Cerium(III) chloride

{{chembox

| Verifiedfields = changed

| Watchedfields = changed

| verifiedrevid = 476998131

| Name = Cerium(III) chloride

| ImageFile = CeriumIIIchloride.jpg

| ImageFileL1 = UCl3 without caption.png

| ImageFileR1 = Cerium bromide (space filling) 2.png

| ImageName = Cerium(III) chloride

| IUPACName = Cerium(III) chloride
Cerium trichloride

| OtherNames = Cerous chloride

|Section1={{Chembox Identifiers

| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}

| ChemSpiderID = 23038

| InChI = 1/Ce.3ClH/h;3*1H/q+3;;;/p-3

| ChEBI_Ref = {{ebicite|correct|EBI}}

| ChEBI = 35458

| Gmelin = 1828

| EINECS = 232-227-8

| SMILES = [Cl-].[Cl-].[Cl-].[Ce+3]

| InChIKey = VYLVYHXQOHJDJL-DFZHHIFOAZ

| StdInChI_Ref = {{stdinchicite|correct|chemspider}}

| StdInChI = 1S/Ce.3ClH/h;3*1H/q+3;;;/p-3

| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}

| StdInChIKey = VYLVYHXQOHJDJL-UHFFFAOYSA-K

| CASNo = 7790-86-5

| CASNo_Ref = {{cascite|correct|CAS}}

| CASNo2_Ref = {{cascite|correct|CAS}}

| CASNo2 = 18618-55-8

| CASNo2_Comment = (heptahydrate)

| UNII_Ref = {{fdacite|Correct|FDA}}

| UNII= TH8E3IE00V

| UNII1_Ref = {{fdacite|correct|FDA}}

| UNII1 =188BE3J495

| UNII1_Comment = (heptahydrate)

| RTECS =

| PubChem = 24636

}}

|Section2={{Chembox Properties

| Formula = CeCl₃

| MolarMass = 246.48 g/mol (anhydrous)
372.58 g/mol (heptahydrate)

| Appearance = fine white powder

| Density = 3.97 g/cm³

| SolubleOther = soluble in alcohol

| MeltingPtC = 817

| MeltingPt_notes = (anhydrous)
90 °C (heptahydrate, decomposes)

| BoilingPtC = 1727

| MagSus = +2490.0·10⁻⁶ cm³/mol

}}

|Section3={{Chembox Structure

| Coordination = Tricapped trigonal prismatic
(nine-coordinate)

| CrystalStruct = hexagonal (UCl₃ type), hP8

| SpaceGroup = P6₃/m, No. 176

}}

|Section7={{Chembox Hazards

| ExternalSDS =

| GHSPictograms = {{GHS05}}{{GHS07}}{{GHS09}}

| GHSSignalWord = Danger

| HPhrases = {{H-phrases|315|318|319|335|410}}

| PPhrases = {{P-phrases|261|264|271|273|280|302+352|304+340|305+351+338|310|312|321|332+313|337+313|362|391|403+233|405|501}}

| FlashPt = Non-flammable

}}

|Section8={{Chembox Related

| OtherAnions = Cerium(III) oxide
Cerium(III) fluoride
Cerium(III) bromide
Cerium(III) iodide

