Related Experiment Video
Updated: Jun 22, 2026

Amide Coupling Reaction for the Synthesis of Bispyridine-based Ligands and Their Complexation to Platinum as Dinuclear Anticancer Agents
Published on: May 28, 2014
Self-assembly of silver(i) and bis-bidentate N,N-donor ligands: from a tetranuclear complex to coordination polymers
Partha Halder1, Ennio Zangrando, Tapan Kanti Paine
1Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata, 700032, India. ictkp@iacs.res.in.
Abstract:
The supramolecular self-assembly structures of one tetranuclear silver(i) complex and three silver(i) coordination polymers derived from bis-bidentate imino-pyridine ligands and their reduced N-methyl derivatives are discussed. Six new ligands were synthesised, and the X-ray structural analysis of L(1), L(2) and L(5) with silver(i) ions indicated the formation of 1D coordination polymers, namely {[AgL(1)]BF(4)}(n) (1), {[AgL(2)]ClO(4)}(n) (2), and {[AgL(5)]ClO(4).H(2)O}(n) (5), whereas ligand L(4) led to a tetranuclear complex {[AgL(4)]ClO(4)}(4) (4). L(1) is the Schiff-base derived from the condensation of alpha,alpha'-diamino-m-xylene and pyridine-2-carboxaldehyde and L(4) that resulting from the reaction of 2-(4-aminophenyl)ethylamine with 6-methyl-pyridine-2-carboxaldehyde, while L(2) and L(5) are the reduced N-methyl derivatives. The structural determination shows achiral syndiotactic polymers for 1 and chiral isotactic for 2 and 5. The 1D coordination chains of 1 are stabilised by intramolecular pi-pi stacking interactions between the phenyl ring of a spacer with the pyridine of a symmetry related adjacent ligand, while the crystal packing of 5 show inter-chain pi-pi interactions. Compound 4 comprises discrete tetranuclear [AgL(4)](4)(4+) complex cations and the rhomboid disposition of the metal ions leads to a globular arrangement of the silver(i) complex. The results provide an insight about the effect of ligand spacer length and flexibility in stabilising the metallo-supramolecular architecture.
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...
Valence Bond Theory
Coordination Compounds and Nomenclature
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
Coordination Number and Geometry

