Synthesis of dual emitting iodocuprates: can solvents switch the reaction outcome?

An unprecedented structure-directing effect of solvents in halocuprate self-assembly reactions was discovered. The compounds presented show remarkable dual luminescence, strongly changing the emission color upon varying temperature.

Synthesis and Structural Characterisation of Lithium, Zinc, and Aluminium Pyrazolate Complexes

The reaction of nBuLi with 3,5-dimethylpyrazole (Me2pzH) in Et2O or tmeda/hexane (tmeda=N,N,N′,N′-tetramethylethane-1,2-diamine) and with 3,5-dimethyl-4-nitropyrazolate (Me2pzHNO2) in THF results in the formation of three structurally diverse lithium pyrazolates: namely an Et2O-solvated tetrameric complex [Li4(Me2pz)4(OEt2)4], bridged entirely with μ-η2:η1-pyrazolate bonding, a hexanuclear complex [Li6(Me2pz)6(tmeda)2] with four different coordination modes (μ-η1:η1, μ-η2:η1, μ3-η1:η2:η1 and μ3-η2:η2:η1), and a new polymeric compound [Li2(Me2pzNO2)2(thf)2]n, with [Li2(Me2pzNO2)2(thf)2] groups linked by –NO2 coordination. A mononuclear zinc complex [Zn(tBu2pz)2(tBu2pzH)2].1/2THF (tBu2pzH=3,5-di-tert-butylpyrazole) was prepared by reaction of tBu2pzH with ZnEt2, unidentate tBu2pz groups being stabilised by N–H⋯N hydrogen bonding. Treatment of 3,5-diphenylpyrazole (Ph2pzH) with trimethylaluminium (mole ratio 3:1) in THF led to the formation of dinuclear [AlMe2(μ-Ph2pz)]2.1/2THF.

Polyphenylcyclopentadienyl Ligands as an Effective Light-Harvesting π-Bonded Antenna for Lanthanide +3 Ions

A new approach to design "antenna-ligands" to enhance the photoluminescence of lanthanide coordination compounds has been developed based on a π-type ligand-the polyphenyl-substituted cyclopentadienyl. The complexes of di-, tri-, and tetraphenyl cyclopentadienyl ligands with Tb and Gd have been synthesized and all the possible structural types from mononuclear to di- and tetranuclear complexes, as well as a coordination polymer were obtained. All types of the complexes have been studied by single-crystal X-ray diffraction and optical spectroscopy. All terbium complexes are luminescent at ambient temperature and two of them have relatively high quantum yields (50 and 60%). Analysis of energy transfer process has been performed and supported by quantum chemical calculations. The role of a low-lying intraligand charge transfer state formed by extra coordination with K⁺ in the Tb³⁺ ion luminescence sensitization is discussed. New aspects for design of lanthanide complexes containing π-type ligands with desired luminescence properties have been proposed.

Lanthanide(III) (Eu, Gd, Tb, Dy) Complexes Derived from 4-(Pyridin-2-yl)methyleneamino-1,2,4-triazole: Crystal Structure, Magnetic Properties, and Photoluminescence

The reaction of lanthanide(III) nitrates with 4-(pyridin-2-yl)methyleneamino-1,2,4-triazole (L) was studied. The compounds [Ln(NO3 )3 (H2 O)3 ]⋅2 L, in which Ln=Eu (1), Gd (2), Tb (3), or Dy (4), obtained in a mixture of MeCN/EtOH have the same structure, as shown by XRD. In the crystals of these compounds, the mononuclear complex units [Ln(NO3 )3 (H2 O)3 ] are linked to L molecules through intermolecular hydrogen-bonding interactions to form a 2D polymeric supramolecular architecture. An investigation into the optical characteristics of the Eu3+ -, Tb3+ -, and Dy3+ -containing compounds (1, 3, and 4) showed that these complexes displayed metal-centered luminescence. According to magnetic measurements, compound 4 exhibits single-ion magnet behavior, with ΔEeff /kB =86 K in a field of 1500 Oe.

Bright green-to-yellow emitting Cu(i) complexes based on bis(2-pyridyl)phosphine oxides: synthesis, structure and effective thermally activated-delayed fluorescence

A series of highly emissive Cu(i) complexes exhibiting green-to-yellow TADF is presented.

An efficient route for design of luminescent composite materials based on polyethylene containing europium dibenzoylmethanate

A Eu-doped luminescent composite material based on polyethylene has been developed and studied by optical spectroscopy, luminescence intensity mapping, and SEM.