Photoinduced spin-crossover

Recent Topics of Photoinduced Spin-Crossover Phenomena... 

Photoinduced spin-related phenomena are a particularly important field of the solid-state photophysics, because fast spin switching is a prospective basis for applications in the field of spintronics. An illustrative example is the production of the metastable state of the iron propyltetrazole (ptz) complex [Fe(ptz)6](BF4)2 by laser light-induced excited spin-state trapping (LIESST) and the determination of the resulting structure by steady-state X-ray photodiffraction [68]. In another example, steady-state X-ray photodiffraction at cryogenic temperatures was successfully utilized to study photoinduced phase transition due to spin crossover in the tris(a-picolylamine)iron(II) complex [69]. The phase transition is accompanied by... 

In the following sections, synthetic approaches to the preparation of multinu-clear cyanide complexes will be discussed. The structures of these compounds will be presented in the order of increasing nuclearity. Finally, the magnetic properties of cyanide complexes, including single-molecule magnetism, photoinduced magnetism, and spin crossover will be described. 

Bond distortion, spin crossover Sensitization, energy transfer Photoinduced electron transfer Hydrogen atom abstraction Photooxidation, photoreduction Photoaddition, photosubstitution Photodissociation, photo-cleavage Photoisomerizations Photodimerization, photo-pol3nnerization... 

Figure 9.12 shows the crystal structure of [Fe(pyrazine) Pt(CN)4 ] [13]. This complex shows a thermally induced spin-crossover transition (Tct = 284 K, T l = 308 K) with a thermal hysteresis of 24 K, which was observed by means of magnetic susceptibility measurement and Raman spectroscopy. The spin-crossover transition has been confirmed by Fe Mossbauer spectroscopy [13]. The Mossbauer spectrum at 300 K in the cooling mode consists of a single doublet with quadrupole splitting (QS) of 1. 159(5) mm s and isomer shift (IS) of 1.047(3) mm s whose values are typical of the HS state ( T2g, S = 2) of Fe(ll). At 80 K, a new doublet with quadrupole splitting of 0.306(4) mm s and isomer shift of 0.439(2) mm s whose values are typical of the LS state ( A g, 5 = 0) of Fe(ll). The photoinduced spin conversion between the LS and HS states around room temperature has been confirmed by means of Raman spectroscopy within the thermal hysteresis loop of spin-crossover transition, which is shown in Fig. 9.13 [13]. In this complex, the frequency of...

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