Selenolato-Bridged Manganese(I)-Based Dinuclear Metallacycles as Potential Anticancer Agents and Photo-CORMs

Abstract

Selenolato-bridged manganese(I)-based dinuclear metallacycles [{(CO)3Mn(μ-SeC6H5)2Mn(CO)3}(μ-L)] (1–4) were achieved in a single-step process by the self-assembly of dimanganese decacarbonyl, diphenyl diselenide, and flexible ditopic ester-functionalized pyridyl ligands [1, L = o-phenylene diisonicotinate (pdi); 2, L = 1,6-hexanediyl di-4-pyridine carboxylate (hdp); 3, L = 4-pyridine carboxylic acid diethylene glycol diester (pcadgd); 4, L = 4-pyridine carboxylic acid triethylene glycol diester (pcatgd)]. Synthesis of a series of selenolato-bridged dinuclear Mn(I)-based metallacycles was facilitated via oxidative addition of C6H5Se–SeC6H5 to (CO)5Mn–Mn(CO)5 with simultaneous coordination of flexible ditopic pyridyl linkers in an orthogonal fashion. The metallacycles were characterized by IR, UV–vis, NMR, and electrospray ionization-mass spectroscopic techniques and elemental analysis. Solid-state structural elucidation of 3 was carried out using single-crystal X-ray diffraction methods. In addition, anticancer activity studies were carried out for compounds 2–4 with various cancer cell lines. Furthermore, compound 3 was probed to evaluate its potential CO-releasing property using myoglobin assay.