Synthesis and Characterization of Electroactive Ferrocene Derivatives: Ferrocenylimidazoquinazoline as a Multichannel Chemosensor Selectively for Hg2+ and Pb2+ Ions in an Aqueous

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• 作者：Rampal Pandey ; Rakesh Kumar Gupta ; Mohammad Shahid ; Biswajit Maiti ; Arvind Misra ; Daya Shankar Pandey
• 刊名：Inorganic Chemistry
• 出版年：2012
• 出版时间：January 2, 2012
• 年：2012
• 卷：51
• 期：1
• 页码：298-311
• 全文大小：810K
• 年卷期：v.51,no.1(January 2, 2012)
• ISSN：1520-510X

文摘

The synthesis and characterization of ferrocene (Fc) derivatives 4-[2,5-diferrocenyl-4-(4-pyridyl)imidazolidin-1-ylmethyl]pyridine (1), ferrocenylmethylenepyridin-3-ylmethylamine (2), N,N鈥?bis(ferrocenylmethylene)-2,4,6-trimethylbenzene-1,3-diamine (3), and 6-ferrocenyl-5,6-dihydro[4,5]imidazo[1,2-c]quinazoline (4) have been described. Structures of 1, 2, and 4 have been determined by single-crystal X-ray diffraction analyses. At 25 掳C, 1鈥?b>3 are nonfluorescent, while 4 displays moderate fluorescence and chromogenic, fluorogenic, and electrochemical sensing selectively toward Hg²⁺ and Pb²⁺ ions. Association constants (K_a) for Hg²⁺ and Pb²⁺ have been determined by the Benesi鈥揌ildebrand method. Job鈥檚 plot analysis supported 1:1 and 1:2 stoichiometries for Hg²⁺ and Pb²⁺ ions. Cyclic voltammograms of 1鈥?b>4 exhibited reversible waves corresponding to a ferrocene/ferrocenium couple. The wave associated with 4 (+0.0263 V) exhibited positive (螖E_pa = 0.136 V) and negative (螖E_pa = 0.025 V) shifts in the presence of Hg²⁺ and Pb²⁺ ions, respectively. The mode of interaction between metal ions and 4 has been supported by ¹H NMR spectroscopy and mass spectrometry studies and verified by theoretical studies. It presents the first report dealing with ferrocene-substituted quinazoline as a multichannel chemosensor for Hg²⁺/Pb²⁺ ions.