Spectroscopic studies on the uranyl complexes with 1,2-disubstituted benzenes

Uranyl complexes with a series of 1,2-disubstituted benzenes, such as phthalic acid (H2ph), salicylic acid (Hsal), pyrocatechol (H2pc), anthranilic acid (Hant), o-aminophenol (amph), and o-phenyleneediamine (phen), have been prepared and studied by i.r., electronic and NMR spectroscopy.Characteristic i.r. stretching frequencing (4000-200 cm−1) are reported for each complex.One or two new strong bands are observed in the region of 340–500 nm in all the complexes except uranyl phthalate, which are considered to be due to the charge transfer transition from the pπ orbital of the donor atoms to 5f- and/or 6d-orbitals of uranium.Characteristic proton magnetic resonance spectra of the complexes are also reported and discussed in relation to the magnetic anisotropy of the uranyl ion and to the drainage of electron density from the donor atom to the metal.