An extremely stable host-guest complex that functions as a fluorescence probe for calcium ions.
Herein, we report a crown ether based molecular cage that forms extremely stable supramolecular complexes with dimethyldiazapyrenium (DMDAP) ions in CD(3)CN through the collaboration of multiple weak C-HO hydrogen bonds. The very strong binding affinity in this host-guest system allows the molecular cage to bleach the fluorescence signal of DMDAP substantially in equimolar solutions at concentrations as low as 1 x 10(-5) M. Remarkably, a 1x10(-5) M equimolar solution of the molecular cage and DMDAP is highly selective toward Ca(2+) ions-relative to other biologically important Li(+), Na(+), K(+), and Mg(2+) ions-and causes a substantial increase in the fluorescence intensity of the solution. As a result, this molecular cage/DMDAP complex behaves as a supramolecular fluorescence probe for the detection of Ca(2+) ions in solution.
Department of Chemistry, National Taiwan University, No. 1 Sec. 4 Roosevelt Road, Taipei, Taiwan, ROC. shchiu@ntu.edu.tw
Chi-Feng
CF
Lin
Yi-Hung
YH
Liu
Chien-Chen
CC
Lai
Shie-Ming
SM
Peng
Sheng-Hsien
SH
Chiu
D001372:Aza Compounds / Q000737:chemistry; D002118:Calcium / Q000032:analysis*; D043844:Crown Ethers / Q000138:chemical synthesis / Q000737:chemistry*; D005456:Fluorescent Dyes / Q000138:chemical synthesis / Q000737:chemistry*; D006860:Hydrogen Bonding; D007477:Ions / Q000032:analysis; D011726:Pyridinium Compounds / Q000737:chemistry; D012996:Solutions / Q000737:chemistry
D001372:Aza Compounds; D043844:Crown Ethers; D005456:Fluorescent Dyes; D007477:Ions; D011726:Pyridinium Compounds; D012996:Solutions; C520876:dimethyldiazapyrenium; D002118:Calcium