Heterometallic Europium(III)-Lutetium(III) Terephthalates as Bright Luminescent Antenna MOFs.

A new series of luminescent heterometallic europium(III)-lutetium(III) terephthalate metal-organic frameworks, namely (EuLu)bdc·nHO, was synthesized using a direct reaction in a water solution. At the Eu concentration of 1-40 at %, the MOFs were formed as a binary mixture of the (EuLu)bdc and (EuLu)bdc·4HO crystalline phases, where the Lnbdc·4HO crystalline phase was enriched by europium(III) ions. At an Eu concentration of more than 40 at %, only one crystalline phase was formed: (EuLu)bdc·4HO.

Excitation-Wavelength-Dependent Emission and Delayed Fluorescence in a Proton-Transfer System.

Manipulating the relaxation pathways of excited states and understanding mechanisms of photochemical reactions present important challenges in chemistry. Here we report a unique zinc(II) complex exhibiting unprecedented interplay between the excitation-wavelength-dependent emission, thermally activated delayed fluorescence (TADF) and excited state intramolecular proton transfer (ESIPT). The ESIPT process in the complex is favoured by a short intramolecular OH⋅⋅⋅N hydrogen bond.

Ln(iii) complexes (Ln = Eu, Gd, Tb, Dy) with a chiral ligand containing 1,10-phenanthroline and (-)-menthol fragments: synthesis, structure, magnetic properties and photoluminescence.

A series of lanthanide(iii) complexes based on the new chiral ligand L, which contains 1,10-phenanthroline and (-)-menthol fragments, namely [LnL(NO)] (Ln = Eu (1), Gd (2), Tb (3), Dy (4)), have been synthesized and structurally characterized. Complexes 1-4 are isostructural and crystallize in the non-centrosymmetric space group P422. The mononuclear complexes comprise a 10-coordinate Ln ion with two bidentate N,N-donor ligands (L) and three bidentate chelating nitrate groups.

Halide impact on emission of mononuclear copper(I) complexes with pyrazolylpyrimidine and triphenylphosphine.

A series of mononuclear heteroleptic copper(I) halide complexes, [CuL(PPh3)X] (X = Cl, Br, I), based on 4-(3,5-diphenyl-1H-pyrazol-1-yl)-6-(piperidin-1-yl)pyrimidine (L) and triphenylphosphine, have been synthesized by reaction between CuX (X = Cl, Br, I), L and PPh3 in a molar ratio of 1/1/1 in MeCN solutions. The copper atom, showing the distorted tetrahedral environment, is bound by the N,N-chelating ligand L, triphenylphosphine and a halide ion. The complexes [CuL(PPh3)Cl] and [CuL(PPh3)Br] are isostructural.

Photophysics of 1,8-naphthalimide/Ln(III) dyads (Ln = Eu, Gd): naphthalimide → Eu(III) energy-transfer from both singlet and triplet states.

Transient absorption and time resolved luminescence spectroscopy were used to study photophysical processes in the macrocycle-appended 1,8-naphthalimide compound H3L, and its Eu(III) and Gd(III) complexes Eu·L and Gd·L, in particular the naphthalimide-Eu(III) energy-transfer process. In all cases aggregation of the naphthalimide chromophores results in a low-energy emission feature in the 470-500 nm region in addition to the naphthalimide fluorescence; this lower-energy emission has a lifetime longer by an order of magnitude than the monomer naphthalimide fluorescence. Transient absorption spectroscopy was used to measure the decay of the naphthalimide triplet excited state, which occurs in the range 30-50 μs.