Reducution of rhenium(V)-oxo schiff base complexesith triphenyl phosphine ligands [abstract]

Abstract

The purpose of this research is to produce radiopharmaceutical drugs for the possible use in therapy and diagnosis of cancer. A radiopharmaceutical drug is composed of a radioactive element contained within chelating agent and linked to a biological targeting molecule. This can be achieved by complexing the radioisotope and conjugating the complex to a biologically active targeting molecule, such as a peptide antibody or antibody fragment. The biological targeting molecule directs radiation to specific peptides, antibodies and antibodies' fragments. The amount of dosage is limited to non-targeted tissue that occurs when free radionuclide is released from a decomposing molecule. Higher kinetic stability will maximize the localization of the radioisotope to the cancer sites and minimize the radiation dose to non-target tissues. This research was a continuation to seek the best pathway that would easily enable us to synthesize a kinetically inert metal complex [Re(Sal2Phen)] attached to a ligand. The rigid Rhenium(V)-oxo Schiff base complex is found in the following form: [ReO(Sal2Phen)Cl]. Initially salicylic aldehyde reacted with bis-2-phenlinediamine to get sal2phen. This tetradentate Schiff base ligand was reacted with TBA [ReOCl4] yielding [ReOCl(Sal2Phen)]. The reduction of Rhenium(V)-oxo core to Rhenium is obtained by reacting [ReO(Sal2Phen)Cl] with a triphenyl phosphine (PPh3) in dichloromethane and ethanol. Products obtained from this reaction were 1[Re(Sal2Phen)(PPh3)2], 2ReCl(Sal2Phen)PPh3, and 3[ReO(Sal2Phen)PPh3].Analysis of the major product were performed through crystals through mass spectrometry, hydrogen and phosphorus NMR, infrared spectra and x-ray crystallography.