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1.
Acta Crystallogr C Struct Chem ; 75(Pt 8): 1128-1133, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-31380795

RESUMO

Noncovalent interactions, such as π-π stacking interactions, C-H...π interactions and hydrogen bonding, are important driving forces for self-assembly in the construction of functional supermolecules and materials, especially in multicomponent supramolecular systems. Herein, a novel compound based on a π-acidic naphthalene diimide derivative and a double hydroxide-bridged dinuclear Al3+ aqua ion cluster, namely bis[N,N'-bis(2-sulfonatoethyl)-1,4,5,8-naphthalene diimide] di-µ-hydroxido-bis[tetraaquaaluminium(III)] tetrahydrate, (C18H12N2O10S2)2[Al2(OH)2(H2O)8]·4H2O, was obtained using the above-mentioned common noncovalent interactions, as well as uncommon lone-pair-π interactions. Functional molecular modules were connected by these noncovalent interactions to generate obvious photochromic properties. The compound was prepared by the self-assembly of N,N'-bis(2-sulfoethyl)-1,4,5,8-naphthalene diimide and Al(NO3)3·9H2O under mixed solvothermal conditions, and was characterized in detail by single-crystal X-ray diffraction, powder X-ray diffraction and FT-IR spectroscopy. The thermal stability and photochromic properties were also investigated; furthermore, in-situ solid-state UV-Vis absorption spectroscopy and electron spin resonance (ESR) were used to clarify the photochromic mechanism.

2.
Dalton Trans ; 48(4): 1418-1426, 2019 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-30628618

RESUMO

Two emissive copper(i) halide complexes (PNNP)Cu2Br2 (1) and (PNNP)Cu2I2 (2), which are constructed from butterfly-shaped dinuclear Cu2X2 cores and a new tetradentate ligand (PNNP = 1,3-bis(1-(2-(diphenylphosphanyl)phenyl)-1H-pyrazol-3-yl)benzene), were synthesized and characterized. These chelates exhibit bright green (λmax = 517 nm, 1) and bluish-green (λmax = 492 nm, 2) photoluminescence in the solid state with quantum yields of 42% (1) and 58% (2), and lifetimes of 13 µs (1) and 8.8 µs (2) at room temperature. Computational density functional theory/time-dependent density functional theory (DFT/TDDFT) calculations were performed to elucidate the nature of their electronic transitions and to predict their detailed photophysical properties. The results of DFT/TDDFT calculations, combined with the temperature dependence of spectroscopic properties and emission decay behaviors, suggest that the emission in the solid state originates from the 1,3(MLCT + XLCT + ILCT) excited states, which are in thermal equilibrium with small energy differences of about 0.1 eV. A comparative study of the titled complexes reveals that the emissive-state characteristics and photophysical properties of these complexes are significantly affected by the ligand field strength and atomic number of the halogen atom, as well as by the percentage of the XLCT transition involved in the lowest excited states. Compared with its bromide counterpart (1), the iodide complex (2) shows a much higher phosphorescence quantum yield (0.94 vs. 0.50), a much shorter phosphorescence decay time (58 µs vs. 274 µs), a much larger phosphorescence rate constant (1.6 × 104 s-1vs. 1.8 × 103 s-1), and a larger phosphorescence contribution (25% vs. 8%) in room-temperature emission, due to the more efficient spin-orbit coupling (SOC).

3.
Chemistry ; 24(41): 10498-10502, 2018 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-29740893

RESUMO

Room-temperature phosphorescence (RTP) was realized for the first time in a polyoxometalate-based charge-transfer (CT) hybrid material bearing polyoxometalates (POMs) as electron-donors (D) and rigid naphthalene diimides (NDIs) as electron-acceptors (A), meanwhile, this hybrid material displayed photochromism as well. The significant D-A anion-π interaction induced an additional through-space charge-transfer pathway. The resulting suitable D-A CT states can efficiently bridge the relatively large energy gap between the NDI-localized 1 π-π* and 3 π-π* states and thus trigger the ligand-localized phosphorescence (3 π-π*).

4.
Dalton Trans ; 47(6): 1796-1800, 2018 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-29354842

RESUMO

A trigonal propeller-shaped hybrid polyoxometalate (POM) (NH2Me2)3{[Nd(Mo4O13)(DMF)4]3(BTC)2}·8DMF (1; BTC = 1,3,5-benzenetricarboxylate) has been synthesized and structurally characterized. The planar {Mo4} segment is tailored from the precursor Lindqvist polyoxoanion [Mo6O19]2- firstly, and plays a key role in the reassembly of 1. Furthermore, the magnetic studies reveal that 1 shows single-molecule magnet (SMM) behavior.

