Synthesis Characterization and Biological Activity of Complexes of Certain Lanthanide Ions with N-and O-Containing Mixed Ligands

Abstract

Lanthanide complexes play a crucial role both stoichiometrically and clinically. The best known Gadolinium complexes are use in cancer therapy, but due to high toxicity its activity is not always satisfactory and side effects are frequently encountered. The aim of present work is to identify noval metal based complexes with reported heterocyclic ligand which are cheaper and easily available in market. If ligand is much more expensive then it not attractive for large scale of application in industry. No doubt much of the interest arises from the potential commercial importance of lanthanide complexes however most of the earlier work was concerned with the preparative aspect of organometallic chemistry. The present work focused on the development of metal based drugs that could act against large number of strains of bacteria and fungus, available from Institute of Agriculture Science University of the Punjab Lahore.New metal ion complexes of Erbium and Praseodymium with easily synthesized hetrocyclic ligands are prepared in search of interesting biological activity. Metal complexes of lanthanide as well as transition metals are synthesized and characterized by the use of spectroscopic methods, elemental analysis, high performance liquid chromatography and thermo gravimetric analysis. Most of the complexes synthesized in this work were tested for series of biological assay. In particular lanthanide complexes exhibit excellent antibacterial and anti-fungal activity as compare to transition metal complexes which show moderate activity against tested microbs. By considering the stability of Lanthanides complexes new metal chelates are synthesized. These complexes acts as effective catalyst in many reactions. My work aims at the study of thermal degradation and stability of synthetic compounds. The compounds exhibited mainly two stage degradation. The weight loss characterized by low activation energy correspond to loss of moisture. The major degradation stage represents a loss of high boiling volatile components which are observed in case of lanthanide complexes. The lanthanide complexes are more stable which is shown by TGA analysis, it means ionic breaking occurs at high temperature. Much of the interest during my research project is to determine and separate metal cations in much less time, so a rapid simple and reliable technique has been developed by HPLC. The different parameters such as PH during extraction, solvent mobile phase and type of columns used is studied. The retention time for elution is different for different complexes, still I am working on other lanthanide metals to synthesize complexes in order to bring advancement in organometallic chemistry and to enhance its applications in biomedical sciences.