Macrocyclic bisbinaphthyl fluorophores and their acyclic analogues: signal amplification and chiral recognition.
A series of optically active macrocyclic and acyclic bisbinaphthyls have been synthesized and characterized. The structure of one of the bisbinaphthyl macrocycles has been established by a single-crystal X-ray analysis. The UV and fluorescence spectra of these chiral compounds in various solvents and at different concentrations are studied. Formation of excimers is observed for the macrocyclic bisbinaphthyl compounds. Introduction of conjugated substituents to the 6,6'-positions of the binaphthyl units in the macrocycles leads to greatly amplified fluorescence signals. Using the 6,6'-substituted bisbinaphthyl macrocycles in place of the unsubstituted macrocycles allows a 2 orders of magnitude reduction in the sensor concentration for the fluorescence measurements. These macrocycles have exhibited highly enantioselective fluorescent enhancements in the presence of chiral alpha-hydroxycarboxylic acids and N-protected alpha-amino acids. They are useful as fluorescent sensors for chiral recognition. The macrocycles show much greater enantioselectivity in the substrate recognition than their acyclic analogues.
Li
Zi-Bo
ZB
Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904-4319, USA.
Lin
Jing
J
Zhang
Hui-Chang
HC
Sabat
Michal
M
Hyacinth
Marilise
M
Pu
Lin
L
D005456:Fluorescent Dyes / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D015394:Molecular Structure; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D013237:Stereoisomerism
D005456:Fluorescent Dyes