RESUMO
A decomposition and self-assembly reaction affords a novel formyl iodoargentate [H2L]n[Ag2I3(µ-CHO)]n (1, L = 2,6-bis(1-imdazoly)pyridine) with an unprecedented CHO- link mode, which provides the only example of iodoargentate incorporating the unstable formyl species under hydrothermal conditions. 1 exhibits luminescent and photocurrent response properties.
RESUMO
In the present work we report the design, synthesis, crystal structure determination, and adsorption properties of two new cadmium-based porous coordination polymers, [Cd(pda)0.5(spiro-4-py)0.5(HCOO)]·2H2O·DMF (compound 1, pda = p-phenylenediacetate, spiro-4-py = (2,2',7,7'-tetra(pyridin-4-yl)-9,9'-spirobi[fluorene], DMF = N,N'-dimethylformamide), and [Cd2(pda)(spiro-4-py) (CH3COO)2]·DMA (compound 2, DMA = N,N'-dimethylacetamide) with similar structures. The coordination between cadmium and two organic linkers, pda and spiro-4-py, has yielded two-dimensional frameworks with rhombic openings. Stacking of these two-dimensional networks does not block the openings but rather results in permanent porosity with one-dimensional channels in the final structures. The permanent porosity of these compounds is confirmed by gas adsorption measurements. Compounds 1 and 2 have Brunauer-Emmett-Teller surface areas of 687 and 584 m2/g, respectively. Both compounds show favorable adsorption toward carbon dioxide over other light gases such as nitrogen, oxygen, and carbon monoxide. Ideal adsorbed solution theory is employed to predict the adsorption selectivity of binary gas mixtures. Though compounds 1 and 2 possess similar structures, differences are observed in their gas adsorption behaviors, which can be attributed to their different terminal ligands of formate and acetate, respectively. Strikingly, both compounds show exceptionally high stability in aqueous media with a wide pH range, a characteristic that is highly desirable for gas separation-related applications. The robustness of these structures suggests that the use of hydrophobic spiro-based multipyridine ligands can lead to water stable frameworks built on late-transition metals that are otherwise sensitive to moisture.
RESUMO
An organic chromophore H4tcbpe-F was synthesized and immobilized into metal-organic frameworks along with two bipyridine derivatives as co-ligands to generate two strongly luminescent materials [Zn2(tcbpe-F)(4,4'-bpy)·xDMA] (1) and [Zn2(tcbpe-F)(bpee)·xDMA] (2) [4,4'-bpy = 4,4'-bipyridine, bpee = 4,4'-bipyridyl-ethylene, tcbpe-F = 4',4''',4''''',4'''''''-(ethene-1,1,2,2-tetrayl)tetrakis(3-fluoro-[1,1'-biphenyl]-4-carboxylic acid), DMA = N,N-dimethylacetamide]. Compounds 1 and 2 are isoreticular and feature a 2-fold interpenetrated three-dimensional porous structure. Both compounds give green-yellow emission under blue light excitation. Compound 1 has a high internal quantum yield of â¼51% when excited at 455 nm and shows selective luminescence signal change (e.g. emission energy and/or intensity) towards different solvents, including both aromatic and nonaromatic volatile organic species. These properties make it potentially useful as a lighting phosphor and a chemical sensor.
RESUMO
A novel interpenetrating metal-organic framework, namely [Zn(3)L(2)(oba)(3)(H(2)O)(2)]·(4)H(2)O (1), has been synthesized under hydrothermal conditions. Its structure was determined by single-crystal X-ray diffraction analysis and further characterized by elemental analysis, IR, and thermogravimetric (TG) analysis. In the structure of 1, the rigid and flexible V-shaped ligands link Zn(ii) to form a 3D structure where two types of helices and four types of pseudo-helical chains containing three pairs of enantiomers and two pairs of conformational isomers have been characterized. One such 3D framework incorporates six identical networks to form a 7-fold interpenetrated 3D framework. From the topological analysis, the Zn(ii) ions act as three- and four-connected nodes, and oba as well as L are linkers. The framework of compound can be classified as a new (6(3))2(6(5)·8) topology, which is a novel (3,3,4)-connected [4 + 3] 7-fold interpenetrating net showing 7-fold interlocking pseudo-helical chains and a unique catenane-like motif with Hopf links. In addition, the luminescence properties of the compound are discussed.
