Coumaric amide rotaxanes: effects of hydrogen bonding and mechanical interlocking on the photochemistry and photophysics.
Secondary amide derivatives of coumaric and ferulic acid are shown to undergo photoisomerization, forming a photostationary mixture of E- and Z-isomers. When the same chromophores are incorporated in rotaxanes, the extent of conversion to the Z-isomers is much smaller. Low temperature fluorescence experiments show that the energy barrier for non-radiative decay of the excited state is higher in the rotaxanes than in the corresponding threads, but the barriers are low in all cases.
Brouwer
Albert M
AM
Van't Hoff Institute for Molecular Sciences, University of Amsterdam, Nieuwe Achtergracht 129, 1018, WS Amsterdam, The Netherlands. a.m.brouwer@uva.nl
Fazio
Sandro M
SM
Haraszkiewicz
Natalia
N
Leigh
David A
DA
Lennon
Claire M
CM
D000577:Amides / Q000737:chemistry* / Q000528:radiation effects; D003198:Computer Simulation; D003373:Coumaric Acids / Q000737:chemistry* / Q000528:radiation effects; D006860:Hydrogen Bonding; D009682:Magnetic Resonance Spectroscopy / Q000379:methods / Q000592:standards; D015394:Molecular Structure; D010777:Photochemistry; D012015:Reference Standards; D043862:Rotaxanes / Q000737:chemistry* / Q000528:radiation effects; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence / Q000379:methods; D013237:Stereoisomerism; D013696:Temperature; D014466:Ultraviolet Rays
D000577:Amides; D003373:Coumaric Acids; D043862:Rotaxanes; C004999:ferulic acid