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1.
Dalton Trans ; 2020 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-31976497

RESUMO

By changing the stoichiometric ratios, the one-pot reaction of the glycinehydroxamic acid (H2glyha) ligand with copper(ii) and lanthanide(iii) salts in the presence of diamagnetic [Na2{Fe(CN)5(NO)}] led to two series of isostructural complexes, which can be designated as heterotrimetallic dimeric clusters [{LnCu5(glyha)5}{Fe(CN)5(NO)}(H2O)4]2·xNO3·yH2O (x = 2, y = 11 for La (1), x = 2, y = 11 for Pr (2), and x = 2, y = 11 for Nd (3)) and heterotetrametallic coordination polymers [Na{LnCu5(glyha)5}{Fe(CN)5(NO)}2(H2O)x·yH2O]n (x = 6, y = 4 for Sm (4), x = 6, y = 0 for Gd (5), x = 6, y = 4 for Tb (6), x = 5, y = 5 Dy (7), and x = 6, y = 4 for Ho (8)). Each molecular structure contains LnIII[15-metallacrown-5] nodes and diamagnetic [Fe(CN)5(NO)]2- linkers. The resulting products demonstrate diversified structural frameworks due to the radius effect of LnIII ions and different bridging fashions of diamagnetic [Fe(CN)5(NO)]2- linkers. An analysis of magnetic susceptibilities reveals that 7 exhibits ferromagnetic coupling between CuII and DyIII ions and field-induced SMM behavior.

2.
Dalton Trans ; 48(36): 13541-13545, 2019 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-31469147

RESUMO

Simultaneously involving abundant [NH2(CH3)2]+ cations and uncoordinated carboxylate oxygen atoms as dual active sites, two microporous CoII-MOFs (LCU-105 and LCU-106, LCU = Liaocheng University) both exhibit highly selective adsorption of CO2/CH4 and CO2/N2. GCMC theoretical simulations provide good verification of the experimental results.

3.
Dalton Trans ; 48(16): 5144-5148, 2019 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-30919864

RESUMO

A microporous metal-organic framework functionalized with in situ generated NHC-CuCl units (1) has been successfully synthesized from a novel imidazolium-containing ligand. In particular, the MOF 1 can catalyze ß-boration of α,ß-unsaturated carbonyl compounds, while the isoreticular version of 1 (1-im) modified with only imidazolium moiety cannot. This work demonstrates for the first time the heterogeneous catalysis of NHC-Cu(i)Cl within a MOF solid.

4.
ACS Appl Mater Interfaces ; 11(8): 7914-7926, 2019 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-30720269

RESUMO

Two series of lanthanide metal-organic frameworks (Ln-MOFs) from two structurally related flexible carboxylate-based ligands were solvothermally synthesized. H3L2 with additional -CH2- group provides more flexibility and different coordination modes and conformations compared with H3L1. As a result, 2-Ln MOFs are modulated from two-dimensional kgd of 1-Ln to three-dimensional rtl topological frameworks and further achieve enhanced chemical stability. The Eu- and Tb-MOFs exhibit strong fluorescent emission at the solid state because of the antenna effect of the ligands. Interestingly, the emissions can be tuned by simply doping Eu3+ and Tb3+ of different concentrations within the Eu xTb1- x MOFs. Notably, 2-Ln MOFs realize nearly white light emission by means of a trichromatic approach (red of Eu(III), green of Tb(III), and blue of the H3L2 ligand). Furthermore, 2-Ln MOFs also exhibit water stability and demonstrate high selective and sensitive sensing activities toward Fe(III) and Cr(VI) in aqueous solutions. The results further highlight the importance of the ligand flexibility on tuning MOF structures with improved structural stability and ion-sensing properties.

5.
J Colloid Interface Sci ; 536: 694-700, 2019 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-30408689

RESUMO

Spontaneous solar-driven water splitting to generate H2 with no pollution discharge is an ideal H2 generation approach. However, its efficiency remains far from real application owing to the poor light-harvesting and ultrafast charge recombination of photocatalysts. To address these issues, herein, we employed a novel but simple chemical bath deposition (CBD) method to construct CdS/SrTiO3 nanodots-on-nanocubes at room temperature (ca. 25 °C). The as-synthesized nanohybrids not only expand light absorption from ultraviolet (UV) to visible light but also significantly retard charge recombination owing to the well-defined heterostructure formation. As a result, the CdS/SrTiO3 exhibits high photocatalytic performance with H2 evolution rate of 1322 µmol g-1 h-1, which is 2.8 and 12.2 times higher than that of pristine CdS and SrTiO3, respectively. This work provides a universal approach for the heterostructure construction, and inspired by this, higher efficient photocatalysts for H2 evolution may be developed in the near future.

