Synthesis and complexation mechanism of europium ion (Eu3+) with spiro[indoline-phenanthrolineoxazine]

A series of spirooxazines containing phenanthroline were synthesized; the opened forms of such molecules have two potential metal-binding sites. By studying the photochromic and thermochromic properties of the complexes of europium ion (Eu3+) with the photomerocyanine of spirooxazine, the complexation mechanism and metal-binding site of Eu3+ were determined.