共查询到20条相似文献,搜索用时 31 毫秒
1.
Nathan J. Oldenhuis K. Peter Qin Shu Wang Hong-Zhou Ye Eric A. Alt Adam P. Willard Troy Van Voorhis Stephen L. Craig Prof. Jeremiah A. Johnson 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(7):2806-2814
Photoresponsive materials that change in response to light have been studied for a range of applications. These materials are often metastable during irradiation, returning to their pre-irradiated state after removal of the light source. Herein, we report a polymer gel comprising poly(ethylene glycol) star polymers linked by Cu24L24 metal–organic cages/polyhedra (MOCs) with coumarin ligands. In the presence of UV light, a photosensitizer, and a hydrogen donor, this “polyMOC” material can be reversibly switched between CuII, CuI, and Cu0. The instability of the MOC junctions in the CuI and Cu0 states leads to network disassembly, forming CuI/Cu0 solutions, respectively, that are stable until re-oxidation to CuII and supramolecular gelation. This reversible disassembly of the polyMOC network can occur in the presence of a fixed covalent second network generated in situ by copper-catalyzed azide-alkyne cycloaddition (CuAAC), providing interpenetrating supramolecular and covalent networks. 相似文献
2.
Guo‐Cheng Liu Yu‐Fei Wang Ai‐Xiang Tian Xiu‐Li Wang Jing‐Jing Cao Song Yang Hong‐Yan Lin 《无机化学与普通化学杂志》2013,639(1):148-157
Three new 2D/3D supramolecular architectures derived from Cu‐organic subunits and Keggin anions, [CuII2(biz)8(HPMoVI10MoV2O40)(H2O)2] · 2H2O ( 1 ), [CuI4(biz)8(SiW12O40)] · 2H2O ( 2 ) and [CuI2(dmbiz)4(Hdmbiz)2(SiW12O40)] ( 3 ) (biz = benzimidazole, dmbiz = 5, 6‐dimethyl benzimidazole), were obtained under hydrothermal conditions. Single crystal X‐ray diffraction analysis reveals that compound 1 has two kinds of [CuII(biz)2]2+ cations, which are further extended by Keggin anions into a 2D (4, 8)‐connected supramolecular network by hydrogen bonding interactions. In compound 2 , four types of [CuI(biz)2]+ subunits link the [SiW12O40]4– anions to form a 3D (2, 6)‐connected supramolecular structure. Compound 3 shows a 3D supramolecular network with a NaCl‐type topology constructed by [CuI(dmbiz)2]+ subunits, anions, and discrete [Hdmbiz]+ cations. Moreover, the electrochemical and photocatalytic properties of compounds 1 and 2 were investigated. 相似文献
3.
Quan‐Guo Zhai Shu‐Ni Li Yu‐Cheng Jiang Man‐Cheng Hu 《Acta Crystallographica. Section C, Structural Chemistry》2010,66(9):m249-m252
In the tetranuclear copper complex tetrakis[μ‐3,5‐bis(2‐pyridyl)‐1,2,4‐triazolido]bis[3,5‐bis(2‐pyridyl)‐1,2,4‐triazolido]dicopper(I)dicopper(II) dihydrate, [CuI2CuII2(C12H8N5)6]·2H2O, the asymmetric unit is composed of one CuI center, one CuII center, three anionic 3,5‐bis(2‐pyridyl)‐1,2,4‐triazole (2‐BPT) ligands and one solvent water molecule. The CuI and CuII centers exhibit [CuIN4] tetrahedral and [CuIIN6] octahedral coordination environments, respectively. The three independent 2‐BPT ligands adopt different chelating modes, which link the copper centers to generate a chair‐like tetranuclear metallomacrocycle with metal–metal distances of about 4.4 × 6.2 Å disposed about a crystallographic inversion center. Furthermore, strong π–π stacking interactions and O—H...N hydrogen‐bonding systems link the tetracopper clusters into a two‐dimensional supramolecular network. 相似文献
4.
