Synthesis and DNA binding behavior of a naphthalene diimide derivative carrying two dicobalt hexacarbonyl complexes as an infrared DNA probe

Naphthalene diimide having two dicobalt hexacarbonyl complexes at its substituent termini 1 was designed and synthesized as an infrared probe for double stranded DNA. Spectrophotometric and viscometric DNA binding studies of 1 and naphthalene diimide having two acetylene moieties 2 as its precursor were carried out to prove their threading intercalation binding modes. Fourier Transform Infrared Reflection–Absorption Spectroscopy (FT-IR RAS) measurements were achieved for DNA-immobilized on a gold surface before and after hybridization with complementary DNA strand. Distinguished absorption peaks assigned to the dicobalt hexacarbonyl complexes were obtained in the case of the formation of double stranded DNA after treatment with 1. This result revealed that 1 can be used as an infrared probe for monitoring double stranded DNA.