Abstract
For 25 years the two metastable electronic states (SI and SII), accessible in the nitroprusside anion [Fe(CN)5NO]2- (NP) by irradiation with blue polarized light, have been the subject of intense investigations from several research groups. This review article summarizes the most important experimental results in the field of photochromatic effects investigated by nuclear resonant methods. The experimentally determined data have been compared with the results derived from density functional theory calculations. The majority of results convincingly indicates: (i) the SI state is represented by the isonitrosyl conformation (Fe-O-N) of the (NO +)-group and (ii) the SII state is represented by a dynamic conformation, in which a bending vibration of Fe-O-N as well as a rotation of the (NO+)-group around the main molecular axis simultaneously occur. A possible formation of a new third metastable state observed in rare-earth nitroprussides, which is stable at room temperature, will be discussed.
| Original language | English |
|---|---|
| Journal | Hyperfine Interactions |
| Volume | 144-145 |
| Issue number | 1-4 |
| Pages (from-to) | 307-323 |
| Number of pages | 17 |
| ISSN | 0304-3843 |
| DOIs | |
| Publication status | Published - 01.12.2002 |
Funding
We would like to thank the Alexander von Humboldt Foundation, AvH (V. R.), the German Academic Exchange Serves, DAAD (Sv. S.) and the German Research Foundation, DFG (A. X. T.) for supporting this research. We specially thank the Organizing Committee of the 5th Seeheim Workshop on Mössbauer Spectroscopy and personally Prof. Dr. P. Gütlich for the invitation to present this contribution at the Seeheim Workshop and for financial support.
