RESUMO
A new alkynylated cluster [Au13 Ag16 (C10 H6 NO)24 ]3- is prepared by a NaBH4 mediated reduction method. The AuAg clusters are confirmed by sophisticated characterization techniques. It has a unique "Aucenter @Ag12 @Au12 Ag4 " metal framework which is protected by 24â atypical alkyne ligands L (L=C10 H6 NO). The ligands construct a unique type of motif L-(Ag)-Au-(Ag)-L at the cluster interface, where the alkyne (C≡C) group of each L was linked by sharing an Au atom through the σ bonds and each C≡C group was discretely connected to a chemically different Ag atom (Agicosahedral /Agcap ) through πâ bonds. The electronic and optical properties of [Au13 Ag16 L24 ]3- were studied. DFT characterized the cluster as a clear 8-electron superatom, and peaks in the optical absorption spectrum were interpreted in terms of the P and D superatom states. The supported Au13 Ag16 L24 /CeO2 catalyst exhibited high catalytic activity and selectivity towards the A3 -coupling reaction involving benzaldehyde, diethylamine, and phenylacetylene.
RESUMO
Arranging ionic liquids (ILs) with long-range order can not only enhance their performance in a desired application, but can also help elucidate the vital between structure and properties. However, this is still a challenge and no example has been reported to date. Herein, we report a feasible strategy to achieve a crystalline IL via coordination self-assembly based reticular chemistry. IL1 MOF, was prepared by designing an IL bridging ligand and then connecting them with metal clusters. IL1 MOF has a unique structure, where the IL ligands are arranged on a long-range ordered framework but have a labile ionic center. This structure enables IL1 MOF to break through the typical limitation where the solid ILs have lower proton conductivity than their counterpart bulk ILs. IL1 MOF shows 2-4 orders of magnitude higher proton conductivity than its counterpart IL monomer across a wide temperature range. Moreover, by confining the IL within ultramicropores (<1â nm), IL1 MOF suppresses the liquid-solid phase transition temperatures to lower than -150 °C, allowing it to function with high conductivity in a subzero temperature range.
RESUMO
Recently, the emergence of photoactive metal-organic frameworks (MOFs) has given great prospects for their applications as photocatalytic materials in visible-light-driven hydrogen evolution. Herein, a highly photoactive visible-light-driven material for H2 evolution was prepared by introducing methylthio terephthalate into a MOF lattice via solvent-assisted ligand-exchange method. Accordingly, a first methylthio-functionalized porous MOF decorated with Pt co-catalyst for efficient photocatalytic H2 evolution was achieved, which exhibited a high quantum yield (8.90 %) at 420â nm by use sacrificial triethanolamine. This hybrid material exhibited perfect H2 production rate as high as 3814.0â µmol g-1 h-1 , which even is one order of magnitude higher than that of the state-of-the-art Pt/MOF photocatalyst derived from aminoterephthalate.
RESUMO
To develop proton-conducting materials under low-humidity conditions and at moderate working temperature still remains challenging for fuel-cell technology. Here, a new type of proton-conducting material, EIMS-HTFSA@MIL, which was prepared by impregnating the binary ionic liquid, EIMS-HTFSA (EIMS=1-(1-ethyl-3-imidazolium)propane-3-sulfonate; HTFSA=N,N-bis(trifluoromethanesulfonyl)amide), into a mesoporous metal-organic framework, MIL-101 ([Cr3 F(H2 O)2 O(BDC)3 â n H2 O] (n≈0.25, BDC=1,4-benzenedicarboxylate)) is reported. By taking advantage of the ionic-liquid properties, such as high thermal stability, non-volatility, non-flammability, and low corrosivity, EIMS-HTFSA@MIL shows potential application as a safe electrolyte in proton conduction above 100 °C.
RESUMO
Metal-organic framework (MOF) glasses are an emerging class of glasses which complement traditional inorganic, organic and metallic counterparts due to their hybrid nature. Although a few zeolitic imidazolate frameworks have been made into glasses, how to melt and quench the largest subclass of MOFs, metal carboxylate frameworks, into glasses remains challenging. Here, we develop a strategy by grafting the zwitterions on the carboxylate ligands and incorporating organic acids in the framework channels to enable the glass formation. The charge delocalization of zwitterion-acid subsystem and the densely filled channels facilitate the coordination bonding mismatch and thus reduce the melting temperature. Following melt-quenching realizes the glass formation of a family of carboxylate MOFs (UiO-67, UiO-68 and DUT-5), which are usually believed to be un-meltable. Our work opens up an avenue for melt-quenching porous molecular solids into glasses.
