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1.
Low‐dimensional lead halide perovskite materials recently have drawn much attention owing to the intriguing broadband emissions; however, the toxicity of lead will hinder their future development. Now, a lead‐free (C4H14N2)2In2Br10 single crystal with a unique zero‐dimensional (0D) structure constituted by [InBr6]3? octahedral and [InBr4]? tetrahedral units is described. The single crystal exhibits broadband photoluminescence (PL) that spans almost the whole visible spectrum with a lifetime of 3.2 μs. Computational and experimental studies unveil that an excited‐state structural distortion in [InBr6]3? octahedral units enables the formation of intrinsic self‐trapped excitons (STEs) and thus contributing the broad emission. Furthermore, femtosecond transient absorption (fs‐TA) measurement reveals that the ultrafast STEs formation together with an efficient intersystem crossing has made a significant contribution to the long‐lived and broad STE‐based emission behavior.  相似文献   

2.
The crystal structures of two crown‐ether‐coordinated caesium halogen salt hydrates, namely di‐μ‐bromido‐bis[aqua(1,4,7,10,13,16‐hexaoxacyclooctadecane)caesium(I)] dihydrate, [Cs2Br2(C12H24O6)2(H2O)2]·2H2O, (I), and poly[[diaquadi‐μ‐chlorido‐μ‐(1,4,7,10,13,16‐hexaoxacyclooctadecane)dicaesium(I)] dihydrate], {[Cs2Cl2(C12H24O6)(H2O)2]·2H2O}n, (II), are reported. In (I), all atoms are located on general positions. In (II), the Cs+ cation is located on a mirror plane perpendicular to the a axis, the chloride anion is located on a mirror plane perpendicular to the c axis and the crown‐ether ring is located around a special position with site symmetry 2/m, with two opposite O atoms exactly on the mirror plane perpendicular to the a axis; of one water molecule, only the O atom is located on a mirror plane perpendicular on the a axis, while the other water molecule is completely located on a mirror plane perpendicular to the c axis. Whereas in (I), hydrogen bonds between bromide ligands and water molecules lead to one‐dimensional chains running along the b axis, in (II) two‐dimensional sheets of water molecules and chloride ligands are formed which combine with the polymeric caesium–crown polymer to give a three‐dimensional network. Although both compounds have a similar composition, i.e. a Cs+ cation with a halogen, an 18‐crown‐6 ether and a water ligand, the crystal structures are rather different. On the other hand, it is remarkable that (I) is isomorphous with the already published iodide compound.  相似文献   

3.
Zero‐dimensional (0D) lead‐free perovskites have unique structures and optoelectronic properties. Undoped and Sb‐doped all inorganic, lead‐free, 0D perovskite single crystals A2InCl5(H2O) (A=Rb, Cs) are presented that exhibit greatly enhanced yellow emission. To study the effect of coordination H2O, Sb‐doped A3InCl6 (A=Rb, Cs) are also synthesized and further studied. The photoluminescence (PL) color changes from yellow to green emission. Interestingly, the photoluminescence quantum yield (PLQY) realizes a great boost from <2 % to 85–95 % through doping Sb3+. We further explore the effect of Sb3+ dopants and the origin of bright emission by ultrafast transient absorption techniques. Furthermore, Sb‐doped 0D rubidium indium chloride perovskites show excellent stability. These findings not only provide a way to design a set of new high‐performance 0D lead‐free perovskites, but also reveal the relationship between structure and PL properties.  相似文献   

4.
Low‐dimensional metal halides have recently attracted extensive attention owing to their unique structure and photoelectric properties. Herein, we report the colloidal synthesis of all‐inorganic low‐dimensional cesium copper halide nanocrystals (NCs) by adopting a hot‐injection approach. Using the same reactants and ligands, but different reaction temperatures, both 1D CsCu2I3 nanorods and 0D Cs3Cu2I5 NCs can be prepared. Density functional theory indicates that the reduced dimensionality in 1D CsCu2I3 compared to 0D Cs3Cu2I5 makes the excitons more localized, which accounts for the strong emission of 0D Cs3Cu2I5 NCs. Subsequent optical characterization reveals that the highly luminescent, strongly Stokes‐shifted broadband emission of 0D Cs3Cu2I5 NCs arises from the self‐trapped excitons. Our findings not only present a method to control the synthesis of low‐dimensional cesium copper halide nanocrystals but also highlight the potential of 0D Cs3Cu2I5 NCs in optoelectronics.  相似文献   

