Cerium(III) bromide
{{chembox
| Watchedfields = changed
| verifiedrevid = 425040058
| Name = Cerium(III) bromide
| ImageFileL1 = UCl3 without caption.png
| ImageFileR1 = Cerium bromide (space filling) 2.png
| ImageName = Cerium(III) bromide
| IUPACName = Cerium(III) bromide
Cerium tribromide
| OtherNames = Cerous bromide
|Section1={{Chembox Identifiers
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 76185
| InChI = 1/3BrH.Ce/h3*1H;/q;;;+3/p-3
| InChIKey = MOOUSOJAOQPDEH-DFZHHIFOAB
| SMILES = [Ce+3].[Br-].[Br-].[Br-]
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/3BrH.Ce/h3*1H;/q;;;+3/p-3
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = MOOUSOJAOQPDEH-UHFFFAOYSA-K
| CASNo_Ref = {{cascite|correct|??}}
| CASNo = 14457-87-5
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII =GEM75FEL39
| EINECS = 238-447-0
| RTECS =
| PubChem = 292780
}}
|Section2={{Chembox Properties
| Formula = CeBr3
| MolarMass = 379.828 g/mol
| Appearance = grey to white solid, hygroscopic
| Density = 5.1 g/cm3, solid
| MeltingPtC = 722
| BoilingPtC = 1457
}}
|Section3={{Chembox Structure
| Coordination = Tricapped trigonal prismatic
(nine-coordinate)
| CrystalStruct = hexagonal (UCl3 type), hP8
| SpaceGroup = P63/m, No. 176
}}
|Section7={{Chembox Hazards
| ExternalSDS =
| GHSPictograms = {{GHS07}}
| GHSSignalWord = Warning
| HPhrases = {{H-phrases|315|319|335}}
| PPhrases = {{P-phrases|}}
| FlashPt = Non-flammable
}}
|Section8={{Chembox Related
| OtherAnions = Cerium(III) fluoride
Cerium(III) chloride
Cerium(III) iodide
| OtherCations = Lanthanum(III) bromide
Praseodymium(III) bromide
}}
}}
Cerium(III) bromide is an inorganic compound with the formula CeBr3. This white hygroscopic solid is of interest as a component of scintillation counters.
Preparation and basic properties
The compound has been known since at least 1899, when Muthman and Stützel reported its preparation from cerium sulfide and gaseous HBr.{{cite journal | last1=Muthmann | first1=W. | last2=Stützel | first2=L. | title=Eine einfache Methode zur Darstellung der Schwefel-, Chlor- und Brom-Verbindungen der Ceritmetalle | journal=Berichte der Deutschen Chemischen Gesellschaft | publisher=Wiley | volume=32 | issue=3 | year=1899 | issn=0365-9496 | doi=10.1002/cber.189903203115 | pages=3413–3419 | url=https://zenodo.org/record/2168157 | language=de}} Aqueous solutions of CeBr3 can be prepared from the reaction of Ce2(CO3)3·H2O with HBr. The product, CeBr3·H2O can be dehydrated by heating with NH4Br followed by sublimation of residual NH4Br. CeBr3 can be distilled at reduced pressure (~ 0.1 Pa) in a quartz ampoule at 875-880 °C.{{cite journal | last1=Rycerz | first1=L. | last2=Ingier-Stocka | first2=E. | last3=Berkani | first3=M. | last4=Gaune-Escard | first4=M. | title=Thermodynamic Functions of Congruently Melting Compounds Formed in the CeBr3−KBr Binary System | journal=Journal of Chemical & Engineering Data | publisher=American Chemical Society (ACS) | volume=52 | issue=4 | year=2007 | issn=0021-9568 | doi=10.1021/je600517u | pages=1209–1212}}
Like the related salt CeCl3, the bromide absorbs water on exposure to moist air. The compound melts congruently at 722 °C, and well ordered single crystals may be produced using standard crystal growth methods like Bridgman or Czochralski.
CeBr3 adopts the hexagonal, UCl3-type crystal structure with the P63/m space group.{{cite journal | last=Morosin | first=B. | title=Crystal Structures of Anhydrous Rare-Earth Chlorides | journal=The Journal of Chemical Physics | publisher=AIP Publishing | volume=49 | issue=7 | year=1968 | issn=0021-9606 | doi=10.1063/1.1670543 | pages=3007–3012| bibcode=1968JChPh..49.3007M }}{{ cite book | first1 = A. F. | last1 = Wells | title = Structural Inorganic Chemistry | edition = 5th | year = 1984 | publisher = Oxford University Press | isbn = 978-0-19-965763-6 | page = 421 }} The cerium ions are 9-coordinate and adopt a tricapped trigonal prismatic geometry.{{Greenwood&Earnshaw2nd|pages=1240–1241}} The cerium–bromine bond lengths are 3.11 Å and 3.16 Å.{{ cite journal | first1 = W. H. | last1 = Zachariasen | authorlink1 = William Houlder Zachariasen | title = Crystal chemical studies of the 5f-series of elements. I. New structure types | journal= Acta Crystallogr. | volume = 1 | issue = 5 | pages = 265–268 | year = 1948 | doi = 10.1107/S0365110X48000703 | bibcode = 1948AcCry...1..265Z }}
Applications
CeBr3-doped lanthanum bromide single crystals are known to exhibit superior scintillation properties for applications in the security, medical imaging, and geophysics detectors.{{cite journal | last1=van Loef | first1=E. V. D. | last2=Dorenbos | first2=P. | last3=van Eijk | first3=C. W. E. | last4=Krämer | first4=K. | last5=Güdel | first5=H. U. | title=High-energy-resolution scintillator: Ce3+ activated LaBr3 | journal=Applied Physics Letters | publisher=AIP Publishing | volume=79 | issue=10 | date=2001-09-03 | issn=0003-6951 | doi=10.1063/1.1385342 | pages=1573–1575| bibcode=2001ApPhL..79.1573V }}{{cite journal | last1=Menge | first1=Peter R. | last2=Gautier | first2=G. | last3=Iltis | first3=A. | last4=Rozsa | first4=C. | last5=Solovyev | first5=V. | title=Performance of large lanthanum bromide scintillators | journal=Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment | publisher=Elsevier BV | volume=579 | issue=1 | year=2007 | issn=0168-9002 | doi=10.1016/j.nima.2007.04.002 | pages=6–10| bibcode=2007NIMPA.579....6M }}
Undoped single crystals of CeBr3 have shown promise as a γ-ray [[Scintillator|
scintillation detector]] in nuclear non-proliferation testing, medical imaging, environmental remediation, and oil exploration.{{cite journal | last1=Higgins | first1=W.M. | last2=Churilov | first2=A. | last3=van Loef | first3=E. | last4=Glodo | first4=J. | last5=Squillante | first5=M. | last6=Shah | first6=K. | title=Crystal growth of large diameter LaBr3:Ce and CeBr3 | journal=Journal of Crystal Growth | publisher=Elsevier BV | volume=310 | issue=7–9 | year=2008 | issn=0022-0248 | doi=10.1016/j.jcrysgro.2007.12.041 | pages=2085–2089| bibcode=2008JCrGr.310.2085H }}
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