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1.
Artigo em Inglês | MEDLINE | ID: mdl-32662185

RESUMO

Metal node design is crucial for obtaining structurally diverse coordination polymers (CPs) and metal-organic frameworks with desirable properties; however, Fe(II) ions are exclusively six-coordinated. Herein, we present a cyanide-bridged three-dimensional (3D) CP, FePd(CN)4, bearing four-coordinate Fe(II) ions, which is synthesized by thermal treatment of a two-dimensional (2D) six-coordinate Fe(II) CP, Fe(H2O)2Pd(CN)4·4H2O, to remove water molecules. Atomic-resolution transmission electron microscopy and powder X-ray and neutron diffraction measurements revealed that the FePd(CN)4 structure is composed of a two-fold interpenetrated PtS topology network, where the Fe(II) center demonstrates an intermediate geometry between tetrahedral and square-planar coordination. This four-coordinate Fe(II) center with the distorted geometry can act as a thermo-responsive "flexible" node in the PtS network.

2.
Artigo em Inglês | MEDLINE | ID: mdl-32608036

RESUMO

Cell membranes contain lateral systems that consist of various lipid compositions and actin cytoskeleton, providing two-dimensional (2D) platforms for chemical reactions. However, such complex 2D environments have not yet been used as a synthetic platform for artificial 2D nanomaterials. Herein, we demonstrate the direct synthesis of 2D coordination polymers (CPs) at the liquid-cell interface of the plasma membrane of living cells. The coordination-driven self-assembly of networking metal complex lipids produces cyanide-bridged CP layers with metal ions, enabling 'pseudo-membrane jackets' that produce long-lived micro-domains with a size of 1-5 µm. The resultant artificial and visible phase separation systems remain stable even in the absence of actin skeletons in cells. Moreover, the jackets achieved the enhancement of cellular calcium response to ATP. This confirms that the artificial nanomaterials formed via moderate coordinative intermolecular interactions create a 2D scaffold on complex cell membrane environments, thereby providing a unique tool for the chemical control of cell functions.

3.
Chem Commun (Camb) ; 56(57): 7957-7960, 2020 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-32537623

RESUMO

Recently, non-crystalline coordination materials have been shown to represent a versatile class of functional materials. However, such materials incorporating metal complex clusters have remained largely unexplored. Herein, we demonstrate that a luminescent tetranuclear ReV cluster melts at 489 K, with the cluster structure being maintained in the corresponding supercooled ionic liquid phase.

4.
Inorg Chem ; 58(19): 12739-12747, 2019 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-31539234

RESUMO

Two-dimensional Hofmann-type coordination polymers of type Mn(H2O)2[Pd(CN)4]·xH2O (1·xH2O; x = 0, 1, and 4), Mn(H2O)(MeOH)[Pd(CN)4]·2MeOH (2·2MeOH), and Mn(MeOH)2[Pd(CN)4]·MeOH (3·MeOH) have been synthesized. The homosolvent-bound 1·4H2O, 1·H2O, and 3·MeOH polymers consist of undulating layer structures, whereas the structure of heterosolvent-bound 2·2MeOH consists of "Janus-like" flat layers in which water-bound and MeOH-bound-sides are present. 1·4H2O and 1·H2O exhibited anisotropic two-dimensional thermal expansions involving structural transformations of the undulating layers; one layer axis expands while the other contracts. 2·2MeOH exhibits anisotropic thermal expansion in which the flat layers shift sideways as the temperature is increased, with colossal interlayer expansion occurring (αc = +200 MK-1 over 140-180 K, αc = +165 MK-1 over 200-280 K). 3·MeOH also showed colossal interlayer expansion (αc = +216 MK-1) together with expansion of the undulating layers.

