Optimized local synthetic conditions induce size reduction and phase purification in {[Fe(Htrz)2(trz)](BF4)}n spin crossover particles

Data set and images from Optimized local synthetic conditions induce size reduction and phase purification in {[Fe(Htrz)2(trz)](BF4)}n spin crossover particles - Publication : Castel T., Marchetti A., Houard F., Daro N., Marchivie M., Chastanet G. and Bernot K. Optimized local synthetic conditions induce size reduction and phase purification in {[Fe(Htrz)2(trz)](BF4)}n spin crossover particles. Crystal Growth & Design 2023 vol.23, n°2, p.1076-1083. HAL : https://hal.science/hal-03945807 Dataset production context : The well-known synthesis of the two polymorphs of the {[Fe(Htrz)2(trz)](BF4)}n spin crossover coordination polymer is explored with new template-free methods that allow a control over the local synthetic conditions. A “one-pot” synthesis approach is developed, in which the solid reactants are mixed together before the addition of the solvent, which is expected to generate instantaneous supersaturation conditions favoring the nucleation of particles over their growth. In a second method, the addition of ultrasound pulses promotes the appearance of local “hot spots” that affect the local temperature and allow exploring a different region of the concentration–temperature phase diagram, leading to an increase in the phase purity of the product. These two syntheses are compared to the classical method in which the reactants are first dissolved in separate solutions before being mixed. The use of a one-pot synthesis, with or without ultrasound pulses, induces a downsizing of the particle size by a factor of 500 on their volume. The addition of ultrasound pulses allows moving from a mixture of polymorphs I and II of this compound to the pure phase I. These approaches open the way to more studies on the control over the size or phase purity in such molecular compounds, without the use of any surfactant. For more information see the article.

数据集及图像来源于《优化局部合成条件实现{[Fe(Htrz)2(trz)](BF4)}n自旋交叉粒子（spin crossover particles）的尺寸减小与相纯化》——出版物：Castel T.、Marchetti A.、Houard F.、Daro N.、Marchivie M.、Chastanet G.及Bernot K.《优化局部合成条件实现{[Fe(Htrz)2(trz)](BF4)}n自旋交叉粒子的尺寸减小与相纯化》，《晶体生长与设计》（Crystal Growth & Design）2023年第23卷第2期，第1076-1083页。HAL链接：https://hal.science/hal-03945807 数据集生成背景：针对{[Fe(Htrz)2(trz)](BF4)}n自旋交叉配位聚合物的两种多晶型物（polymorphs），研究人员采用可调控局部合成条件的新型无模板法对其已知合成过程进行了探索。研究开发了一种“一锅法”（one-pot）合成策略：先将固体反应物混合，再加入溶剂，此举旨在产生瞬时过饱和条件（supersaturation conditions），从而促进粒子成核（nucleation）而非生长。第二种方法中，超声脉冲的加入促使局部“热点”（hot spots）形成，这些热点会影响局部温度，进而可探索浓度-温度相图（phase diagram）的不同区域，最终提高产物的相纯度。这两种合成方法与经典方法进行了对比——经典方法是先将反应物分别溶解于不同溶液中，再进行混合。无论是否添加超声脉冲，采用一锅法合成均能使粒子体积缩小500倍。添加超声脉冲可将该化合物的多晶型物I与II的混合物转化为纯相I。这些方法为无需使用表面活性剂（surfactant）即可调控此类分子化合物的尺寸或相纯度的进一步研究开辟了道路。更多信息请参阅原文。