Efficient Visible Light Induced Nuclease Activity of a Ternary Mono-1,10-phenanthroline Copper(II) Complex Containing 2-(Methylthio)ethylsalicylaldimine

Ternary Schiff base copper(II) complex [CuL(phen)](ClO4), where
HL is 2-(methylthio)ethylsalicylaldimine and phen is 1,10-phenanthroline, has been prepared and structurally characterized by X-ray
crystallography. The complex shows a CuN3OS coordination in a
square-pyramidal (4 + 1) geometry with the sulfur as an equatorial
ligand. The complex is an avid binder to double-stranded DNA in
the minor groove and exhibits both photonuclease and chemical
nuclease activity. When exposed to UV light of 312 nm (96 W) or
visible light of 532 nm (125 W) under aerobic conditions, the
complex causes significant cleavage of supercoiled pUC19 DNA
in the absence of any externally added reducing agent or H2O2.