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1.
A pair of propeller‐like chiral trinuclear CuI clusters ( R/S‐Cu3 ) with unique photoinduced fluorescence enhancement were prepared. R/S‐Cu3 showed intense variable luminescence after UV light irradiation, which was attributed to the stepwise oxidation of ligand in the clusters. It exhibited typical aggregation‐induced emission (AIE) (αAIE=17.3). Mechanism studies showed that metal cluster‐centered (MCC) and triplet metal‐to‐ligand charge‐transfer (3MLCT) processes are the origin of the luminescence; the processes are regulated by a restriction of intramolecular motions mechanism in a different state. The chiral structure and AIE feature endow R/S‐Cu3 with remarkable circularly polarized luminescence (glum=2×10?2) in the aggregated state. It shows good capability for producing reactive oxygen species. This work enriches the kinds of atomically precise AIE clusters, gains insight into their luminescence mechanism, and offers the prospect of application in multifunctional materials.  相似文献   

2.
A pair of propeller-like chiral trinuclear CuI clusters ( R/S-Cu3 ) with unique photoinduced fluorescence enhancement were prepared. R/S-Cu3 showed intense variable luminescence after UV light irradiation, which was attributed to the stepwise oxidation of ligand in the clusters. It exhibited typical aggregation-induced emission (AIE) (αAIE=17.3). Mechanism studies showed that metal cluster-centered (MCC) and triplet metal-to-ligand charge-transfer (3MLCT) processes are the origin of the luminescence; the processes are regulated by a restriction of intramolecular motions mechanism in a different state. The chiral structure and AIE feature endow R/S-Cu3 with remarkable circularly polarized luminescence (glum=2×10−2) in the aggregated state. It shows good capability for producing reactive oxygen species. This work enriches the kinds of atomically precise AIE clusters, gains insight into their luminescence mechanism, and offers the prospect of application in multifunctional materials.  相似文献   

3.
Aggregation‐induced emission (AIE) is an attractive phenomenon in which materials display strong luminescence in the aggregated solid states rather than in the conventional dissolved molecular states. However, highly luminescent inks based on AIE are hard to be obtained because of the difficulty in finely controlling the crystallinity of AIE materials at nanoscale. Herein, we report the preparation of highly luminescent inks via oil‐in‐water microemulsion induced aggregation of Cu–I hybrid clusters based on the highly soluble copper iodide‐tris(3‐methylphenyl)phosphine (Cu4I4(P‐(m‐Tol)3)4) hybrid. Furthermore, we can synthesize a series of AIE inks with different light‐emission colors to cover the whole visible spectrum range via a facile ligand exchange processes. The assemblies of Cu–I hybrid clusters with AIE characteristics will pave the way to fabricate low‐cost highly luminescent inks.  相似文献   

4.
In this study, a pair of chiral copper(I) cluster-assembled materials (R/S- 2 ) was prepared, exhibiting unique photo-response characteristics with a concentration-wavelength correlation property in DMSO solution. By the combination of R/S- 2 with a polymethyl methacrylate (PMMA) matrix, the first photo-activated circularly polarized luminescence (CPL) film was developed, the CPL signal (glum=9×10−3) of which could be induced by UV light irradiation. Moreover, the film exhibited a reversible photo-response and extremely good fatigue resistance. Mechanism study revealed that the photo-response properties of the R/S- 2 solution and film are attributed to the aggregation-induced emission (AIE) characteristics of R/S- 2 and a photo-induced deoxygenation process. This study enriches the types of luminescent cluster-assembled molecules and provides a new strategy for the construction of metal cluster-based stimuli-responsive composite materials.  相似文献   

5.
Chiral Au nanoclusters have promising application prospects in chiral sensing, asymmetric catalysis, and chiroptics. However, enantiopure superatomic homogold clusters with crystallographic structures emitting bright circularly polarized luminescence (CPL) remain challenging. In this study, we designed chiral N-heterocyclic carbenes (NHCs), and for the first time enantioselectively synthesized a pair of monovalent cationic superatomic Au13 clusters. This new enantiomeric pair of clusters has a quasi-C2 symmetric core and exhibited CPL with an unprecedent solution-state quantum yield (QY) of 61 % among those of the atomically precise Au nanoclusters. DFT calculations provided insights into the circular dichroism behavior, and revealed the origin of CPL from superatomic Au clusters. This work opens a new avenue for developing novel homochiral nanoclusters using chiral NHC ligands and provides fundamental understanding of the origin of the chiroptics of metal clusters.  相似文献   