5.
A water‐stable luminescent terbium‐based metal–organic framework (MOF), {[Tb(L1)1.5(H2O)] ? 3 H2O}n (Tb‐MOF), with rod‐shaped secondary building units (SBUs) and honeycomb‐type tubular channels has been synthesized and structurally characterized by single‐crystal X‐ray diffraction. The high green emission intensity and the microporous nature of the Tb‐MOF indicate that it can potentially be used as a luminescent sensor. In this work, we show that Tb‐MOF can selectively sense Fe3+ and Al3+ ions from mixed metal ions in water through different detection mechanisms. In addition, it also exhibits high sensitivity for 2,4,6‐trinitrophenol (TNP) in the presence of other nitro aromatic compounds in aqueous solution by luminescence quenching experiments.  相似文献   

6.
Polysulfonylamines. CLXIII. Crystal Structures of Metal Di(methanesulfonyl)amides. 12. The Orthorhombic Double Salt Na2Cs2[(CH3SO2)2N]4·3H2O: A Three‐Dimensional Coordination Polymer Built up from Cesium‐Anion‐Water Layers and Intercalated Sodium Ions The packing arrangement of the three‐dimensional coordination polymer Na2Cs2[(MeSO2)2N]4·3H2O (orthorhombic, space group Pna21, Z′ = 1) is in some respects similar to that of the previously reported sodium‐potassium double salt Na2K2[(MeSO2)2N]4·4H2O (tetragonal, P43212, Z′ = 1/2). In the present structure, four multidentately coordinating independent anions, three independent aquo ligands and two types of cesium cation form monolayer substructures that are associated in pairs to form double layers via a Cs(1)—H2O—Cs(2) motif, thus conferring upon each Cs+ an irregular O8N2 environment drawn from two N, O‐chelating anions, two O, O‐chelating anions and two water molecules. Half of the sodium ions occupy pseudo‐inversion centres situated between the double layers and have an octahedral O6 coordination built up from four anions and two water molecules, whereas the remaining Na+ are intercalated within the double layers in a square‐pyramidal and pseudo‐C2 symmetric O5 environment provided by four anions and the water molecule of the Cs—H2O—Cs motif. The net effect is that each of the four independent anions forms bonds to two Cs+ and two Na+, two independent water molecules are involved in Cs—H2O—Na motifs, and the third water molecule acts as a μ3‐bridging ligand for two Cs+ and one Na+. The crystal cohesion is reinforced by a three‐dimensional network of conventional O—H···O=S and weak C—H···O=S/N hydrogen bonds.  相似文献   

7.
Presented herein are two luminescent magnesium coordination polymers (Mg‐CPs), namely [Mg2(H2O)2(2‐NDC)4(1,10‐phen)2] ( 1 ) and [Mg2(H2O)(1,4‐NDC)2(1,10‐phen)] ( 2 ), in which 2‐NDCH=2‐naphthalenecarboxylic acid, 1,4‐NDCH2=1,4‐naphthalene dicarboxylic acid, and 1,10‐phen=1,10‐phenanthroline. Based on the mixed ligands, the title compounds exhibit linker‐based photoluminescence (PL) properties thanks to the unique configuration of the Mg2+ ions. The two compounds show interesting dual emission on excitation of the different luminophores of the mixed linkers. In particular, the emissions of compound 2 could be tuned from green to yellow simply by varying the excitation energies. Furthermore, 2 could be excited by using a commercial λ=450 nm blue LED chip to generate white‐light emission, which allows the fabrication of a white‐light‐emitting diode (WLED) with 20 lm W?1 luminous efficacy. This work may provide a new method for designing tunable PL CPs by using the low‐cost and abundant magnesium ion.  相似文献   

8.
The two new title complexes, [Mn(C5H3N6)2(H2O)2] and [Zn(C5H3N6)2(H2O)2], are isomorphous. In both compounds, the metal atom is located on an inversion center and is coordinated by four N atoms from two 5‐(pyrazin‐2‐yl)‐1H‐tetra­zolate anions in the basal plane and by two O atoms of water ligands in the apical positions to form a distorted octa­hedral geometry. Inter­molecular hydrogen‐bond inter­actions between the uncoordinated N atoms of the tetra­zolate anions and the H atoms of the water mol­ecules lead to the formation of a three‐dimensional network.  相似文献   