A Ruthenium(II)–Copper(II) Dyad for the Photocatalytic Oxygenation of Organic Substrates Mediated by Dioxygen Activation
下载免费PDF全文
![点击此处可从《Angewandte Chemie (International ed. in English)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Dr. Wissam Iali Dr. Pierre‐Henri Lanoe Dr. Stéphane Torelli Dr. Damien Jouvenot Prof. Frédérique Loiseau Colette Lebrun Dr. Olivier Hamelin Dr. Stéphane Ménage 《Angewandte Chemie (International ed. in English)》2015,54(29):8415-8419
Dioxygen activation by copper complexes is a valuable method to achieve oxidation reactions for sustainable chemistry. The development of a catalytic system requires regeneration of the CuI active redox state from CuII. This is usually achieved using extra reducers that can compete with the CuII(O2) oxidizing species, causing a loss of efficiency. An alternative would consist of using a photosensitizer to control the reduction process. Association of a RuII photosensitizing subunit with a CuII pre‐catalytic moiety assembled within a unique entity is shown to fulfill these requirements. In presence of a sacrificial electron donor and light, electron transfer occurs from the RuII center to CuII. In presence of dioxygen, this dyad proved to be efficient for sulfide, phosphine, and alkene catalytic oxygenation. Mechanistic investigations gave evidence about a predominant 3O2 activation pathway by the CuI moiety. 相似文献
5.
Christopher Paolucci Anuj A. Verma Shane A. Bates Vincent F. Kispersky Jeffrey T. Miller Rajamani Gounder W. Nicholas Delgass Fabio H. Ribeiro William F. Schneider 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2014,126(44):12022-12027
Operando X‐ray absorption experiments and density functional theory (DFT) calculations are reported that elucidate the role of copper redox chemistry in the selective catalytic reduction (SCR) of NO over Cu‐exchanged SSZ‐13. Catalysts prepared to contain only isolated, exchanged CuII ions evidence both CuII and CuI ions under standard SCR conditions at 473 K. Reactant cutoff experiments show that NO and NH3 together are necessary for CuII reduction to CuI. DFT calculations show that NO‐assisted NH3 dissociation is both energetically favorable and accounts for the observed CuII reduction. The calculations predict in situ generation of Brønsted sites proximal to CuI upon reduction, which we quantify in separate titration experiments. Both NO and O2 are necessary for oxidation of CuI to CuII, which DFT suggests to occur by a NO2 intermediate. Reaction of Cu‐bound NO2 with proximal NH4+ completes the catalytic cycle. N2 is produced in both reduction and oxidation half‐cycles. 相似文献
6.
Jiang‐Hong Fu Yu‐Ling Wang Ying Chen Chang‐Hui Hu Li Tang 《Acta Crystallographica. Section C, Structural Chemistry》2012,68(8):m209-m212
The title compound, [CuNa(C4H3O7S)(C10H8N2)(H2O)3]n, consists of one CuII cation, one NaI cation, one 2‐sulfonatobutanedioate trianion (SSC3−), one 2,2′‐bipyridyl (bpy) ligand and three coordinated water molecules as the building unit. The coordination of the CuII cation is composed of two pyridyl N atoms, one water O atom and two carboxylate O atoms in a distorted square‐pyramidal coordination geometry with an axial elongation. The NaI cation is six‐coordinated by three water molecules and three carboxylate O atoms from three SSC3− ligands in a distorted octahedral geometry. Two SSC3− ligands link two CuII cations to form a Cu2(SSC)2(bpy)2 macrocyclic unit lying across an inversion centre, which is further linked by NaI cations via Na—O bonds to give a one‐dimensional chain. Interchain hydrogen bonds link these chains to form a two‐dimensional layer, which is further extended into a three‐dimensional supramolecular framework through π–π stacking interactions. The thermal stability of the title compound has also been investigated. 相似文献
7.
