Anhydrous Actinide Starting Materials: Synthesis and Structural Characterization of [UCl4(Et2O)2], an Alternative Route to [UO2Cl2(THF)2]2, and Comments on the Synthesis of [ThCl4(dme)2]

Abstract A new diethyl ether adduct of uranium tetrachloride, [UCl 4 (Et 2 O) 2 ] ( 1 ), along with the previously reported mono‐etherate complex [UCl 4 (Et 2 O)] n ( 2 ), have been synthesized and characterized by powder X‐ray diffraction, elemental analysis, and in the case of 1 , single crystal X‐ray diffraction. Additionally, reaction of anhydrous [UO 2 (OAc) 2 ] n with HCl in Et 2 O/THF was found to afford the uranyl dichloride complex [UO 2 Cl 2 (THF) 2 ] 2 ( 3 ) in high purity and yield, providing an alternative and convenient entry point into anhydrous uranyl chemistry. Furthermore, comments are provided regarding the literature synthesis of [ThCl 4 (dme) 2 ] via the reaction of [ThCl 4 (H 2 O) 4 ] with Me 3 SiCl in dme, highlighting important considerations for the compound's preparation in good yield.