6.
The aggregation‐induced emission (AIE) properties of two different copper iodide clusters have been studied. These two [Cu4I4L4] clusters differ by their coordinated phosphine ligand and the luminescent mechanochromic properties are only displayed by one of them. The two clusters are AIE‐active luminophors that exhibit an intense emission in the visible region upon aggregation. The formed particles present luminescent thermochromism comparable to that of the bulk compounds. The observed AIE properties can be attributed to suppression of nonradiative relaxation of the excited states in a more rigid state, in relation to the large structural relaxation of the excited triplet state. The differences observed in the AIE properties of the two clusters can be related to the different ligands. A correlation between the luminescence mechanochromic properties and the AIE effect is not straightforward, but the formation of “soft” molecular solids is a common characteristic that can explain the photoactive properties of these compounds.  相似文献   

7.
The potential use of circularly polarized luminescence for object identification in a sensor application is demonstrated. New luminescence probes using pyrene derivatives as sensor luminophores were developed. (R,R)‐Im2Py and (S,S)‐Im2Py contain two chiral imidazole moieties at 1,6‐positions through ethynyl spacers (angle between spacers ca. 180°). The probe molecules spontaneously self‐assemble into chiral stacks (P or M helicity) upon coordination to metal ions with tetrahedral coordination (Zn2+). The chiral probes display neither circular dichroism (CD) nor circularly polarized luminescence (CPL) without metal ions. However, (R,R)‐Im2Py and (S,S)‐Im2Py exhibit intense chiroptical activity (CD and CPL) upon self‐assembly with Zn2+ ions. (R,R)‐Im2Py and (S,S)‐Im2Py with chemical stimuli‐responsibility allow sensing using the CPL signal as detection output, enabling us to discriminate between a signal from the target analyte and that from non‐target species.  相似文献   

8.
The synthesis of chiral C1‐symmetrical copper(I) complexes supported by chiral carbene ligands is described. These complexes are yellow emitters with modest quantum yields. Circularly polarized luminescence (CPL) spectra show a polarized emission band with dissymmetry factors |glum|=1.2×10?3. These complexes are the first reported examples of molecular copper(I) complexes exhibiting circularly polarized luminescence. In contrast with most CPL‐emitting molecules, which possess either helical or axial chirality, the results presented show that simple chiral architectures are suitable for CPL emission and unlock new synthetic possibilities.  相似文献   

9.
Copper(I) alkynyl complexes have attracted tremendous attention in structural studies, as luminescent materials, and in catalysis, and homoleptic complexes have been reported to form polymers or large clusters. Herein, six unprecedented structures of CuI alkynyl complexes and a procedure to measure the cone angles of alkynyl ligands based on the crystal structures of these complexes are reported. An increase of the alkynyl cone angle in the complexes leads to a modulation of the structures from polymeric [((PhC≡CC≡C)Cu)2(NH3)], to a large cluster [(TripC≡CC≡C)Cu]20(MeCN)4, to a relatively small cluster [(TripC≡C)Cu]8 (Trip=2,4,6‐iPr3‐C6H2). The complexes exhibit yellow‐to‐red phosphorescence at ambient temperature in the solid state and the luminescence behavior of the Cu20 cluster is sensitive to acetonitrile.  相似文献   

