Ruthenium(II)-arene RAPTA Type Complexes Bearing Dibenzoylmethane: Organometallic Chemistry and Biological Activity

Half-sandwich η6-arene-ruthenium(II) complexes represent a very important class of organometallic compounds which have been extensively studied and appropriately modified to obtain compounds with various biological properties.1 Dibenzoylmethane is a natural β-diketone that occurs in small amount in licorice roots. It exhibits several biological features such as activity against ischemic diseases2 and different types of tumours.3 On the basis of our previous research on Ru(II)-arene complexes with acylpirazolones4 and curcuminoids5, in the present work we report the synthesis and the characterization of a series of arene-Ruthenium(II) (arene = p-cymene, hexamethylbenzene or benzene) complexes containing dibenzoylmethane and the ionic derivatives with PTA (1,3,5-triaza-7- phosphaadamantane) (Scheme 1). Preliminary results on their biochemical studies and their antitumor activity evaluated in vitro in U266 and RPMI human multiple myeloma cell lines will also be reported.