Halogen-Bonds-Based Strategy for the Design of Highly Luminescent Lanthanide Coordination Polymers as Taggants for Plastic Waste Sorting.

Reactions in water between a lanthanide ion and 3,4,5,6-tetrachloro-phthalate lead to a new series of iso-structural coordination polymers with general chemical formula [Ln2(tcpa)3(H2O)6]∞ with Ln = Eu-Yb plus Y. The crystal structure has been solved on the Y-derivative. This compound crystallizes in the monoclinic system, space group P21/n (no. 14) with the following cell parameters: a = 6.2155(2) Å, b = 19.6652(7) Å, c = 30.3720(9) Å, ß = 94.631(1)°, V = 3700.22(37) Å3, and Z = 4. Luminescence properties of homo- and heterolanthanide coordination polymers that belong to this structural family have been studied in detail. This study shows that, in this system, intermetallic energy transfers are very efficient and that dilution by an optically non active Gd3+ ion leads to quite efficient luminescent heterolanthanide coordination polymers. The luminescence of these compounds, dispersed at a low doping rate in a poly(methyl methacrylate) (PMMA) matrix, can be observed even with the naked eye. This study opens the way to the use of such compounds as taggants for optical sorting of plastic waste and consecutive recycling.

Synthesis and crystal structure of a new coordination polymer based on lanthanum and 1,4-phenyl-enedi-acetate ligands.

Reaction in gel between the sodium salt of 1,4-phenyl-enedi-acetic acid (Na2C10O4H8-Na2 p-pda) and lanthanum chloride yields single crystals of the three-dimensional coordination polymer poly[[tetra-aqua-tris-(µ-1,4-phenyl-enedi-acetato)-dilanthanum(III)] octa-hydrate], {[La2(C10H8O4)3(H2O)4]·8H2O}∞. The LaIII coordination polyhedron can be described as a slightly distorted monocapped square anti-prism. One of the two p-pda2- ligands is bound to four LaIII ions and the other to two LaIII ions. Each LaIII atom is coordinated by five ligands, thereby generating a metal-organic framework with potential porosity properties.

Lanthanide-Based Coordination Polymers with a 4,5-Dichlorophthalate Ligand Exhibiting Highly Tunable Luminescence: Toward Luminescent Bar Codes.

Reactions in water of 4,5-dichlorophthalate (dcpa2-) with the heaviest lanthanide ions lead to a family of compounds with the general chemical formula [Ln2(dcpa)3(H2O)5·3H2O]∞, where Ln = Tb-Lu, Y. The synthesis, crystal structure, thermal behavior, and luminescent properties of this series of homonuclear compounds are described. Additionally, this family can be extended to isostructural heteronuclear compounds that can contain some light lanthanide ions and therefore present some original photophysical properties. These compounds show potential interest as multiemissive materials (visible and infrared light between 450 and 1600 nm) and could find application as luminescent bar codes.

Poly[[hexa-aqua-sesqui(µ-benzene-1,2,4,5-tetra-carboxyl-ato)dicopper(II)disodium] monohydrate].

In the title compound, {[Cu2Na2(C10H2O8)1.5(H2O)6]·H2O} n , the Cu(2+) ion is hexa-coordinated by five O atoms from benzene-1,2,4,5-tetra-carboxyl-ate (btec(4-)) ligands and one water mol-ecule. The Na(+) ion is also hexa-coordinated, by four O atoms from btec(4-) ligands and two water mol-ecules. One of the two btec(4-) mol-ecules sits on a crystallographic inversion centre. CuO6 and NaO6 octa-hedra are connected, forming bi-dimensional layers. These layers, which extend parallel to the ac plane, are further inter-connected by µ10- or µ11-bridging btec(4-) ligands and by O-H⋯O hydrogen bonds, involving both btec(4-) ligands and water mol-ecules, forming a three-dimensional network.

Poly[[nona-aqua-bis-(µ-5-hy-droxy-benzene-1,3-di-carboxyl-ato)(5-hy-droxy-benzene-1,3-di-carboxyl-ato)dicerium(III)] hexa-hydrate].

In the title coordination polymer, {[Ce2(C8H4O5)3(H2O)9]·6H2O} n , the asymmetric unit is formed by two Ce(III) atoms, three 5-hy-droxy-benzene-1,3-di-carboxyl-ate ligands, nine coordinating water mol-ecules and six water mol-ecules of crystallization. The two Ce(III) atoms are bridged by 5-hy-droxy-benzene-1,3-di-carboxyl-ate ligands acting in a bis-bidentate coordination mode, generating infinite chains along [101]. Both independent metal atoms are nine-coordinated, one by four O atoms from the carboxyl-ate groups of two bridging 5-hy-droxy-benzene-1,3-di-carboxyl-ate ligands and five O atoms from water mol-ecules, generating a tricapped trigonal-prismatic geometry. The coordination around the second Ce(III) atom is similar, except that one of the water mol-ecules is replaced by an O atom from an additional 5-hy-droxy-benzene-1,3-di-carboxyl-ate ligand acting in a monodentate coordination mode and forming a capped square-anti-prismatic geometry.

Poly[[octaaqua-µ4-(benzene-1,2,4,5-tetra-carboxyl-ato)-dicobalt(II)] octa-hydrate].

The title polymeric coordination compound, {[Co2(C10H2O8)(H2O)8]·8H2O} n , was obtained by slow diffusion of a dilute aqueous solution of CoCl2 and the sodium salt of benzene-1,2,4,5-tetracarboxylic acid (H4btec) through an agar-agar gel bridge in a U-shaped tube. The two independent Co(2+) ions are each situated on an inversion centre and are coordinated in a slightly distorted octa-hedral geometry by four water O atoms and two carboxyl-ate O atoms from two btec(4-) ligands (-1> symmetry), forming a layer parallel to (11-1). This layer can be described as a mol-ecular two-dimensional square grid with the benzene rings at the nodes and the Co(II) atoms connecting the nodes. O-H⋯O hydrogen-bonding interactions involving the coordinating water molecules, the carboxylate O atoms and lattice water molecules lead to the formation of a three-dimensional network.

New 3-D La(III)-Cu(II)-containing coordination polymer with a high potential porosity.

A new 3-D coordination polymer containing both 3d and 4f ions has been designed. Its chemical formula is La2[Cu(pba)]3(H2O)8 . 8H2O. It crystallizes in the quadratic system, space group I41/a with a = 42.4947(9) Angstrom, c = 16.3378(3) Angstrom, and Z = 16. Its crystal structure can be described as a 3-D molecular framework exhibiting a complex network of interconnected zigzaglike channels. Once crystallization water molecules are removed, this compound presents a high potential porosity and a low density. The porosity has been evaluated using Connolly's algorithm.