Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 31
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
Asunto de la revista
País de afiliación
Intervalo de año de publicación
1.
Chemistry ; 19(10): 3297-301, 2013 Mar 04.
Artículo en Inglés | MEDLINE | ID: mdl-23386517

RESUMEN

A change for the better: Exchange of Cd(II) in the catalytically inactive framework MMPF-5 (see scheme) with Co(II) afforded a metalloporphyrin-based nanoreactor, MMPF-5(Co). This framework, consisting of small cubicuboctahedral cages, demonstrated interesting performances in the catalytic epoxidation of trans-stilbene with tBuOOH.

2.
Inorg Chem ; 51(8): 4423-5, 2012 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-22449128

RESUMEN

The self-assembly of a custom-designed bifunctional ligand featuring both 1,2,3-triazolate and carboxylate donor groups with a pentanuclear zinc cluster generated in situ affords a double-walled metal triazolate framework (MTAF) material, MTAF-1 (Zn(5)(µ(3)-O)(2)(C(9)N(3)H(5)O(2))(5)(H(+))(4)(H(2)O)(17)(C(3)H(7)NO)(10)), which exhibits a surface area of 2300 m(2)/g and demonstrates interesting selective CO(2) uptake performances.

3.
J Am Chem Soc ; 133(27): 10382-5, 2011 Jul 13.
Artículo en Inglés | MEDLINE | ID: mdl-21682253

RESUMEN

Microperoxidase-11 has for the first time been successfully immobilized into a mesoporous metal-organic framework (MOF) consisting of nanoscopic cages and it demonstrates superior enzymatic catalysis performances compared to its mesoporous silica counterpart.


Asunto(s)
Enzimas Inmovilizadas/química , Compuestos Organometálicos/química , Peroxidasas/química , Benzoquinonas/química , Catálisis , Catecoles/química , Metanol/química , Nanoestructuras/química , Porosidad , Conformación Proteica , Dióxido de Silicio/química
4.
J Am Chem Soc ; 133(41): 16322-5, 2011 Oct 19.
Artículo en Inglés | MEDLINE | ID: mdl-21954963

RESUMEN

An unprecedented nanoscopic polyhedral cage-containing metal-metalloporphyrin framework, MMPF-1, has been constructed from a custom-designed porphyrin ligand, 5,15-bis(3,5-dicarboxyphenyl)porphine, that links Cu(2)(carboxylate)(4) moieties. A high density of 16 open copper sites confined within a nanoscopic polyhedral cage has been achieved, and the packing of the porphyrin cages via an "ABAB" pattern affords MMPF-1 ultramicropores which render it selective toward adsorption of H(2) and O(2) over N(2), and CO(2) over CH(4).


Asunto(s)
Cobre/química , Metaloporfirinas/química , Nanoestructuras/química , Polímeros/química , Modelos Moleculares , Estructura Molecular , Porosidad , Propiedades de Superficie
5.
Chemistry ; 16(17): 5205-14, 2010 May 03.
Artículo en Inglés | MEDLINE | ID: mdl-20358553

RESUMEN

Metal-organic frameworks (MOFs) are a novel family of physisorptive materials that have exhibited great promise for methane storage. So far, a detailed understanding of their methane adsorption mechanism is still scarce. Herein, we report a comprehensive mechanistic study of methane storage in three milestone MOF compounds (HKUST-1, PCN-11, and PCN-14) the CH(4) storage capacities of which are among the highest reported so far among all porous materials. The three MOFs consist of the same dicopper paddlewheel secondary building units, but contain different organic linkers, leading to cagelike pores with various sizes and geometries. From neutron powder diffraction experiments and accurate data analysis, assisted by grand canonical Monte Carlo (GCMC) simulations and DFT calculations, we unambiguously revealed the exact locations of the stored methane molecules in these MOF materials. We found that methane uptake takes place primarily at two types of strong adsorption site: 1) the open Cu coordination sites, which exhibit enhanced Coulomb attraction toward methane, and 2) the van der Waals potential pocket sites, in which the total dispersive interactions are enhanced due to the molecule being in contact with multiple "surfaces". Interestingly, the enhanced van der Waals sites are present exclusively in small cages and at the windows to these cages, whereas large cages with relatively flat pore surfaces bind very little methane. Our results suggest that further, rational development of new MOF compounds for methane storage applications should focus on enriching open metal sites, increasing the volume percentage of accessible small cages and channels, and minimizing the fraction of large pores.

