Qu J, Xia Q, Ji W, Jing S, Zhu D, Li L, Huang L, An Z, Xin C, Ni Y, Li M, Jia J, Song Y, Huang W. A ferrocene∩europium assembly showing phototriggered anticancer activity and fluorescent modality imaging.
Dalton Trans 2018;
47:1479-1487. [PMID:
29309070 DOI:
10.1039/c7dt04492e]
[Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Two macrocyclic ferrocenophanes containing a coumarin fluorophore, Se2N[7]ferrocenophane (fc1), and Se4N2[7,7]ferrocenophane (fc2), construct an assembly of fc1-H+ClO4[Eu(C10H21COO)2(H2O)2(ClO4)] (fc1∩Eu) and fc2-2H+{ClO4[Eu(C10H21COO)2(H2O)2(ClO4)]}2 (fc2∩Eu) via a N-HO hydrogen bond and a coordinate bond between EuIII and ClO4-. In fc1∩Eu, UV light irradiation triggers non-covalent bond cleavage to release a ferrocenium and EuII complex, accompanying chromism and luminescence signals. Investigations through the steady-state UV-vis absorption, fluorescence, time-resolved fluorescence, femtosecond transient absorption spectra and electrochemical characterization elucidate a stepwise mechanism: firstly, an effective electron transfer occurs from a ferrocene unit to the singlet state of a coumarin unit; the following proton-coupled electron transfer (PCET) reduces EuIII and results in a non-covalent interaction cleavage. Further in vitro exploration of fc1∩Eu in HepG2 cells demonstrated phototriggered integrated cell cytotoxicity and fluorescent modality imaging.
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