Related Experiment Video
Updated: May 12, 2026

An Aptamer-based Sensor for Unchelated Gadolinium(III)
Published on: January 9, 2017
Gelation-induced visible supramolecular chiral recognition by fluorescent metal complexes of quinolinol-glutamide
Wangen Miao1, Li Zhang, Xiufeng Wang
1Beijing National Laboratory for Molecular Science, CAS Key Laboratory of Colloid, Interface and Chemical Thermodynamics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, PR China.
Abstract:
Three metal complexes consisting of Li(+), Zn(2+), and Al(3+) and quinolinol-functionalized L-glutamides (HQLG), (abbreviated as LiHQLG, Zn(HQLG)2, and Al(HQLG)3) were found to form fluorescent metallogels in several organic solvents. In solution, these chiral complexes showed neither any CD signal in the chromophore region nor chiral recognition of the chiral species. However, upon gel formation, the supramolecular chirality emerged because of the self-assembled nanostructures, which provided an opportunity for the chiral recognition of enantiomeric ligands. The metallogels showed different fluorescence changes when they met with enantiomeric (R,R)- or (S,S)-1,2-diaminocyclohexane. Among them, the Al(HQLG)3 metallogels did not show any change whereas the LiHQLG gels exhibited the same decrease in fluorescence. Interestingly, the Zn(HQLG)2 gels showed obviously different fluorescent color with respect to (R,R)- and (S,S)-1,2-diaminocyclohexane, thus providing visible chiral recognition via the naked eye. Such different recognition ability was discussed on the basis of the assembled chiral nanostructures and the primary molecular structures of the metal complexes. It was shown that both of them played important roles in chiral recognition.
More Related Videos
Related Concept Videos
Complexation Equilibria: The Chelate Effect
Colors and Magnetism
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human eye.
Stereoisomerism
Isomers are different chemical species that have the same chemical formula.
Transition metal complexes often exist as geometric isomers, in which the same atoms are connected through the same types of bonds but with differences in their orientation in space. Coordination complexes with two different ligands in the cis and trans positions from a ligand of interest form isomers. For example, the octahedral [Co(NH3)4Cl2]+ ion has two isomers (Figure 1) In the cis...
Metal-Ligand Bonds
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
Valence Bond Theory

