Investigation of heteroligand vanadium(5) complex with o-nitrophenylfluorene and diantipyrylmethane

Complexing in the system V(5)-O-nitrophenylfluorene (o-NPF)-diantipyrylmethane (DAM) has been studied. 2x10-3 mol/l vanadium solution, alcohol solution 3x10-3 mol/l o-NPF, alcohol solution 0.1 mol/l DAM were used. It is established, that in the given system V(5) preserves its valence. Vanadium (5) interacts with o-NPF and DAM in acid medium in pH ranae 1.1-4.0 (pHsub(opt.)=2.0-2.5) For the optimum complexin g 10-12-fold excess of o-NPF and 700-fold one of DAM are required. A mixture of chloroform with amyl alcohol is the best extracting agent, which extracts the complex into organic phase practically completely per one cycle (R=98.4%). The composition of different ligand complex is determined by the ratio: V:DAM:o-NPF:ClO4=1:2:1:1. The complex is solvated by six molecules of chloroform and one molecule of amul alcohol. Using the method of IR spectroscopy the structure of the complex is established. Addtion of o-NPF to vanadium takes place in the form of the complex o-NPF-DAM. Its coordination with vanadium is realized via oxygen atoms of phenol and quinone groups of o-NPF in ortho-position to each other. Complexing takes place in two stages. Equilibrium constant of different ligand complex equals 1.45x104. VO(OH)2+ ion is a complex-forming one. Probable structure of the complex is presented