Synthesis and characterisation of some 1st row transition metal complexes with the ligand 2-[(3= hydroxypropylimino)methyl]naphthol

Abstract

The coordination compounds formed hetween the Schiff base ligand ?.-[(1-hydroxypropylimino)methyl]naphthol (naphHPrH) and metal salts of Cu2+, Cr2+, Fe2 +,Fe3+, Mn2+, Ti2+ and Ti3+ were synthesised and characterised using Infrared and Ultraviolet spectroscopy. The ligand and the aldehyde starting material were analysed using proton NMR spectroscopy. A new method employing the use of a dehydrating agent as a way for synthesizing the ligand was used, which did away for the need of an aezeotropic mixture of water and benzene. Where possible, it was the tetrafluoroborate salts of the metals which were used prior to the coordination step. This is because the tetrafluoroborate anion proves to be less co-ordinating than nitrates and halides, thus translating into cleaner spectra and better characterisation. It also avoids the use of perchlorates which are strong oxidising species and also pose a health risk especially when used together with organic solvents. IR and UV spectra obtained indicated that complexation took place as certain shifts in some peaks were noticed which served as evidence to this. No NMR characterisation was carried out for the complexes as this would not have yielded any interpretable spectra due to the rapid relaxation times.