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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.
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.

4.
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.

5.
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.

6.
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.

7.
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.

8.
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.

9.
Dalton Trans ; 43(45): 16986-91, 2014 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-25315719

RESUMO

Reaction of Mn(OAc)2·4H2O with the H2L ligand affords a new manganese 22-MC-8 azametallacrown [Mn8(µ3-O)2(µ3-OH)2(µ2-OH)2(L)6(OAc)2(OH2)4]·2DMF (H2L = 3-(2-oxyphenyl)-5-(pyrazin-2-yl)-1,2,4-triazole). The structural analysis of the complex reveals that the azaMC ring possesses -[Mn-O-Mn-N-N-Mn-N-N-Mn-N-N]- connectivity. The magnetic behavior of the complex shows the dominant antiferromagnetic interactions between the manganese ions with S = 4 and the frequency-dependent out-of-phase signal.

10.
Dalton Trans ; 43(42): 15708-12, 2014 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-25238057

RESUMO

Two Cu(II)-based MOFs have been constructed by synergistic assembly involving the mixed-ligand synthetic strategy and the solvent effect. Compound is a 3D structure and represents a cds topology, while compound displays a rare structure built by three distinct {Cu4} clusters as SBUs. Moreover, the magnetic properties of have been thoroughly investigated.

11.
Acta Crystallogr C Struct Chem ; 70(Pt 9): 843-6, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25186354

RESUMO

The one-dimensional coordination polymer catena-poly[[[di-µ2-acetato-tetrakis[µ3-(pyridin-2-yl)methanolato]tetracopper(II)]-di-µ2-diacetamidato] acetonitrile monosolvate], {[Cu4(C6H6NO)4(CH3COO)2(C2N3)2]·CH3CN}n, has been prepared from the direct reaction of 2-(hydroxymethyl)pyridine with Cu(OAc)2·H2O (OAc(-) is acetate) in a methanol-acetonitrile mixture. The four Cu centres are bridged by four O atoms from discrete (pyridin-2-yl)methanolate ligands and two acetate groups, forming a capped [Cu4O4] cubane core. Each core is doubly bridged to each of two adjacent cores by [N(CN)2](-) anions, resulting in one-dimensional chains. The magnetic properties of the complex were also studied.

12.
J Inorg Biochem ; 137: 101-8, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24838006

RESUMO

Three new salicylidene Schiff base nickel(II) complexes [Ni(L(1))(CH3COOH)2]2 (1), [Ni2(L(1))2(CH3OH)] (2), [Ni(L(2))2]·3H2O (3) {H2L(1)=N,N'-bis(salicylidene)-3,6-dioxa-1,8-diaminooctane, HL(2)=2-ethyl-2-(2-hydroxybenzylideneamino)propane-1,3-diol} were synthesized and characterized fully by structural, analytical, and spectral methods. The single-crystal X-ray structures of complexes 1 and 2 exhibit the symmetrical ligands coordinated to the nickel(II) ion in a tetradentate fashion via ONNO donor atoms, while the unsymmetrical ligand L(2) presented a ONO tridentate coordination mode in complex 3. The nickel(II) ions lie in the six-coordinated octahedral environment for the mononuclear complexes 1 and 3, along with dinuclear complex 2. The interaction of the complexes with calf thymus DNA (CT-DNA) has been explored by absorption and emission titration methods, which revealed that complexes 1-3 could interact with CT-DNA through intercalation. The interactions of the complexes with bovine serum albumin (BSA) were also investigated using UV-Vis, fluorescence and synchronous fluorescence spectroscopic methods. The results indicated that all of the complexes could quench the intrinsic fluorescence of BSA in a static quenching process. Further, the in vitro cytotoxic effect of the complexes examined on cancerous cell lines such as human lung carcinoma cell line (A549), human colon carcinoma cell lines (HCT-116), human promyelocytic leukemia cells (HL-60) and colonic cancer cell line Caco-2 showed that all three complexes exhibited substantial cytotoxic activity.


Assuntos
Cobre/química , Proteínas de Ligação a DNA/química , Níquel/química , Bases de Schiff/química , Animais , Células CACO-2 , Bovinos , Cristalografia por Raios X , DNA/química , DNA/efeitos dos fármacos , Clivagem do DNA/efeitos dos fármacos , Humanos , Ligantes , Soroalbumina Bovina/química
13.
Acta Crystallogr C ; 69(Pt 4): 394-9, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23579714

RESUMO

Reactions of 2-(hydroxymethyl)pyridine (Hhmp) with PbCl2 and Pb(NO3)2 at room temperature led to the formation of two novel compounds, namely tetrakis[µ3-(pyridin-2-yl)methanolato]-tetrahedro-tetrakis[chloridolead(II)], [Pb4(C6H6NO)4Cl4], (I), and poly[(µ2-nitrato)[µ2-(pyridin-2-yl)methanolato]lead(II)], [Pb(C6H6NO)(NO3)]n, (II). Compound (I) exhibits a tetranuclear Pb4O4 cubane structure, which is connected through π-π stacking interactions between the pyridine groups of the (pyridin-2-yl)methanolate (hmp(-)) ligands and through C-H···Cl interactions to form an interesting threefold diamondoid network. Compound (II) possesses two-dimensional (4,4)-sql topology based on a Pb2O2 unit, which is further extended into a three-dimensional supramolecular network through π-π stacking interactions between adjacent pyridine rings and through C-H···O interactions between the pyridine C atoms of the hmp(-) ligands and the nitrate anions.

