三碘化铑(RhI₃)是一种黑色晶体粉末,其中Rh含量为19.5~21.3%,在空气中易潮解。它主要用作羰基化合成反应的催化剂,在合成醋酸、醋酐、乙二醇等反应中发挥重要作用。
制备CN201010153085.9 公开了一种制备羰化碘化铑溶液的方法,包括以下步骤:
碘化铑是一种黑色晶体,在常温常压下较为稳定,但在675℃时开始发生分解。目前常见的合成方法主要有溶液合成法和直接合成法。它常作为羰基合成的主催化剂,特别适用于醋酸和醋酐的合成。
理化性质三碘化铑是一种黑色固体,呈单斜晶系结晶结构,密度为665g/cm³。在常温下较为稳定,但在675℃以上开始分解,并具有吸湿性。它能溶于酒精、水和丙酮中。
制备方法直接合成法:利用碘在引发剂作用下形成碘游离基的特性,使铑粉与碘粉直接反应生成碘化铑。反应方程式为 2Rh + 3I₂ = 2RhI₃。
溶液合成法:将三氯化铑溶于水中,加入适量的碘化钾或氢碘酸,并在一定温度下进行3小时的反应。
新合成法:将2g铑粉和100mL复合溶剂R101(由无机酸类和引发剂组成)加入反应釜,缓慢加热直至釜内温度升至要求值时保持回流2小时。待金属完全溶解后转移至旋转蒸发器中,回收并循环使用溶剂。在剩余少量液体中加入碘化钾,在80℃恒温下反应0.5小时。经过冷却结晶、过滤、洗涤和干燥步骤后,即可得到黑色固体粉末的碘化铑。
三碘化铑作为羰基合成的主催化剂,特别适用于醋酸和醋酐的合成。上述概述、理化性质及制备方法由Chemicalbook的丁红编辑整理(2015-12-21)。
生产方法:金属铑粉与I₂在400℃下反应可以生成结晶态的碘化铑;若向RhCl₃溶液中加入KI溶液,则会生成无定形的RhI₃沉淀。
The complexes of the cycloserine derivative, 4,4'-[1,4-phenylenebis(methylidynenitrilo)]bis(isoxazolidin-3-one) or terizidone, with chromium(III), ruthenium(III) and rhodium(III) have been synthetized; their structures have been suggested on the basis of analytical, conductivity, spectral (visible, infrared and far-infrared) and magnetic data, and the thermal analyses have revealed the extent of coordinated water among the chromium and ruthenium complexes. The various ligand field parameters have been evaluated; the B' values suggest a strong covalency in the metal-ligand σ bond and the Dq values show a medium-strong ligand field. The position and multiplicity of the metal-halogen stretching modes in the far-infrared region have been extensively investigated and discussed; the results are particularly useful in distinguishing between the mer- and fac-isomers in the octahedral compounds of the ML3X3 type. The ligand is monodentate O-bonded or N-bonded through the oxygen of the keto group or through the nitrogen of the imino group of the isoxazole ring. We have never observed a metal-induced cycloserine ring opening under the present experimental conditions.