A Molecular Nanotube with Three‐Dimensional π‐Conjugation1. Issue 25 (7th May 2015)

• Record Type: Journal Article
• Authors: Neuhaus, Patrik; Cnossen, Arjen; Gong, Juliane Q.; Herz, Laura M.; Anderson, Harry L.
• Is Part Of: Angewandte Chemie international edition. Volume 54:Issue 25(2015)
• Page Start: 7344
• Page End: 7348
• Publication Date: 2015-05-07
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201502735
• Languages: English
• ISSNs: 1433-7851

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>A π‐conjugated twelve‐porphyrin tube is synthesized in 32 % yield by a template‐directed coupling reaction that joins together six porphyrin dimers, forming twelve new CC bonds. The nanotube has two bound templates, enclosing an internal volume of approximately 4.5 nm³. Its UV/Vis/NIR absorption and fluorescence spectra resemble those of a previously reported six‐porphyrin ring, but are red‐shifted by approximately 300 cm⁻¹, reflecting increased conjugation. Ultrafast fluorescence spectroscopy demonstrates extensive excited‐state delocalization. Transfer of electronic excitation from an initially formed state polarized in the direction of the nanotube axis (<italic>z</italic> axis) to an excited state polarized in the <italic>xy</italic> plane occurs within 200 fs, resulting in a negative fluorescence anisotropy on excitation at 742 nm.</p> </abstract>