Electronic decay constant of carotenoid polyenes from single-molecule measurements.
The conductance of carotenoid polyenes chemically bound at each end to gold contacts has been measured for single molecules containing 5, 7, 9, and 11 carbon-carbon double bonds in conjugation. The electronic decay constant, beta, is determined to be 0.22 +/- 0.04 A-1, in close agreement with the value obtained from first principles simulations (0.22 +/- 0.01 A-1). The absolute values of the molecular conductance are within a factor of 3 of those calculated from first principles. The small value of beta demonstrates that conductivity drops off only slowly with chain length, confirming that carotenoid conjugated chains are relatively good molecular "wires".
He
Jin
J
Department of Physics and Astronomy, Department of Chemistry and Biochemistry, and Biodesign Institute, Arizona State University, Tempe, AZ 85287, USA.
Chen
Fan
F
Li
Jun
J
Sankey
Otto F
OF
Terazono
Yuichi
Y
Herrero
Christian
C
Gust
Devens
D
Moore
Thomas A
TA
Moore
Ana L
AL
Lindsay
Stuart M
SM