10.
Chiral assembly and asymmetric synthesis are critically important for the generation of chiral metal clusters with chiroptical activities. Here, a racemic mixture of [K(CH3OH)2(18‐crown‐6)]+[Cu5(StBu)6]? ( 1?CH3OH ) in the chiral space group was prepared, in which the chiral red‐emissive anionic [Cu5(StBu)6]? cluster was arranged along a twofold screw axis. Interestingly, the release of the coordinated CH3OH of the cationic units turned the chiral 1?CH3OH crystal into a mesomeric crystal [K(18‐crown‐6)]+[Cu5(StBu)6]? ( 1 ), which has a centrosymmetric space group, by adding symmetry elements of glide and mirror planes through both disordered [Cu5(StBu)6]? units. The switchable chiral/achiral rearrangement of [Cu5(StBu)6]? clusters along with the capture/release of CH3OH were concomitant with an intense increase/decrease in luminescence. We also used cationic chiral amino alcohols to induce the chiral assembly of a pair of enantiomers, [d /l ‐valinol(18‐crown‐6)]+[Cu5(StBu)6]? ( d /l ‐Cu5V ), which display impressive circularly polarized luminescence (CPL) in contrast to the CPL‐silent racemic mixture of 1?CH3OH and mesomeric 1 .  相似文献   

11.
Cu(CF3COO)2 reacts with tert‐butylacetylene (tBuC≡CH) in methanol in the presence of metallic copper powder to give two air‐stable clusters, [CuI15(tBuC≡C)10(CF3COO)5]?tBuC≡CH ( 1 ) and [CuI16(tBuC≡C)12(CF3COO)4(CH3OH)2] ( 2 ). The assembly process involves in situ comproportionation reaction between Cu2+ and Cu0 and the formation of two different clusters is controlled by reactants concentration. The clusters consist of Cu15 and Cu16 cores co‐stabilized by strong by σ‐ and π‐bonded tert‐butylethynide and CF3COO? (together with methanol molecule in 2 ). Their stabilities in solution were confirmed using electrospray ionization mass spectrometry in which the cluster core remains intact for 1 in chloroform and acetone, and for 2 in acetonitrile. Strong thermochromic luminescence in the near infrared (NIR) region was observed in the solid‐state. Of particular interest, the emission maximum of 1 is red‐shifted from 710 nm at 298 K to 793 nm at 93 K, along with a 17‐fold fluorescence enhancement. In contrast, 2 exhibits red shift from 298 to 123 K followed by blue shift from 123 to 93 K. The emission wavelength was correlated with the structural parameters using variable‐temperature X‐ray single‐crystal analyses. The rich cuprophilic interaction plays a significant role in the formation of 3LMCT (tBuC≡C→Cux) excited state mixed with cluster‐centered (3CC) characters, which can be considerably influenced by temperature, leading to thermochromic luminescence. The present work provides 1) a new synthetic protocol for the high‐nuclear CuI–alkynyl clusters; 2) a comprehensive insight into the mechanism of thermochromic luminescence; 3) unusual emissive materials with the characters of NIR and thermochromic luminescence simultaneously.  相似文献   

12.
The hardness of oxo ions (O2?) means that coinage‐metal (Cu, Ag, Au) clusters supported by oxo ions (O2?) are rare. Herein, a novel μ4‐oxo supported all‐alkynyl‐protected silver(I)–copper(I) nanocluster [Ag74?xCuxO12(PhC≡C)50] ( NC‐1 , avg. x=37.9) is characterized. NC‐1 is the highest nuclearity silver–copper heterometallic cluster and contains an unprecedented twelve interstitial μ4‐oxo ions. The oxo ions originate from the reduction of nitrate ions by NaBH4. The oxo ions induce the hierarchical aggregation of CuI and AgI ions in the cluster, forming the unique regioselective distribution of two different metal ions. The anisotropic ligand coverage on the surface is caused by the jigsaw‐puzzle‐like cluster packing incorporating rare intermolecular C?H???metal agostic interactions and solvent molecules. This work not only reveals a new category of high‐nuclearity coinage‐metal clusters but shows the special clustering effect of oxo ions in the assembly of coinage‐metal clusters.  相似文献   

