Photochromism of the ternary system of europium-N, N-bis(N-methylenesuccinimido) glycine-1,10-phenanthroline

In the present paper, N,N-bis (N-methylenesuccinimido) glycine(MSIG) was sy nthesized and characterized by elemental analysis, IR, H-1 NMR and MS. It i s demonstrated by experiment that the europium complex of MSIG with 1,10-ph enanthroline has reversible photochromism which occurs rarely in lanthanide complexes. Photochromic behavior of the europium complex was investigated in H2O and H2O-C2H5OH solvents, The irradiation of the europium complex sol ution led to a new absorption band with the maximum wavelength at similar t o 616 nm while the color of the solution turned from yellow to green, and w hen the photolysate was kept in dark, the absorption spectrum turned to its initial figure, The results show that the spectral signal at similar to 61 6 nm appeared on irradiation and in general disappeared within 1 h at ambie nt temperature. The yellow color of the europium complex solution turns gre en rapidly when irradiated as pH of the solution increases in a range of 4 similar to 6, On heating the color changes from green to yellow readily. Th e absorption spectra, the fluorescence spectra and the conductance measurem ent show that the europium ion is bonded to the carboxyl group of MSIG and the nitrogen atoms from 1,10-phenanthroline, and probably to water and hydr oxyl group in the colored europium species.