A Complex Comprising a Cyanine Dye Rotaxane and a Porphyrin Nanoring as a Model Light‐Harvesting System. (23rd July 2020)

• Record Type: Journal Article
• Authors: Pruchyathamkorn, Jiratheep; Kendrick, William J.; Frawley, Andrew T.; Mattioni, Andrea; Caycedo‐Soler, Felipe; Huelga, Susana F.; Plenio, Martin B.; Anderson, Harry L.
• Is Part Of: Angewandte Chemie. Volume 132:Number 38(2020)
• Page Start: 16597
• Page End: 16600
• Publication Date: 2020-07-23
• Subjects: Cyanine dyes -- excitonic coupling -- light harvesting -- porphyrin -- rotaxanes; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.202006644
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: A nanoring‐rotaxane supramolecular assembly with a Cy7 cyanine dye (hexamethylindotricarbocyanine) threaded along the axis of the nanoring was synthesized as a model for the energy transfer between the light‐harvesting complex LH1 and the reaction center in purple bacteria photosynthesis. The complex displays efficient energy transfer from the central cyanine dye to the surrounding zinc porphyrin nanoring. We present a theoretical model that reproduces the absorption spectrum of the nanoring and quantifies the excitonic coupling between the nanoring and the central dye, thereby explaining the efficient energy transfer and demonstrating similarity with structurally related natural light‐harvesting systems. Abstract : Colorful to the core : Rotaxane formation was used to lock a cyanine dye along the axis of a porphyrin nanoring to form a complex that mimics the photophysical behavior of the light‐harvesting complex LH1 and the reaction center in purple photosynthetic bacteria. Energy is transferred rapidly between the axial dye and the surrounding nanoring.