Related Experiment Video
Updated: Jun 23, 2026

Synthesis and Characterization of Self-Assembled Metal-Organic Framework Monolayers Using Polymer-Coated Particles
Published on: June 14, 2024
Grafting ligands to direct the self-assembly of Co/Ni2+ substituted polyoxometalate clusters
Chris Ritchie1, Thomas Boyd, De-Liang Long
1WestCHEM, Department of Chemistry, The University of Glasgow, University Avenue, Glasgow, UK.
Abstract:
Four transition metal incorporated phosphotungstates have been synthesized through the reaction of Na(2)WO(4), H(3)PO(4), Co/Ni(NO(3))(2), and the multifunctional amine N,N'-Bis(2-hydroxyethyl) piperazine (bhep). Na(2){MHbhep(H(2)O)(4)}[PW(10)M(2)O(38){Hbhep}(2)] M = Co(2+) (1), and Ni(2+)(2) represent rare examples of complete transition metal chelate encapsulation within a Keggin polyanion. Slight modification of the reaction procedure yielding 1 also yields the two dimensional material (H(2)bhep)(3)Na(4)[Co(4)(H(2)O)(2)(PW(9)O(34))(2)].15H(2)O (3). Finally, the isolation of a phosphotungstate cluster containing 18 Co(2+) ions is achieved through the bridging of two [Co(9)(OH)(3)(H(2)O)(6)(HPO(4))(2)(B-alpha-PW(9)O(34))(3)](16-) clusters by the bhep ligand to form the [{Co(9)(OH)(3)(H(2)O)(3)(HPO(4))(2)(B-alpha-PW(9)O(34))(3)}(2) {C(8)H(18)N(2)O(2)}(3)](32-) dimer (4). The dimerisation process is achieved via the monodentate coordination of the hydroxyl groups from three bhep ligands to each polyanion by displacing the water ligands typically found coordinated to the {Co(9)} core forming a nanoscale cylinder-like capsule capped by two {Co(9)P(5)W(27)} with three BHEP-based ligand spacers.
Related Concept Videos
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...
Complexometric Titration: Ligands
Structural Isomerism
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can be...
Complexation Equilibria: The Chelate Effect
Valence Bond Theory
Ziegler–Natta Chain-Growth Polymerization: Overview

