Crystal growth methods dedicated to low solubility actinide oxalates

Two novel crystal growth syntheses dedicated to low solubility actinide-oxalate systems and adapted to glove box handling are described. These methods based on the use of precursors of either actinide metal or oxalic acid have been optimized on lanthanide systems (analogue of actinides(III)) and then assessed on real actinide systems. They allow the synthesis of several actinide oxalate single crystals, Am-2(C2O4)(3)(H2O)(3) center dot xH(2)O, Th(C2O4)(2) center dot 6H(2)O, M2+x[(Pu2-xPuxIII)-Pu-IV(C2O4)(5)]center dot nH(2)O and M1-x[(Pu1-xPuxIV)-Pu-III (C(2)O4)(2) center dot H2O]center dot nH(2)O. It is the first time that these well-known compounds are formed by crystal growth methods, thus enabling direct structural studies on transuranic element systems and acquisition of basic data beyond deductions from isomorphic (or not) lanthanide compounds. Characterizations by X-ray diffraction, UV-visible solid spectroscopy, demonstrate the potentialities of these two crystal growth methods to obtain oxalate compounds. (C) 2015 Elsevier Inc. All rights reserved.