Cerium(III) Chloride

Abstract

[7790-86-5] (·7H2O) CeCl3 (MW 246.47) InChI = 1S/Ce.3ClH/h;3*1H/q+3;;;/p-3 InChIKey = VYLVYHXQOHJDJL-UHFFFAOYSA-K [18618-55-8] H14CeCl3O7 (MW 372.59) InChI = 1S/Ce.3ClH.7H2O/h;3*1H;7*1H2/q+3;;;;;;;;;;/p-3 InChIKey = KPZSTOVTJYRDIO-UHFFFAOYSA-K (mild Lewis acid capable of selective acetalization;2 organocerium reagents have increased oxo-3 and azaphilicity4 and greatly reduced basicity;5 in combination with NaBH4 is a selective 1,2-reducing agent6; commercially available lanthanide reagent which is a mild Lewis acid, water tolerant, nontoxic, easy to handle, inexpensive7; in combination with NaI its activity is increased dramatically, cerium(III) chloride/NaI supported on silica gel has been developed by Bartoli and marcantoni,8 to improve its utility in organic synthesis) Alternate Name: cerous chloride; cerium trichloride. Physical Data: mp 848 °C; bp 1727 °C; d 3.92 g cm−3. Solubility: insol cold H2O; sol alcohol and acetone; slightly sol THF. Form Supplied in: white solid; widely available. Drying: for some applications the cerium trichloride must be strictly anhydrous. The following procedure has proven most efficacious: a one-necked base-washed flask containing the heptahydrate and a magnetic stirring bar was evacuated to 0.1 Torr and heated slowly to 140 °C over a 2 h period. At 70 and 100 °C, considerable amounts of water are given off, and these critical temperature zones should not be passed through too quickly. The magnetically stirred white solid is heated overnight at 140 °C, cooled, blanketed with nitrogen, treated with dry THF (10 mL g−1), and agitated at rt for 3 h. To guarantee the complete removal of water, t-butyllithium is added dropwise until an orange color persists. Handling, Storage, and Precautions: anhydrous CeCl3 should be used as prepared for best results. Cerium is reputed to be of low toxicity.