5.
Angew Chem Int Ed Engl ; 57(40): 13066-13070, 2018 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-30105766

RESUMO

Inorganic chemical cells (iCHELLs) are compartment structures consisting of polyoxometalates (POMs) and cations, offering structured and confined reaction spaces bounded by membranes. We have constructed a system capable of efficient anisotropic and hierarchical photo-induced electron transfer across the iCHELL membrane. Mimicking photosynthesis, our system uses proton gradients between the compartment and the bulk to drive efficient conversion of light into chemical energy, producing hydrogen upon irradiation. This illustrates the power of the iCHELL approach for catalysis, where the structure, compartmentalisation and variation in possible components could be utilised to approach a wide range of reactions.

6.
Angew Chem Int Ed Engl ; 57(31): 9823-9827, 2018 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-29896769

RESUMO

The palladium-hydrogen system is one of the most famous hydrogen-storage systems. Although there has been much research on ß-phase PdH(D)x , we comprehensively investigated the nature of the interaction between Pd and H(D) in α-phase PdH(D)x (x<0.03 at 303 K), and revealed the existence of Pd-H(D) chemical bond for the first time, by various in situ experimental techniques and first-principles theoretical calculations. The lattice expansion, magnetic susceptibility, and electrical resistivity all provide evidence. In situ solid-state 1 H and 2 H NMR spectroscopy and first-principles theoretical calculations revealed that a Pd-H(D) chemical bond exists in the α phase, but the bonding character of the Pd-H(D) bond in the α phase is quite different from that in the ß phase; the nature of the Pd-H(D) bond in the α phase is a localized covalent bond whereas that in the ß phase is a metallic bond.

7.
Dalton Trans ; 47(12): 4036-4039, 2018 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-29424376

RESUMO

Nonanuclear Ni(ii) complexes, [Ni9(Ln)6(OH)6(H2O)6] (Ni9Ln, n = 1-4; H2Ln = 6-acetoacetyl-2-pyridinecarboxylic acid derivatives), were prepared via self-assembly using the asymmetric multidentate ligands H2Ln. A corner-sharing tetrahedron-type structure, [Ni7(µ3-OH)6]8+, and terminal mononuclear units constitute the nonanuclear structure in a [1-7-1] formation. The electrochemical and magnetic properties of Ni9Ln were modulated by the introduction of various substituents in H2Ln.

8.
Langmuir ; 34(4): 1666-1672, 2018 01 30.
Artigo em Inglês | MEDLINE | ID: mdl-29323910

RESUMO

Coordination polymer (CP) nanoparticles (NPs) formed by a self-assembly of organic ligands and metal ions are one of the attractive materials for molecular capture and deliver/release in aqueous media. Control of particle size and prevention of aggregation among CP NPs are important factors for improving their adsorption capability in water. We demonstrate here the potential of a liposome incorporating an antibiotic ion channel as a vessel for synthesizing Prussian blue (PB) NPs, being a typical CP. In the formation of PB NPs within liposomes, the influx rate of Fe2+ ions into liposome encapsulated [Fe(CN)6]3- through channels was fundamental for the change of NPs' sizes. The optimized PB NP-liposome composite showed higher adsorption capacity of Cs+ ions than that of aggregated PB NPs that are prepared without liposome in aqueous media.


Assuntos
Césio/química , Ferrocianetos/química , Canais Iônicos/química , Lipossomos/química , Lipossomos/síntese química , Nanopartículas/química , Adsorção , Polímeros/química
9.
Dalton Trans ; 46(40): 14002-14011, 2017 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-28976513

RESUMO

Controlled nucleation in a micromixer and further crystal growth were used to synthesize Ni2(2,6-ndc)2dabco (2,6-ndc - 2,6-naphthalenedicarboxylate, dabco - 1,4-diazabicyclo[2.2.2]octane), also termed DUT-8(Ni) (DUT = Dresden University of Technology), with narrow particle size distribution in a range of a few nm to several µm. The crystal size was found to significantly affect the switching characteristics, in particular the gate opening pressure in nitrogen adsorption isotherms at 77 K for this highly porous and flexible network. Below a critical size of about 500 nm, a type Ia isotherm typical of rigid MOFs is observed, while above approximately 1000 nm a pronounced gating behaviour is detected, starting at p/p0 = 0.2. With increasing crystal size this transition gate becomes steeper indicating a more uniform distribution of activation energies within the crystal ensemble. At an intermediate size (500-1000 nm), the DUT-8(Ni) crystals close during activation but cannot be reopened by nitrogen at 77 K possibly indicating monodomain switching.

