Uranyl complex with phenolate–sulphonate and diphenyldiazenecarbohydrazonate ligands

Reaction of uranyl nitrate hexahydrate with 3-(2-(2,4-dioxopentan-3-ylidene)hydrazinyl)-2-hydroxybenzenesulfonic acid (H3L) and bis((E)-phenyldiazenyl)methanone (bpm) yields mononuclear zwitterionic uranyl complex, [UO2(HL)(bpm)(H2O)2]∙3H2O (1), which was characterized by IR, ESI-MS spectroscopies, and elemental and X-ray single-crystal analyses. In 1, the uranium center is in distorted pentagonal bipyramidal geometry with HL2 − and bpm ligands coordinated in equatorial plane. The coordination to uranyl and intramolecular hydrogen bonding assist the tautomerization of bpm and formation of zwitterion.