%0 Journal Article
%A Basa, Prem N.
%A Sykes, Andrew G.
%D 2016
%T Differential Sensing of
Zn(II) and Cu(II) via Two
Independent Mechanisms
%U https://acs.figshare.com/articles/journal_contribution/Differential_Sensing_of_Zn_II_and_Cu_II_via_Two_Independent_Mechanisms/2480506
%R 10.1021/jo301193n.s001
%2 https://acs.figshare.com/ndownloader/files/4123186
%K presence
%K NaBH 4
%K analysis results
%K colorimetric change
%K metal ion response
%K anthracene fluorophore formation
%K competition studies
%K hydrolysis phenomenon
%K 1 H NMR
%K XRD
%K Lewis base
%K fluorescence data
%K Zn
%K UV
%K FTIR
%K spectroscopic changes
%K 1.0 equiv
%K Cu
%K 13 C NMR
%K Spectroscopic investigations
%K Independent MechanismsSelective reduction
%K imine hydrolysis
%X Selective reduction of an anthracenone–quinoline
imine derivative, 2, using 1.0 equiv of NaBH4 in 95% ethanol affords
the corresponding anthracen-9-ol derivative, 3, as confirmed
by 1H NMR, 13C NMR, ESI-MS, FTIR, and elemental
analysis results. UV–vis and fluorescence data reveal dramatic
spectroscopic changes in the presence of Zn(II) and Cu(II). Zinc(II)
coordination induces a 1,5-prototropic shift resulting in anthracene
fluorophore formation via an imine–enamine tautomerization
pathway. Copper(II) induces a colorimetric change from pale yellow
to orange-red and results in imine hydrolysis in the presence of water.
Spectroscopic investigations of metal ion response, selectivity, stoichiometry,
and competition studies all suggest the proposed mechanisms. ESI-MS
analysis, FTIR, and single-crystal XRD further support the hydrolysis
phenomenon. This is a rare case of a single sensor that can be used
either as a chemosensor (reversibly in the case of Zn(II)) or as a
chemodosimeter (irreversibly in the case of Cu(II)); however, the
imine must contain a coordinating Lewis base, such as quinoline, to
be active for Cu(II).
%I ACS Publications