Bimetallic complexes supported by bis(diphenylphosphino)methane anti and syn to the MnPd bonds

A review on 1,1-bis(diphenylphosphino)methane bridged homo- and heterobimetallic complexes for anticancer applications: Synthesis, structure, and cytotoxicity

Herein, we review developments in synthesis, structure, and biological (anti-cancer) activities of 1,1-bis(diphenylphosphino)methane (dppm) bridged homo- and heterobimetallic systems of the type L_mM(μ₂-dppm)M'L_n (M and M' are transition metals which may be different or the same and L_n,m are co-ligands) since the first such reported bimetallic system in 1987 until the present time (2020). As the simplest diphosphine, dppm enables facile formation of bimetallic complexes, where, given the short spacer between the PPh₂ groups, close spatial proximity of the metal centres is ensured. We concentrate on complexes bearing no M-M interaction and contrast biological activities of these complexes with mononuclear counterparts and positive control agents such as cisplatin, in an attempt to elucidate patterns in the biological activities of these complexes.

PdCl[PPh2CH2CH2CHCH2CH2PPh2] as a precursor to homo- and hetero-metallic species directed by ESMS (electrospray ionisation mass spectrometry)

The cyclometallated Pd compound [upper bond 1 start]PdCl[PPh(2)CH(2)CH(2)C[upper bond 1 end]HCH(2)CH(2)PPh(2)], obtained from PdCl(2)(Ph(2)P(CH(2))(5)PPh(2)) in refluxing DMF (N,N-dimethylformamide), was characterized by NMR and X-ray single-crystal diffraction analysis. The cyclometallation of MCl(2)(Ph(2)P(CH(2))(5)PPh(2))(M = Pd, Pt) to give and its Pt(ii) analogue was probed using electrospray ionisation mass spectrometry (ESMS). The reactivity of towards neutral ligands such as phosphines and pyridines as well as basic metal complexes such as pyridine-thiolate compounds of Au(i), Hg(ii) and Pt(ii) in solution was also investigated. The results showed that the chloride trans to the Pd-C bond is susceptible to ligand replacement. A number of entry metalloligands was examined in an attempt to establish a route to cyclometallated aggregates and clusters.