RESUMO
Environmentally sensitive hydrogels as one of the most potential drug delivery systems have gained considerable interest in recent years. In the present study, we synthesized a newly temperature-responsive composite hydrogel based on attapulgite (ATP) and poly (N-isopropylacrylamide) (PNIPAM) as the localized drug carriers for drug delivery. The as-prepared ATP/PNIPAM hydrogel has large aperture which significantly improved the quantity of adsorption of drugs, exhibiting the excellent properties of drug release. The scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and X-ray diffraction (XRD) were used to characterize the ATP/PNIPAM. The swelling/deswelling behaviors and the release of ciprofloxacin lactate were studied. When the temperature was below the low critical solution temperature (LCST), the swelling property of hydrogels was excellent and the swelling rate was large. And, the drug release rate increased with the increase of the content of attapulgite in the composite hydrogel when it was put in the buffer solution (pH7.38) at 37.0°C. Therefore, the composite hydrogels might be very useful for its application in biomedical fields.
Assuntos
Resinas Acrílicas/química , Portadores de Fármacos/síntese química , Compostos de Magnésio/química , Compostos de Silício/química , Ciprofloxacina/química , Ciprofloxacina/metabolismo , Liberação Controlada de Fármacos , Hidrogel de Polietilenoglicol-Dimetacrilato/química , Concentração de Íons de Hidrogênio , Microscopia Eletrônica de Varredura , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura , Termogravimetria , Difração de Raios XRESUMO
A diphenylphosphinoyl radical-initiated sequential reaction of 1,4-diaryl-1-butynes and analogues is developed for the synthesis of 2-phosphinoylated 3,4-dihydronaphathalenes and related compounds.
RESUMO
A new mixed-valence thioarsenate(II,III) [Ni(dap)3]4-[As10Cu2S18] (1, dap = diaminopropane) has been solvothermally synthesized and structurally characterized. 1 features a new heterometallic thioarsenate [As10Cu2S18](8-) with mixed valence As(2+)/As(3+) ions, which is constructed by combination of the chair-shaped tetramer cyclo-[As4S8] and the rare heterometallic cluster [As3CuS6]. 1 is the first example of transition metal ions encapsulated within mixed-valent thioarsenates(II,III). The optical properties of 1 have also been investigated.
RESUMO
Three new lanthanoid thioarsenates [Eu(en)3(η²-AsS4)] (1, en = ethylenediamine), [Er(teta)(en)(η²-AsS4)] (2, teta = triethylenetetramine) and [La2(tepa)2(µ-η¹,η³-AsS3)2] (3, tepa = tetraethylenepentamine) have been solvothermally synthesized and structurally characterized. In compounds 1 and 2, the tetrathioarsenate [AsS4]³â» anions act as η²-AsS4 chelating ligands to the lanthanide complexes [Eu(en)3]³âº/[Er(teta)(en)]³âº, leading to neutral molecules [Eu(en)3(η²-AsS4)]/[Er(teta)(en)(η²-AsS4)], whereas the [AsS3]³â» anion in compound 3 acts as a µ-η¹,η³-AsS3 tetradentate bridging ligand to link [La(tepa)]³âº ions into neutral centrosymmetric [La2(tepa)2(µ-η¹,η³-AsS3)2] moieties, where a new coordination mode of µ-η¹,η³-AsS3 is observed for the [AsS3]³â» ligand. Compounds 1-3 are the only examples of solvothermally synthesized thioarsenates where the [AsS4]³â»/[AsS3]³â» anions act as ligands in the lanthanide complex. Compound 1 exhibits a fluorescence emission at room temperature. Density functional theory calculations for compounds 2 and 3 also have been performed, and the absorption edges of compounds 1-3 have been investigated by UV-vis spectroscopy.
