A novel efficient antenna complex of Eu(3+) [Eu(CPFHP)(3)(DDXPO)] supported by a highly fluorinated carbazole-substituted β-diketonate ligand, namely, 1-(9H-carbazol-2-yl)-4,4,5,5,5-pentafluoro-3-hydroxypent-2-en-1-one (CPFHP) and the 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene oxide (DDXPO) ancillary ligand, has been synthesized, structurally characterized, and its photoluminescent behavior examined. The single-crystal X-ray diffraction analysis of Eu(CPFHP)(3)(DDXPO) revealed that this complex is mononuclear, and that the central Eu(3+) ion is surrounded by eight oxygen atoms, six of which are provided by the three bidentate β-diketonate ligands. The remaining two oxygen atoms are furnished by the chelating phosphine oxide ligand. The coordination polyhedron is best described as that of a distorted square antiprism. The photophysical properties of Eu(CPFHP)(3)(DDXPO) benefit from adequate protection of the metal by the ligands with respect to non-radiative deactivation as well as an efficient ligand-to-metal energy transfer process which exceeds 66% in chloroform solution with a quantum yield of 47%. As an integral part of this work, the synthesis, characterization, and luminescent properties of poly(methyl methacrylate) (PMMA) polymer films doped with Eu(CPFHP)(3)(DDXPO) are also reported. The luminescent efficiencies of the doped films (photoluminescence quantum yields 79-84%) are dramatically enhanced in comparison with that of the precursor complex. The new luminescent PMMA-doped Eu(CPFHP)(3)(DDXPO) complex therefore shows considerable promise for polymer light-emitting diode and active polymer optical fiber applications.

A novel highly fluorinated beta-diketonate ligand, 1-(3,5-bis(benzyloxy)phenyl)-4,4,5,5,5-pentafluoropentane-1,3-dione (HBBPPF) and its corresponding europium(III) ternary complex, Eu(BBPPF)(3)(DDXPO) [DDXPO = 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene oxide] were synthesized via a dexterously designed routine, characterized and its photophysical properties (PL) investigated. PL measurement results indicated that the europium(III) ternary complex exhibits intense red emission under UV light excitation with a solid-state quantum yield of 39%. An organic-inorganic mesoporous luminescent hybrid material was also constructed by linking the ternary europium(III) complex to the functionalized hexagonal mesoporous MCM-41 through the modified beta-diketonate ligand (SiBBPPF-Na). Beta-diketonate grafted to the coupling agent 3-(triethoxysilyl)propyl isocyanate was used as the precursor for the preparation of mesoporous materials. A modified MCM-41 mesoporous material containing ternary europium(iii) complex covalently bonded to the silica-based network, designated as Eu(BBPPF-Si)(3)(DDXPO)/MCM-41, was obtained by interacting SiBBPPF-Na with europium nitrate, DDXPO and MCM-41 via a ligand-exchange reaction. The new mesoporous hybrid material was characterized by powder X-ray diffraction, nitrogen adsorption-desorption, thermogravimetry, transmission electron microscopy, dynamic light scattering, FT-IR, (29)Si CP MAS NMR and (13)C NMR solid-state techniques, and photoluminescence spectroscopy. Eu(BBPPF-Si)(3)(DDXPO)/MCM-41 exhibits an efficient intramolecular energy transfer process from the silylated beta-diketonate to the central Eu(3+), namely, the "antenna effect", which favours a strong luminescent intensity (quantum yield = 43%). Thermogravimetric analysis on Eu(BBPPF-Si)(3)(DDXPO)/MCM-41 demonstrated that the thermal stability of the lanthanide complex was evidently improved as it was covalently bonded to the mesoporous MCM-41 matrix.

