Structure of photochromic spiroxazines. I. 1,3,3-Trimethylspiro[indoline-2,3'-[3H]-naphtho[2,1-b][1,4]oxazine]

Structure of an organic photochromic compound. 6,7,8a,9-Tetrahydro-17,17-dimethylnaphtho[1'',2'':5',6'][1,4]oxazino[3',2':2,3][1,4]oxazino[4,3-a][3H]indole

“…The structure of compound (III) is very similar to those of (I) and (II). In (I) and (II), the spiro atom is shared by two rings and displays regular sp 3 hybridi- grini, Crisci & Malatesta, 1991). Other distances are comparable to those in (I) and (II).…”

Photochromic spironaphthoxazines: A theoretical study

“…Although a few theoretical studies have been carried out on [14] spiropyrans, the aim being the understanding of the mechanism of photoconversion of the spiro parent structure to the open forms, the spironaphthoxazine system has not, so far, been addressed. We recently completed an X-ray diffraction structural characterization of several spironaphthoxazine derivatives, la, 2a, and the 6'-piperidinyl derivative of la (Chart 1) [15], and a kinetic study of the thermal bleaching of the corresponding merocyanines [16]. We felt that it would be useful to describe, from a theoretical point of view, the merocyanine isomeric distribution, identify the most stable structure, and calculate the activation energy for the thermal back reaction to the spiro form.…”

Synthesis and structure of spirooxazines of the thieno[3,2-b]pyrroline series

“…15, 16 (To make the comparison of molecular parameters more convenient, we give a general atom numbering in Scheme 4).…”