Photodegradation of Hydrophobic Pyridineketoximes in Toluene and Heptane
摘要:
AbstractThe goal of the research was to study the reactivity of the hydrophobic 2‐ and 3‐pyridineketoximes under exposure to UV‐VIS light. The photodegradation was conducted in both toluene and heptane for 10 h under atmosphere of argon. Ten‐hour irradiation experiments demonstrated that the pyridineketoximes underwent the facile E‐Z photoisomerization, photo‐Beckmann rearrangement, and to a lesser extent, the photosubstitution to the pyridine ring. From LC‐MS and NMR analysis of the irradiated solutions, it was found that the photosubstitution proceeded to give the corresponding 6‐substituted 2‐ or 3‐pyridylketoxime via the replacement of the ring hydrogen by the benzyl or heptyl group. The photo‐Beckmann rearrangement led to the formation of the corresponding amides, but also other products formed in the photo‐decomposition reaction.
Synthese d'isoalloxazine substitueeen 7,8 par un 18-crown-6; complexation avec des alcalins ou l'ion ammonium (cinetiques); reaction avec des derives de dihydro-1,4 nicotinamide
合成这些 d'isoalloxazine substituee en 7,8 par un 18-crown-6;络合 avec des alcalins ou l'ion 铵 (cinetiques); 反应 avec des 衍生 de dihydro-1,4 nicotinamide
Functional Flavin Receptors. Bis-melamine Derivatives Bearing a Guanidinium Ion Which Bind 6-Azaflavin and a Thymine-Linked Substrate through Hydrogen Bonds in Chloroform
Bis-melamine derivatives bearing a guanidinium ion bind 6-azaflavin via five hydrogen bonds and an NADH model having a thymine moiety via three H-bonds in CHCl3, resulting in the rate acceleration due to the proximity effect.
There is described a thermal recording system which utilizes a donor element comprising a substrate and a thermal transfer material layer having a dye-containing phase which is amorphous and wherein the dye or dyes present in the amorphous phase form a continuous film. Imagewise heating of the medium transfers portions of the transfer layer to a receiver sheet, thus forming an image. The transfer layer may also include a non-dye phase comprising a thermal solvent. During the heating of the donor element, the crystalline thermal solvent melts and dissolves or liquefies at least a portion of the dye-containing phase, thereby lowering the temperature at which transfer of the transfer layer occurs.
Thermal transfer recording system having an amorphous dye phase
申请人:Polaroid Corporation
公开号:EP1493593A1
公开(公告)日:2005-01-05
There is described a thermal recording system which utilizes a donor element comprising a substrate and a thermal transfer material layer having a dye-containing phase which is amorphous and wherein the dye or dyes present in the amorphous phase form a continuous film. Imagewise heating of the medium transfers portions of the transfer layer to a receiver sheet, thus forming an image. The transfer layer may also include a non-dye phase comprising a thermal solvent. During heating of the donor element, the crystalline thermal solvent melts and dissolves or liquefies at least a portion of the dye-containing phase, thereby lowering the temperature at which transfer of the transfer layer occurs.