Related Experiment Video
Updated: May 9, 2026

Discovery and Synthesis Optimization of Isoreticular Al(III) Phosphonate-Based Metal-Organic Framework Compounds Using High-Throughput Methods
Published on: October 6, 2023
Phosphonates containing 8-hydroxyquinoline moiety and their metal complexes: structures, fluorescent and magnetic
Deng-Ke Cao1, Bei Liu, Yan-Wei Gu
1State Key Laboratory of Coordination Chemistry, Coordination Chemistry Institute, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, PR China. dkcao@nju.edu.cn
Abstract:
Two kinds of solid-state structures of 5-phosphonomethyl-8-hydroxyquinoline (5pm8hqH3) have been obtained, namely 1·HCl·H2O and 1·H2O, involving different hydrogen bonds and/or aromatic stacking interactions. As a derivative of 5pm8hqH3, 5-phosphonomethyl-8-(carboxymethoxy)quinoline (5pm8cmoqH3) was synthesized. Based on 5pm8hqH3 and 5pm8cmoqH3, three new metal phosphonates have been hydrothermally prepared, including Zn(5pm8hqH)(H2O)·H2O (2), Cu(5pm8cmoqH)·2H2O (3) and Fe(5pm8cmoqH) (4), exhibiting layered structures for 2 and 4, and a three-dimensional open framework for 3. The 8-hydroxyquinoline moieties in 1·H2O and 2-4 exhibit three kinds of interesting aromatic stacking modes, including pyridine ring-pyridine ring stacking between a pair of moieties, double benzene ring-pyridine ring stacking between a pair of moieties and alternating benzene ring-benzene ring and pyridine ring-pyridine ring stacking among a number of moieties in the layered structure. The solid-state fluorescence measurements indicate the emissions of 1·HCl·H2O and 1·H2O are significantly different due to their distinct packing structures. Compound 2 exhibits both ligand-centered (LC) and ligand-to-metal charge transition (LMCT) emissions. Magnetic studies reveal dominant antiferromagnetic interactions in 3 and 4.
Related Concept Videos
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.
Photoluminescence: Applications
Variables Affecting Phosphorescence and Fluorescence
Valence Bond Theory
Complexation Equilibria: Factors Influencing Stability of Complexes
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...

