Different properties of P,C-donor Pd(II) and Pt(II); spectroscopic and X-ray analysis, catalytic potential and anti-proliferative potency

Abstract

This account describes our recent studies on pallada-and platinaphosphacycle complexes with an unsymmetrical phosphonium ylide, Ph2PC(CH2)PPh2 = C(H)C(O)C6H4-p-NO2 (Y), derived from 1,1-bis(diphenylphosphino)ethylene (dppee). These complexes have been prepared through reactions between (Y) and [MCl2(cod)] (M = Pd (C1) or Pt (C2); cod = 1,5-cyclooctadiene) in equimolar ratio in the hope of finding new compounds that may be useful in stereoselective catalysis and find use as antitumor metallodrugs. Characterization of these compounds was performed by elemental analysis, IR, 1H, 13C, and 31P NMR spectroscopic methods. The structures of the Pd and Pt complexes were determined by single crystal x-ray structural analyses, showing that both complexes consist of five-membered rings formed by coordination of the phosphorus ylide (Y) through the phosphine group and the ylidic carbon atom to the metal center. The catalytic activity of the complexes, using the Mizoroki–Heck and Suzuki-Miyaura cross-coupling reactions, have been evaluated and compared. Moreover, both compounds have been found to have antitumor activity against AGS (gastric carcinoma), MCF-7 (breast carcinoma) and A549 (non-small lung carcinoma) cells with the average of IC50 values from 61.19 to 290.17 μM. Generally, C2 reveals high anticancer activity than C1.