Related Experiment Video
Updated: May 19, 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
Unusual nitro-coordination of europium(III) and terbium(III) with pyridinyl ligands
Ana de Bettencourt-Dias1, Sebastian Bauer, Subha Viswanathan
1Department of Chemistry, University of Nevada, Reno, Reno, Nevada, USA. abd@unr.edu
Abstract:
A new ligand family based on picoline, bipyridine and terpyridine containing a nitro moiety has been synthesized and its coordination and sensitization ability for lanthanide ions has been studied. Three new complexes were characterized by X-ray single crystal diffraction and all three show uncommon coordination of the nitro moiety to the lanthanide ion. 5cTb, a terpyridine-nitro derivative with Tb(NO(3))(3), crystallizes in the orthorhombic space group Pbca with a = 15.125(3), b = 13.776(3), c = 18.716(4) Å, and V = 3899.8(13) Å(3) and is isostructural with its Eu(III) analog (5cEu) with cell parameters a = 15.1341(4), b = 13.7070(4), c = 18.8277(5) Å. 6Eu, a tripodal amine with a nitro-derivatized pyridine with Eu(CF(3)SO(3))(3), crystallizes in the triclinic space group P1 with a = 11.067(2), b = 11.633(2), c = 12.772(3) Å, α = 110.94(3), β = 97.49(3), γ = 91.42(3)° and V = 1518.1(5) Å(3). Finally, ligand 5a, a bipyridine-nitro derivative, crystallizes in the orthorhombic space group P2(1)/n with a = 3.7128(3), b = 11.7806(8), c = 19.9856(14) Å, β = 92.925(2)° and V = 873.01(11) Å(3). All four ligands show sensitization of Eu(III) and Tb(III) luminescence.
Related Concept Videos
Valence Bond Theory
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...
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...
Coordination Number and Geometry
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.
Coordination Compounds and Nomenclature