6.
J Am Chem Soc ; 131(18): 6445-51, 2009 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-19379001

RESUMEN

Solvothermal reactions of a predesigned amphiphilic ligand, 4'-tert-butyl-biphenyl-3,5-dicarboxylate (BBPDC), with Zn(NO(3))(2), Co(NO(3))(2), and Cu(NO(3))(2) gave rise to three isostructural mesh-adjustable molecular sieves (MAMSs), MAMS-2, MAMS-3, and MAMS-4, respectively. The three new MAMSs all exhibit temperature-tuned molecular sieving effect. There exists a linear relationship between mesh size and temperature, D = D(0) + alphaT (D, mesh size at temperature T K; D(0), mesh size at 0 K; and alpha, constant). Constants D(0) and alpha are characteristics of a ligand in a certain structure, independent of the choice of metal. As a result, all of the three MAMSs based on the BBPDC ligand have a D(0) of 2.83 and an alpha of 0.0073.

7.
Inorg Chem ; 48(5): 2072-7, 2009 Mar 02.
Artículo en Inglés | MEDLINE | ID: mdl-19235968

RESUMEN

Under solvothermal conditions, the reactions of trigonal-planar ligand, TATB (4,4',4''-s-triazine-2,4,6-triyl-tribenzoate) with Dy(NO(3))(3), Er(NO(3))(3), Y(NO(3))(3), Yb(NO(3))(3), gave rise to four microporous lanthanide metal-organic frameworks (MOFs), designated as PCN-17 (Dy), PCN-17 (Er), PCN-17 (Y), and PCN-17 (Yb), respectively. The four porous MOFs are isostructural, with their crystal unit parameters shrinking in the order of PCN-17 (Dy), PCN-17 (Y), PCN-17 (Er), and PCN-17 (Yb), which also reflects the lanthanides' contraction trend. All of them adopt the novel square-planar Ln(4)(mu(4)-H(2)O) cluster as the secondary building unit and contain coordinatively linked doubly interpenetrated (8,3)-connected nets. In addition to exhibiting interesting photoluminescence phenomena, the coordinatively linked interpenetration restricts the pore sizes and affords them selective adsorption of H(2) and O(2) over N(2) and CO, as well as renders them with high thermal stability of 500-550 degrees C as demonstrated from TGA profiles.

8.
Inorg Chem ; 48(16): 7519-21, 2009 Aug 17.
Artículo en Inglés | MEDLINE | ID: mdl-19606845

RESUMEN

A new porous metal-organic framework, PCN-20 with a twisted boracite net topology, was constructed based on a highly conjugated planar tricarboxylate ligand; PCN-20 possesses a large Langmuir surface area of over 4200 m(2)/g as well as demonstrates a high hydrogen uptake capacity of 6.2 wt % at 77 K and 50 bar.

11.
Chem Commun (Camb) ; 49(15): 1533-5, 2013 Feb 21.
Artículo en Inglés | MEDLINE | ID: mdl-23321927

RESUMEN

A highly porous porphyrin-based organic polymer, PCPF-1, was constructed via homo-coupling reaction of the custom-designed porphyrin ligand, 5,10,15,20-tetrakis(4-bromophenyl)porphyrin. PCPF-1 possesses a large BET surface area of over 1300 m(2) g(-1) (Langmuir surface area of over 2400 m(2) g(-1)) and exhibits strong hydrophobicity with a water contact angle of 135°, and these features afford it the highest adsorptive capacities for saturated hydrocarbons and gasoline among sorbent materials reported thus far, as well as render it the capability to remove oil from water.

13.
Chem Commun (Camb) ; 48(57): 7173-5, 2012 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-22691954

RESUMEN

A porous metal-metalloporphyrin framework, MMPF-2, has been constructed from a custom-designed octatopic porphyrin ligand, tetrakis(3,5-dicarboxyphenyl)porphine, that links a distorted cobalt trigonal prism secondary building unit. MMPF-2 possesses permanent microporosity with the highest surface area of 2037 m(2) g(-1) among reported porphyrin-based MOFs, and demonstrates a high uptake capacity of 170 cm(3) g(-1) CO(2) at 273 K and 1 bar.


