Metal-Based Netropsin Mimics Showing AT-Selective DNA Binding and DNA Cleavage Activity at Red Light

Copper(II) bis-arginate [Cu(l-arg)2](NO3)2 (1) and [Cu(l-arg)(phen)Cl]Cl (2) as mimics of the minor-groove-binding natural antibiotic netropsin show preferential binding to the AT-rich region of double-stranded DNA. The complexes with a d−d band near 600 nm display oxidative DNA cleavage activity on photoirradiation at UV-A light of 365 nm and at red light of 647.1 nm (Ar−Kr laser) in a metal-assisted photoexcitation process forming singlet oxygen (1O2) species in a type-2 pathway.