Resonance Raman Study of Spin‐Crossover [Fe(Htrz)₂(trz)](BF₄)·H₂O Particles Coated with Gold

Abstract

Abstract Spin‐crossover (SCO) particles of the [Fe(Htrz) 2 (trz)](BF 4 ) · H 2 O polymeric complex were deposited on a glass slide and coated with gold. We found that normal Raman scattering is not appropriate for analysing such a material. However, the spin transition and the thermal hysteresis of the coated particles were successfully monitored by means of Raman spectroscopy using the 325 nm excitation line that is in pre‐resonance with the Metal to Ligand Charge Transfer (MLCT) electronic absorption band of the low‐spin state. The results obtained confirm the persistence of the spin‐crossover properties of the gold coated particles. The strong enhancement of the Raman scattering using the 325 nm excitation opens interesting opportunities for monitoring the SCO of particles integrated in miniaturised devices.