Synthesis and antiproliferative activity of the heterobimetallic complexes [RuClCp(PPh3)-μ-dmoPTA-1κP:2κ2N,N′-MCl2] (M = Co, Ni, Zn; dmoPTA = 3,7-dimethyl-1,3,7-triaza-5-phosphabicyclo[3.3.1]nonane)

Abstract

The synthesis and characterization of three novel heterobimetallic derivatives of general formula [RuClCp(PPh₃)-μ-dmoPTA-1κP:2κ²N,N′-MCl₂] (M = Co (1), Ni (2) and Zn (3), dmoPTA = 3,7-dimethyl-1,3,7-triaza-5-phosphabicyclo[3.3.1]nonane) are described. The sizes of their diffusing units are in agreement with the solid-state structures of 2 and 3, supporting a similar solid-state structure for complex 1. The diamagnetic ruthenium–zinc derivative 3 was fully characterized in solution at 193 K by NMR. Electrochemical properties of the complexes were investigated by cyclic voltammetry, supporting the influence of the {MCl₂} moiety on the electronic properties of the Ru-unit. For the three complexes the GI₅₀ values were in the range 0.8–6.5 μM and comparable to those of the standard anticancer drug cis-platin in the same cell lines.