6.
Angew Chem Int Ed Engl ; 57(49): 16067-16071, 2018 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-30338921

RESUMO

The removal of C2 H2 and C2 H6 from C2 H4 streams is of great significance for feedstock purification to produce polyethylene and other commodity chemicals but the simultaneous adsorption of C2 H6 and C2 H2 over C2 H4 from a ternary mixture has never been realized. Herein, a robust metal-organic framework, TJT-100, was designed and synthesized, which demonstrates remarkably selective adsorption of C2 H2 and C2 H6 over C2 H4 . Breakthrough experiments show that TJT-100 can be used as an adsorbent for high-performance purification of C2 H4 from a ternary mixture of C2 H2 /C2 H4 /C2 H6 (0.5:99:0.5) to afford a C2 H4 purity greater than 99.997 %, beyond that required for ethylene polymerization. Computational studies reveal that the uncoordinated carboxylate oxygen atoms and coordinated water molecules pointing towards the pore can trap C2 H2 and C2 H6 through the formation of multiple C-H⋅⋅⋅O electrostatic interactions, while the corresponding C2 H4 -framework interaction is unfavorable.

7.
Chem Commun (Camb) ; 54(85): 12105-12108, 2018 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-30302448

RESUMO

The double chloride-bridged dimer of a dinuclear dysprosium(iii) single-molecule magnet (SMM) was successfully isolated by assembling centrosymmetric dinuclear Dy2 SMMs. Such structural transformation involves the generation and cleavage of chloride bridges and leads to consecutive transformations of one- and two-step slow relaxation of magnetization.

8.
Inorg Chem ; 57(19): 12347-12353, 2018 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-30230324

RESUMO

Both heteroleptic (phthalocyaninato)(hemiporphyrazinato) and homoleptic bis(hemiporphyrazinato) dysprosium double-decker complexes, Dy[H(Hp)2] (1) and Dy[H(Pc)(Hp)] (2) (H2Pc = metal-free phthalocyanine; H2Hp = metal-free hemiporphyrazine), were designed, synthesized, and structurally characterized. The dysprosium center in both double-deckers are octa-coordinated with a nearly ideal square-antiprismatic coordination geometry, which provides an increased molecular anisotropy for the dysprosium ion and ensures the strengthened magnetic properties of both single-ion magnets (SIMs) in terms of coordination geometry. Magnetic studies reveal that both double-deckers exhibit typical SIM behavior with a spin reversal energy barrier of 80.1 ± 6.3 K for 1 and 57.3 ± 3.8 K for 2 as well as the hysteresis loops emerging at 3 K. In particular, introduction of two Hp ligands with four pyridine nitrogen atoms coordinated with the dysprosium spin center endows Dy[H(Hp)2] (1) with the thus far highest energy barrier among the sandwich-type dysprosium SIMs with N4-macrocyclic ligands, revealing the potential applications of sandwich-type lanthanide complexes with Hp ligands in molecular-based information storage.

9.
Org Lett ; 20(11): 3332-3336, 2018 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-29771129

RESUMO

A series of bibenzo[ b][1,4]thiazines with various functional groups has been synthesized by a free-radical condensation reaction. Bibenzo[ b][1,4]thiazines were obtained in moderate to good yield (up to 85%) through a one-step reaction of readily available 2,2'-dithiodianiline and methyl aryl ketones with AIBN as radical initiator in HOAc. Bibenzo[ b][1,4]thiazines exhibit diversiform solid-state packing.

