New Complexes of Actinides with Monobromoacetate Ions: Synthesis and Structures.

Synthesis, FTIR spectral study, and X-ray diffraction analysis of single crystals of (CH3)4N[UO2(mba)3] (I), (CH3)4N[NpO2(mba)2(NO3)] (II), (CH3)4N[PuO2(mba)2(NO3)] (III), and (CH3)4N[NpO2(mba)(NO3)2] (IV), where mba is a monobromoacetate ion (CH2BrCOO-), were conducted. The main structural units of crystals I-IV are mononuclear anionic complexes of the [AnO2(mba)3]-, [AnO2(mba)2(NO3)]-, or [AnO2(mba)(NO3)2]- composition. All these complex units are characterized with the same crystal-chemical formula AB 01 3 (A = AnO2 2+ and B 01 = CH2BrCOO- or NO3 -). Using the method of molecular Voronoi-Dirichlet polyhedra, the contributions of various types of noncovalent interactions into the formation of supramolecular structures of the obtained complexes were characterized. The analysis of coordination modes of all monobromoacetate-containing compounds from the Cambridge Structural Database was accomplished. Actinide contraction in the studied compounds is discussed.