Simple bis-thiocarbono-hydrazones as sensitive, selective, colorimetric, and switch-on fluorescent chemosensors for fluoride anions.
Bis-thiocarbono-hydrazones are found to be a class of sensitive, selective, ratiometric, and colorimetric chemosensors for anions such as fluoride (F(-)) or acetate (Ac(-)). The sensitivities, or the binding constants of the sensors with anions, were found to be strongly dependent on the substituents appended on the pi-conjugation framework, the delocalization bridge CH==N, the aromatic moiety, and the hetero atom in the C==X group (X=O, S) of the sensors. Single-crystal structures and (1)H NMR titration analysis shows that the --CH==N-- moiety is a hydrogen-bond donor, and it is proposed that an additional CHF hydrogen bond is formed for the sensors in the presence F(-). A sensor bearing anthracenyl groups is demonstrated as a switch-on fluorescent chemosensor for F(-) and Ac(-). The recognition of F(-) in acetonitrile (MeCN) by a sensor with nitrophenyl substituents is tolerant to MeOH (MeCN/MeOH=10:1, v/v) and water (MeCN/H(2)O=30:1, v/v); at these solvent ratios the absorption intensity of the sensor-F(-) complex solution at maximal absorption wavelength was attenuated to half of the original value in pure MeCN.
Han
Feng
F
State Key Laboratory of Fine Chemicals, Dalian University of Technology, 158 Zhongshan Road, Dalian 116012, P.R. China.
Bao
Yuhui
Y
Yang
Zhigang
Z
Fyles
Thomas M
TM
Zhao
Jianzhang
J
Peng
Xiaojun
X
Fan
Jiangli
J
Wu
Yunkou
Y
Sun
Shiguo
S
D000042:Absorption; D000085:Acetates / Q000737:chemistry; D000097:Acetonitriles / Q000737:chemistry; D000838:Anions; D015374:Biosensing Techniques / Q000379:methods*; D002244:Carbon / Q000737:chemistry; D003124:Colorimetry / Q000379:methods; D018360:Crystallography, X-Ray; D005456:Fluorescent Dyes / Q000737:chemistry*; D005459:Fluorides / Q000032:analysis*; D006835:Hydrazones / Q000737:chemistry*; D006860:Hydrogen Bonding; D009682:Magnetic Resonance Spectroscopy; D000432:Methanol / Q000737:chemistry; D009584:Nitrogen / Q000737:chemistry; D010100:Oxygen / Q000737:chemistry; D012997:Solvents / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D014867:Water / Q000737:chemistry
D000085:Acetates; D000097:Acetonitriles; D000838:Anions; D005456:Fluorescent Dyes; D006835:Hydrazones; D012997:Solvents; D014867:Water; D002244:Carbon; D009584:Nitrogen; D005459:Fluorides; D010100:Oxygen; D000432:Methanol; C032159:acetonitrile