13.
By using a linear tetraphosphine, meso‐bis[(diphenylphosphinomethyl)phenylphosphino]methane (dpmppm), nona‐ and hexadecanuclear copper hydride clusters, [Cu9H7(μ‐dpmppm)3]X2 (X=Cl ( 1 a ), Br ( 1 b ), I ( 1 c ), PF6 ( 1 d )) and [Cu16H14(μ‐dpmppm)4]X2 (X2=I2 ( 2 c ), (4/3) PF6?(2/3) OH ( 2 d )) were synthesized and characterized. They form copper‐hydride cages of apex‐truncated supertetrahedral {Cu9H7}2+ and square‐face‐capped cuboctahedral {Cu16H14}2+ structures. The hydride positions were estimated by DFT calculations to be facially dispersed around the copper frameworks. A kinetically controlled synthesis gave an unsymmetrical Cu8H6 cluster, [Cu8H6(μ‐dpmppm)3]2+ ( 3 ), which readily reacted with CO2 to afford linear Cu4 complexes with formate bridges, leading to an unprecedented hydrogenation of CO2 into formate catalyzed by {Cu4(μ‐dpmppm)2} platform. The results demonstrate that new motifs of copper hydride clusters could be established by the tetraphosphine ligands, and the structures influence their reactivity.  相似文献   

14.
The synthesis of chiral C1-symmetrical copper(I) complexes supported by chiral carbene ligands is described. These complexes are yellow emitters with modest quantum yields. Circularly polarized luminescence (CPL) spectra show a polarized emission band with dissymmetry factors |glum|=1.2×10−3. These complexes are the first reported examples of molecular copper(I) complexes exhibiting circularly polarized luminescence. In contrast with most CPL-emitting molecules, which possess either helical or axial chirality, the results presented show that simple chiral architectures are suitable for CPL emission and unlock new synthetic possibilities.  相似文献   

15.
Organometallic Compounds of Copper. XX On the Reaction of the Alkyne Copper(I) Complexes [CuCl(S‐Alkyne)] and [Cu2Br2(S‐Alkyne)(dms)] (S‐Alkyne = 3,3,6,6‐Tetramethyl‐1‐thiacyclohept‐4‐yne; dms = Dimethylsulfide) with the Lithiumorganyls Phenyllithium und Fluorenyllithium The alkyne copper(I) bromide complex [Cu2Br2(S‐Alkyne)(dms)] ( 3 b ) (S‐Alkyne = 3,3,6,6‐tetramethyl‐1‐thiacyclohept‐4‐yne; dms = dimethylsulfide) reacts with phenyllithium to form a tetranuclear copper(I) complex of the composition [Cu4(C6H5)2(S‐Alkenyl)2] ( 7 ) in low yield (4%). The reaction of the alkyne copper(I) chloride complex [CuCl(S‐Alkyne)] ( 2 a ) with fluorenyllithium in tetrahydrofuran (thf) affords a lithium cuprate of the composition [Li(thf)4]+ [Cu2(fluorenyl)3(S‐Alkyne)2] ( 8 ) (yield 32%). The structures of both new complexes 7 and 8 were determined by X–ray diffraction.  相似文献   

16.
Organic fluorescent molecules are gaining importance because of their potential applications in many devices. Optically active N,N′-bis((1R)-1-naphthylethyl)perylene-3,4,9,10-tetracarboxylic diimide [(R,R)-1-BNP] and N,N′-bis((1R)-2-naphthylethyl)perylene-3,4,9,10-tetracarboxylic diimide [(R,R)-2-BNP] and their antipode, [(S,S)-1-BNP and (S,S)-2-BNP], emit aggregation-induced enhanced (AIEnh) circularly polarized luminescence (CPL) on both a solid organic polymer film (poly(methyl methacrylate)) and solid inorganic KBr pellet. An opposite chirality is essential for generating CPL of inverted sign. However, a pair of enantiomeric organic molecules may not always be easy to prepare. Interestingly, the chiral perylene fluorophores synthesized in this study can emit both positive and negative AIEnh-CPL in the solid state, depending on their position on the naphthylene groups. In addition, no CPL was observed in these compounds from their dilute solutions.  相似文献   

17.
With our new home‐built circularly polarized luminescence (CPL) instrument, we measured fluorescence and CPL spectra of the enantiomeric pairs of two quasi‐isomeric BODIPY DYEmers 1 and 2 , endowed with axial chirality. The electronic circular dichroism (ECD) and CPL spectra of these atropisomeric dimers are dominated by the exciton coupling between the main π–π* transitions (550–560 nm) of the two BODIPY rings. Compound 1 has strong ECD and CPL spectra (glum=4×10?3) well reproduced by TD‐DFT and SCS‐CC2 (spin‐component scaled second‐order approximate coupled‐cluster) calculations using DFT‐optimized ground‐ and excited‐state structures. Compound 2 has weaker ECD and CPL spectra (glum=4×10?4), partly due to the mutual cancellation of electric–electric and electric–magnetic exciton couplings, and partly to its conformational freedom. This compound is computationally very challenging. Starting from the optimized excited‐state geometries, we predicted the wrong sign for the CPL band of 2 using TD‐DFT with the most recommended hybrid and range‐separated functionals, whereas SCS‐CC2 or a DFT functional with full exact exchange provided the correct sign.  相似文献   

