The one-pot synthesis and the fluorescence and cytotoxicity studies of chlorotricarbonyl(α-diimine)rhenium(I), fac-(CO)3(α-diimine)ReCl, complexes

An one-pot reaction of Re2(CO)10 and an α-diimine (1:2 molar ratio) in refluxed 2-chloroethanol afforded the corresponding chlorotricarbonyl(α-diimine)rhenium(I) complexes, fac-(CO)3(α-diimine)ReCl, 1-4, in very high yield. The α-diimines in 1-4 are 2,2′-bipyridyl, 1,10-phenanthroline, 2,9-dimethyl-1,10-phenanthroline, and 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline, respectively. Alternatively, an one-pot reaction of Re2(CO)10 and an α-diimine (1:2 mole ratio) in refluxed 1-pentanol in the presence of CO2 and HCl yielded the corresponding chloro complexes, 1-4, in very high yield. 1-4 were characterized spectroscopically. Additionally, 3 and 4 were characterized through X-ray crystal structure determinations. The chloro complexes, 1-4 exhibit fluorescence both in the solid states and in solutions. Surprisingly, 1-4 are cytotoxic against breast, prostate, and lung cancer cell lines.