyridine and 1-methyl-1H-5-(, -dicarbomethoxyvinyl)-(formyl, acetyl)indeno[3,2-b]pyridines were obtained by treatment of N-methyl-4-azafluorenium iodide, as well as mixtures of it with acetylenedicarboxylic ester, dimethylformamide (DMF), and phosphorus oxychloride or acetic anhydride, with bases. 4-Azafluoronenone was used to synthesize 9-(p-methoxyphenyl)-4-azafluoren-9-ol, which was reduced to 9-(p-methoxyphenyl)-4-azafluorene, and 1-methyl-1H-5-(p-methoxyphenyl)indeno[3,2-b]pyridine was obtained from the methiodide of the latter.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1382–1386, October, 1981.     

New approach to the synthesis of 3-amino-1,2-benzothiazine 1,1-dioxides

The possibility of obtaining 3-amino-1,2-benzothiazine 1,1-dioxides by nucleophilic substitution of the chlorine atom in 5-nitro-2-chlorobenzenesulfonamides by carbanions generated from substituted acetonitriles was studied.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 264–266, February, 1992.