POLARIZED INFRARED-ABSORPTION SPECTRA OF NA-2 [FE(CN)5NO].2H2O WITH PART OF THE ANIONS IN THE ELECTRONICALLY EXCITED METASTABLE STATE

IR spectra of the nitroprusside ion in Na//2 left bracket Fe(CN)5NO right bracket multiplied by (times) 2H//2O in the metastable electronic state produced by irradiation at boiling air temperature with the 514. 5 nm line of an Ar** plus laser were obtained for thin (100) single crystal plates in the ranges 4000-430 cm** minus **1 and 4000-550 cm** minus **1 for polarizations along the b and c-axes, respectively. The spectra showed that the suggested bending of the FeNO group upon excitation occurs in the (a,b)mirror plane of the ground state crystal. In addition to bands corresponding to Raman lines, reported as due to excited nitroprusside, new bands appeared in the infrared spectra. Some of them showed a strong dichroic behavior. On heating the samples some of the new bands disappeared earlier than the bands corresponding to the Raman lines.