Highly selective colorimetric and electrochemical Pb2+ detection based on TTF-pi-pyridine derivatives.
[reaction: see text] The pyridineethenyl-substituted tetrathiafulvalene (TTF) compounds, 4-(4-pyridineethenyl)tetrathiafulvalene (1a) and 4,4'(5')-[bis-(4-pyridineethenyl)]tetrathiafulvalene (2a) together with the styryl-substituted TTF compounds, 4-styryltetrathiafulvalene (1b) and 4,4'(5')-bis-styryltetrathiafulvalene (2b), have been designed and synthesized. All these compounds exhibit strong absorption bands in the range of 370 to 550 nm, which are assigned to the intramolecular charge-transfer transition from the HOMO in TTF to the LUMO in the pyridyl or phenyl group. Compared to compounds 1b and 2b, the pyridineethenyl-substituted TTF compounds 1a and 2a show remarkable sensing and coordinating properties to Pb2+. With the addition of micromolar concentrations of Pb2+ to the solution, 1a or 2a displays dramatic changes in the UV-vis absorption spectrum, 1H NMR spectrum, and redox property.
Xue
Hai
H
Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100101, China.
Tang
Xin-Jing
XJ
Wu
Li-Zhu
LZ
Zhang
Li-Ping
LP
Tung
Chen-Ho
CH
D000042:Absorption; D003124:Colorimetry; D004563:Electrochemistry; D005030:Ethylenes / Q000737:chemistry*; D006571:Heterocyclic Compounds / Q000737:chemistry*; D007854:Lead / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D015394:Molecular Structure; D010084:Oxidation-Reduction; D011725:Pyridines / Q000737:chemistry*; D012680:Sensitivity and Specificity; D013056:Spectrophotometry, Ultraviolet / Q000379:methods
D005030:Ethylenes; D006571:Heterocyclic Compounds; D011725:Pyridines; D007854:Lead; C063887:tetrathiafulvalene