5.
Dalton Trans ; 47(4): 1027-1031, 2018 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-29271439

RESUMO

Utilizing metal-ligand binding as the driving force, a unique photochromic hydrogel cross-linked by metal ions and π-acidic naphthalene bisimide dyes was obtained by simply mixing a two-phase solution. The mechanism of the coordination-driven self-assembly is elucidated by the morphological, XRD, FT-IR, ESR, UV-Vis and TGA studies and the controlled experiments.

6.
Angew Chem Int Ed Engl ; 56(47): 15006-15009, 2017 11 20.
Artigo em Inglês | MEDLINE | ID: mdl-28990260

RESUMO

Two efficient blue thermally activated delayed fluorescence compounds, B-oCz and B-oTC, composed of ortho-donor (D)-acceptor (A) arrangement were designed and synthesized. The significant intramolecular D-A interactions induce a combined charge transfer pathway and thus achieve small ΔEST and high efficiencies. The concentration quenching can be effectively inhibited in films of these compounds. The blue non-doped organic light emitting diodes (OLEDs) based on B-oTC prepared from solution processes shows record-high external quantum efficiency (EQE) of 19.1 %.

7.
Chem Commun (Camb) ; 53(70): 9701-9704, 2017 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-28776615

RESUMO

Lone pair-π interaction-induced charge-transfer was successfully used for switching the conductance of a coordination network, through variation of the degree of charge transfer caused by external photostimulation. The underlying mechanism is attributed to the changes in efficient charge-carriers by photoinduced strong charge transfer, which was investigated by in situ UV-Vis absorption, ESR, and computational studies.

8.
Dalton Trans ; 46(15): 4898-4901, 2017 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-28317991

RESUMO

The first visible-light-responsive photochromic polyoxometalate-templated lanthanide-organic framework (LOF) has been constructed from a carboxyphenyl-substituted naphthalenediimide (NDI) derivative, which displays an unusual four-fold interpenetration of an srs topological network, featuring a variety of anion-π interactions between polyoxoanions and π-acidic NDI moieties, and undergoes a rapid reversible photochromic transformation upon blue light irradiation.

9.
Inorg Chem ; 55(15): 7467-75, 2016 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-27404980

RESUMO

Two mononuclear cuprous complexes [Cu(PNNA)(POP)]BF4 (1) and [Cu(PNNA)(Xantphos)]BF4 (2) (PNNA = 9,9-dimethyl-10-(6-(3-phenyl-1H-pyrazol-1-yl)pyridin-3-yl)-9,10-dihydroacridine, POP = bis[2-(dipenylphosphino)phenyl]ether, Xantphos =4,5-bis(diphenylphosphino)-9,9-dimethylxanthene), with intense bluish-green luminescence based on a new diimine ligand were designed and synthesized. Their structural, electrochemical, and photophysical properties were characterized by single-crystal X-ray analysis, cyclic voltammetry, temperature dependence of spectroscopy, time-dependent emission spectroscopy, etc. The complexes exhibit high photoluminescence quantum yields in doped films (up to 74.6%) at room temperature. Thermally activated delayed fluorescence based on intraligand charge transfer was observed by grafting a strong electron-donor moiety, 9,9-dimethylacridan, on the diimine ligand, which is supported by the density functional theory calculations on two complexes. Highly efficient solution-processed OLEDs based on these two complexes were fabricated, among which the electroluminescent device using 2 as dopant shows a peak external quantum efficiency of 7.42%, a peak current efficiency of 20.24 cd/A, and a maximum brightness of 5579 cd/m(2).

10.
Chem Commun (Camb) ; 52(46): 7394-7, 2016 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-27192943

RESUMO

An unusual room-temperature light sensitivity was realized in a polyoxometalate-based hybrid material due to cooperative multicomponent molecular charge-transfer interactions taking place in this material, mainly among POMs, NDIs, and other molecules. The functional π-acidic NDI linkers and POM clusters in the discussed hybrid material were individually designed as photosensors and electron reservoirs. To propose a photo-induced charge-transfer mechanism, EPR, XPS, UV-Vis and computational studies were carried out, and indicated the presence of active charge-transfer interactions among several of the components.