RESUMO
Three new thioindate-thioantimonates [Ni(en)(3)][In(2)Sb(2)S(7)] (1, en = ethylenediamine), [(Ni(en)(3))](3)(en)[In(6)Sb(6)S(21)] (2), and [Co(tren)InSbS(4)] (3, tren = tris(2-aminoethyl)amine) have been solvothermally synthesized and structurally characterized. Compound 1 contains dimeric [In(2)S(7)] units built of two tetrahedral [InS(4)] units sharing one corner and [SbS(3)] trigonal-pyramids, which are interconnected to form a puckered [In(2)Sb(2)S(7)](n)(2n-) layer with 4-, 5- and 6-heterorings. [Ni(en)(3)](2+) complex cations as structure-directing and charge-balancing agents are located at the interlayer spaces. Compound 2 consists of a 3-D polymeric [In(6)Sb(6)S(21)](n)(6n-) anion, [Ni(en)(3)](2+) cations, free en molecule and a water molecule. The 3-D polymeric [In(6)Sb(6)S(21)](n)(6n-) anion is composed of [In(2)Sb(2)S(8)](n)(4n-) chains and heterometallic [In(2)Sb(2)S(9)] clusters, which are interconnected to give 3-D frameworks with 10-ring helical channels, 14- and 20-ring channels. Compound 3 contains dimeric [In(2)S(6)] units constructed by two tetrahedral [InS(4)] sharing a common edge and [SbS(3)] trigonal-pyramids, which link to form a new [InSbS(4)](n)(2n-) layer with large 10-heterorings. Each [Co(tren)](2+) group is appended within the cavity of the 10-heteroring via one Co-S-Sb bond. 3 represents the first example of the incorporation of transition metal ions into a In-S-Sb framework. Density functional theory calculation for 3 also has been performed, and the optical properties of 1-3 have been characterized by UV-vis spectra.
RESUMO
Two novel lanthanoid thioantimonates [Sm(4)(tepa)(4)(µ-η(2),η(3)-Sb(3)S(7))(2)(µ-Sb(2)S(4))] (1, tepa = tetraethylenepentamine) and [Eu(2)(tepa)(2)(µ-SbS(3))(µ-OH)](2)(SbS(4))(OH)·H(2)O (2) were solvothermally synthesized. Compound 1 represents the only example of different types of [Sb(3)S(7)](5-) and [Sb(2)S(4)](2-) anions coexisting in the same lanthanoid thioantimonate framework, while 2 displays rare mixed-valent Sb(3+)/Sb(5+) character with the Sb(3+) in a noncondensed pyramid [Sb(III)S(3)](3-). The theoretical band structure and luminescence properties have also been investigated.
RESUMO
One novel 1-D europium thioindate-thioantimonate {[Eu(tepa)](2)[µ(2)-SbS(3)](µ(2)-H(2)O)}[Eu(tepa)In(4)S(9)]·0.25tepa (1, tepa = tetraethylenepentamine) has been solvothermally synthesized. 1 represents the first example of the coordination of a soft Lewis basic 1-D polymeric [In(4)S(9)(6-)](n) ligand to a hard Lewis acidic Eu(3+) ion. The wide-band-gap semiconductor and photoluminescence properties of 1 have been investigated.
RESUMO
A series of new lanthanide thiostannates(IV), [Y(2)(dien)(4)(µ-OH)(2)]Sn(2)S(6) (1, dien = diethyl-enetriamine), (tetaH)(2)[Ln(2)(teta)(2)(tren)(2)(µ-Sn(2)S(6))]Sn(2)S(6) [Ln = Eu (2), Sm (3); teta = triethylenetetramine; tren = tris(2-aminoethyl)amine] and [Eu(2)(tepa)(2)(µ-OH)(2)(µ-Sn(2)S(6))](tepa)(0.5)·H(2)O (4, tepa = tetraethylene-pentamine) were solvothermally synthesized and structurally characterized. 1 consists of a binuclear [Y(2)(dien)(4)(µ(2)-OH)(2)](4+) cation and a discrete dimeric [Sn(2)S(6)](4-) anion. Both 2 and 3 are isostructural and composed of [Ln(2)(teta)(2)(tren)(2)(µ-Sn(2)S(6))](2+) cations, protonated triethylenetetramines (tetaH), and discrete dimeric [Sn(2)S(6)](4-) anions. A Sn(2)S(6)(4-) anion bridges two [Ln(teta)(tren)](3+) cations via the trans-S(t) (t = terminal) atoms to form the first examples of inorganic-organic hybrid thiostannate cations [Ln(2)(teta)(2)(tren)(2)(µ-Sn(2)S(6))](2+). 4 consists of one-dimensional (1-D) neutral chains [Eu(2)(tepa)(2)(µ-OH)(2)(µ-Sn(2)S(6))](n) built up from the linkage of dinuclear complex cations [Eu(2)(tepa)(2)(µ(2)-OH)(2)](4+) and bridging anions [Sn(2)S(6)](4-), free tepa molecules, and lattice water molecules. The present compounds exhibit wide-band gap semiconducting properties with absorption band edges between 2.40 and 2.91 eV.