10.
Dalton Trans ; 47(17): 6240-6249, 2018 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-29687120

RESUMO

Three new luminescent transition coordination polymers, namely, {[Cd(L)(4,4-bpy)]·DMF·H2O}n (1), {[Cd2(L)2(bpe)2]·3DMF·2.5H2O}n (2), and {[Cd(L)(bibp)]·2DMF}n (3), (H2L = 4,4'-[benzene-1,3-diylbis(methanediylsulfanediyl)]dibenzoic acid, 4,4-bpy = 4,4-bipyridine, bpe = 1,2-bis(4-pyridyl)ethylene, and bibp = 4,4'-bis(benzoimidazo-1-ly)biphenyl), were solvothermally synthesized using Cd2+ ions and S-containing dicarboxylate acid in the presence of different N coligands. These complexes were fully characterized via elemental analysis, infrared spectroscopy (IR), single crystal X-ray diffraction analysis, and thermal gravimetric analysis (TGA). Complexes 1-3 consist of 2-D structures through the connectivity of similar 1-D Cd-L chains by different N coligands. With an increase in the size of the N coligands, these complexes show structural changes from 2D → 3D with 3-fold interpenetration of complexes 1 and 2 to the 2-D packing modes of complex 3. The luminescence properties of these three complexes were studied in detail. The results reveal that each complex exhibits selectivity and sensitivity towards Fe3+ and Cr2O72- ions, and complex 2 demonstrates the lowest detection limit towards both ions.

11.
Dalton Trans ; 47(3): 726-733, 2018 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-29230458

RESUMO

By the combination of Pd-complexes and [V10O28]6-, three Pd-decavanadate compounds [Pd(NH3)4]3[V10O28]·8H2O (1), [Pd(deta)(H2O)]2(NH4)2[V10O28]·2H2O (2) (deta = diethylenetriamine) and [Pd(dpa)2](Hdpa)2(Et3NH)2[V10O28]·2H2O (3) (dpa = 2,2'-dipyridylamine) have been successfully synthesized and thoroughly characterized using single X-ray diffraction (SXRD), powder X-ray diffraction (PXRD), infrared spectroscopy (FT-IR) and elemental analyses (EA). Interestingly, in the three compounds, the molar ratios of Pd to decavanadate vary from 3 : 1 to 1 : 1 by changing N-ligands. The three Pd-decavanadates as heterogeneous catalysts are active in the aerobic oxidation of benzylic hydrocarbons under solvent-free conditions without adding any additives and co-catalysts. Moreover, compound 1 can be reused three times without losing its activity.

12.
Dalton Trans ; 46(38): 13027-13034, 2017 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-28937171

RESUMO

Herein, a new family of LnIII[18-metallacrown-6] compounds with the formula [Fe6O2Ln(tBu-sao)6(OH)(MeO)4(MeOH)(H2O)]·6MeOH [Ln = DyIII (1), TbIII (2), GdIII (3), and YIII (4), tBu-saoH2 = 3,5-di-tert-butylsalicylaldoxime] was synthesized through one-pot reactions using tBu-saoH2, Fe(ClO4)3·6H2O, and Ln(NO3)3·6H2O. The four compounds are isostructural, and the encapsulation of a Ln ion in the ring cavity of 18-metallacrown-6 (18-MC-6) was exhibited for the first time. The structural analysis shows a ship-like 18-MC-6 core with a beset lanthanide ion connecting six ring oxygen atoms (OMC). Magnetic measurements reveal domain antiferromagnetic coupling interactions between metal ions and field-dependent slow magnetic relaxation in 1-3.

13.
Chem Commun (Camb) ; 53(15): 2394-2397, 2017 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-28174776

RESUMO

Two Fe-based porous MOFs have been constructed from dimeric Fe-clusters and rod-shaped heterobimetallic {Fe2Na3}n chains as SBUs, respectively. Both of them exhibit highly selective CO2 adsorption over CH4 and N2, owing to their abundant multiple active sites.

14.
Dalton Trans ; 46(7): 2137-2145, 2017 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-28120975

RESUMO

Two cobalt(ii) compounds, namely, {[Co(HL)(bpy)(H2O)2]·DMF}n (1), and {[Co(HL)(bpe)]·0.5bpe}n (2) (H3L = 1,3-bis(2-carboxylphenoxy)benzoic acid, bpy = 4,4'-bipyridine, bpe = 4,4'-vinylenedipyridine), have been synthesized using cobalt(ii) transition metal salt with phenolic carboxylic acid and different N-donor ligands. The compounds were fully characterized by elemental analysis, infrared spectroscopy (IR), single crystal X-ray diffraction analysis, and thermogravimetric analysis (TGA). Both compounds exhibit 2-D (4,4)-sql networks but with a wavelike and a double layered arrangement, respectively. Remarkably, these two compounds not only exhibit field-induced single-ion relaxation magnetization but also exceptional catalytic activities of benzylic C-H oxidation (conv. 90.3-99%; sele. 98.1-99%).