9.
The asymmetric unit in the structure of the title compound, [K2(C9H4O9S)(H2O)2]n, consists of two eight‐coordinated KI cations, one 2,4‐dicarboxy‐5‐sulfonatobenzoate dianion (H2SBTC2−), one bridging water molecule and one terminal coordinated water molecule. One KI cation is coordinated by three carboxylate O atoms and three sulfonate O atoms from four H2SBTC2− ligands and by two bridging water molecules. The second KI cation is coordinated by four sulfonate O atoms and three carboxylate O atoms from five H2SBTC2− ligands and by one terminal coordinated water molecule. The KI cations are linked by sulfonate groups to give a one‐dimensional inorganic chain with cage‐like K4(SO3)2 repeat units. These one‐dimensional chains are bridged by one of the carboxylic acid groups of the H2SBTC2− ligand to form a two‐dimensional layer, and these layers are further linked by the remaining carboxylate groups and the benzene rings of the H2SBTC2− ligands to generate a three‐dimensional framework. The compound displays a photoluminescent emission at 460 nm upon excitation at 358 nm. In addition, the thermal stability of the title compound has been studied.  相似文献   

10.
Via utilizing the mixed‐ligand method, two novel Zn(II)‐containing meta‐organic frameworks with the chemical formula of {[Zn(L)(5‐HIP)]·H2O}n ( 1 ) and [Zn(L)(2,6‐NDC)]n ( 2 ) were prepared under the solvothermal conditions by applying aromatic dicarboxylic acids ligands (5‐H2HIP = 5‐hydroxyisophthalic acid; 2,6‐H2NDC = 2,6‐naphthalenedicarboxylic acid) and 1,4‐bis(benzimidazol‐1‐yl)‐2‐butylene (L). Due to its good water stability as well as the strong luminescent emission around room temperature, complex 2 has the high selectivity and sensibility of fluorescence detection to the ceftriaxone sodium (a kind of antibiotic) with the detection limit up to ppm lever. The treatment activity of the compounds on age‐related macular degeneration was assessed and the specific mechanism was investigated. First of all, the inflammasome activation in the endothelial cells of retina was evaluated with western blot. In addition to this, the down‐stream production of the inflammasome activation was also measured with ELISA detection kit.  相似文献   

11.
Reactions of Cd(NO3)2 · 4H2O with 2‐quinolinecarboxylic acid (H‐QLC) in the presence of 1,4‐benzenedicarboxylic acid (H2‐BDC) or 1,3,5‐benzenetricarboxylic acid (H‐BTC) in DMF/H2O solvent afforded two compounds, namely, [Cd(QLC)(BDC)1/2(H2O)]n ( 1 ) and [Cd(QLC)(BTC)1/3]n ( 2 ). Both compounds are two‐dimensional (2D) frameworks but feature different cadmium‐carboxylate clusters as a result of the presence of the polycarboxylate ligands with different geometries and coordination preference. The dinuclear Cd2(QLC)2 units in 1 are bridged by the pairs of bridging water ligands to give a one‐dimensional (1D) chain, which is further linked by the second ligand of BDC2– to form a 2D structure. Compound 2 is constructed from unique hexanuclear macrometallacyclic Cd6(QLC)6 clusters, which are linked by the surrounding BTC3– ligands to generate a 2D structure. Photoluminescence studies showed both compounds exhibit ligand‐centered luminescent emissions with emission maxima at 405 and 401 nm, respectively.  相似文献   

12.
The crystal structure of the title compound, {[Tm(C8H3O7S)(H2O)5]·1.5C10H8N2·0.5H2O}n, is built up from two [Tm(SIP)(H2O)5] molecules (SIP3− is 5‐sulfonatobenzene‐1,3‐dicarboxylate), three 4,4′‐bipyridyl (bpy) molecules and one solvent water molecule. One of the bpy molecules and the solvent water molecule are located on an inversion centre and a twofold rotation axis, respectively. The TmIII ion coordination is composed of four carboxylate O atoms from two trianionic SIP3− ligands and five coordinated water molecules. The Tm3+ ions are linked by the SIP3− ligands to form a one‐dimensional zigzag chain propagating along the c axis. The chains are linked by interchain O—H...O hydrogen bonds to generate a two‐dimensional layered structure. The bpy molecules are not involved in coordination but are linked by O—H...N hydrogen bonds to form two‐dimensional layers. The two‐dimensional layers are further bridged by the bpy molecules as pillars and the solvent water molecules through hydrogen bonds, giving a three‐dimensional supramolecular structure. π–π stacking interactions between the parallel aromatic rings, arranged in an offset fashion with a face‐to‐face distance of 3.566 (1) Å, are observed in the crystal packing.  相似文献   