11.
Inorg Chem ; 54(9): 4345-50, 2015 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-25859742

RESUMO

An effective strategy to synthesize multifunctional materials is the incorporation of functional organic moieties and metal oxide clusters via self-assembly. A rare multifunctional radical-doped zinc-based host-guest crystalline material was synthesized with a fast-responsive reversible ultraviolet visible light photochromism, photocontrolled tunable luminescence, and highly selective photocatalytic oxidation of benzylic alcohols as a result of blending of distinctively different functional components, naphthalenediimide tectons, and polyoxometalates (POMs). It is highly unique to link π-electron-deficient organic tectons and POMs by unusual POMs anion-π interactions, which are not only conducive to keeping the independence of each component but also effectively promoting the charge transfer or exchange among the components to realize the fast-responsive photochromism, photocontrolled tunable luminescence, and photocatalytic activity.

12.
Dalton Trans ; 44(20): 9496-505, 2015 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-25915167

RESUMO

The hydrothermal reactions of a mixture of (NH4)6Mo7O24·4H2O, Cu(Ac)2·H2O and 3-bpo ligands at different temperatures result in the isolation of two novel inorganic-organic hybrid materials containing different but related isopolymolybdate units, [Cu(3-bpo)(H2O)(Mo4O13)]·3H2O () and [Cu2(3-bpo)2(Mo6O20)] (). The {Mo4O13}n chains in and unprecedented [Mo6O20](4-) isopolyhexamolybdate anions in are linked by octahedral Cu(2+) ions into two-dimensional hybrid layers. Interestingly, 3-bpo ligands in both and are located on either side of these hybrid layers and serve as arched footbridges to link Cu(ii) ions in the layer via pyridyl N-donors, and at the same time connect these hybrid layers into 3D supramolecular frameworks via weak MoNoxadiazole bonds. Another important point for is that water clusters are filled in the 1D channels surrounded by isopolytetramolybdate units. In addition, dye adsorption and photocatalytic properties of and magnetic properties of have been investigated. The results indicated that complex is not only a good heterogeneous photocatalyst in the degradation of methyl orange (MO) and methylene blue (MB), but also has high absorption capacity of MB at room temperature and can selectively capture MB molecules from binary mixtures of MB/MO or MB/RhB. All MB molecules absorbed on can be completely released and photodegraded in the presence of adequate peroxide. The temperature dependence of magnetic susceptibility revealed that complex exhibits antiferromagnetic ordering at about 5 K, and a spin-flop transition was observed at about 5.8 T at 2 K, indicating metamagnetic-like behaviour from antiferromagnetic to ferromagnetic phases.

13.
Artigo em Inglês | MEDLINE | ID: mdl-24046562

RESUMO

In the title complex, [Cu(C13H10N3O)2] n , the copper(II) cation is located on a crystallographic inversion centre and adopts an elongated octa-hedral coordination geometry with the equatorial plane provided by trans-arranged bis-N,O-chelating acyl-hydrazine groups from two ligands and the apices by the N atoms of two pyridine rings belonging to symmetry-related ligands. The ligand adopts a Z conformation about the C=N double bond. The dihedral angle between the pyridine and phenyl rings is 2.99 (13)°. An intra-ligand C-H⋯N hydrogen bond is observed. In the crystal, each ligand bridges two adjacent metal ions, forming a (4,4) grid layered structure. π-π stacking inter-actions [centroid-centroid distances in the range 3.569 (4)-3.584 (9) Å] involving rings of adjacent layers result in the formation of a three-dimensional supra-molecular network.

14.
Acta Crystallogr C ; 69(Pt 6): 613-5, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23744379

RESUMO

The title compound, [Cu8(C15H10N3O3S)4Cl4(C3H7NO)2]·2C3H7NO, consisting of eight Cu(II) cations, four trianionic 1-(2-oxidobenzoyl)-2-(2-oxo-2-phenylethanethioyl)hydrazine-1,2-diide ligands, four chloride ligands and two coordinated and two solvent dimethylformamide molecules, crystallizes with the octanuclear molecule located on an inversion centre. The two halves of the molecule are connected by two bridging Cl atoms. This is the first example of an octanuclear complex based on a thiosemicarbazone-derived ligand.


Assuntos
Complexos de Coordenação/química , Tiossemicarbazonas/química , Cloretos , Cristalografia por Raios X , Dimetilformamida , Ligações de Hidrogênio , Ligantes , Conformação Molecular , Estrutura Molecular
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