15.
J Photochem Photobiol B ; 163: 403-12, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27619741

RESUMO

A series of novel copper (II) and nickel (II) complexes derived from chiral Schiff-base ligands [(R)/(S)-H2L(1)=(R)/(S)-2-[(1-Hydroxymethyl-propylimino)-methyl]-5-methoxy-phenol and (R)/(S)-H2L(2)=(R)/(S)-2-[(1-Hydroxymethyl-2-phenyl-ethylimino)-methyl]-5-methoxy-phenol], were synthesized and characterized by elemental analyses, (1)H NMR spectra, FT-IR spectrum. The crystal structures of complexes 1-5 were determined through single crystal X-ray diffraction (SXRD). The structures showed the ligands coordinated to the Cu/Ni (II) ion in a neutral manner via ONO donor atoms, and oxygen atoms of solvent molecules occupy the axial positions in Ni (II) complexes 3 and 4. The complexes interactions with BSA and CT-DNA were investigated by various spectroscopic methods (UV-Visible, circular dichroism spectrum, fluorescence spectroscopic and synchronous fluorescence spectra). Interactions of chiral copper (II) complexes are stronger than nickel (II) complexes. Further, the cytotoxicities of the complexes 1-6 towards three kinds of cancerous cell lines, were human lung adenocarcinoma (A549), human cervical carcinoma cell (HeLa) and human breast cancer cell (MCF-7) respectively, were evaluated by MTT assay. All complexes exhibited good cytotoxic activity. Furthermore, Cu (II) complex 5 derived from (R)-Schiff-base ligand was found to be more effective towards HeLa cancerous cell. The results showed that chirality and metal ion have important influence on their anticancer activities and interactions with DNA/BSA.


Assuntos
Cobre/química , DNA/metabolismo , Níquel/química , Compostos Organometálicos/síntese química , Compostos Organometálicos/farmacologia , Soroalbumina Bovina/metabolismo , Antineoplásicos/síntese química , Antineoplásicos/química , Antineoplásicos/metabolismo , Antineoplásicos/farmacologia , Técnicas de Química Sintética , Células HeLa , Humanos , Espaço Intracelular/efeitos dos fármacos , Espaço Intracelular/metabolismo , Ligantes , Simulação de Acoplamento Molecular , Compostos Organometálicos/química , Compostos Organometálicos/metabolismo , Conformação Proteica , Espécies Reativas de Oxigênio/metabolismo , Bases de Schiff/química , Soroalbumina Bovina/química , Estereoisomerismo
16.
Nanotechnology ; 27(38): 385602, 2016 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-27518499

RESUMO

A novel simple method was proposed to synthesize BiOCl/Bi2Sn2O7 heterojunction photocatalysts through the treatment of Bi2Sn2O7 with HCl solution of different concentrations. The as-synthesized photocatalysts were characterized by x-ray diffraction, scanning electron microscopy, transmission electron microscopy, photoluminescence, x-ray photoelectron spectroscopy and ultraviolet-visible diffuse reflectance spectroscopy. The experimental results show that sheet-like BiOCl particles were obtained after the HCl treatment. Bi2Sn2O7 nanoparticles were distributed on the BiOCl sheets, resulting in the low aggregation of the Bi2Sn2O7 nanoparticles. As compared to BiOCl and Bi2Sn2O7, BiOCl/Bi2Sn2O7 showed enhanced photocatalytic activity under visible light irradiation, which can be attributed to the effective separation of photogenerated electrons and holes due to the formation of a BiOCl/Bi2Sn2O7 heterojunction. In addition, the dominant active species and the photocatalytic mechanism were discussed in detail.

17.
Inorg Chem ; 55(12): 5914-23, 2016 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-27228007

RESUMO

The mixed 3d-4f pentanuclear complex (Bu4N)[Mn(III)4Y(III)(shi)4(OAc)4(CH3OH)4]·CH3OH·H2O (1) (H3shi = salicylhydroxamic acid) was synthesized by the direct reaction of Y(NO3)3·6H2O, Mn(OAc)2·4H2O, and H3shi. When an additional ligand, (NHBu3)3[W(CN)8]·2H2O, was added, the mixed 3d-4f-5d hexanuclear complex (Et4N)5[Mn(III)4Y(III)(shi)4(OAc)4W(V)(CN)8](WO4)0.5 (2) was obtained. X-ray crystallographic analysis shows that the 3d-4f complex 1 represents a 12-metallacrown-4 (12-MC-4) structure, in which the metallacrown ring [Mn-N-O]4 connection captures one Y(III) ion with four bridging acetate anions, completing the eight-coordinated environment around Y(III) ion, while four methanol molecules each coordinate to the Mn(III) ions on the other side of the Y(III) ion. After octacyanotungstate is introduced, the [W(V)(CN)8] group substitutes for four methanol molecules of 1 to form complex 2. Magnetic studies indicate the overall antiferromagnetic coupling present within the MC ring of complex 1. However, interestingly, the dominant ferromagnetic coupling between Mn(III) ions was observed in complex 2. A susceptibility analysis shows that the natural spin alignments in 12-MC-4 metallacrowns are tuned from overall antiferromagnetic to dominant ferromagnetic fashions by magnetic coupling between Mn(III) ions and the W(V) ion. Complex 1 [Mn(III)4Y(III)] retains an S = 0 ground state, and complex 2 [Mn(III)4Y(III)W(V)] shows obvious single-molecule magnet (SMM) behavior with an ST = 11/2 ground state, respectively, before and after introduction of the octacyanotungstate group. The spin frustration geometrical structure constructed by four Mn(III) ions and one W(V) ion was considered as the key factor for switching on the SMM properties of the 12-MC-4 system.