The new phosphonate-carboxylate ligand from 4-phosphono-biphenyl-4′-carboxylic acid (H 2 O 3 P-(C 6-H 4) 2-CO 2 H, H 3 BPPA) is based on the rigid biphenyl system and is studied toward the coordination behavior of group 12 elements zinc, cadmium and mercury. The crystalline products from hydrothermal syntheses highlight the versatile and different coordination modes with the (partially) deprotonated H 3 BPPA ligand to give coordination polymeric 3D-[Zn 5 (μ 3-OH) 4 (μ 4-O 3 P-(C 6 H 4) 2-CO 2-μ 2) 2 ] n (5), 2D-[Zn(μ 6-O 3 P-(C 6 H 4) 2-CO 2 H)] n (6), 3D-[Cd 3 (μ 5-O 3 P-(C 6 H 4) 2-CO 2-μ 2)(μ 6-O 3 P-(C 6 H 4) 2-CO 2-μ 3)] n (7) and 2D-[Hg(μ 3-HO 3 P-(C 6-H 4) 2-CO 2 H)] n (8). The cobalt complex, 2D-[Co(μ 4-O 3 P-(C 6 H 4) 2-CO 2 H)] n (9) is isostructural to 6. Through additional classic strong carbonyl O-H⋯O hydrogen bonding the dimensionality of the 2D coordination networks increases to 3D supramolecular frameworks. The carboxy-phosphonate ligand shows five different coordination modes which can be described as μ 4-O 3 P-CO 2-μ 2 (5), μ 6-O 3 P-(6), μ 5-O 3 P-CO 2-μ 2 , μ 5-O 3 P-CO 2-μ 3 (7), and μ 3-O 3 P-(8), that is, the ligand bridges altogether between 3 to 8 metal atoms with the phosphonate group alone connecting already 3 to 6 metal atoms. Layers of metal-oxygen polyhedra are interconnected via the biphenyl linker, which either coordinates metal atoms with both donor groups or the-COOH end forms tail-to-tail hydrogen bonds to create 3D or 2D coordination networks, respectively. In the flat {MO x } layers in 6 and 7 the Zn and Cd metal nodes represent a honeycomb and an mcm net, respectively. The coordination polyhedra of the Cd atoms in compound 7 were analyzed towards a trigonal-prismatic coordination environment. The complexes are hydrolytically very stable due to their hydrothermal preparation from aqueous solution at 180-200°C. The compounds could be stored in water or air for months without apparent decomposition. Compounds 5 and 7, where the ligand is fully deprotonated, start to decompose at ∼400°C. The fluorescence emission spectrum of the ligand, 4, shows an intense peak at 365 nm (λ ex = 316 nm). The fluorescence emission of the metal complexes 5, 7 and 9 is shifted towards larger wavelengths with values of 417 nm, 415 nm and 410 nm, respectively (λ ex = 354 nm for 5, λ ex = 350 nm for 7, λ ex = 400 nm for 8, λ ex = 360 nm for 9). In addition, the crystal structures of the H 3 BPPA ligand precursors 4-iodo-4′-biphenylcarboxylic acid methyl ester, and 4-diethylphosphono-4′-biphenylcarboxylic acid methyl ester are described here for the first time.

Visible-light-excited Eu 3+ complexes have received much attention in the last years due to the rapidly increasing demand for less-harmful biomarkers and low-voltage driven emitters in optoelectronics. Nevertheless, these complexes usually exhibit poor emission quantum yields, contrarily to the ones excited in the ultraviolet spectral region. To address this challenge, a series of complexes based on trivalent lanthanide ions, [Eu(bpyO2)(2), Gd (5)} and Ln(tta) 3 (bpyO2) {Ln = Eu (3), Gd (6)}, were synthesized using 2-thenoyltrifluoroacetone (Htta) as primary ligand and 2,2′-dipyridyl N,N′-dioxide (bpyO2) as neutral donor, and characterized, with special emphasis on their crystal struc-[a] Phantom-g, CICECO -was achieved through chemical modifications of the ligand structure with an expanded π-conjugated system [40] and using either neutral tris-(Q Ln L = 0.75 at 415 nm [49] and 0.40 at 400 nm [46] ) or anionic tetrakis-Eu 3+ --diketonates (Q Ln L = 0.80 at 410 nm [40] and Q Ln L = 0.45 at 400 nm [48] ).In this work, we followed a rational design to synthesize three Eu 3+ --diketonate complexes, 1, 2 and 3, using 2-thenoyltrifluoroacetone (Htta) and 2,2′-dipyridyl N,N′-dioxide (bpyO2) as the primary and ancillary ligands, respectively. The excitation window of 3 unprecedently extends into the visible region (up to 480 nm), well-above what was reported previously for analogous visible-light-excitable Eu 3+ -based complexes (up to 440-450 nm). [40,46,48] Detailed theoretical calculations performed with both time-dependent density functional theory (TD-DFT) and LUMPAC software [51] are also presented showing an excellent accord with the experimental intensity parameters, radiative and non-radiative decay rates, and intrinsic and absolute emission quantum yields. Moreover, 3 displayed excellent colour purity, with Commission Internationale d'Éclairage (CIE) chromaticity coordinates (0.66, 0.33), and was successfully employed for the fabrication of organic light-emitting diodes (OLEDs). Results and DiscussionScheme 1 summarizes the adopted synthesis procedure. Complexes 1-3 were characterized using ATR/FT-IR spectroscopy, mass spectrometry, and elemental analyses. In the FT-IR spectra, the stretching and bending vibrations of N-O group of bpyO2 ligand are observed in 1 (1260, 853 and 837 cm -1 ) and 3 (1255, 856 and 836 cm -1 ) ( Figure S1). The carbonyl stretching frequency of Htta has been shifted from 1645 cm -1 to 1600 and 1, 2, 3, 4, and 6 were analysed by singlecrystal XRD. The most relevant structural features of 1-3 are depicted in Figure 1 and those of 4 and 6 are given in Figure S3 and S4, respectively. Selected bond lengths and bond angles Eur. Single-Crystal X-ray Structures Suitable crystals of

A series of visible light excited Eu3+–carbazole based β-diketonate complexes has been developed by molecular engineering.