Asunto(s)
Cobalto/química , Metaloporfirinas/química , Porfirinas/química , Adsorción , Dióxido de Carbono/aislamiento & purificación , Ligandos , Modelos Moleculares , Porosidad
14.
Dalton Trans ; 40(19): 5200-9, 2011 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-21468394

RESUMEN

In the presence of ammonia, the reactions of cyanamide and Cu(II) ions with different organic blocking ligands afford three hydrogencyanamido bridged dinuclear complexes: [(dmbpy)(4)Cu(2)(HNCN)](ClO(4))(3)·H(2)O (1, dmbpy = 4,4'-dimethyl-2,2'-bipyridine), [(phen)(4)Cu(2)(HNCN)](ClO(4))(3)·2H(2)O (2, phen = 1,10-phenanthroline) and [(bpy)(2)Cu(2)(HNCN)(2)(ClO(4))(2)] (3, bpy = 2,2'-bipyridine), respectively. However, using the di(2-pyridyl)ketone (dpk) ligand in similar experimental conditions, an interesting reaction between the hydrogencyanamido anion and dpk is observed. Using Cu(ClO(4))·6H(2)O or Co(ClO(4))·6H(2)O as the metal source, it gives the mixed bridged hexanuclear complex [(dpk·OMe)(4)(dpk·NCN)(2)Cu(6)(H(2)O)(2)](ClO(4))(4) (4), or the mononuclear complex [(dpk·OMe)(dpk·HNCN)Co](ClO(4))·2H(2)O (5), respectively. Their structures are characterized by single crystal X-ray diffraction analyses. Magnetic measurements reveal moderate antiferromagnetic interaction between the Cu(II) ions in complex 1, weak ferromagnetic coupling in complex 2, and strong antiferromagnetic interactions for complexes 3 and 4. The magnetostructural correlations of these complexes are discussed.

15.
Chem Commun (Camb) ; 46(29): 5223-5, 2010 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-20574568

RESUMEN

Cavities up to 4 nm have been introduced into a hierarchically-assembled metal-organic framework by adopting an angular, semi-flexible tetratopic ligand. The resulting MOF possesses permanent porosity and exhibits stepwise sorption isotherms for O(2) and N(2) gases.

17.
Inorg Chem ; 46(9): 3432-4, 2007 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-17407286

RESUMEN

An interpenetrating microporous metal-organic framework based on a mu3-oxotrinickel basic carboxylate secondary building unit has been synthesized and structurally characterized. It exhibits pronounced gas-sorption hysteresis and selective adsorption of carbon dioxide over methane.

18.
Inorg Chem ; 46(21): 8499-501, 2007 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-17854186

RESUMEN

An ultramicroporous metal-organic framework based on 9,10-anthracenedicarboxylate (PCN-13) has been synthesized and structurally characterized. The desolvated PCN-13 demonstrates selective adsorption of oxygen and hydrogen over nitrogen and carbon monoxide.

19.
J Am Chem Soc ; 128(51): 16474-5, 2006 Dec 27.
Artículo en Inglés | MEDLINE | ID: mdl-17177376

RESUMEN

A mesoporous metal-organic framework possessing permanent porosity has been synthesized and characterized for the first time.


Asunto(s)
Aminobenzoatos/química , Cobre/química , Compuestos Organometálicos/química , Triazinas/química , Cristalografía por Rayos X , Ligandos , Modelos Moleculares , Compuestos Organometálicos/síntesis química , Tamaño de la Partícula , Porosidad , Temperatura
20.
Chem Soc Rev ; 34(3): 208-25, 2005 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-15726158

RESUMEN

Highly stable Cu(I)-olefin coordination oligomers and polymers have been successfully prepared and applied to construct metal-organic frameworks (MOFs) with interesting physical and chemical functions in recent years. In this review, we present the olefin-Cu(I) coordination oligomers and polymers and their novel physical properties. From structure to functions, particular emphasis is placed on the coordination and organometallic chemistry of olefin-Cu(I) coordination oligomers and polymers, their structures and potential applications as solids possessing unusual physical functional properties such as electrochemical, chiral separation, fluorescent sensing and ferroelectricity.


Asunto(s)
Alquenos/química , Cobre/química , Compuestos Organometálicos/química , Polímeros/química , Electroquímica , Modelos Químicos , Conformación Molecular , Espectrometría de Fluorescencia , Estereoisomerismo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA