Neutral and cationic osmium(II)-arene metallodendrimers: Synthesis, characterisation and anticancer activity

• Polynuclear osmium(II)-arene metallodendrimers have been prepared.
• Neutral Os(II) dendrimers were synthesised containing salicylaldimine ligands.
• Cationic Os(II) dendrimers were synthesised containing iminopyridyl ligands.
• The anticancer activity of the metallodendrimers was evaluated.

Two neutral and two cationic half-sandwich Os(II)-arene metallodendrimers, of general formula [DAB-PPI-{(η6-p-cym)Os((C7H5NO)-κ2-N,O)Cl}n] and [DAB-PPI-{(η6-p-cym)Os((C6H5N2)-κ2-N,N)Cl}n][PF6]n (where n = 4 (G1) or 8 (G2)) have been synthesised. In addition, two cationic half-sandwich Os(II)-arene metallodendrimers, containing PTA (1,3,5-triaza-7-phosphatricyclo[3.3.1.1.] decane), of general formula [DAB-PPI-{(η6-p-cym)Os((C7H5NO)-κ2-N,O)PTA}n][PF6]n are also reported. All complexes have been characterised using analytical (i.e. HR-ESI or EI mass spectrometry and elemental analysis) and spectroscopic (i.e.1H, 13C{1H} NMR and infrared) methods. Model mononuclear analogues have been prepared and their molecular structures determined by single-crystal X-ray crystallography. The cytotoxicity of the complexes were evaluated against the A2780 and A2780cisR human ovarian carcinoma cell lines and some display moderate activity.

Two generations of neutral and cationic poly(propyleneimine) salicylaldimine and iminopyridyl dendrimers incorporating osmium-arene moieties on the periphery have been synthesised and characterised. The in vitro cytotoxicities of these osmium-arene metallodendrimers were evaluated using A2780 and A2780cisR human ovarian carcinoma cancer cell lines.Figure optionsDownload as PowerPoint slide