Syntheses, crystal structures and DNA-binding activities of divalent Fe, Cu, Zn and Cd complexes with 4′-(furan-2-yl)-2,2′:6′,2″-terpyridine

Abstract

Abstract Five coordination complexes [Fe(ftpy)2](ClO4)2·(H2O)2 (1), [Cu(ftpy)(NO3)(H2O)](NO3) (2), [Cu(ftpy)2]2(ClO4)4·(C2H5OH) (3), [Zn(ftpy)2]·(ClO4)2·(H2O)1.5 (4) and [Cd(ftpy)2]2(ClO4)4·(C2H5OH) (5) (ftpy=4′-(furan-2-yl)-2,2′:6′,2′-terpyridine) have been synthesized and characterized by IR, elemental analysis and single-crystal X-ray diffraction. With the exception of 4, all complexes adopt normal homoleptic [M(ftpy)2]2+ motifs. In the crystal, both hydrogen bonds and face-to-face interactions between furyl and pyridyl rings facilitate the construction of three-dimensional networks. The DNA-binding activities of the five complexes have been investigated by fluorescence emission titration at room temperature suggesting an intercalative mode for 1–3 with a relative order, 3>2>1, and a combined static and dynamic mode for 4 and 5.