Эротические рассказы

Diarylethene Molecular Photoswitches. Masahiro IrieЧитать онлайн книгу.

Diarylethene Molecular Photoswitches - Masahiro Irie


Скачать книгу
target="_blank" rel="nofollow" href="#fb3_img_img_9c82f7f6-be1e-5218-ad73-6520d674ebe1.png" alt="Chemical reaction depicts disrotatory and conrotatory cyclization reactions of hexatriene."/>

      The cycloreversion reaction is allowed photochemically in the conrotatory mode and thermally in the disrotatory mode. From this simple symmetry consideration of the HT molecular framework, the thermal stability of the open‐ring isomer of 2,3‐di(2,5‐dimethyl‐3‐thienyl)‐2‐butene and thermal irreversibility in the cycloreversion reaction cannot be explained. A state energy calculation is necessary to discuss the thermal stability.

Schematic illustration of the state correlation diagrams for the electrocyclic reactions in disrotatory mode. 9c and 11c are the closed-ring isomers, in which two hydrogens attached to the reactive central carbons are in a cis configuration. Schematic illustration of the state correlation diagrams for the electrocyclic reactions in conrotatory mode. 9c and 11c are closed-ring isomers, in which two hydrogens attached to the reactive central carbons are in a trans configuration.
Compound Disrotatory (kJ/mol) Conrotatory (kJ/mol)
1,2‐Diphenylethene (9) 175 114
1,2‐Di(3‐pyrrolyl)ethene (10) 135 65
1,2‐Di(3‐furyl)ethene (11) 113 38
1,2‐Di(3‐thienyl)ethene (12) 51 −14
Schematic illustration of the correlation between the ground state energy difference between open- and closed-ring isomers and the energy barrier. Schematic illustration of the structure changes of phenyl and five-membered heterocyclic rings <hr><noindex><a href=Скачать книгу
Яндекс.Метрика