STRUCTURE OF 3 NOVEL PHOTOCHROMIC COMPOUNDS - X-RAY CRYSTALLOGRAPHIC AND THEORETICAL-STUDIES

5,7-Dimethoxy-1',3',3'-trimethylspiro[2H-1,4-benzoxazine-2,2'-indoline], C20H22N2O3, M(r) = 338.4, monoclinic, P2(1)/c, a = 12.151 (2), b = 12.090 (4), c = 24.836 (4) Angstrom, beta = 90.31 (1)degrees, V = 3648 (2) Angstrom(3), Z = 8, D-x = 1.23 Mg m(-3), lambda(Cu K alpha) = 1.54178 Angstrom, mu = 0.637 mm(-1), F(000) = 1440, T = 296 K, R = 0.063 for 3106 unique observed reflections. (2) 5,5',7-Trimethoxy-1',3',3'-trimethylspiro[2H-1,4-benzoxazine-2,2'-indoline], C21H24N2O4, M(r) = 368.4, monoclinic, P2(1)/c, a = 8.025 (2), b = 12.415 (3), c = 19.319 (4) Angstrom, beta = 99.31 (2)degrees, V = 1899.4 (8) Angstrom(3), Z = 4, D-x = 1.288 Mg m(-3), lambda(Cu K alpha) = 1.54178 Angstrom, mu = 0.084 mm(-1), F(000) = 784, T = 173 K, R = 0.0486 for 1611 unique observed reflections. (3) 5'-Fluoro-5,7-dimethoxy-1',3',3'-trimethylspiro[2H-1,4-benzoxazine-2,2'-indoline], C20H21N2O3F, M(r) = 356.4, monoclinic, P2(1)/c, a = 11.484 (3), b = 13.832 (2), c = 11.511 (1) Angstrom, beta = 98.90 (1)degrees, V = 1810.4 (6) Angstrom(3), Z = 4, D-x = 1.308 Mg m(-3), lambda(Cu K alpha) = 1.54178 Angstrom, mu = 0.754 mm(-1), F(000) = 752, T = 173 K, R = 0.0468 for 2229 unique observed reflections. These three monomeric compounds consist of a substituted benzoxazine ring orthogonally coupled to an indoline ring through a spiro C atom.