Crystal-Phase Transitions and Photocatalysis in Supramolecular Scaffolds

Journal Article · Mon Apr 24 00:00:00 EDT 2017 · Journal of the American Chemical Society

DOI:https://doi.org/10.1021/jacs.6b13156· OSTI ID:1352707

Kazantsev, Roman V.; Dannenhoffer, Adam J.; Weingarten, Adam S.; Phelan, Brian T. ; Harutyunyan, Boris; Aytun, Taner; Narayanan, Ashwin; Fairfield, Daniel J. ; Boekhoven, Job; Sai, Hiroaki ; Senesi, Andrew ^[1]; O’Dogherty, Pascual I.; Palmer, Liam C.; Bedzyk, Michael J. ; Wasielewski, Michael R. ; Stupp, Samuel I.

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1. X-ray Science Division, Argonne National Laboratory, Argonne, Illinois 60439, United States

The energy landscape of a supramolecular material can include different molecular packing configurations that differ in stability and function. We report here on a thermally driven crystalline order transition in the landscape of supramolecular nanostructures formed by charged chromophore amphiphiles in salt-containing aqueous solutions. An irreversible transition was observed from a metastable to a stable crystal phase within the nanostructures. In the stable crystalline phase, the molecules end up organized in a short scroll morphology at high ionic strengths and as long helical ribbons at lower salt content. This is interpreted as the result of the competition between electrostatic repulsive forces and attractive molecular interactions. Only the stable phase forms charge-transfer excitons upon exposure to visible light as indicated by absorbance and fluorescence features, second-order harmonic generation microscopy, and femtosecond transient absorbance spectroscopy. Interestingly, the supramolecular reconfiguration to the stable crystalline phase nanostructures enhances photosensitization of a proton reduction catalyst for hydrogen production.

• Research Organization: Northwestern Univ., Evanston, IL (United States); Energy Frontier Research Centers (EFRC) (United States). Argonne-Northwestern Solar Energy Research Center (ANSER); Energy Frontier Research Centers (EFRC) (United States). Center for Bio-Inspired Energy Science (CBES)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES); National Science Foundation (NSF)
• Grant/Contract Number: SC0001059; FG02-00ER45810; AC02-06CH11357; SC0000989
• OSTI ID: 1352707
• Alternate ID(s): OSTI ID: 1361505; OSTI ID: 1821191; OSTI ID: 1846945
• Journal Information: Journal of the American Chemical Society, Journal Name: Journal of the American Chemical Society Vol. 139 Journal Issue: 17; ISSN 0002-7863
• Publisher: American Chemical Society
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
36 MATERIALS SCIENCE
77 NANOSCIENCE AND NANOTECHNOLOGY
99 GENERAL AND MISCELLANEOUS
Crystals
Nanostructures
Crystallization
Absorption
Phase transitions
Crystals
Nanostructures
Crystallization
Absorption
Phase transitions