Amy KaufmanKatz Liat Shimoni‐Livny Oshrit Navon Nadav Navon CharlesW. Bock JennyP. Glusker 《Helvetica chimica acta》2003,86(5):1320-1338
In this paper, we report the results of a study involving the coordination geometries of CuI, CuII, and CuIII crystal structures in the Cambridge Structural Database, and on Cu binding sites in proteins taken from the Protein Data Bank. The motifs used to bind two bridged Cu ions are also described. In addition, we report the results of ab initio molecular‐orbital calculations performed on a variety of model CuI/CuII complexes (CuI/CuII?XnYm (X, Y=NH3, SH2); n+m=4; n=0–4) to provide data on the structural and energetic changes that occur in isolated complexes when the oxidation state of the Cu ion is changed from II to I while the coordination number is conserved. The use of such simple ligands in these calculations eliminates constraints on the geometric changes that may be imposed by more‐complicated ligands. 相似文献
8.
Visible‐Light‐Accelerated Copper(II)‐Catalyzed Regio‐ and Chemoselective Oxo‐Azidation of Vinyl Arenes
下载免费PDF全文
![点击此处可从《Angewandte Chemie (International ed. in English)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
M. Sc. Asik Hossain Dr. Adiyala Vidyasagar M. Sc. Christian Eichinger Dr. Christian Lankes M. Sc. Jenny Phan Prof. Dr. Julia Rehbein Prof. Dr. Oliver Reiser 《Angewandte Chemie (International ed. in English)》2018,57(27):8288-8292
The visible‐light‐accelerated oxo‐azidation of vinyl arenes with trimethylsilylazide and molecular oxygen as stoichiometric oxidant was achieved. In contrast to photocatalysts based on iridium, ruthenium, or organic dyes, [Cu(dap)2]Cl or [Cu(dap)Cl2] were found to be unique for this transformation, which is attributed to their ability to interact with the substrates through ligand exchange and rebound mechanisms. CuII is proposed as the catalytically active species, which upon coordinating azide will undergo light‐accelerated homolysis to form CuI and azide radicals. This activation principle (CuII‐X→CuI+X.) opens up new avenues for copper‐based photocatalysis. 相似文献
9.
Sai‐Rong Fan Guo‐Qiang Cai Long‐Guan Zhu Hong‐Ping Xiao 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(4):m177-m179
The title compound, [Cu(C7H3O6S)2(C10H9N3)2][CuI(C10H9N3)2]2·2H2O, consists of anionic CuII moieties, cationic CuI species and uncoordinated water molecules. The anionic dimeric unit consists of one crystallographically independent fully deprotonated 5‐sulfosalicylate (2‐oxido‐5‐sulfonatobenzoate) anion, a di‐2‐pyridylamine group and a CuII atom. Each CuII atom is five‐coordinate within a square‐pyramidal geometry. The anion lies on a special position of site symmetry. In the cationic monomer, the CuI atom adopts tetrahedral geometry. The cations and anions are connected by O—H·O and N—H·O hydrogen bonds. 相似文献
10.
Nikos G. Tsierkezos Michal Buchta Petr Holý Detlef Schröder 《Rapid communications in mass spectrometry : RCM》2009,23(11):1550-1556
Electrospray ionization mass spectrometry (ESI‐MS) is used to probe the metal‐binding selectivity of a macrocyclic thiacrown ether (C44H32S20) towards CoII, NiII, CuII, and ZnII. In homogeneous 1:1 v/v methanol/dichloromethane solutions, it is found that the thia ligand very selectively binds traces of copper even in the presence of an excess of the other metal ions. The large selectivity is ascribed to the redox‐active nature of copper which enables a reduction from CuII to CuI, occurring upon ESI‐MS, whereas CoII, NiII and ZnII cannot undergo similar redox reactions. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
11.
