Time-Resolved Study of the Photoswitching of Gold Nanorods Coated with a Spin-Crossover Compound Shell

We investigate the spin-state photoswitching process in Au@SCO nanohybrids made of gold nanorods coated by a spin crossover (SCO) shell of polymeric triazole based Fe(II) complexes of [Fe(Htrz) 2 trz] (BF 4). Our research is performed exciting our samples with near-infrared quasi-continuous wave or nanosecond pulse, tunable from visible to near-infrared range. Time-resolved experiments ranging from millisecond down to nanosecond timescales reveal the dynamics during the spin-state transition. Upon excitation, the thermal photoswitching of the sample happens within hundreds of milliseconds for quasi-continuous wave excitation. It happens within tens of nanoseconds for a nanosecond pulse. Compared to the SCO [Fe(Htrz) 2 trz] (BF 4) nanoparticles powder, the peak power of quasi-continuous wave or fluence of the nanosecond laser required to induce the spin state transition in the nanohybrid is reduced. ANanomatériaux hybrides pour une commutation photo-thermique contrôlé