Investigation of the Anticancer Activity of Coordination-Driven Self-AssembledTwo-Dimensional Ruthenium Metalla-Rectangle

Coordination-driven self-assembly is an effective synthetic tool for the construction of spatially and electronically tunable supramolecular coordination complexes (SCCs), which are useful in various applications. Herein, we report the synthesis of a two-dimensional discrete metalla-rectangle [(η(6)-p-cymene)(4)Ru(4)(C(6)H(2)O(4))(2)(2)(2)](CF(3)SO(3))(4) (3) by the reaction of a dinuclear half-sandwich ruthenium (II) complex [Ru(2)(η(6)-p-cymene)(2)(C(6)H(2)O(4))Cl(2)] (1) and bis-pyridyl amide linker (2) in the presence of AgO(3)SCF(3). This cationic ruthenium metalla-rectangle (3) has been isolated as its triflate salt and characterized by analytical techniques including elemental analysis, Fourier-transform infrared spectroscopy (FT-IR), proton nuclear magnetic resonance spectroscopy ((1)H-NMR), carbon nuclear magnetic resonance spectroscopy ((13)C-NMR), (1)H-(1)H correlation spectroscopy (COSY), (1)H-(1)H nuclear Overhauser effect spectroscopy (NOESY), diffusion ordered spectroscopy (DOSY), and high-resolution electrospray ionization mass spectrometry (HR-ESI-MS). Significantly, the 2D cationic ruthenium metalla-rectangle showed better anticancer activity towards three different cell lines (A549, Caki-1 and Lovo) as compared with the parent ruthenium complex (1) and the commercially used drug, cisplatin.