The First Family of Actinide Carboxyphosphinates: Two- and Three-Dimensional Uranyl Coordination Polymers

Reaction of uranyl dications with (2-carboxyethyl)(phenyl)phosphinic acid (CPPA, H2L) under hydrothermal conditions gave two layered isomers (UO2)(2)(L)(2), namely, CPP-U1 and CPP-U2. Both of them feature edge-sharing uranyl dimers as structure-building units, which are ligated by CPP ligands in different ways, thus leading different layered arrangements. With the addition of imidazole derivatives, two three-dimensional structures UO2(L)(dib)(0.5) (CPP-U3) and UO2(L)(bbi)(0.5) CPP-U4) were generated, in which the similar uranyl-phosphinate layers are connected by two different imidazole derivatives by means of the U-N connection [dib = 1,4-di(1H-imidazol-1-yl) benzene; bbi = 1,1'-(1,4-butanediyl)bis(imidazole)]. The syntheses, structure, as well as the IR spectra, and luminescent and photocatalytic properties of these uranyl organophosphinates are reported in this paper.