Novel complexes of zirconium and uranium derived from bifunctional azodyes donor ligands containing hydrogen bonds

Novel complexes of zirconium(IV) and uranium(II) with selective azodyes containing nitrogen and oxygen donor ligands have been prepared and characterized by elemental analysis, 1H NMR and electronic spectral techniques. The important bands in the IR spectra and main 1H NMR signals are assigned and discussed in relation to the proposed molecular structure of the complexes. The IR data of the azodye ligands suggested a bidentate binding involving azodye nitrogen and C–O/OH oxygen atom of enolic group. They also showed the presence of Cl/OAc coordinating with the metal ion. The prepared complexes of Zr(IV) fall into four types. In the stoichiometric formulae of (1:1), the chelate rings are six-membered/five coordinate; whereas in the (1:2) they are six-membered/six coordinate and all of the complexes possess non-electrolytic properties. The UO2(II) complex, in the mean time, possesses a planar hexagonal structure with nitrogen and oxygen atoms in the axial position. The stretching vibrations and force constant interactions of the uranyl complexes have been determined and from which the U–O bond distances are calculated. These bond distances as well as the effect of Hamett’s constant are also, in turn, calculated and discussed.