Synthesis and crystal structure of 1, 3- bis- ( 3, 3- dimethyl- 2 -methylene indoleine) squarylium cyanine dyes
LI JUCAI;CHEN YIZHAO;LI WENZAO;YU LINZHUANG
Chin. J. Org. Chem. . 1992, (4): 366 -372 .