Structures and photo- and thermochromic properties of spiropyrans of the 2-oxaindan series with polycondensed chromene fragments

✍ Scribed by S. M. Aldoshin; V. A. Lokshin; A. N. Rezonov; N. V. Volbushko; N. E. Shelepin; M. I. Knyazhanskii; L. O. Atovmyan; V. I. Minkin

• Book ID: 104785629
• Publisher: Springer US
• Year: 1987
• Tongue: English
• Weight: 946 KB
• Volume: 23
• Category: Article
• ISSN: 0009-3122
• DOI: 10.1007/bf00486903

✦ Synopsis

Spiropyrans of the 2-oxaindan series with 2H-chromene fragments benzo-and 2,3naphthoannelated at the 7-8 bond were synthesized. The molecular structures of four of the spiropyrans obtained were determined by x-ray diffraction studies, and their photo-and thermochromic properties were studied. Annelation of arene rings significantly increases the relative stabilities fo the photocolored forms of the spiropyrans.

A correlation between the length of the Cspiro-O bond and the capacity of spiropyrans for photocoloration was discovered.-In addition, the free energies of activation of the thermochromic transformations of spiropyrans determined by dynamic Nq~R spectroscopy are insensitive to variations in the length of the indicated bond. *Communication XlX from the series "Photo-and thermochromic spirans." See [i] for Communication XVIII.