Antiferromagnetic Coupling of Stacked CuII–Salen Complexes in DNA


  • This work was supported by the BBSRC (BB/F004583/1), the Volkswagen-Stiftung, and the SFB 749. G.H.C. and S.J.R. thank the Studienstiftung des Deutschen Volkes and the Stiftung Stipendien-Fonds des Verbands der Chemischen Industrie e.V. for fellowships.


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A pretty couple: Two copper–salen metal–base pairs were incorporated into a DNA double helix in neighboring positions (see picture). The two paramagnetic CuII ions are antiferromagnetically coupled, and the exchange coupling constant is −2J=22.4 cm−1. The dipolar coupling constant yielded a Cu⋅⋅⋅Cu distance of 3.7 Å, which is comparable to the base-pair distance in natural B-type DNA.