Berkelium(III) chloride also known as berkelium trichloride, is a binary inorganic compound of berkelium and chlorine with the formula BkCl3. It is a water-soluble green salt with a melting point of 603 °C. This compound forms the hexahydrate, BkCl3·6H2O.
Preparation and reactions
This compound was first prepared in 1970 by reacting hydrogen chloride gas and berkelium(IV) oxide or berkelium(III) oxide at 520 °C:1
Bk2O3 + 6HCl → 2BkCl3 + 3H2OBerkelium(III) chloride reacts with beryllocene to produce berkelocene(Bk(C5H5)3).2 It also reacts with oxalic acid to produce berkelium oxalate. This reaction is used to purify this compound, by reacting the oxalate with hydrochloric acid.3
Structure
Anhydrous berkelium(III) chloride has a hexagonal crystal structure, is isostructural to uranium trichloride, and has the person symbol hP6. When heated it its melting point, it converts to an orthorhombic phase.4 However, the hexahydrate has a monoclinic crystal structure and is isostructural to americium trichloride hexahydrate with the lattice constants a = 966 pm, b = 654 pm and c = 797 pm.5 This hexahydrate consists of BkCl2(OH2)6+ ions and Cl− ions.
Complexes
Caesium sodium berkelium chloride is known with the formula Cs2NaBkCl6 and is produced by the reaction of berkelium(III) hydroxide, hydrochloric acid, and caesium chloride.6
References
J. R. Peterson; B. B. Cunningham (1968). "Crystal structures and lattice parameters of the compounds of berkelium—II: Berkelium trichloride". Journal of Inorganic and Nuclear Chemistry. 3 (3): 823–828. doi:10.1016/S0898-8838(08)60204-4. /wiki/Doi_(identifier) ↩
Peter G. Laubereau; John H. Burns (1970). "Microchemical preparation of tricyclopentadienyl compounds of berkelium, californium, and some lanthanide elements". Inorg. Chem. 9 (5): 1091–1095. doi:10.1021/ic50087a018. /wiki/Doi_(identifier) ↩
J. R. Peterson; J. P. Young; D. D. Ensor; R. G. Haire (1986). "Absorption spectrophotometric and x-ray diffraction studies of the trichlorides of berkelium-249 and californium-249". Inorg. Chem. 25 (21). en: 3779–3782. doi:10.1021/ic00241a015. /wiki/Doi_(identifier) ↩
J. R. Peterson; B. B. Cunningham (1968). "Crystal structures and lattice parameters of the compounds of berkelium—II: Berkelium trichloride". Journal of Inorganic and Nuclear Chemistry. 3 (3): 823–828. doi:10.1016/S0898-8838(08)60204-4. /wiki/Doi_(identifier) ↩
John H. Burns; Joseph Richard Peterson (1971). "Crystal structures of americium trichloride hexahydrate and berkelium trichloride hexahydrate". Inorg. Chem. 10 (1): 147–151. doi:10.1021/ic50095a029. /wiki/Doi_(identifier) ↩
Peterson J. R. and Hobart D. E. "The Chemistry of Berkelium" in Harry Julius Emeléus (Ed.) Advances in inorganic chemistry and radiochemistry, Volume 28, Academic Press, 1984 ISBN 0-12-023628-1, pp. 29–64, doi:10.1016/S0898-8838(08)60204-4 https://books.google.com/books?id=U-YOlLVuV1YC&pg=PA29 ↩