Long-range photoinduced electron transfer through a DNA helix

Journal Article · Fri Nov 12 00:00:00 EST 1993 · Science (Washington, D.C.); (United States)

DOI:https://doi.org/10.1126/science.7802858· OSTI ID:5183600

Murphy, C J; Arkin, M R; Jenkins, Y; Barton, J K ^[1]; Ghatlia, N D; Bossmann, S H; Turro, N J ^[2]

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1. California Institute of Technology, Pasadena, CA (United States)
2. Columbia Univ., New York, NY (United States)

Rapid photoinduced electron transfer is demonstrated over a distance of greater than 40 angstroms between metallointercalators that are tethered to the 5' termini of a 15-base pair DNA duplex. An oligomeric assembly was synthesized in which the donor is Ru(phen)[sub 2]dppz[sup 2+] (phen, phenanthroline, and dppz, dipyridophenazine) and the acceptor is Rh(phi)[sub 2]phen[sup 3+] (phi, phenanthrenequinone diimine). These metal complexes are intercalated either one or two base steps in from the helix termini. Although the ruthenium-modified oligonucleotide hybridized to an unmodified complement luminesces intensely, the ruthenium-modified oligomer hybridized to the rhodium-modified oligomer shows no detectable luminescence. Time-resolved studies point to a lower limit of 10[sup 9] per second for the quenching rate. No quenching was observed upon metallation of two complementary octamers by Ru(phen)[sub 3][sup 2+] and Rh(phen)[sub 3][sup 3+] under conditions where the phen complexes do not intercalate. The stacked aromatic heterocycles of the DNA duplex therefore serve as an efficient medium for coupling electron donors and acceptors over very long distances.

• OSTI ID: 5183600
• Journal Information: Science (Washington, D.C.); (United States), Vol. 262:5136; ISSN 0036-8075
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
DNA
PHOTOCHEMICAL REACTIONS
ORGANOMETALLIC COMPOUNDS
ELECTRON TRANSFER
RHODIUM COMPLEXES
RUTHENIUM COMPLEXES
CLATHRATES
CHEMICAL REACTIONS
COMPLEXES
NUCLEIC ACIDS
ORGANIC COMPOUNDS
TRANSITION ELEMENT COMPLEXES
400201* - Chemical & Physicochemical Properties