One laser shot induced complete phase transition in the spin crossover complex Fe(pyrazine)[Pt(CN)4]

A photo-induced phase transition in the spin crossover complex Fe(pyrazine)[Pt(CN)4] has been triggered by a 4 ns green pulsed laser excitation within its thermal hysteresis loop. Complete spin conversion from the low spin to the high spin state has been repeatedly observed by irradiating a polycrystalline powder sample. In addition, the non-linear behaviour of the photoconversion efficiency and, in particular, the occurrence at ca. 5 mJ/cm2 of an energy density threshold, below which no light-induced phase transition appears, is observed. This threshold is shown to be temperature dependent, which is confirmed by a simple theoretical description.

Graphical abstractA complete photo-induced phase transition from the low-spin to the high-spin state is triggered by exciting the spin crossover complex Fe(pyrazine)[Pt(CN)4] with a single laser shot at 532 nm. A non-linear behaviour of the photo-conversion efficiency characterised by the occurrence of an energy density threshold is notably observed.Figure optionsDownload full-size imageDownload as PowerPoint slide