《Acta Crystallographica. Section C, Structural Chemistry》2017,73(12):1098-1103
Mixed‐valence copper(I/II) atoms have been introduced successfully into a Pb/I skeleton to obtain two heterometallic iodoplumbates, namely poly[bis(tetra‐n‐butylammonium) [bis(μ3‐dimethyldithiocarbamato)dodeca‐μ3‐iodido‐hexa‐μ2‐iodido‐tetracopper(I)copper(II)hexalead(II)]], {(C16H36N)2[Cu4ICuIIPb6(C3H6NS2)2I18]}n , (I), and poly[[μ3‐iodido‐tri‐μ2‐iodido‐iodido[bis(1,10‐phenanthroline)copper(I)]copper(I)copper(II)lead(II)] hemiiodine], {[CuICuIIPbI5(C12H8N2)2]·0.5I2}n , (II), under solution and solvothermal conditions, respectively. Compound (I) contains two‐dimensional anionic layers, which are built upon the linkages of CuII(S2CNMe2)2 units and one‐dimensional anionic Pb/I/CuI chains. Tetra‐n‐butylammonium cations are located between the anionic layers and connected to them via C—H…I hydrogen‐bonding interactions. Compound (II) exhibits a one‐dimensional neutral structure, which is composed of [PbI5] square pyramids, [CuII4] tetrahedra and [CuIIN4I] trigonal bipyramids. Face‐to‐face aromatic π–π stacking interactions between adjacent 1,10‐phenanthroline ligands stabilize the structure and assemble compound (II) into a three‐dimensional supramolecular structure. I2 molecules lie in the voids of the structure. 相似文献
12.
Jiawei Li Jianhua Liao Yanwei Ren Chi Liu Chenglong Yue Jiaming Lu Huanfeng Jiang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(48):17308-17312
Described here is a new and viable approach to achieve Pd catalysis for aerobic oxidation systems (AOSs) by circumventing problems associated with both the oxidation and the catalysis through an all‐in‐one strategy, employing a robust metal–organic framework (MOF). The rational assembly of a PdII catalyst, phenanthroline ligand, and CuII species (electron‐transfer mediator) into a MOF facilitates the fast regeneration of the PdII active species, through an enhanced electron transfer from in situ generated Pd0 to CuII, and then CuI to O2, trapped in the framework, thus leading to a 10 times higher turnover number than that of the homogeneous counterpart for Pd‐catalyzed desulfitative oxidative coupling reactions. Moreover, the MOF catalyst can be reused five times without losing activity. This work provides the first exploration of using a MOF as a promising platform for the development of Pd catalysis for AOSs with high efficiency, low catalyst loading, and reusability. 相似文献
13.
Dr. Frédéric Niess Dr. Vincent Duplan Christian S. Diercks Prof. Jean‐Pierre Sauvage 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(41):14393-14400
Two large rings, 66‐ (m‐66 ) and 78‐membered ( m‐78 ) rings, each one incorporating two pairs of transition‐metal‐complexing units, have been prepared. The coordinating fragments are alternating bi‐ and tridentate chelating groups, namely, 2,9‐diphenyl‐1,10‐phenanthroline (dpp) and 2,2′,2′,6′′‐terpyridine (terpy) respectively. Both macrocycles form molecular figures‐of‐eight in the presence of FeII, affording a classical bis‐terpy complex as the central core. The larger m‐78 ring can accommodate a four‐coordinate CuI center with the formation of a {Cu(dpp)2}+ central complex and a highly twisted figure‐of‐eight backbone, whereas m‐66 is too small to coordinate CuI. Macrocycle m‐78 thus affords stable complexes with both FeII and CuI; the ligand around the metal changes from (terpy)2 to (dpp)2. This bimodal coordination situation allows for a large amplitude rearrangement of the organic backbone. When coordinated to preferentially octahedrally coordinated FeII or CuII, the height of the molecule along the coordinating axis of the tridentate terpy ligands is only about 11 Å, whereas the height of the molecule along the same vertical axis is several times as large for the tetrahedral CuI complex. Chemically or electrochemically driven contraction and extension motions along a defined axis make this figure‐of‐eight particularly promising as a new class of molecular machine prototype for use as a constitutive element in muscle‐like dynamic systems. 相似文献
14.
