[Fe(Htrz)2(trz)](BF4) nanoparticle production in a milli-scale segmented flow crystalliser

Microfluidics has become well established as the benchmark method of nanoparticle production but the need for special equipment and the challenge of scale-up can make it prohibitive for many laboratories. In contrast, the larger scale millifluidics methodology provides a platform for controlled nanoparticle production in a simple set-up without risk of blockages, increasing the volume of material produced while continuing to offer control over particle attributes. Nanoparticle size can have a profound effect on the properties exhibited, in the case of spin-crossover materials the size of nanoparticles can have a direct correspondence with the hysteresis of magnetic susceptibility vs temperature. Nanoparticle synthesis of the spin-crossover coordination polymer [Fe(Htrz)2(trz)](BF4) (Htrz = 1,2,4-1H-triazole) has hitherto been reported through batch methods alone. Here we present the first flow synthesis of [Fe(Htrz)2(trz)](BF4) in a milli-scale segmented flow crystalliser (the Kinetically
Regulated Automated Input Crystalliser, KRAIC).