10.
Dalton Trans ; 46(22): 7141-7144, 2017 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-28534572

RESUMO

The synthesis of a luminescent coordination polymer (Tb-BTC) within the confined environment of a liposome allowed for the anisotropic growth of nanosized Tb-BTC crystals. Consequently, the resulting composite Tb-BTC@Lipo exhibited a higher fluorescence sensitivity to fluoride anions in aqueous media compared to the independent Tb-BTC in bulk.

11.
Dalton Trans ; 45(42): 16784-16788, 2016 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-27731876

RESUMO

Cobalt-iron Prussian blue analogues are magnetic functional compounds that exhibit charge-transfer-induced spin transition (CTIST), however, the role of guest species such as water in influencing the magnetic behaviour has remained unclear. Here, we report the water-dependent CTIST behaviour of Na0.46Co[Fe(CN)6]0.78(H2O)1.31 together with its single crystal X-ray structural analysis, for the first time.

12.
R Soc Open Sci ; 2(7): 150006, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26587262

RESUMO

The ability to design and control properties of nano-sized space in porous coordination polymers (PCPs) would provide us with an ideal stage for fascinating physical and chemical phenomena. We found an interconversion of nuclear-spin isomers for hydrogen molecule H2 adsorbed in a Hofmann-type PCP, {Fe(pz)[Pd(CN)4]} (pz=pyrazine), by the temperature dependence of Raman spectra. The ortho (o)-para (p) conversion process of H2 is forbidden for an isolated molecule. The charge density study using synchrotron radiation X-ray diffraction reveals the electric field generated in coordination nano-space. The present results corroborate similar findings observed on different systems and confirm that o-p conversion can occur on non-magnetic solids and that electric field can induce the catalytic hydrogen o-p conversion.

13.
Inorg Chem ; 54(17): 8529-35, 2015 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-26280936

RESUMO

Proton conduction of the La(III)M(III) compounds, LaM(ox)3·10H2O (abbreviated to LaM; M = Cr, Co, Ru, La; ox(2-) = oxalate) is studied in view of their networks. LaCr and LaCo have a ladder structure, and the ladders are woven to form a channel network. LaRu and LaLa have a honeycomb sheet structure, and the sheets are combined to form a layer network. The occurrence of these structures is explained by the rigidness versus flexibility of [M(ox)3](3-) in the framework with large La(III). The channel networks of LaCr and LaCo show a remarkably high proton conductivity, in the range from 1 × 10(-6) to 1 × 10(-5) S cm(-1) over 40-95% relative humidity (RH) at 298 K, whereas the layer networks of LaCr and LaCo show a lower proton conductivity, ∼3 × 10(-8) S cm(-1) (40-95% RH, 298 K). Activation energy measurements demonstrate that the channels filled with water molecules serve as efficient pathways for proton transport. LaCo was gradually converted to La(III)Co(II)(ox)2.5·4H2O, which had no channel structure and exhibited a low proton conductivity of less than 1 × 10(-10) S cm(-1). The conduction-network correlation of LaCo(ox)2.5·4H2O is reported.

14.
Dalton Trans ; 44(32): 14200-3, 2015 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-26200295

RESUMO

A new lipophilic Ru salen complex with cholesterol groups can be efficiently incorporated into liposome bilayers, allowing the photoinduced release of nitric oxide (NO) and the membrane transport of NO to coexisting liposomes.


