Lanthanide(III) Ions and 5-Methylisophthalate Ligand Based Coordination Polymers: An Insight into Their Photoluminescence Emission and Chemosensing for Nitroaromatic Molecules.

The work presented herein reports on the synthesis, structural and physico-chemical characterization, luminescence properties and luminescent sensing activity of a family of isostructural coordination polymers (CPs) with the general formula [Ln(μ-5Meip)(DMF)] (where Ln(III) = Sm (), Eu (), Gd (), Tb () and Yb () and 5Meip = 5-methylisophthalate, DMF = N,N-dimethylmethanamide). Crystal structures consist of 3D frameworks tailored by the linkage between infinite lanthanide(III)-carboxylate rods by means of the tetradentate 5Meip ligands. Photoluminescence measurements in solid state at variable temperatures reveal the best-in-class properties based on the capacity of the 5Meip ligand to provide efficient energy transfers to the lanthanide(III) ions, which brings intense emissions in both the visible and near-infrared (NIR) regions.

An experimental and theoretical study of the magnetic relaxation in heterometallic coordination polymers based on 6-methyl-2-oxonicotinate and lanthanide(III) ions with square antriprismatic environment.

Two new isostructural compounds based on 6-methyl-2-oxonicotinate (6m2onic) ligand and sodium and lanthanide(III) ions are reported. The structural and chemical characterization reveals the following chemical formula: {[Ln(6m2onic)(μ-6m2onic)Na(HO)]·8HO} [where Ln(III) = Dy (1Dy) and Er (2Er)]. These compounds crystallize in the form of one-dimensional arrays held together into a hydrogen-bonded structure, in which 6m2onic ligands establish four ,' chelating rings with the lanthanide to render a distorted square antiprism (SAPR) geometry.

Combined experimental and theoretical investigation on the magnetic properties derived from the coordination of 6-methyl-2-oxonicotinate to 3d-metal ions.

Five new compounds are reported herein starting from 2-hydroxy-6-methylnicotinic acid (H2h6mnic) and first-row transition metal ions, although H2h6mnic shows a prototropy in solution to lead to the 6-methyl-2-oxonicotinate (6m2onic) ligand that is the molecule eventually present in the compounds. The structural and chemical characterization reveals the following chemical formulae: {[MnNa(μ-6m2onic)(μ-6m2onic)(MeOH)]·HO·MeOH} (1Mn), {[MNa(μ-6m2onic)(μ-6m2onic)(μ-HO)(HO)](NO)} [M = Co (2Co) and Ni (3Ni)], 2[Cu(6m2onic)(μ-6m2onic)(MeOH)]·[Cu(6m2onic)(μ-6m2onic)]·2[Cu(6m2onic)(MeOH)]·32HO (4Cu) and {[Cu(μ-6m2onic)]·6HO} (5Cu) (where 6m2onic = 6-methyl-2-oxonicotinate). An unusual structural diversity is observed for the compounds, ranging from isolated complexes (in 4Cu), 1D arrays (in 1Mn and 5Cu) and 3D frameworks (in 2Co and 3Ni).