RESUMO
Two germanium thioantimonates [Co(dien)(2)](2)GeSb(4)S(10) (1, dien = diethylenetriamine) and [Mn(en)(3)]GeSb(2)S(6) (2, en = ethylenediamine) have been solvothermally synthesized and characterized by IR, UV/Vis, fluorescence spectroscopy, elemental analysis, thermogravimetric analysis, powder X-ray diffraction and single-crystal X-ray diffraction. 1 contains heterometallic pseudosemicube [GeSb(2)S(7)] clusters and chain-like Sb(4)S(10) tetramers, which are interconnected to form a unique double layer of [GeSb(4)S(10)](4-) with 10-MR helical channels. 2 features a sheet layer of [GeSb(2)S(6)](2-) with ellipse-like 12-MR, where one [GeS(4)] tetrahedra, one [SbS(3)] trigonal-pyramid and one Ψ-[SbS(4)] trigonal bipyramid are combined to form another heterometallic [GeSb(2)S(8)] cluster as a building unit. 1 and 2 exhibit absorption edges at 2.36 eV and 2.10 eV, respectively. 2 exhibits a fluorescence emission at room temperature.
RESUMO
Two novel open-framework thioindate-thioantimonates [M(dap)3]InSb3S7 [M = Co(1), Ni (2); dap = 1,2-diaminopropane] have been solvothermally synthesized and structurally characterized. 1 and 2 consist of InS4 tetrahedra and SbS3(3-) trigonal pyramids, which are interconnected to form the first examples of three-dimensional In-Sb-S open frameworks with 8-, 12-, and 16-ring intersecting channels.
Assuntos
Antimônio/química , Cobalto/química , Complexos de Coordenação/química , Índio/química , Níquel/química , Modelos Moleculares , Conformação Molecular , Solventes , Espectrofotometria Ultravioleta , Compostos de Sulfidrila/química , Difração de Raios XRESUMO
In the title compound, [Zn(C(10)H(4)Cl(2)NO(2))(2)(H(2)O)(2)]·H(2)O, the Zn atom has a distorted square-pyramidal geometry comprising two O atoms and one N atom from two distinct 3,7-dichloro-quinoline-8-carboxyl-ate ligands, and two water mol-ecules. The free water mol-ecules are involved in inter-molecular O-Hâ¯O hydrogen bonding with the coordinated water mol-ecules and carboxyl-ate O atoms, to give a one-dimensional helical chain along the [100] direction.
RESUMO
Mol-ecules of the title compound, C(11)H(17)O(4)P, are linked into chiral helical chains along the crystallographic b axis via O-Hâ¯O hydrogen bonds between the hydr-oxy group and an O atom of the phospho-nate group. One ethyl group is disordered over two positions; the site occupancy factors are ca 0.7 and 0.3.
RESUMO
The title compound, C(12)H(9)Cl(2)NO(2), was prepared by the esterification of 3,7-dichloro-quinoline-8-carboxylic acid with triethyl phosphite. The crystal structure is stabilized by aromatic π-π stacking between the benzene and the pyridine rings of neighbouring mol-ecules [centroid-centroid distances = 3.716â (2) and 3.642â (2)â Å]. In addition, weak inter-molecular C-Hâ¯N hydrogen bonds are present in the structure.