Soft X-ray induced excited spin state trapping and soft X-ray photochemistry at the iron L2,3 edge in [Fe(phen)2(NCS)2] and [Fe(phen)2(NCSe)2] (phen = 1,10-phenanthroline) ‡

The first observation of soft X-ray induced excited spin state trapping has been made for [Fe(phen)2(NCS)2] and [Fe(phen)2(NCSe)2] (phen = 1,10-phenanthroline) at ca. 45 K, analogous to light induced excited spin state trapping but at much higher energy. Soft X-ray photochemistry has also been observed in the high- and low-spin states of [Fe(phen)2(NCS)2] and [Fe(phen)2(NCSe)2], resulting in the formation of a thermally irreversible low-spin state. The rate of formation of this low-spin state is greater from low than from high spin, and is also greater in [Fe(phen)2(NCSe)2] than in [Fe(phen)2(NCS)2].