Jean Luc Pozzo

Specific Structural Features and Photochemical Properties of Three Benzo-Annulated 2,2-Diphenyl[2H]chromenes

The crystal structures of 3,3-diphenylbenzo[f]-chromene, C 25 H 18 O, 1,3,3-triphenylbenzo[f]chromene, C 31 H 22 O, and 2,2-diphenylbenzofuro[2,3-g]chromene, C 27 H 18 O 2 , have been determined. Annulated 2,2-di- phenylchromenes are of interest because of the influence of steric strain energy in the pyran ring on the photochromic properties of these compounds.

A Photochromic Pyrido-Annulated 2,2-Diphenylchromene

A photochromic pyrido-annulated chromene, 3,3-diphenylpyrano[5,6-f]quinoline, C 24 H 17 NO, has been studied. The photoreactive C sp3 -O bond length is longer than the standard values observed for oxygen-containing heterocycles as a result of steric interactions between the two phenyl groups

Photochromic Pyrido-Annelated 2,2-Dimethylchromene

An X-ray analysis of the title photochromic pyrido-annelated 2,2-dimethylchromene, 3,3-dimethylpyrano[3,2-f]quinoline, has been undertaken. It forms a crystallohydrate, C 14 H 13 NO.H 2 O. The influence of the molecular structure on its photochemical properties has been investigated.