Assuntos
Etilenodiaminas/química , Lipossomos , Óxido Nítrico/metabolismo , Fotoquímica , Compostos de Rutênio/química , Cristalografia por Raios X , Estrutura Molecular
15.
Dalton Trans ; 44(34): 15126-9, 2015 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-25954861

RESUMO

A composite containing a liposome and a lipophilic ruthenium complex was synthesized to regulate an O2 evolution reaction using cerium(IV) ammonium nitrate as an oxidizing reagent. We found that the surrounding environment of the reaction centre is an important factor for controlling the O2 evolution catalytic reaction. We successfully regulated the reaction activity using the linker length of the lipophilic ligand and using the head groups of the phospholipid component.


Assuntos
Cério/química , Lipossomos/química , Oxigênio/química , Fosfolipídeos/química , Rutênio/química , Catálise , Eletroquímica , Desenho de Equipamento , Ligantes , Nitratos/química , Oxirredução , Energia Solar , Propriedades de Superfície , Água/química
16.
Angew Chem Int Ed Engl ; 54(4): 1139-43, 2015 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-25476115

RESUMO

Novel organic-inorganic hybrid liposomes, so-called coordination polymersomes (CPsomes), with artificial domains that exhibit strong lateral cohesion were prepared by a three-step procedure that formed a coordinative interaction leading to a lipid bilayer. First, the lipophilic complex (dabco-C18)[Mn(N)(CN)4(dabco-C18)] (1; dabco-C18(+)=1,4-diazabicyclo[2,2,2]octane-(CH2)17-CH3 cation), was synthesized. 1 has a lipophilic alkyl tail part and a tetracyanometallate head group, which can be used for an expansion to two-dimensional coordination networks. Second, 1 and 1,2-dipalmitoyl-sn-glycero-3-phosphocholine were mixed to prepare the liposomes. Finally, CPsomes were obtained by the addition of transition-metal ions (M) to form unilamellar faceted liposomes with plain CP raft domains with Mn-CN-M linkages. The concentration of 1 influences the size of the CP raft domains and the shape of the CPsomes. The synthesis of coordination polymers in lipid bilayers is a novel approach for the construction of artificial architectures as raft domains, for example, in cell membranes.


Assuntos
Lipossomos/síntese química , 1,2-Dipalmitoilfosfatidilcolina/química , Cianetos/química , Íons/química , Bicamadas Lipídicas/química , Lipossomos/química , Polímeros/química , Elementos de Transição/química
17.
Chemistry ; 20(40): 12864-73, 2014 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-25145295

RESUMO

The synthesis, structure, and magnetic properties of three clathrate derivatives of the spin-crossover porous coordination polymer {Fe(pyrazine)[Pt(CN)4]} (1) with five-membered aromatic molecules furan, pyrrole, and thiophene is reported. The three derivatives have a cooperative spin-crossover transition with hysteresis loops 14-29 K wide and average critical temperatures Tc =201 K (1⋅fur), 167 K (1⋅pyr), and 114.6 K (1⋅thio) well below that of the parent compound 1 (Tc =295 K), confirming stabilization of the HS state. The transition is complete and takes place in two steps for 1⋅fur, while 1⋅pyr and 1⋅thio show 50 % spin transition. For 1⋅fur the transformation between the HS and IS (middle of the plateau) phases occurs concomitantly with a crystallographic phase transition between the tetragonal space groups P4/mmm and I4/mmm, respectively. The latter space group is retained in the subsequent transformation involving the IS and the LS phases. 1⋅pyr and 1⋅thio display the tetragonal P4/mmm and orthorhombic Fmmm space groups, respectively, in both HS and IM phases. Periodic calculations using density functional methods for 1⋅fur, 1⋅pyr, 1⋅thio, and previously reported derivatives 1⋅CS2 , 1⋅I, 1⋅bz(benzene), and 1⋅pz(pyrazine) have been carried out to investigate the electronic structure and nature of the host-guest interactions as well as their relationship with the changes in the LS-HS transition temperatures of 1⋅Guest. Geometry-optimized lattice parameters and bond distances in the empty host 1 and 1⋅Guest clathrates are in general agreement with the X-ray diffraction data. The concordance between the theoretical results and the experimental data also comprises the guest molecule orientation inside the host and intermolecular distances. Furthermore, a general correlation between experimental Tc and calculated LS-HS electronic energy gap was observed. Finally, specific host-guest interactions were studied through interaction energy calculations and crystal orbital displacement (COD) curve analysis.

