Multinuclear biologically active Ru, Rh, Os and Ir arene complexes

Abstract The development of multinuclear homometallic biologically active complexes is attractive for modern bioinorganic chemistry, because this concept offers a multiplication of the therapeutic effect of mononuclear complexes and a variation of mechanism of action (MoA). In addition to homometallic complexes containing two or more metal centres of the same element, heterometallic complexes combine various metal centres within one complex species. Since MoA of anticancer transition metal complexes is usually metal-specific, a combination of different metals affecting various processes in the exposed cells should ensure a unique MoA of such heterometallic complexes. This review is focused on multinuclear complexes derived from half-sandwich ruthenium(II), rhodium(III), osmium(II) or iridium(III) arene moieties, covalently bridged with one or more metal-based species within a homo- or heterometallic entities. The overviewed complexes are categorized according the element in the metal–arene moiety and types of the conjugated species. In most cases, complexes were studied for their cytotoxicity, fewer compounds were tested for their antimicrobial activity. Special attention was paid to the comparison of structurally similar analogues differing in the number or type of metal centres.