Spontaneous Partitioning of Californium from Curium: Curious Cases from the Crystallization of Curium Coordination Complexes

• Published in: Inorganic chemistry Vol. 54; no. 23; pp. 11399 - 11404
• Main Authors: Cary, Samantha K, Silver, Mark A, Liu, Guokui, Wang, Jamie C, Bogart, Justin A, Stritzinger, Jared T, Arico, Alexandra A, Hanson, Kenneth, Schelter, Eric J, Albrecht-Schmitt, Thomas E
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 07-12-2015; American Chemical Society (ACS)
• Subjects: Actinides; Californium; Crystallization; Crystals; Curium; Evaporation; Parents; Partitioning
• ISSN: 0020-1669; 1520-510X
• DOI: 10.1021/acs.inorgchem.5b02052

The reaction of 248CmCl3 with excess 2,6-pyridinedicarboxylic acid (DPA) under mild solvothermal conditions results in crystallization of the tris-chelate complex Cm­(HDPA)3·H2O. Approximately half of the curium remains in solution at the end of this process, and evaporation of the mother liquor results in crystallization of the bis-chelate complex [Cm­(HDPA)­(H2DPA)­(H2O)2Cl]­Cl·2H2O. 248Cm is the daughter of the α decay of 252Cf and is extracted in high purity from this parent. However, trace amounts of 249,250,251Cf are still present in all samples of 248Cm. During the crystallization of Cm­(HDPA)3·H2O and [Cm­(HDPA)­(H2DPA)­(H2O)2Cl]­Cl·2H2O, californium­(III) spontaneously separates itself from the curium complexes and is found doped within crystals of DPA in the form of Cf­(HDPA)3. These results add to the growing body of evidence that the chemistry of californium is fundamentally different from that of earlier actinides.