Synthesis of symmetric N,O-donor ligands derived from pyridoxal (vitamin B6): DFT studies and structural features of their binuclear chelate complexes with the oxofilic uranyl and vanadyl(V) cations

•Synthesis of the Schiff bases H6Pyr2oxdihyd and H10pyr2sucdihyd.•Structures of [(UO2)2(H6pyr2oxdihyd−4H+)(DMSO)4]/[(VO)2(H10pyr2sucdihyd−4H+)(MeO)2].•Use of computational methods in the study of intra and intermolecular bonds.

The synthesis and the structural characterization of symmetric dimers containing uranium and vanadium atoms provide an outstanding opportunity for the study of hydrogen bonding in supramolecular architectures and unusual interactions. On the search of ligands able to coordinate itself to two metal ions simultaneously, we have synthesized the Schiff bases bis((3-hydroxy-5-(hydroxymethyl)-2-methylpyridin-4-yl)methylene) oxalohydrazide (H6Pyr2oxdihyd) and bis((3-hydroxy-5-(hydroxymethyl)-2-methylpyridin-4-yl)methylene) succinohydrazide (H10pyr2sucdihyd), efficient symmetric ligands with an inversion center, obtained through the reaction of pyridoxine/pyridoxal hydrochloride with oxalyl dihydrazide and succinic dihydrazide. Their reactions and the products obtained with the oxofilic uranyl(VI) and vanadyl(V) cations were discussed, as well as computational methods were used as complementary tools in the study of intra and intermolecular bonds.

Graphical abstractDerivatization of biologically active molecules such as pyridoxal, provides the attainment of compounds with high complexation efficiency of more than one metal center. We have synthesized the Schiff bases bis((3-hydroxy-5-(hydroxymethyl)-2-methylpyridin-4-yl)methylene) oxalohydrazide and bis((3-hydroxy-5-(hydroxymethyl)-2-methylpyridin-4-yl)methylene) succinohydrazide. Their reactions and the products obtained with oxofilic uranyl and vanadyl cations are discussed, as well as the computational methods used as complementary tools in the study of intra and intermolecular bonds.Figure optionsDownload full-size imageDownload as PowerPoint slide