13.
The title compound, [Cu(C7H5O3)2(C6H6N2O)2(H2O)2], is a two‐dimensional hydrogen‐bonded supramolecular complex. The CuII ion resides on a centre of symmetry and is in an octahedral coordination environment comprising two pyridine N atoms, two carboxylate O atoms and two O atoms from water molecules. Intermolecular N—H...O and O—H...O hydrogen bonds produce R22(4), R22(8) and R22(15) rings which lead to one‐dimensional polymeric chains. An extensive two‐dimensional network of N—H...O and O—H...O hydrogen bonds and C—H...π interactions are responsible for crystal stabilization.  相似文献   

14.
In xanthinium nitrate hydrate [systematic name: 2,6‐dioxo‐1,2,3,6‐tetrahydro‐9H‐purin‐7‐ium nitrate monohydrate], C5H5N4O2+·NO3·H2O, (I), and xanthinium hydrogen sulfate hydrate [systematic name: 2,6‐dioxo‐1,2,3,6‐tetrahydro‐9H‐purin‐7‐ium hydrogen sulfate monohydrate], C5H5N4O2+·HSO4·H2O, (II), the xanthine molecules are protonated at the imine N atom with the transfer of an H atom from the inorganic acid. The asymmetric unit of (I) contains a xanthinium cation, a nitrate anion and one water molecule, while that of (II) contains two crystallographically independent xanthinium cations, two hydrogen sulfate anions and two water molecules. A pseudo‐quadruple hydrogen‐bonding motif is formed between the xanthinium cations and the water molecules via N—H...O and O—H...O hydrogen bonds in both structures, and leads to the formation of one‐dimensional polymeric tapes. These cation–water tapes are further connected by the respective anions and aggregate into two‐dimensional hydrogen‐bonded sheets in (I) and three‐dimensional arrangements in (II).  相似文献   

15.
The two‐dimensional polymeric structures of the caesium complexes with the phenoxyacetic acid analogues (4‐fluorophenoxy)acetic acid, (3‐chloro‐2‐methylphenoxy)acetic acid and the herbicidally active (2,4‐dichlorophenoxy)acetic acid (2,4‐D), namely poly[[μ5‐(4‐fluorophenoxy)acetato][μ4‐(4‐fluorophenoxy)acetato]dicaesium], [Cs2(C8H6FO3)2]n, (I), poly[aqua[μ5‐(3‐chloro‐2‐methylphenoxy)acetato]caesium], [Cs(C9H8ClO3)(H2O)]n, (II), and poly[[μ7‐(2,4‐dichlorophenoxy)acetato][(2,4‐dichlorphenoxy)acetic acid]caesium], [Cs(C8H5Cl2O3)(C8H6Cl2O3)]n, (III), are described. In (I), the Cs+ cations of the two individual irregular coordination polyhedra in the asymmetric unit (one CsO7 and the other CsO8) are linked by bridging carboxylate O‐atom donors from the two ligand molecules, both of which are involved in bidentate chelate Ocarboxy,Ophenoxy interactions, while only one has a bidentate carboxylate O,O′‐chelate interaction. Polymeric extension is achieved through a number of carboxylate O‐atom bridges, with a minimum Cs...Cs separation of 4.3231 (9) Å, giving layers which lie parallel to (001). In hydrated complex (II), the irregular nine‐coordination about the Cs+ cation comprises a single monodentate water molecule, a bidentate Ocarboxy,Ophenoxy chelate interaction and six bridging carboxylate O‐atom bonding interactions, giving a Cs...Cs separation of 4.2473 (3) Å. The water molecule forms intralayer hydrogen bonds within the two‐dimensional layers, which lie parallel to (100). In complex (III), the irregular centrosymmetric CsO6Cl2 coordination environment comprises two O‐atom donors and two ring‐substituted Cl‐atom donors from two hydrogen bis[(2,4‐dichlorophenoxy)acetate] ligand species in a bidentate chelate mode, and four O‐atom donors from bridging carboxyl groups. The duplex ligand species lie across crystallographic inversion centres, linked through a short O—H...O hydrogen bond involving the single acid H atom. Structure extension gives layers which lie parallel to (001). The present set of structures of Cs salts of phenoxyacetic acids show previously demonstrated trends among the alkali metal salts of simple benzoic acids with no stereochemically favourable interactive substituent groups for formation of two‐dimensional coordination polymers.  相似文献   