Electrochemiluminescence of Supramolecular Nanorods and Their Application in the “On–Off–On” Detection of Copper Ions
下载免费PDF全文
![点击此处可从《Chemistry (Weinheim an der Bergstrasse, Germany)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Yan‐Mei Lei Dr. Min Zhao Ai Wang Yan‐Qing Yu Prof. Ya‐Qin Chai Prof. Ruo Yuan Prof. Ying Zhuo 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(24):8207-8214
In this work, an “on–off–on” switch system has been successfully applied through the construction of an electrochemiluminscent biosensor for copper ion (Cu2+) detection based on a new electrochemiluminescence (ECL) emitter of supramolecular nanorods, which was achieved through supramolecular interactions between 3,4,9,10‐perylenetetracarboxylic acid (PTCA) and aniline. The initial “signal‐on” state with strong and stable ECL emission was obtained by use of the supramolecular nanorods with a new signal amplification strategy involving a co‐reaction accelerator. In addition, ECL quencher probes (Fc‐NH2/Cu‐Sub/nano‐Au) were fabricated by immobilizing aminoferrocene (Fc‐NH2) on Cu‐substrate strand modified Au nanoparticles. The quencher probes were hybridized with the immobilized Cu‐enzyme strand to form Cu2+‐specific DNAzyme. Similarly, the “signal‐off” state was obtained by the high quenching effect of Fc‐NH2 on the ECL of the excited‐state PTCA (1PTCA*). As expected, the second “switch‐on” state could achieved by incubating with the target Cu2+, owing to the Cu2+‐specific DNAzyme, which was irreversibly cleaved, resulting in the release of the quencher probes from the sensor interface. Herein, on the basis of the ECL intensity changes (ΔIECL) before and after incubating with the target Cu2+, the prepared Cu2+‐specific DNAzyme‐based biosensor was used for the determination of Cu2+ concentrations with high sensitivity, excellent selectivity, and good regeneration. 相似文献
15.
Combined EXAFS and DFT Structure Calculations Provide Structural Insights into the 1:1 Multi‐Histidine Complexes of CuII,CuI, and ZnII with the Tandem Octarepeats of the Mammalian Prion Protein
下载免费PDF全文
![点击此处可从《Chemistry (Weinheim an der Bergstrasse, Germany)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Dr. M. Jake Pushie Kurt H. Nienaber Dr. Alex McDonald Prof. Dr. Glenn L. Millhauser Prof. Dr. Graham N. George 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(31):9770-9783
The metal‐coordinating properties of the prion protein (PrP) have been the subject of intense focus and debate since the first reports of its interaction with copper just before the turn of the century. The picture of metal coordination to PrP has been improved and refined over the past decade, but structural details of the various metal coordination modes have not been fully elucidated in some cases. In the present study, we have employed X‐ray absorption near‐edge spectroscopy as well as extended X‐ray absorption fine structure (EXAFS) spectroscopy to structurally characterize the dominant 1:1 coordination modes for CuII, CuI, and ZnII with an N‐terminal fragment of PrP. The PrP fragment corresponds to four tandem repeats representative of the mammalian octarepeat domain, designated as OR4, which is also the most studied PrP fragment for metal interactions, making our findings applicable to a large body of previous work. Density functional theory (DFT) calculations have provided additional structural and thermodynamic data, and candidate structures have been used to inform EXAFS data analysis. The optimized geometries from DFT calculations have been used to identify potential coordination complexes for multi‐histidine coordination of CuII, CuI, and ZnII in an aqueous medium, modelled using 4‐methylimidazole to represent the histidine side chain. Through a combination of in silico coordination chemistry as well as rigorous EXAFS curve‐fitting, using full multiple scattering on candidate structures derived from DFT calculations, we have characterized the predominant coordination modes for the 1:1 complexes of CuII, CuI, and ZnII with the OR4 peptide at pH 7.4 at atomic resolution, which are best represented as square‐planar [CuII(His)4]2+, digonal [CuI(His)2]+, and tetrahedral [ZnII(His)3(OH2)]2+, respectively. 相似文献
16.
