Photo- and Ionochromism of Benzoxazolyl-Substituted Spirobenzopyrans

8-Benzoxazolyl-6-formyl-substituted spirobenzopyrans with different acceptor groups in the 5'- position of the indoline moiety have been synthesized. Novel spiropyrans exhibit photochromic properties in an acetone solution at room temperature and form intensely colored complexes with heavy metal cations.