RESUMO
In the title complex, [Ag(NO(3))(C(9)H(7)N(3)OS)](n), η(1):η(1):η(1):µ(2)-bridging 2-(pyridin-4-ylsulfinyl)pyrimidine (pypmSO) ligands with opposite chiralities are alternately arranged to link the Ag(I) cations through two N atoms and one sulfinyl O atom of each ligand, leading to an extended zigzag coordination chain structure along the [ Ì 201] direction. An FT-IR spectroscopic study shows a decreased stretching frequency for the η(1)-O-bonded S=O group compared with that of the free ligand. The parallel chains are arranged and interconnected via O(S=O)···π(pyridine/pyrimidine) and C-H(pyridine)···O(NO(3)(-)) interactions to furnish a layer almost parallel to the ac plane. Along the b axis, the layers are stacked and stabilized through anion(NO(3)(-))···π(pyrimidine) interactions to form a three-dimensional supramolecular framework. The ligand behaviour of the new diheterocyclic sulfoxide and the unconventional O(S=O)···π(pyridine/pyrimidine) and anion(NO(3)(-))...π(pyrimidine) interactions in the supramolecular assembly of the title complex are presented.
RESUMO
In the title molecular salt, C(11)H(10)N(2)O(2+)·2ClO(4) (-), the complete cation is generated by crystallographic twofold symmetry. The dihedral angle between the pyridyl rings is 67.07â (7)°. The crystal structure features N-Hâ¯Cl hydrogen bonds, forming sheets in the ab plane.
RESUMO
In the title compound, C(8)H(6)N(4)O(3)S, the dihedral angle between the pyrazine rings is 85.04â (1)°. In the crystal, mol-ecules are arranged along the a axis and are linked by C-Hâ¯N hydrogen bonds and pyrazine-pyrazine π-π inter-actions [centroid-centroid distance = 3.800â (1)â Å, forming an infinite chain array. The chains are connected by C-Hâ¯O(oxide) hydrogen bonds into layers lying parallel to the ab plane. Along the c axis, the layers are stacked and linked through C-Hâ¯O(sulfon-yl) inter-actions, forming a three-dimensional network.
RESUMO
Solid-state electrolyte (SSE) is crucial for a high-performance all-solid-state battery. Here, a new solid sodium electrolyte based on the ionic liquid EIMS-NaTFSI and one metal-organic framework (MOF) UiO-67-MIMS functionalized with zwitterion groups MIMS was obtained (UiO-67 and was assembled with 4,4'-biphenyldicarboxylate linker and cluster Zr6O4(OH)4) (EIMS = 1-(1-ethyl-3-imidazolio)propane-3-sulfonate, NaTFSI = sodium bis(trifluoromethanesulfonyl)imide, MIMS = 1-(1-mthyl-3-imidazolio)propane-3-sulfonate). By contacting and pairing EIMS-NaTFSI (abbreviated as EN-1) to the MIMS group on the framework, EN-1 was directed and arranged along the channels within UiO-67-MIMS, forming a solid composite EN-1@UiO-67-MIMS with Bragg scatter, i.e., a crystalline ionic liquid containing Na+ salts (NaTFSI). Such an ionic liquid EN-1@UiO-67-MIMS bearing crystalline MOF matrix showed and preserved fast ion conduction (1.02 × 10-2 S cm-1) at 150 °C even after 30 days, and exhibited 1-2 orders of magnitude higher conductivities than the bulk ionic liquid EN-1 within a wide temperature range, although the ion content in the latter was higher. The infinite pathway paved by the EN-1 arranged and contacted the MIMS along the channels within MOF well accounts for the fast ion transmission and the stability of the solid-state electrolyte. Such MOF-based crystalline ionic liquid provides a new strategy for developing high-performance solid-state electrolytes for ions.
RESUMO
In the title compound, C(16)H(12)FNO(3), the dihedral angle between the benzene ring and the plane of the indole ring system is 71.60â (6)°. In the crystal, mol-ecules stack along the b axis through π-π inter-actions between the adjacent indole-2,3-dione units with a centroid-centroid distance of 3.649â (3)â Å. Inter-molecular C-Hâ¯O=C and C-Hâ¯π inter-actions further stabilize the structure, forming a three-dimensional framework.
