Phenanthroline-derived ratiometric chemosensor for ureas.
The syntheses of 1,10-phenanthroline fluorophore-based chemosensor 7 and its truncated analog 9 are reported. Interactions of these compounds with urea, thiourea, 1,3-dimethylurea, tetrahydropyrimidin-2(1H)-one, imidazolidin-2-one, and selected uronium salts were assessed by three-dimensional excitation-emission spectroscopy, UV-vis absorbance, and fluorescence titrations. Chemosensor 7 was found to be capable of distinguishing between neutral ureas and their salts, by producing a different optical response for each type of compounds. The complexation of urea by 7 was also studied by selective-NOE 1H NMR, 13C NMR (using 13C-labeled guest), and MALDI-TOF mass spectrometry. In addition, we performed DFT calculations (B3LYP 3-21g** level) for structures of complexes of 7 with urea, imidazolidin-2-one, and tetrahydropyrimidin-2(1H)-one. Development of chemosensor 7-type compounds in conjunction with differential excitation-emission spectroscopy represents an important step toward the development of novel tools for ureas and their salts analysis.
Engel
Yoni
Y
School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 69978, Israel.
Dahan
Adi
A
Rozenshine-Kemelmakher
Emily
E
Gozin
Michael
M
D002623:Chemistry Techniques, Analytical / Q000295:instrumentation* / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D010618:Phenanthrolines / Q000737:chemistry*; D010777:Photochemistry; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014508:Urea / Q000032:analysis* / Q000737:chemistry*
D010618:Phenanthrolines; D014508:Urea