Quinoline-attached triazacyclononane (TACN) derivatives as fluorescent zinc sensors

作者：Mikata Yuji^*; Nodomi Yuki; Kizu Asako; Konno Hideo

来源：Dalton Transactions, 2014, 43(4): 1684-1690.

DOI：10.1039/c3dt52107a

TACN (1,4,7-triazacyclononane) derivatives with three 6-methoxy-2-quinolylmethyl or 1-isoquinolyl-methyl moieties were examined as fluorescent zinc sensors. Upon the addition of zinc, 6-MeOTQTACN (5) exhibited a 9-fold fluorescence increase at 420 nm (lambda(ex) = 341 nm, phi(Zn) = 0.070). Fluorescence enhancement is specific for zinc and cadmium, although cadmium induces smaller increases (I-Cd/I-0 = 3.6 and I-Cd/I-Zn = 40%). The isoquinoline analog 1-isoTQTACN (6) exhibits minimal fluorescence enhancement upon zinc binding. TPEN (N,N,N',N'-tetrakis(2-pyridylmethyl)ethylene-diamine) does not extract zinc from the 6-MeOTQTACN-Zn complex (5-Zn). The quantum yield, metal ion selectivity and metal binding affinity differences between TACN and ethylenediamine (EN) skeletons in quinoline-based ligands are discussed based on the X-ray crystallographic analysis of zinc and cadmium complexes, demonstrating the superiority of quinoline-TACN conjugates.

• 出版日期2014