Cooperative Enhancement of Two-Photon Absorption in Self-Assembled Zinc-Porphyrin Nanostructures
Alexander Mikhaylov, Dmitry V. Kondratuk, Arjen Cnossen, Harry L. Anderson, Mikhail Drobizhev, Aleksander Rebane
The Journal of Physical Chemistry C
Femtosecond two-photon absorption (2PA) spectra were measured of a series of butadiyne-linked zinc-porphyrin oligomers assembled in single- and double-strand linear and cyclic structures containing 6, 12, or 24 porphyrin units, in the excitation wavelength range 900â€“1600 nm. We observe strong enhancement of the 2PA cross-section in the Soret region, with maximum values up to Ïƒ2PA âˆ¼ 105 GM depending on the geometry of the construct, which we quantitatively explain in terms of a three essential energy level model and cooperative enhancement of the transition dipole moments between the states. The Zn-coordinated template-bound ring of 6 porphyrin units, which resembles some natural light-harvesting systems, results in the highest 2PA cross-section per porphyrin unit (âˆ¼104 GM). It is remarkable that this molecule gives such strong Ïƒ2PA, when the S0â€“S1 (0â€“0) transition is essentially forbidden for one photon transition.
How is this information collected?
This collection of Montana State authored publications is collected by the Library to highlight the achievements of Montana State researchers and more fully understand the research output of the University. They use a number of resources to pull together as complete a list as possible and understand that there may be publications that are missed. If you note the omission of a current publication or want to know more about the collection and display of this information email Leila Sterman.