A highly sensitive fluorescent sensor for Al3+ detection based on luminescent Eu(III)-β-dicetonate complexes

The structure of the Eu(III) complexes were determined by single-crystal X-ray diffraction. The results showed that these complexes exist as a heteronuclear of Eu(III)-Na(I) in which ion Eu3+ is coordinated through eight oxygen atoms of four β-dixetone ligands. The authors found that the monomeric europium-sodium complex displays a very strong red emission with a quantum yield up to 47.5% at λex=370 nm. The authors have successfully designed a simple process to put the Eu(III) complexes on anion exchange resin to create Resin-EuTFNB and Resin-EuTFPB materials. The products have a luminescent intensity that is stronger than that of the precursor complexes due to the removal of the coordination solvents in these complexes. Initially, using these materials to test the ability to recognise Al3+ ion at low concentrations, Resin-EuTFNB and Resin-EuTFPB played a role as a sensing chemosensor based on turn-off mechanism. In the future, they are expected to detect Al3+ion in the biological system.

Synthesis and crystal structure of a heterobimetallic cadmium–sodium complex of 1,3,5-triazine-2,4,6-trione, [CdNa2(C3H2N3O3)4(H2O)8]

Heterobimetallic crystals of a cadmium–sodium complex of 1,3,5-triazine-2,4,6-trione, namely, μ-aqua-1:2κ2 O:O-heptaaqua-1κ3 O,2κ2 O,3κ2 O-bis(μ-4,6-dioxo-1,4,5,6-tetrahydro-1,3,5-triazin-2-olato)-1:2κ2 O 2:N 1;2:3κ2 N 1:O 2-bis(4,6-dioxo-1,4,5,6-tetrahydro-1,3,5-triazin-2-olato)-1κO 2,3κO 2-2-cadmium-1,3-disodium, [CdNa2(C3H2N3O3)4(H2O)8], were grown by the single gel diffusion technique. The asymmetric unit of the title compound comprises four 1,3,5-triazine-2,4,6-trione ligands, two sodium atoms and one cadmium atom. Of the four ligands, two are monodentately coordinated to two Na atoms. The third ligand is coordinated bidentately to one Na and the Cd atom and the fourth is also coordinated bidentately to the Cd atom and the other Na atom. All the metal atoms are six-coordinate with a distorted octahedral geometry. The water molecules bridge the Na atoms, constructing coordination polymer chains along the a axis and hence are linked by two Cd and one Na coordinations through the cyanuric acid ligands present in the coordination polymer chains, generating a two-dimensional coordination polymer in the (110) plane. The polymer formation is further assisted by means of many intermolecular and intramolecular N—H...O, O—H...O and O–H...N hydrogen bonds between the water molecules and the ligands.