Search

A new cationic iridium(III) complex exhibiting "aggregation induced emission (AIE)" activity, [Ir(PPh3)2(bipy)(H)2]A (bipy = 2,2′-bipyridine; A = counterions), has been synthesized in a straightforward synthetic route. Interestingly, the emission color of solid state samples of this complex varied with different counteranions [A = Cl-, BF4-, PF6-, N(CN)2-] and crystallization induced emission was observed. The emission properties for the compounds with A= Cl-, PF6- are discussed by analyzing the crystal packing, the frontier molecular orbitals, and the calculation of the relevant low-lying excited states using time-dependent density functional theory. The restriction of internal rotation of the phenyl rings in the phosphine ligands due to intermolecular interactions is suggested as the most plausible origin of the observed AIE effect in these crystals. [ABSTRACT FROM AUTHOR]

Two new d10 metal supramolecular metal–organic frameworks (SMOFs) with general formula [ML2(H2O)2]n (M = Zn, Cd) have been synthetized using the sodium salt of the anionic 1-(3,4-dimethylphenyl)-5-methyl-1H-1,2,3-triazole-4-carboxylate ligand (Na+L−). Both SMOFs have been structurally characterized by single-crystal X-ray diffraction analysis and IR spectroscopy. The compounds are isostructural and form supramolecular aggregates via hydrogen bonds with the presence of less common dihydrogen bonds. Interestingly, they show ionic conductivity and porosity. The luminescent properties have been also studied by means of the excitation and emission spectra. Periodic DFT and molecular TD-DFT calculations have been used to unravel the emergence of luminescence in the otherwise non-emitting 1-(3,4-dimethylphenyl)-5-methyl-1H-1,2,3-triazole-4-carboxylate ligand once incorporated in the SMOFs. Our results also illustrate the importance of considering the dielectric environment in the crystal when performing excited state calculations for isolated fragments to capture the correct electronic character of the low-lying states, a practice which is not commonly adopted in the community. [ABSTRACT FROM AUTHOR]