Synthesis and complex formation of spirobenzopyranindolines containing rhodamine fragment

Abstract

The interaction of 7-hydroxy-6-formyl-substituted spiropyrans and Rhodamine B aminoethylamide has afforded spirobenzopyrans containing rhodamine fragment bound to the benzopyran part via the methyleneaminoethyl spacer. The prepared spiropyrans exist in the spiropyran-spirolactam form in the acetone solution and exhibit weak photochromism at 283 K. The addition of Cd, Co, Ni, and Zn perchlorates to the spiropyrans solution results in the coloration due to the complex formation. The composition and stability of the complexes has been determined by means of spectrophotometry.