THERMAL DECAY OF THE OPTICAL-ACTIVITY IN THE LIGHT-INDUCED METASTABLE STATE OF AN NA2[FE(CN)5NO]CENTER-DOT-2H2O CRYSTAL

The metastable state of an Na2[Fe(CN)5NO] . 2H2O crystal induced by irradiation with blue laser light at 77 K has a novel optical property, which originates in the optical activity and ''the accidental optical isotropy in the birefringent crystal''. The optical activity begins to diminish at 180 K, which is the onset temperature of the thermal decay of one of the metastable molecules characterized by a 1836 cm-1 band. The thermal decay of another species characterized by a 1665 cm-1 band, which decays at around 130 K, does not affect the optical activity. The space group of the metastable state that agrees with the observed optical properties is D2(3) - P2(1)2(1)2.