RESUMO
Two new sets of UiO-Zr metal-organic framework (MOF) bearing mixed linkers BDC-(SCH3)2 and BDC-(SOCH3)2 that have different band gaps and edges were prepared through post oxidation and direct methods, namely, UiO-66-(SCH3)2-xh (x = 4, 9, 12 oxidation hours) and UiO-66-(SOCH3)x(SCH3)2-x (x = 0, 0.4, 0.6, 2), respectively. These composites with stoichiometric components were fully characterized via proton nuclear magnetic resonance (1H NMR) spectroscopy, powder X-ray diffraction (PXRD), transmission electron microscopy (TEM), Fourier-transform infrared (FT-IR) spectra, Brunauer-Emmett-Teller (BET), photo electrochemical measurements, and femtosecond transient absorption (fs-TA) spectroscopy. The structure, electronic property, and photoresponsive and catalytic ability as the functions of the molar ratio of linkers and the synthetic protocol were first investigated. The mixed-linker UiO-66-(SCH3)2-xh and UiO-66-(SOCH3)x(SCH3)2-x exhibited improved performances as compared to the UiO-66-(SCH3)2 and UiO-66-(SOCH3)2 possessing neat linkers only. Their photo response and catalytic activity varied with different linker ratios. For UiO-66-(SCH3)2-xh, the performance increased with the increasing linker BDC-(SOCH3)2 ratio upon oxidation but reached the highest as the BDC-(SOCH3)2 being of 24.4% in UiO-66-(SCH3)2-9h. In comparison, the best photocurrent (80.74 uA/cm-2) and the highest H2 generation rate (2018.8 µmol g-1 h-1) (λ > 400 nm) in UiO-66-(SCH3)2-9h are about twice those of UiO-66-(SOCH3)0.4(SCH3)1.6 obtained by direct synthesis, although the linker BDC-(SOCH3)2 ratio of those two composites is almost the same (24.4% vs 23.9%). Recorded shorter lifetime and higher charge separation efficiency of the former than those of the latter suggest the postsynthetic protocol as the efficient method for achieving the mixed-liner-MOF-based photocatalyst with high performance. A new type-II tailored homojunction is proposed in these mixed-linker MOFs for their efficient charge separation and improved activity.
RESUMO
The new ligand dipyrazinyl sulfoxide (also named sulfinyldipyrazine and abbreviated as pyz(2)SO) and a series of its metal complexes including {[Ag(pyz(2)SO)](NO(3)).CH(3)CN}(infinity) (1), {[Ag(pyz(2)SO)](PF(6))}(infinity) (2), [Ag(3)(pyz(2)SO)(2)(ClO(4))(3)](infinity) (3), [Ag(pyz(2)SO)(CF(3)CO(2))](infinity) (4), {[Zn(pyz(2)SO)(H(2)O)(4)](NO(3))(2).H(2)O}(infinity) (5), {[Zn(pyz(2)SO)(H(2)O)(2)](ClO(4))(2)}(infinity) (6), and {[Cd(pyz(2)SO)(2)(H(2)O)](ClO(4))(2).H(2)O}(infinity) (7) have been synthesized and characterized by single-crystal X-ray analysis. The counteranions in these complexes prefer to be embraced by a pair of pi-acidic heterocyclic rings via anion-pi interactions, which consequently affect the process of supramolecular assembly. Seven distinct ligation modes of pyz(2)SO involving various bonding combinations of the sulfoxide oxygen and/or pyrazinyl nitrogen atoms (labeled A-G) are observed. Diverse coordination motifs such as (4,4) network, ladder-type, necklace-like, linear, and zigzag-chain structures are found in 1-7. Interestingly, the sulfoxide group of the pyz(2)SO ligand exhibits unusual dipolar sulfinyl...sulfinyl and S=O...pi(pyrazinyl) intermolecular interactions in the supramolecular assemblies of neat pyz(2)SO, 1, and 3-5.
RESUMO
In the title complex, [Cd(C(7)H(4)ClO(2))(2)(H(2)O)](n), the Cd atom lies on a twofold axis and adopts a square-pyramidal coordination geometry. The water mol-ecule occupies the axial site with O atoms from four different 4-chloro-benzoato ligands in the equatorial plane. Pairs of 4-chloro-benzoato ligands bridge adjacent Cd(II) ions, generating an infinite chain structure along the c axis. Parallel polymeric chains are further inter-connected through water-acetate O-Hâ¯O hydrogen bonds, forming layers in the bc plane.