| OtherCations = Lanthanum(III) chloride
Praseodymium(III) chloride

}}

Cerium(III) chloride (CeCl₃), also known as cerous chloride or cerium trichloride, is a compound of cerium and chlorine. It is a white hygroscopic salt; it rapidly absorbs water to form hydrates, which may be of variable composition.The hexa- and heptahydrate CeCl₃·7H₂O are known.{{cite journal |doi=10.1063/1.4823707 |title=The observation of scintillation in a hydrated inorganic compound: CeCl3·6H2O |date=2013 |last1=Boatner |first1=L. A. |last2=Neal |first2=J. S. |last3=Ramey |first3=J. O. |last4=Chakoumakos |first4=B. C. |last5=Custelcean |first5=R. |journal=Applied Physics Letters |volume=103 |issue=14 }} All forms are highly soluble in water, and the anhydrous derivative is soluble in ethanol and acetone.{{cite book |title=Handbook of Reagents for Organic Synthesis: Reagents, Auxiliaries and Catalysts for C-C Bond Formation |last=Paquette |first=L. A. |editor=Coates, R. M. |editor2=Denmark, S. E. |year=1999 |publisher=Wiley |location=New York |isbn=0-471-97924-4 }}{{cite journal |doi=10.1063/1.3049137 |title=Single-crystal CeCl3(CH3OH)4: A new metal-organic cerium chloride methanol adduct for scintillator applications |date=2008 |last1=Boatner |first1=L. A. |last2=Wisniewski |first2=D. |last3=Neal |first3=J. S. |last4=Ramey |first4=J. O. |last5=Kolopus |first5=J. A. |last6=Chakoumakos |first6=B. C. |last7=Wisniewska |first7=M. |last8=Custelcean |first8=R. |journal=Applied Physics Letters |volume=93 |issue=24 }}

Preparation of anhydrous CeCl<sub>3</sub>

Simple rapid heating of the hydrate alone may cause small amounts of hydrolysis.{{cite book |title=Synthetic Methods of Organometallic and Inorganic Chemistry |volume=VI |last=Edelmann |first=F. T. |author2=Poremba, P. |editor=Herrmann, W. A. |year=1997 |publisher=Georg Thieme Verlag |location=Stuttgart |isbn=3-13-103021-6 }}

A useful form of anhydrous CeCl₃ can be prepared if care is taken to heat the heptahydrate gradually to {{convert|140|°C|°F|abbr=on}} over many hours under vacuum.{{cite journal |last=Johnson |first=C. R. |author2=Tait, B. D. |year=1987 |title=A cerium(III) modification of the Peterson reaction: methylenation of readily enolizable carbonyl compounds |journal=Journal of Organic Chemistry |volume=52 |issue=2 |pages=281–283 |issn=0022-3263 |doi=10.1021/jo00378a024 }}{{cite journal |last=Dimitrov |first=Vladimir |author2=Kostova, Kalina |author3=Genov, Miroslav |year=1996 |title=Anhydrous cerium(III) chloride — Effect of the drying process on activity and efficiency |journal=Tetrahedron Letters |volume=37 |issue=37 |pages=6787–6790 |doi=10.1016/S0040-4039(96)01479-7 }} This may or may not contain a little CeOCl from hydrolysis, but it is suitable for use with organolithium and Grignard reagents. Pure anhydrous CeCl₃ can be made by dehydration of the hydrate either by slowly heating to {{convert|400|°C|°F|abbr=on}} with 4–6 equivalents of ammonium chloride under high vacuum,{{cite journal |last=Taylor |first=M. D. |author2=Carter, P. C. |year=1962 |title=Preparation of anhydrous lanthanide halides, especially iodides |journal=Journal of Inorganic and Nuclear Chemistry |volume=24 |issue=4 |pages=387–391 |doi=10.1016/0022-1902(62)80034-7 }}{{cite journal |last=Kutscher |first=J. |author2=Schneider, A. |year=1971 |title= Notiz zur Präparation von wasserfreien Lanthaniden-Haloge-niden, Insbesondere von Jodiden|journal=Inorg. Nucl. Chem. Lett. |volume=7 |issue= 9|pages=815 |doi= 10.1016/0020-1650(71)80253-2}}{{cite book |title=Chemistry of the Elements |last=Greenwood |first=N. N. |author2=Earnshaw, A. |year=1984 |publisher=Pergamon Press |location=New York |isbn=0-08-022056-8 }} or by heating with an excess of thionyl chloride for three hours.{{cite journal |last=Freeman |first=J. H. |author2=Smith, M. L. |year=1958 |title=The preparation of anhydrous inorganic chlorides by dehydration with thionyl chloride |journal=Journal of Inorganic and Nuclear Chemistry |volume=7 |issue=3 |pages=224–227 |doi=10.1016/0022-1902(58)80073-1 }} The anhydrous halide may alternatively be prepared from cerium metal and hydrogen chloride.{{cite journal |last=Druding |first=L. F. |author2=Corbett, J. D. |year=1961 |title=Lower Oxidation States of the Lanthanides. Neodymium(II) Chloride and Iodide |journal=Journal of the American Chemical Society |volume=83 |issue= 11|pages=2462–2467 |issn=0002-7863 |doi=10.1021/ja01472a010}}{{cite journal |last=Corbett |first=J. D. |year=1973 |title=Reduced Halides of the Rare Earth Elements |journal=Rev. Chim. Minérale |volume=10 |pages=239 }} It is usually purified by high temperature sublimation under high vacuum. Soxhlet extraction of {{chem2|CeCl3}} with thf gives {{chem2|CeCl3(thf)1.04}}.{{cite journal |doi=10.1021/acs.organomet.2c00029 |title=Cerium Fluorenyl Complexes Including CC Coupling Reactions |date=2022 |last1=Hirneise |first1=Lars |last2=Buschmann |first2=Dennis A. |last3=Maichle-Mössmer |first3=Cäcilia |last4=Anwander |first4=Reiner |journal=Organometallics |volume=41 |issue=8 |pages=962–976 |s2cid=248065310 }}

