Assembly of new Schiff base ligands derived from vitamin B6 and stabilization through complexation of N,N '-bis-(pyridoxylideneimine)-o-phenylene: Synthesis and X-ray Structural features of pyridoxal/o-phenylenediamine adducts and of [UO2(H2pyr2phen)Cl]NO3 and [UO2(Hpyr2phen)Cl] {pyr2phen=N,Nprime-bis-(pyridoxylideneiminato)2-phenylene}

摘要

The new Schiff bases ligands 1 and 2 were obtained through reaction of vitamin B6 and o-phenylenediamine in methanol, and characterized structurally by X-ray diffractometry. The reaction of I with UO2(NO3)(2) center dot 6H(2)O leads to the stabilization of N,N'-bis-(pyridoxylideneimine)-o-phenylene, giving [UO2(H(2)pyr(2)phen)Cl]NO3 (3) and [UO2(Hpyr(2)phen)Cl] (4). In the new chelate compounds 3 and 4 the uranium ions are the centers of distorted pentagonal bipyramides, characteristic for the coordination number 7. The positive charge of 3 is counter balanced by NO3- ions in the lattice. Deprotonation of an endo hydroxyl group of the ligand yields a neutral complex, in the case of 4. In both complexes a Cl- ion accomplishes the seventh coordination space around the uranium atom. (C) 2008 Elsevier Ltd. All rights reserved.