14.
Acta Crystallogr Sect E Struct Rep Online ; 64(Pt 2): m438, 2008 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-21201379

RESUMO

The asymmetric unit of the crystal structure of the title complex, [Ni(C(18)H(12)N(2)O(3))(C(5)H(5)N)(3)]·3C(5)H(5)N, contains two independent Ni(II) complex mol-ecules and six uncoordinated pyridine mol-ecules. Each Ni(II) atom is coordinated by two O and four N atoms, from three pyridine and a chelating 3-hydr-oxy-N'-(2-oxidobenzyl-idene)-2-naphthohydrazide dianionic ligand, with a distorted octa-hedral geometry. Intra-molecular O-H⋯N hydrogen bonding exists in both complex mol-ecules but no inter-molecular hydrogen bonding is observed in the crystal structure.

15.
Acta Crystallogr Sect E Struct Rep Online ; 64(Pt 3): m489, 2008 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-21201872

RESUMO

The title complex, bis-(µ-benzene-18-crown-6)-3κ(6)O:4κO;4κ(6)O:3κO-bis-(benzene-18-crown-6)-1κ(6)O,6κ(6)O-tetra-µ-thiocyanato-1:2κ(2)S:N;2:3κ(2)N:S;4:5κ(2)S:N;5:6κ(2)N:S-dithio-cyanato-2κN,5κN-2,5-dicopper(I)-1,3,4,6-tetra-potassium(I), [K(4)Cu(2)(NCS)(6)(C(16)H(24)O(6))(4)] or {[K(C(16)H(24)O(6))](4)[Cu(NCS)(3)](2)}, consists of four [K(benzene-18-crown-6)](+) cations and two [Cu(NCS)(3)](2-) anions, forming a dimeric structure with site symmetry . In each [Cu(NCS)(3)](2-) anion, the Cu(I) atom is coordinated by three N atoms of thio-cyanate ligands in a trigonal-planar coordination geometry. Each [Cu(NCS)(3)](2-) anion bridges two [K(benzene-18-crown-6)](+) cations, with K-S distances of 3.317 (3) and 3.198 (3) Å, and two [K(benzene-18-crown-6)](+) cations are linked across a crystallographic centre of inversion, with K-O distances of 2.903 (5) Å.

16.
Acta Crystallogr Sect E Struct Rep Online ; 64(Pt 1): m47, 2007 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-21200618

RESUMO

In the title complex, [Fe(C(11)H(10)N(5)O(4))(CH(3)O)(C(5)H(5)N)]·CH(4)O, the Fe(III) ion has a distorted penta-gonal-bipyramidal geometry. In the crystal structure, mol-ecules are linked into one-dimensional chains along [1] via inter-molecular O-H⋯O and N-H⋯O hydrogen bonds.

17.
Acta Crystallogr C ; 62(Pt 2): m60-2, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16456275

RESUMO

The structure of the title compound, (C5H12N)4[V10O26(CH3O)2], reveals the presence of four protonated piperidinium cations and a [{V10O26}(OCH3)2]4- polyanion having an embedded centre of inversion. The compound is distinguished by presenting, in contrast with other anionic decavanadates, two methoxy groups bridging the outermost V atoms, and it becomes the first example of this type among reported decavanadates.


Assuntos
Compostos Organometálicos/química , Vanadatos/química , Cristalografia por Raios X , Modelos Moleculares , Estrutura Molecular
18.
Acta Crystallogr C ; 61(Pt 8): m400-2, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16082092

RESUMO

The title complex, trans-(mu-2,2'-[(1,2-dioxoethane-1,2-diyl)diimino]diethanoato(4-))bis[diaquacopper(II)] dihydrate, [Cu2(C6H4N2O6)(H2O)4] x 2H2O, with a three-dimensional framework, displays a square-pyramidal coordination geometry. The structure consists of a neutral centrosymmetric binuclear unit in which the oxamide ligand has a trans geometry, is fully deprotonated and acts in a bis-tridentate fashion.


Assuntos
Compostos Organometálicos/química , Cristalografia por Raios X , Análise de Fourier , Ligações de Hidrogênio , Indicadores e Reagentes , Modelos Moleculares
19.
J Zhejiang Univ Sci B ; 6(1): 69-73, 2005 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-15593396

RESUMO

Thermodynamic parameters of complexation of naphto-15-crown-5 with four alkaline earth ions in aqueous media was determined using titration microcalorimetry at 298.15 K. The stability of the complexes, thermal effect and entropy effect of the complexation is discussed on the basis of the guest ions structure and the solvent effect. The stability constants tendency to vary with ion radius was interpreted. Complex of naphtha-15-crown-5 with calcium ion is very stable due to the synergism of static electric interaction and size selectivity between the host and the guest.


Assuntos
Calorimetria/métodos , Éteres de Coroa/química , Metais Alcalinoterrosos/química , Microquímica/métodos , Íons/química , Substâncias Macromoleculares/análise , Substâncias Macromoleculares/química
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