18.
Inorg Chem ; 55(11): 5139-51, 2016 06 06.
Artigo em Inglês | MEDLINE | ID: mdl-27168002

RESUMO

From a methyl-substituted thieno[2,3-b]thiophene dicarboxylate, three types of three-dimensional (3-D) microporous lanthanide-based metal-organic frameworks, {[Ln(DMTDC)1.5(H2O)2]·DEF}n (type I, Ln = Eu 1, Tb 2), {[Ln(DMTDC)1.5(H2O)2]·0.5DMF·0.5H2O}n (type II, Ln = Gd 3, Dy 4, Er 5), and {[Ln4(DMTDC)6(DMF)2]·0.5DMF·1.5H2O}n (type III, Ln = Er 6) (H2DMTDC = 3,4-dimethylthieno[2,3-b]thiophene-2,5-dicarboxylic acid, DEF = N,N'-diethylformamide, DMF = N,N'-dimethylformamide), have been solventhermally synthesized. Types I and II are isostructural, which exhibit 1-D triangular channels constructed by double-stranded rod-shaped {Ln(CO2)2}n chains. Type III demonstrates an intriguing framework with triple-stranded rod-shaped {Ln(CO2)3}n chains arranged along the (1,1,0) and (1,-1,0) axes and possesses two kinds of triangular channels along two axes, respectively. Immobilization of the Lewis basic sites of thiophene groups induced gas adsorption and sensing properties into these microporous frameworks. Complexes 5(Er) and 6(Er) display moderate adsorption properties toward N2 and CO2, and the Qst of CO2 are as high as 36.3 and 34.8 kJ mol(-1), respectively. Complexes 1(Eu) and 2(Tb) exhibit sensing properties toward nitrobenzene, acetone, and the Cu(2+) ion in both DMF and aqueous solution. Complex 3(Gd) shows a significant magnetocaloric effect with ΔSm = 24.3 J·kg(-1)·K(-1) at 3.0 K and 7 T. Complex 4(Dy) exhibits slow magnetic relaxation with the energy barrier Δ/kB of 48.29 K.

19.
Chemistry ; 21(41): 14478-85, 2015 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-26295925

RESUMO

Mixed 3d-4f 12-azametallacrown-4 complexes, [Mn2 Ln2 (OH)2 (hppt)4 (OAc)2 (DMF)2 ]⋅2 DMF⋅H2 O [Ln=Dy (1), Er (2), Yb (3), Tb (4) and Y (5), H2 hppt=3-(2-hydroxyphenyl)-5-(pyrazin-2-yl)-1,2,4-triazole)], were synthesized by reactions of H2 hppt with Mn(OAc)2 ⋅4 H2 O and Ln(NO3 )3 ⋅6 H2 O. This is the first 3d-4f azametallacrown family to incorporate Ln ions into the ring sets. These isostructural complexes exhibit alternating arrangements of two Mn and two Ln ions in the rings with each pair of metal centers bound by an NN group and µ2 -O bridging. Magnetic measurements revealed dominant antiferromagnetic interactions between metal centers, and frequency-dependent out-of-phase (${\chi {^\prime}{^\prime}_{\rm{M}} }$) signals below 4 K suggest slow relaxation of magnetization.

20.
Chem Commun (Camb) ; 51(75): 14211-4, 2015 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-26256775

RESUMO

Two microporous MOFs have been constructed from different metal cluster SBUs. Both of them exhibit highly selective CO2 adsorption capacity over CH4 and N2 owing to their abundant active sites.

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