Vinyl Polymerization by Metal Complexes. VII

Abstract

The photopolymerization of vinyl monomers by metal salt-saccharide system was investigated in various solvents. The rate of polymerization in the presence of a iron(III) salt in aqueous media was remarkably accelerated by the addition of saccharides. The acceleration caused by a series of saccharides was found to be in the following order: glucose > fructose > lactose maltose. α-Methyl-d-glucoside and sucrose exhibited very little effect. The overall activation energy for the photopolymerization of acrylonitrile in the presence of glucose was found to be 2.7 kcal/mole, about half of the value obtained in the absence of glucose.     

Reagents and Synthetic Methods 33. Improved One-Step Beckmann Rearrangement from Ketones and Hydroxylamine in Formic Acid Solution.

An improved One-step Beckmann rearrangement is described.     

Vinylpolymerisation mit Metall-Komplexen 8. Mitt. Zur Kinetik der Photopolymerisation von Vinylmonomeren mit Fe(III)-Salz/Saccharid-Systemen

Ohne Zusammenfassung     

Vinylpolymerisation mit Metallkomplexen. 7. Mitt. Photopolymerisation von Vinylmonomeren mit Metallsalz-Saccharid-Systemen

Ohne Zusammenfassung     

A convenient synthetic approach to alpha-amino-beta-lactam synthesis promoted by phenyl dichlorophosphate reagent

The ready and economical phenyl dichlorophosphate, in contrast to many reagents developed for activating carboxyl groups for the beta-lactam synthesis, is shown to be very efficient for the synthesis of alpha-vinylamino-beta-lactams from Dane salts and Schiff bases. Some observations toward the scope of the method are also briefly described. The interaction of acetic acids with ethanolimines afforded beta-lactams and/or oxazolidines according to the synthetic methodology used.     

Functional monomers and polymers. LXXXVI. Photochemical reactions on synthetic polymers with pendant thymine bases: Effect of solvents

Photodimerization of thymine bases present on the side chain of acryloyl and methacryloyl-type polymers was studied in dimethyl sulfoxide, dimethylformamide, and dimethyl sulfoxide—ethylene glycol mixture. Quantum efficiencies for photodimerization and quenching with isoprene were influenced by the solvents. The self-association of thymine bases estimated from their ultraviolet (UV) spectra and intrinsic viscosity were related to the effect of solvent on the photodimerization.     

The role of tetrahydrobiopterin in catalysis by nitric oxide synthase

Electronic structure calculations show that the cofactor H4B can be a key factor in a proton transfer relay in nitric oxide synthase, and that 4-amino-H4B cannot fulfill this role.     

Functional monomers and polymers. XXXV. Oxidation of hydroquinone catalyzed by Cu(II)–polyelectrolyte complexes

Oxidation of hydroquinone catalyzed by copper(II) complexes of poly-1-vinylimidazole, vinylamine-vinylacetamide copolymer, and polyethyleneimine was studied in aqueous solution at 25°C. The rate of oxidation was determined spectrophotometrically over several pH values. The rate of copper(II) reduction was evaluated from copper(I)–cuproin complex formation, and the reoxidation of copper(I) to copper(II) was observed by visible spectroscopy. Among the copper(II) complexes, poly-1-vinylimidazole complex exhibited excellent catalytic activity, which amounted to over 20 times that of aqueous copper(II) ion solution, while the reduction of copper(II) in the former system was slower than that in the latter system. The reoxidation of copper(I) to copper(II) was found to be completed immediately in the presence of polymer ligands such as poly-1-vinylimidazole, while copper(I) ion was only slowly reoxidized. The discussion of the reaction mechanism emphasizes the importance of the reoxidation process.     

Graft copolymers containing nucleic acid bases and L-α-amino acids

Graft copolymers of nucleic acid bases and L-α-amino acids on polyethyleneimine were synthesized, and carboxyl derivatives of adenine and thymine were grafted by the p-nitrophenyl ester method onto linear and branched polyethyleneimine. The carboxyl derivatives of nucleic acid bases were also grafted onto the monomeric graft copolymers of L -α-amino acids on polyethyleneimine; the carboxyl derivatives were obtained by the condensation of polyethyleneimine with L -α-amino acids with a coupling agent.     

Functional monomers and polymers. CLIV. Application of nucleic acid base containing polymers to high performance liquid chromatography

Poly-L -lysine (PLL) derivatives containing pendant nucleic acid base, such as thymine or adenine, were bonded successfully to 3-aminopropylsilanized silica (APS-silica) and silica gel. These resins were found to be useful as the column of high performance liquid chromatography (HPLC) for the selective separation of oligoethyleneimine derivatives having pendant thymine or adenine bases.