Thin Deposits and Patterning of Room-Temperature-Switchable One-Dimensional Spin-Crossover Compounds

We present a study on thin deposits and patterning of 1-D spin-crossover compounds Fe-II-(L)(2)H](ClO4)(3)center dot MeOH [L = 4'-(4'''-pyridyl)-1,2':6'1 ''-bis-(pyrazolyl) pyridine] (1) that exhibit a reversible, thermally driven spin transition at room temperature. Micrometric rodlike crystals of 1 on silicon surfaces are achieved by drop casting and solvent annealing. We observed that the crystallinity of thin deposits and spin-transition properties critically depends on the deposition procedure. Furthermore, we proved processability and patterning using unconventional wet lithography that reduces the crystallite formation time by 1 order of magnitude. Thin deposits of 1 were characterized by atomic force microscopy, polarized optical microscopy and X-rays, and the switching properties were characterized by Raman spectroscopy.