4-methylcoumaro cryptand

HEPES) was obtained from Sigma. NH Cl, CaCl2, MgCl2, LiCl, NaCl, KCl, ethanol and methanol were purchased from Fisher. DMSO and quinine sulfate were procured from Aldrich. The water used was purified by MILLI-Q water system (Millipore). Stock solutions (2 mM) of the 4-methylcoumaro-cryptands were prepared in DMSO and diluted with water or methanol. Stock solutions (0.1 M) were prepared in 50 50 ethanol-water for 4-methylcoumaro-crown ethers and diluted with the same solvent mixture. 

Methyl) Coumaro (211) Cryptand Figure 3 4-Methylcoumaro-cryptands... 

Even though the feasibility of using coumarln in chemosensors has been established with the crown ethers, these systems are not sufficiently sensitive to be used in commercial devices. Since cryptands are several orders of magnitude more selective and sensitive than crown ethers f9.13.141. we synthesized three 4-<-methylcoumaro-cryptands shown in Figure 3 and evaluated their performance. 

The spectra were not corrected for the spectral variation in the excitation source and photomultiplier tube sensitivity. Background scattered light was zeroed electronically before the acquisition of the fluorescence of 4-methylcoumaro-[222]cryptand. Absorption spectra were obtained using Perkin Elmer Lambda 7 UV/VIS Spectrophotometer. 

Figure 6 Calibration of 4 /xM 4-Methylcoumaro[222] Cryptand in Aqueous Solution (pH 7.4)...

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