18.
Dalton Trans ; 43(22): 8508-14, 2014 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-24756312

RESUMO

Three new manganese coordination polymers, {[Mn2(1,4-NDC)2(phen)2](H2O)}n (1), [Mn2(1,4-NDC)2(phen)(H2O)]n (2) and {[Mn4(1,4-NDC)4(phen)4](DMF)2}n (3) (1,4-H2NDC = 1,4-naphthalene dicarboxylic acid; phen = 1,10-phenanthroline; DMF = N,N-dimethylformamide), have been synthesized solvo/hydrothermally. 1,4-NDC(2-) ligands adopt different coordination modes under different solvents and concentrations which promotes different crystal structure formation. X-ray crystal structural data reveal that compounds 1, 2 and 3 crystallize in monoclinic space groups C2/c, P21/c and C2/c, respectively. Compound 1 has Mn2 dimers connected by 1,4-NDC(2-) linkers, packing into a 2D structure in a grid pattern. Compound 2 has a three-dimensional (3D) structure which is constructed by Mn2 dimers and 1,4-NDC(2-) linkers. Each MnO4N2 node of compound 3 is linked to another by 1,4-NDC(2-) ligands to form a two-dimensional (2D) structure. Variable-temperature magnetic susceptibilities of compounds 1-3 exhibit overall weak antiferromagnetic coupling between the adjacent Mn(II) ions.


Assuntos
Complexos de Coordenação/síntese química , Manganês/química , Naftalenos/química , Fenantrolinas/química , Complexos de Coordenação/química , Cristalografia por Raios X , Ligantes , Fenômenos Magnéticos , Modelos Moleculares , Estrutura Molecular , Termogravimetria
19.
Inorg Chem ; 52(21): 12777-83, 2013 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-24124923

RESUMO

The chemisorption of sulfur dioxide (SO2) on the Hofmann-like spin crossover porous coordination polymer (SCO-PCP) {Fe(pz)[Pt(CN)4]} has been investigated at room temperature. Thermal analysis and adsorption-desorption isotherms showed that ca. 1 mol of SO2 per mol of {Fe(pz)[Pt(CN)4]} was retained in the pores. Nevertheless, the SO2 was loosely attached to the walls of the host network and completely released in 24 h at 298 K. Single crystals of {Fe(pz)[Pt(CN)4]}·nSO2 (n ≈ 0.25) were grown in water solutions saturated with SO2, and its crystal structure was analyzed at 120 K. The SO2 molecule is coordinated to the Pt(II) ion through the sulfur atom ion, Pt-S = 2.585(4) Å. This coordination slightly stabilizes the low-spin state of the Fe(II) ions shifting the critical temperatures of the spin transition by 8-12 K. DFT calculations have been performed to rationalize these observations.


Assuntos
Compostos Ferrosos/química , Dióxido de Enxofre/química , Adsorção , Cristalografia por Raios X , Estrutura Molecular
20.
Dalton Trans ; 42(45): 15893-7, 2013 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-23877189

RESUMO

To implement specific guest responsivity, a hydrophobic cholesterol-based co-ligand, cholest-5-en-3-yl-4-isonicotinate (Cholpy), was incorporated into a two-dimensional Hofmann-type Co(II)Ni(II) coordination polymer. The chemically programmed structure successfully demonstrated the unique guest response with remarkable chromatic changes.


Assuntos
Colesterol/química , Cobalto/química , Complexos de Coordenação/química , Níquel/química , Ligantes , Modelos Moleculares , Polímeros/química
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