Abstract
Four new fluorescent chemosensors for metal ions based on 8-hydroxyquinoline (8-HDQ) derivatives and sulfur-containing macrocyclic units were synthesized and characterized, namely 1-(5-chloro-8-hydroxy-7- quinolinylmethyl)-1-aza-4,7,10-trithiacyclododecane (L1), 1-(5-chloro-8-hydroxy- 7-quinolinylmethyl)-1-aza-4,13-dithia-7,10-dioxacyclopentadecane (L2), 1-(8-hydroxy-2-quinolinylmethyl)-1-aza-4,7,10-trithiacyclododecane (L3), and 1-(8-hydroxy-2-quinolinylmethyl)-1-aza-4,13-dithia-7,10-dioxacyclopentadecane (L4). Preliminary fluorimetric titrations indicated L1 as the only member of the family of ligands to give a selective CHEF-type response to the presence of Zn2+ in MeCN-H2O (1:1, v/v) solutions, which allowed imaging of this metal ion in Cos-7 cells in vitro. The other ligands either did not show any fluorescence response (L3, L4) to any of the metal ions considered (Cu2+, Zn2+, Cd2+, Hg2+ and Pb 2+) or gave (L2) a CHEF-type response also to the presence of Cd 2+. The coordination properties of L1 towards Zn2+ were, therefore, fully investigated by potentiometric measurements and absorption and emission spectroscopy at different pH values, which indicated that the formation of 2:1 L1/Zn2+ complexes is responsible for the CHEF-type effect observed. The complexes [Zn(L1)2H2O](BF4) 2 and [Zn(L3)](ClO4)2 were characterized in the solid state by X-ray crystallography, and DFT calculations were performed to understand the origin of the Zn2+/Cd2+ optical discrimination of the 8-HDQ-based "conjugate" fluorescent chemosensors reported. © 2013 The Royal Society of Chemistry.
Original language | English |
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Pages (from-to) | 14516-14530 |
Number of pages | 15 |
Journal | Dalton Transactions |
Volume | 42 |
Issue number | 40 |
DOIs | |
Publication status | Published - 28 Oct 2013 |
Keywords
- 8-Hydroxyquinoline
- 8-hydroxyquinoline derivatives
- Absorption and emission spectroscopy
- Coordination properties
- DFT calculation
- Fluorescent chemosensors
- Fluorimetric titration
- Potentiometric measurements
- Emission spectroscopy
- Fluorescence
- Lead
- Ligands
- Metal ions
- Physiology
- Sulfur
- X ray crystallography
- Zinc
- Copper
- 8 quinolinol
- cadmium
- fluorescent dye
- macrocyclic compound
- sulfur
- zinc
- animal
- chemical structure
- chemistry
- Chlorocebus aethiops
- COS 1 cell line
- light related phenomena
- quantum theory
- spectrofluorometry
- synthesis
- article
- cell strain COS1
- Animals
- Cadmium
- Cercopithecus aethiops
- COS Cells
- Fluorescent Dyes
- Macrocyclic Compounds
- Models, Molecular
- Molecular Structure
- Optical Processes
- Oxyquinoline
- Quantum Theory
- Spectrometry, Fluorescence