Synthetic nucleases which rapidly cleave nucleic acids under mild conditions have many important potential applications ranging from the synthesis of custom-designed artificial restriction enzymes to the development of new antitumor drugs. Nonenzymatic hydrolysis of nucleic acids has been attracting increasing interest. However, the cleavage of nucleic acids by lanthanides has rarely been reported, and only Sumaoka et al. observed enor Synthetic nucleases which rapidly cleave nucleic acids under mild conditions have many important potential applications ranging from the synthesis of custom-designed artificial restriction enzymes to the development of new antitumor drugs. Nonenzymatic hydrolysis of nucleic acids has been attracting increasing interest. However, the cleavage of nucleic acids by lanthanides has rarely been reported, and only Sumaoka et al. observed enor