18.
The concept of aggregation‐induced emission (AIE) has been exploited to render non‐luminescent CuISR complexes strongly luminescent. The CuISR complexes underwent controlled aggregation with Au0. Unlike previous AIE methods, our strategy does not require insoluble solutions or cations. X‐ray crystallography validated the structure of this highly fluorescent nanocluster: Six thiolated Cu atoms are aggregated by two Au atoms (Au2Cu6 nanoclusters). The quantum yield of this nanocluster is 11.7 %. DFT calculations imply that the fluorescence originates from ligand (aryl groups on the phosphine) to metal (CuI) charge transfer (LMCT). Furthermore, the aggregation is affected by the restriction of intramolecular rotation (RIR), and the high rigidity of the outer ligands enhances the fluorescence of the Au2Cu6 nanoclusters. This study thus presents a novel strategy for enhancing the luminescence of metal nanoclusters (by the aggregation of active metal complexes with inert metal atoms), and also provides fundamental insights into the controllable synthesis of highly luminescent metal nanoclusters.  相似文献   

19.
Complexes with Macrocyclic Ligands. V Dinuclear Copper(II) Complexes with Chiral Macrocyclic Ligands of Schiff‐Base Type: Syntheses and Structures The synthesis and properties of four chiral, dinuclear, macrocyclic, cationic copper(II) complexes, [Cu2(Lm,n)]2+ ( 1 – 4 ), are described. The two symmetrical compounds [Cu2(L2,2)][ClO4]2 ( 1 and 2 ) were synthesized in a one‐step reaction from 2,6‐diformyl‐4‐tert.‐butylphenol, copper(II)‐perchlorate and the chiral diamine (1S,2S)‐1,2‐diphenylethylenediamine (synthesis of 1 ) and (1R,2R)‐1,2‐diaminocyclohexane (synthesis of 2 ), respectively. For the synthesis of the two unsymmetrical compounds [Cu2(LPh,n)][ClO4]2 ( 3 and 4 ) the mononuclear, neutral copper(II) complex [CuLPh] ( 5 ) [synthesized from 2,6‐diformyl‐4‐tert.‐butylphenol, copper(II)‐acetate and 1,2‐phenylenediamine] was reacted with (1R,2R)‐1,2‐diaminocyclohexane (synthesis of 3 ) and (S)‐1,1′‐binaphthyl‐2,2′‐diamine (synthesis of 4 ), respectively. The structures of the two unsymmetrical copper(II) compounds ( 3 and 4 ) were determined by X‐ray diffraction.  相似文献   

20.
The structurally precise Cu‐rich hydride nanoclusters [PdCu14H2(dtc/dtp)6(C≡CPh)6] (dtc: di‐butyldithiocarbamate ( 1 ); dtp: di‐isopropyl dithiophosphate ( 2 )) were synthesized from the reaction of polyhydrido copper clusters [Cu28H15(S2CNnBu2)12]+ or [Cu20H11{S2P(OiPr)2}9] with phenyl acetylene in the presence of Pd(PPh3)2Cl2. Their structures and compositions were determined by single‐crystal X‐ray diffraction and the results supported by ESI‐mass spectrometry. Hydride positions in 1 were confirmed by single‐crystal neutron diffraction. Each hydride is connected to one Pd0 and four CuI atoms in slightly distorted trigonalbipyramidal geometry. The anatomies of clusters 1 and 2 are very similar and DFT calculations allow rationalizing the interactions between the encapsulated [PdH2]2? unit and its Cu14 bicapped icosahedral cage. As a result, Pd has the highest coordination number (14) so far recorded.  相似文献   

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