Fluorescence detection of Zn 2 + and Cd 2 + is of continuing interest due to their significant importance in biological and environmental sciences. Strict discrimination of Zn 2 + and Cd 2 + by fluorescent probe molecules has still been a challenging task because of the small difference in ionic radii of these group 12 metal ions. In this study, three heptadentate fluorescent probes with a common 2,6-lutidylenediamine core and four quinoline/ isoquinoline sidearms are presented. The N,N,N',N'-tetrakis(2quinolylmethyl)-2,6-lutidylenediamine (TQLN) exhibits Zn 2 + -spe-cific fluorescence enhancement via an excimer formation, while the N,N,N',N'-tetrakis(1-isoquinolylmethyl)-2,6-lutidylenediamine (1-isoTQLN) responds specifically to Cd 2 + at the short wavelength region by monomer emission. The N,N,N', responds to both Zn 2 + and Cd 2 + at different emission wavelengths, acting as a dual sensor with hybrid properties of TQLN and 1-isoTQLN. Methoxy-substituted derivatives of 1-and 3-isoTQLN were also examined.

A bis­(μ-oxo)­diiron­(IV,IV) complex as a model for intermediate Q in the methane monooxygenase reaction cycle has been prepared. The precursor complex with a [FeIIIFeIV(μ-O)2] core was fully characterized by X-ray crystallography and other spectroscopic analyses and was converted to the [FeIV 2(μ-O)2] complex via electrochemical oxidation at 1000 mV (vs Ag/Ag+) in acetone at 193 K. The UV–vis spectral features, Mössbauer parameters (ΔE Q = 2.079 mm/s and δ = −0.027 mm/s), and EXAFS analysis (Fe–O/N = 1.73/1.96 Å and Fe···Fe = 2.76 Å) support the structure of the low-spin (S = 1, for each Fe) [FeIV 2(μ-O)2] core. The rate constants of the hydrogen abstraction reaction from 9,10-dihydroanthracene at 243 K suggest the high reactivity of these synthetic bis­(μ-oxo)­diiron complexes supported by simple N4 tripodal ligand.