Synthesis and photophysical investigation of squaraine rotaxanes by "clicked capping".
Pseudorotaxane complexes of squaraine dyes and tetralactam macrocycles are converted into permanently interlocked rotaxane structures using copper-catalyzed and copper-free cycloaddition reactions with bulky stopper groups. The photophysical properties of the encapsulated squaraine depend on the structure of the macrocycle. In one case, squaraine rotaxanes are produced in near-quantitative yields and with intense near-IR fluorescence. In another case, squaraine fluorescence is greatly diminished upon macrocyclic encapsulation but the signal can be restored by dye displacement with anions.
Gassensmith
Jeremiah J
JJ
Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, USA.
Barr
Lorna
L
Baumes
Jeffrey M
JM
Paek
Agelina
A
Nguyen
Anh
A
Smith
Bradley D
BD
D003503:Cyclobutanes / Q000138:chemical synthesis / Q000737:chemistry*; D047029:Lactams, Macrocyclic / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D010636:Phenols / Q000138:chemical synthesis / Q000737:chemistry*; D010777:Photochemistry; D043862:Rotaxanes / Q000138:chemical synthesis / Q000737:chemistry*; D013050:Spectrometry, Fluorescence
D003503:Cyclobutanes; D047029:Lactams, Macrocyclic; D010636:Phenols; D043862:Rotaxanes; C480596:squaraine