SYNTHESIS, SPECTROSCOPIC CHARACTERIZATIONS AND DFT STUDIES ON THE METAL COMPLEXES OF AZATHIOPRINE IMMUNOSUPPRESSIVE DRUG

A complex of the immunosuppressive drug azathioprine with Cr(II), Mn(II), Fe(II), Zn(II), Cu(II), Ni(II), and Co(II) were synthesized and characterized through spectroscopic and thermal studies. The infrared spectra show the coordination of azathioprine via N(9) to the metal, also, the range around 640-650 cm(-1) remains unchanged in the complexes, indicating the possibility that the ether group may not be involved in the binding. Thermogravimetric analysis (TG), thermogravimetric derivational analysis (DTG), and differential thermogravimetric analysis (DTA) have been studied in the temperature range from 0 degrees C to 1000 degrees C. The study of pyrolysis showed that all complexes decompose in more than one step and that the final decomposition product is metal oxide. The DFT (density functional theory) with B3LYP/6-31G++ level of theory was used to study the optimized geometry, HOMO -> LUMO energy gap, and molecular electrostatic potential map of azathioprine before and after deprotonation.

Automated summary

Complexes of the immunosuppressive drug azathioprine with various metal ions were synthesized and characterized through spectroscopic and thermal studies. The coordination of azathioprine to the metal ions was confirmed by infrared spectroscopy, while the absence of changes in a specific range suggested that the ether group may not be involved in the binding. Thermal analysis showed that the complexes decomposed in multiple steps, leading to the formation of metal oxides.