Synthesis And Anticancer Studies Of Methylene Bridged N-Heterocyclic Carbene Silver(I) And Palladium(II) Complexes Derived From Imidazol-2-Ylidenes

Loading...
Thumbnail Image
Date
2015-08
Authors
Hasanudin, Noorhafizah
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
This thesis presents the synthesis, characterization (1H, 13C NMR, CHN, melting point) and anticancer activity of new methylene-bridged bis-imidazolium salts (1-4) and their respective silver(I)-N-heterocylic carbene (NHC) complexes. All bis-imidazolium salts were treated with a basic metal source, silver oxide, via a simple complexation reaction to afford four silver complexes (5-8) in exceptionally good yields (61-71%). The use of silver(I)-NHC complex as NHC transfer reagents was shown to be successful to synthesize palladium(II)-NHC complex (9). All isolated compounds were characterized by spectral and analytical techniques viz., NMR (1H and 13C) spectroscopy and elemental analysis. Molecular structure of three imidazolium salts, two silver complexes and one palladium complex were established through the single crystal X-ray diffraction technique. X-ray structural studies for silver complexes established that the structures of each silver complex are comprised of two silver cations sandwiched by two NHC units. The structural analysis of palladium complex 9 show that it is a mononuclear Pd(II) complex, chelated by two units of ligands. All the prepared salts, silver complexes and palladium complexes were non-hygroscopic and showed stability towards air, moisture and heat. The in vitro anticancer activity of all bis-imidazolium salts, silver complexes and palladium complexes were investigated against the human breast cancer (MCF-7) cell line, using tamoxifen as standard drug (IC50 = 2.4 μM). The bis-imidazolium salts demonstrated no activity for MCF-7 cell line, except salt 4; showing moderate activity (IC50 = 30 μM). Whereas, all the silver and palladium complexes displayed significant activity with IC50 values in the range 0.5-6.2 μM against tested cell line.
Description
Keywords
Methylene Bridged N-Heterocyclic Carbene Silver(I) , Palladium(II)
Citation