RESUMO
In the title mononuclear complex, [Ag(C(10)H(6)N(4))(2)]BF(4), the Ag(I) atom adopts a square-planar N(4 )coordination geometry and is surrounded by two 5-(2-pyrid-yl)pyrazine-2-carbonitrile ligands. The tetra-fluorido-borate anions link the mononuclear cations through inter-molecular C-Hâ¯F hydrogen-bonding inter-actions, forming an infinite tape structure along [110]. Other weak inter-actions occur: π-π stacking with centroid-centroid distances of 3.820â (2) and 3.898â (1)â Å between pyridyl rings and 3.610â (2) and 3.926â (2)â Å between pyrazinyl rings as well as Fâ¯π contacts involving the tetra-fluorido-borate anions and pyrazine rings [Fâ¯centroid = 2.999â (3)â Å]; these combine with the hydrogen-bonding inter-actions to link the mononuclear cations into a three-dimensional supra-molecular architecture.
RESUMO
In the title mononuclear complex, [Pt(CH(3))Cl(C(45)H(41)N(3)P(2))], the pyridine-2,6-diamine ligand can be viewed as a centrosymmetric motif having two pendant N-benzyl-N-[(diphenyl-phosphan-yl)meth-yl] arms, the two P atoms of which chelate to the Pt(II) ion, forming a ten-membered metallocycle. A distorted square-planar coordination geometry around the Pt(II) atom is completed by a methyl ligand and a chloride ion. The packing between the mononuclear units is achieved through C-Hâ¯π inter-actions, which link the mol-ecules into chains along the c axis.
RESUMO
In the title compound, C(21)H(20)N(4)O(4)S(2, )the piperazine ring adopts a chair conformation. The 1-ethyl-indoline-2,3-dione system links to one N atom of the piperazine ring via a carbodithio-ate group. The indoline-2,3-dione ring and the nitro-benzene ring subtend adihedral angle of 37.27â (7)°. In the crystal structure, weak C-Hâ¯O and π-π stacking inter-actions [centroid-centroid distances = 3.534â (5) and 3.797â (5)â Å] may help to establish the packing.
RESUMO
In the title complex, [Mn(3)(CH(3)CO(2))(6)(C(2)H(6)SO)(2)](n), the Mn(II) ions exhibit similar MnO(6) octa-hedral coordination geometries but with different coordination environments. One type of Mn(II) ion is surrounded by five acetate groups and a terminal dimethyl sulfoxide group, while the other lies on a twofold axis and is coordinated by six O atoms from three symmetry-related acetate ions. The acetate anions exhibit three independent bridging modes, which flexibly bridge the Mn(II) ions along the c-axis direction, forming an infinite chain structure; the chains are further inter-connected through weak C-Hâ¯O and C-Hâ¯S hydrogen-bonding inter-actions.
RESUMO
In the title compound, C(9)H(6)Cl(3)NO, the pyrrole ring is almost coplanar with the benzene ring [dihedral angle = 1.90â (9)°], while the Cl-C-N-C torsion angle is 98.78â (17)°. In the crystal, pairs of mol-ecules are inter-connected by pairs of Clâ¯Cl inter-actions [3.564â (5)â Å], forming dimers, which are further peripherally connected through inter-molecular C-Hâ¯O=C and π-π inter-actions [centroid-centroid distances = 4.134â (7), 4.134â (6) and 4.238â (7)â Å], forming a two-dimensional network.
RESUMO
In the mononuclear title complex, [Pt(CH(3))Cl(C(25)H(23)N(2)P)], the N-benzyl-N-(diphenyl-phosphanylmeth-yl)pyridin-2-amine functions as a bidentate ligand with the pyridyl N atom and the phosphine P atom chelating the Pt(II) ion, forming a six-membered metallocycle. The Pt(II) atom adopts a square-planar coordination geometry with one methyl group and one chloride ligand bonding to the metal center in a cis relationship. C-Hâ¯π and C-Hâ¯Cl inter-actions help to consolidate the packing.
RESUMO
In the mononuclear title complex, [Pt(C(7)H(7))(2)(C(8)H(12))], the Pt(II) ion exhibits a square-planar coordination geometry defined by two methyl-phenyl ligands and the mid-points of the two π-coordinated double bonds of cyclo-octa-1,5-diene. The two methyl-phenyl groups have a cis relationship with a C-Pt-C bond angle of 88.54â (18)° and a dihedral angle between the mean planes of the benzene rings of 83.87â (1)°. Each complex mol-ecule links to four symmetry-related ones through inter-molecular C-Hâ¯π inter-actions, forming a layer almost parallel to the bc plane.