Uses

Cerium(III) chloride can be used as a starting point for the preparation of other cerium salts, such as the Lewis acid cerium(III) trifluoromethanesulfonate.{{cite journal |last=Mine |first=Norioki |author2=Fujiwara, Yuzo |author3=Taniguchi, Hiroshi |year=1986 |title=Trichlorolanthanoid (LnCl₃)-catalyzed Friedel-Crafts alkylation reactions |journal=Chemistry Letters |volume=15 |issue=3 |pages=357–360 |doi=10.1246/cl.1986.357 }}

=Organic synthesis=

Cerium(III) chloride is a reagent in several procedures used in organic synthesis.{{cite book |doi=10.1002/047084289X.rc041.pub3 |chapter=Cerium(III) Chloride |title=Encyclopedia of Reagents for Organic Synthesis |date=2021 |last1=Paquette |first1=Leo A. |last2=Sabitha |first2=G. |last3=Yadav |first3=J. S. |last4=Scheuermann |first4=Angelique M. |last5=Merchant |first5=Rohan R. |pages=1–15 |isbn=9780471936237 }}

Luche reduction{{cite journal |last=Luche |first=Jean-Louis |author2=Rodriguez-Hahn, Lydia |author3=Crabbé, Pierre |year=1978 |title=Reduction of natural enones in the presence of cerium trichloride |journal=Journal of the Chemical Society, Chemical Communications |issue= 14|pages=601–602|doi=10.1039/C39780000601 }} of alpha, beta-unsaturated carbonyl compounds has become a popular method in organic synthesis, where CeCl₃·7H₂O is used in conjunction with sodium borohydride. For example, carvone gives only the allylic alcohol 1 and none of the saturated alcohol 2. Without CeCl₃, a mixture of 1 and 2 is formed.

File:Luche-Reduktion CeCl3 german (cropped).svg

It can also deprotect MEM group to alcohol in the presence of other acetal protecting groups (e.g. THP.)

Another important use in organic synthesis is for alkylation of ketones, which would otherwise form enolates if simple organolithium reagents were to be used. For example, compound 3 would be expected to simply form an enolate without CeCl₃ being present, but in the presence of CeCl₃ smooth alkylation occurs:

File:Cerium alkylation.png

It is reported that organolithium reagents work more effectively in this reaction than do Grignard reagents.

Cerium(III) chloride

Preparation of anhydrous CeCl<sub>3</sub>

Uses

=Organic synthesis=

References

Further reading