16.
The spatial localization of charge carriers to promote the formation of bound excitons and concomitantly enhance radiative recombination has long been a goal for luminescent semiconductors. Zero‐dimensional materials structurally impose carrier localization and result in the formation of localized Frenkel excitons. Now the fully inorganic, perovskite‐derived zero‐dimensional SnII material Cs4SnBr6 is presented that exhibits room‐temperature broad‐band photoluminescence centered at 540 nm with a quantum yield (QY) of 15±5 %. A series of analogous compositions following the general formula Cs4?xAxSn(Br1?yIy)6 (A=Rb, K; x≤1, y≤1) can be prepared. The emission of these materials ranges from 500 nm to 620 nm with the possibility to compositionally tune the Stokes shift and the self‐trapped exciton emission bands.  相似文献   

17.
The use of pyridine‐2,4‐dicarboxylic acid (H2pydc) in the construction of SrII and SrII‐MII (M=Co, Ni, Zn and Cu) coordination polymers is reported. Eight complexes, that is, [Sr(pydc)H2O]n ( 1 ), [MSr(pydc)2(H2O)2]n (M=Co ( 2 ), Ni ( 3 ), Zn ( 4 )), [ZnSr(pydc)2(H2O)7]n?4 nH2O ( 5 ), [SrCu(pydc)2]n ( 6 ), [SrCu(pydc)2(H2O)3]n?2 nH2O ( 7 ), and [Cu3Sr2(pydc)4(Hpydc)2(H2O)2]n ( 8 ), have been synthesized via dexterously choosing the appropriate strontium sources and transition metal salts, and rationally controlling the temperature of the reaction systems. Complexes 1 , 2 ( 3 , 4 ), 6 , and 8 display four types of 3‐D framework structures. Complexes 5 and 7 exhibit a 2‐D network and a 1‐D chain structure, respectively. The 2‐D complex 7 can be reversibly transformed into 3‐D compound 6 through temperature‐induced solvent‐mediated structural transformation. The luminescent property studies indicated that complex 1 shows a strong purple luminescent emission and 4 exhibits a strong violet luminescence emission. The magnetic properties of 2 , 3 , and 8 were also studied. Antiferromagnetic MII???MII interactions were determined for these complexes.  相似文献   

18.
The hydrothermal synthesis of the novel complex poly[aqua(μ4‐benzene‐1,2,3‐tricarboxylato)[μ2‐4,4′‐(hydrazine‐1,2‐diylidenedimethanylylidene)dipyridine](μ3‐hydroxido)dizinc(II)], [Zn(C9H3O6)(OH)(C12H10N4)(H2O)]n, is described. The benzene‐1,2,3‐tricarboxylate ligand connects neighbouring Zn4(OH)2 secondary building units (SBUs) producing an infinite one‐dimensional chain. Adjacent one‐dimensional chains are connected by the N,N′‐bis[(pyridin‐4‐yl)methylidene]hydrazine ligand, forming a two‐dimensional layered structure. Adjacent layers are stacked to generate a three‐dimensional supramolecular architecture via O—H...O hydrogen‐bond interactions. The thermal stability of this complex is described and the complex also appears to have potential for application as a luminescent material.  相似文献   

19.
In the coordination polymer catena‐poly[[[diaqua[5‐carboxy‐2‐(pyridin‐3‐yl)‐1H‐imidazole‐4‐carboxylato‐κ2N3,O4]lead(II)]‐μ‐5‐carboxy‐2‐(pyridin‐3‐yl)‐1H‐imidazole‐4‐carboxylato‐κ3N3,O4:N2] dihydrate], {[Pb(C10H6N3O4)(H2O)2]·2H2O}n, the two 5‐carboxy‐2‐(pyridin‐3‐yl)‐1H‐imidazole‐4‐carboxylate ligands have different coordination modes, one being terminal and the other bridging. The bridging ligand links PbII cations into one‐dimensional coordination polymer chains. The structure is also stabilized by intra‐ and interchain π–π stacking interactions between the pyridine rings, resulting in the formation of a two‐dimensional network. Extensive hydrogen‐bonding interactions lead to the formation of a three‐dimensional supramolecular network.  相似文献   

20.
The title one‐dimensional chain nickel(II)–di­sulfide complex, [Ni(C14H8O4S2)(C5H5N)2(H2O)]n, has each NiII cation coordinated by two N atoms from two pyridine ligands, three carboxyl­ate O atoms from two different di­thio­dibenzoate ligands and one O atom from a coordinated water mol­ecule, in a distorted octahedral coordination geometry. Each di­thio­dibenzoate ion links two NiII cations through its carboxyl­ate O atoms, making the structure polymeric. Hydro­gen‐bond interactions between two shoulder‐to‐shoulder chains lead to the formation of a ladder‐like structure.  相似文献   

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