Flexible and Optically Transparent Polymer Embedded Nano/Micro Scale Spin Crossover Fe(II) Complex Patterns/Arrays

A novel highly soluble spin-crossover (SCO) [Fe II ( L ) 2 ](BF 4 ) 2 complex ( I ) was prepared, where L = 4,4″-dioctylated 2′,6′-bispyrazolylpyrine. Complex I shows reversible temperature dependent SCO behavior with a T 1/2 centered around 270 K. Exploiting the high solubility and hence superior processability of complex I nano/micro scale arrays and square patterns were fabricated on a glass substrate. Additionally, for the first time, for the possible flexible technological applications, the SCO arrays (area: 2 mm 2 ) were successfully embedded within an optically transparent thin polystyrene film and studied using Raman spectroscopy/imaging technique. Variable temperature Raman spectroscopy studies further confirmed the SCO behavior of complex I .