Dr. Suman Maji Dr. Jason C.‐M. Lee Yu‐Jhang Lu Dr. Chang‐Li Chen Mu‐Cheng Hung Dr. Peter P.‐Y. Chen Prof. Steve S.‐F. Yu Prof. Sunney I. Chan 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(13):3955-3968
The dioxygen activation of a series of CuICuICuI complexes based on the ligands ( L ) 3,3′‐(1,4‐diazepane‐ 1,4‐diyl)bis(1‐{[2‐(dimethylamino)ethyl](methyl)amino}propan‐2‐ol) ( 7‐Me ) or 3,3′‐(1,4‐diazepane‐1,4‐diyl)bis(1‐{[2‐(diethylamino)ethyl](ethyl)amino}propan‐2‐ol) ( 7‐Et ) forms an intermediate capable of mediating facile O‐atom transfer to simple organic substrates at room temperature. To elucidate the dioxygen chemistry, we have examined the reactions of 7‐Me , 7‐Et , and 3,3′‐(1,4‐diazepane‐1,4‐diyl)bis[1‐(4‐methylpiperazin‐1‐yl)propan‐2‐ol] ( 7‐N‐Meppz ) with dioxygen at ?80, ?55, and ?35 °C in propionitrile (EtCN) by UV‐visible, 77 K EPR, and X‐ray absorption spectroscopy, and 7‐N‐Meppz and 7‐Me with dioxygen at room temperature in acetonitrile (MeCN) by diode array spectrophotometry. At both ?80 and ?55 °C, the mixing of the starting [CuICuICuI( L )]1+ complex ( 1 ) with O2‐saturated propionitrile (EtCN) led to a bright green solution consisting of two paramagnetic species: the green dioxygen adduct [CuIICuII(μ‐η2:η2‐peroxo)CuII( L )]2+ ( 2 ) and the blue [CuIICuII(μ‐O)CuII( L )]2+ species ( 3 ). These observations are consistent with the initial formation of [CuIICuII(μ‐O)2CuIII( L )]1+ ( 4 ), followed by rapid abortion of this highly reactive species by intercluster electron transfer from a second molecule of complex 1 to give the blue species 3 and subsequent oxygenation of the partially oxidized [CuIICuICuI( L )]2+ ( 5 ) to form the green dioxygen adduct 2 . Assignment of 2 to [CuIICuII(μ‐η2:η2‐peroxo)CuII( L )]2+ is consistent with its reactivity with water to give H2O2 and the blue species 3 , as well as its propensity to be photoreduced in the X‐ray beam during X‐ray absorption experiments at room temperature. In light of these observations, the development of an oxidation catalyst based on the tricopper system requires consideration of the following design criteria: 1) rapid dioxygen chemistry; 2) facile O‐atom transfer from the activated cluster to substrate; and 3) a suitable reductant to rapidly regenerate complex 1 to accomplish efficient catalytic turnover. 相似文献
17.
Almudena Amoedo‐Portela Rosa Carballo Jos S. Casas Emilia García‐Martínez Concepcin Gmez‐Alonso Angeles Snchez‐Gonzlez Jos Sordo Ezequiel M. Vzquez‐Lpez 《无机化学与普通化学杂志》2002,628(5):939-950
Bis(2‐pyridylthio)methane [bpytm, (pyS)2CH2] and complexes of this ligand with ZnII, HgII, CuI, and AgI have been prepared and characterised by elemental analysis, by IR, Raman and 1H and 13C NMR spectroscopy, and by X‐ray diffractometry. The ligand is N, N′‐didentate in the ZnII complexes; N‐monodentate in one HgII complex and N, N′‐bis(monodentate) in the other; N‐mono‐N′, S‐didentate in the CuI complex; and N, S′‐bis(mono)‐N′, S‐didentate in the AgI complex. The structural parameters of the ligand in each coordination mode are compared with those of the free ligand and those of the triiodide salt of the protonated ligand. 相似文献
18.
Postsynthetic Metal and Ligand Exchange in MFU‐4l: A Screening Approach toward Functional Metal–Organic Frameworks Comprising Single‐Site Active Centers
下载免费PDF全文
![点击此处可从《Chemistry (Weinheim an der Bergstrasse, Germany)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Dmytro Denysenko Dr. Jelena Jelic Prof. Dr. Karsten Reuter Prof. Dr. Dirk Volkmer 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(22):8188-8199
The isomorphous partial substitution of Zn2+ ions in the secondary building unit (SBU) of MFU‐4l leads to frameworks with the general formula [MxZn(5–x)Cl4(BTDD)3], in which x≈2, M=MnII, FeII, CoII, NiII, or CuII, and BTDD=bis(1,2,3‐triazolato‐[4,5‐b],[4′,5′‐i])dibenzo‐[1,4]‐dioxin. Subsequent exchange of chloride ligands by nitrite, nitrate, triflate, azide, isocyanate, formate, acetate, or fluoride leads to a variety of MFU‐4l derivatives, which have been characterized by using XRPD, EDX, IR, UV/Vis‐NIR, TGA, and gas sorption measurements. Several MFU‐4l derivatives show high catalytic activity in a liquid‐phase oxidation of ethylbenzene to acetophenone with air under mild conditions, among which Co‐ and Cu derivatives with chloride side‐ligands are the most active catalysts. Upon thermal treatment, several side‐ligands can be transformed selectively into reactive intermediates without destroying the framework. Thus, at 300 °C, CoII‐azide units in the SBU of Co‐MFU‐4l are converted into CoII‐isocyanate under continuous CO gas flow, involving the formation of a nitrene intermediate. The reaction of CuII‐fluoride units with H2 at 240 °C leads to CuI and proceeds through the heterolytic cleavage of the H2 molecule. 相似文献
19.
Kai‐Long Zhong Li Chen Lin Chen 《Acta Crystallographica. Section C, Structural Chemistry》2011,67(2):m62-m64
The title compound, [Cu2(SO4)2(C10H8N2)2(C2H6O2)2(H2O)2]n, contains two crystallographically unique CuII centres, each lying on a twofold axis and having a slightly distorted octahedral environment. One CuII centre is coordinated by two bridging 4,4′‐bipyridine (4,4′‐bipy) ligands, two sulfate anions and two aqua ligands. The second is surrounded by two 4,4′‐bipy N atoms and four O atoms, two from bridging sulfate anions and two from ethane‐1,2‐diol ligands. The sulfate anion bridges adjacent CuII centres, leading to the formation of linear ...Cu1–Cu2–Cu1–Cu2... chains. Adjacent chains are further bridged by 4,4′‐bipy ligands, which are also located on the twofold axis, resulting in a two‐dimensional layered polymer. In the crystal structure, extensive O—H...O hydrogen‐bonding interactions between water molecules, ethane‐1,2‐diol molecules and sulfate anions lead to the formation of a three‐dimensional supramolecular network structure. 相似文献
20.
Dr. Shun‐Ze Zhan Mian Li Prof. Dr. Seik Weng Ng Prof. Dr. Dan Li 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(31):10217-10225
Two classical copper(I)‐cluster‐based luminophores, namely, Cu4I4 and [Cu3Pz3]2 (Pz=pyrazolate), are immobilized in a supramolecular system through the formation of metal–organic framework (MOF) materials. This series of luminescent MOF materials, namely, [Cu4I4(NH3)Cu3( L1 )3]n, [Cu4I4(NH2CH3)Cu3( L1 )3]n, and [Cu4I4Cu3( L2 )3]n ( L1 =3‐(4‐pyridyl)‐5‐(p‐tolyl)pyrazolate; L2 =3‐(4‐pyridyl)‐5‐(2,4‐dimethylphenyl)pyrazolate), exhibit diverse thermochromism attributed to the relative functioning efficacy of the two coordination luminophores. Such an intriguing chemopalette effect is regulated by the different supramolecular microenvironments between the two‐dimensional layers of these MOFs, and in particular, by the fine‐tuned Cu–Cu distances in the excimeric [Cu3Pz3]2 luminophore. The structure–property elucidation of the thermochromic behavior allows one to understand these optical materials with unusual dual‐emissive properties. 相似文献