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1.
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
2.
3.
Isaac Garcia‐Bosch Dr. Xavi Ribas Dr. Miquel Costas 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(7):2113-2122
Reactions of the unsymmetric dicopper(II) peroxide complex [CuII2(μ‐η1:η1‐O2)(m‐XYLN3N4)]2+ ( 1 O2 , where m‐XYL is a heptadentate N‐based ligand), with phenolates and phenols are described. Complex 1 O2 reacts with p‐X‐PhONa (X=MeO, Cl, H, or Me) at ?90 °C performing tyrosinase‐like ortho‐hydroxylation of the aromatic ring to afford the corresponding catechol products. Mechanistic studies demonstrate that reactions occur through initial reversible formation of metastable association complexes [CuII2(μ‐η1:η1‐O2)(p‐X‐PhO)(m‐XYLN3N4)]+ ( 1 O2 ?X‐PhO) that then undergo ortho‐hydroxylation of the aromatic ring by the peroxide moiety. Complex 1 O2 also reacts with 4‐X‐substituted phenols p‐X‐PhOH (X=MeO, Me, F, H, or Cl) and with 2,4‐di‐tert‐butylphenol at ?90 °C causing rapid decay of 1 O2 and affording biphenol coupling products, which is indicative that reactions occur through formation of phenoxyl radicals that then undergo radical C? C coupling. Spectroscopic UV/Vis monitoring and kinetic analysis show that reactions take place through reversible formation of ground‐state association complexes [CuII2(μ‐η1:η1‐O2)(X‐PhOH)(m‐XYLN3N4)]2+ ( 1 O2 ?X‐PhOH) that then evolve through an irreversible rate‐determining step. Mechanistic studies indicate that 1 O2 reacts with phenols through initial phenol binding to the Cu2O2 core, followed by a proton‐coupled electron transfer (PCET) at the rate‐determining step. Results disclosed in this work provide experimental evidence that the unsymmetric 1 O2 complex can mediate electrophilic arene hydroxylation and PCET reactions commonly associated with electrophilic Cu2O2 cores, and strongly suggest that the ability to form substrate?Cu2O2 association complexes may provide paths to overcome the inherent reactivity of the O2‐binding mode. This work provides experimental evidence that the presence of a H+ completely determines the fate of the association complex [CuII2(μ‐η1:η1‐O2)(X‐PhO(H))(m‐XYLN3N4)]n+ between a PCET and an arene hydroxylation reaction, and may provide clues to help understand enzymatic reactions at dicopper sites. 相似文献
4.
Two‐Color Valence‐to‐Core X‐ray Emission Spectroscopy Tracks Cofactor Protonation State in a Class I Ribonucleotide Reductase 下载免费PDF全文
Ryan J. Martinie Dr. Elizabeth J. Blaesi Prof. Dr. J. Martin Bollinger Jr. Prof. Dr. Carsten Krebs Dr. Kenneth D. Finkelstein Dr. Christopher J. Pollock 《Angewandte Chemie (International ed. in English)》2018,57(39):12754-12758
Proton transfer reactions are of central importance to a wide variety of biochemical processes, though determining proton location and monitoring proton transfers in biological systems is often extremely challenging. Herein, we use two‐color valence‐to‐core X‐ray emission spectroscopy (VtC XES) to identify protonation events across three oxidation states of the O2‐activating, radical‐initiating manganese–iron heterodinuclear cofactor in a class I‐c ribonucleotide reductase. This is the first application of VtC XES to an enzyme intermediate and the first simultaneous measurement of two‐color VtC spectra. In contrast to more conventional methods of assessing protonation state, VtC XES is a more direct probe applicable to a wide range of metalloenzyme systems. These data, coupled to insight provided by DFT calculations, allow the inorganic cores of the MnIVFeIV and MnIVFeIII states of the enzyme to be assigned as MnIV(μ‐O)2FeIV and MnIV(μ‐O)(μ‐OH)FeIII, respectively. 相似文献
5.
Observation of a CuII2(μ‐1,2‐peroxo)/CuIII2(μ‐oxo)2 Equilibrium and its Implications for Copper–Dioxygen Reactivity 下载免费PDF全文
Dr. Matthew T. Kieber‐Emmons Jake W. Ginsbach Dr. Patrick K. Wick Dr. Heather R. Lucas Dr. Matthew E. Helton Dr. Baldo Lucchese Prof. Masatatsu Suzuki Prof. Andreas D. Zuberbühler Prof. Kenneth D. Karlin Prof. Edward I. Solomon 《Angewandte Chemie (International ed. in English)》2014,53(19):4935-4939
Synthesis of small‐molecule Cu2O2 adducts has provided insight into the related biological systems and their reactivity patterns including the interconversion of the CuII2(μ‐η2:η2‐peroxo) and CuIII2(μ‐oxo)2 isomers. In this study, absorption spectroscopy, kinetics, and resonance Raman data show that the oxygenated product of [(BQPA)CuI]+ initially yields an “end‐on peroxo” species, that subsequently converts to the thermodynamically more stable “bis‐μ‐oxo” isomer (Keq=3.2 at ?90 °C). Calibration of density functional theory calculations to these experimental data suggest that the electrophilic reactivity previously ascribed to end‐on peroxo species is in fact a result of an accessible bis‐μ‐oxo isomer, an electrophilic Cu2O2 isomer in contrast to the nucleophilic reactivity of binuclear CuII end‐on peroxo species. This study is the first report of the interconversion of an end‐on peroxo to bis‐μ‐oxo species in transition metal‐dioxygen chemistry. 相似文献
6.
Jeffrey J. Liu Maxime A. Siegler Kenneth D. Karlin Pierre Moënne‐Loccoz 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(32):11052-11056
We report the formation of a new copper peroxynitrite ( PN ) complex [CuII(TMG3tren)(κ1‐OONO)]+ ( PN1 ) from the reaction of [CuII(TMG3tren)(O2.?)]+ ( 1 ) with NO.(g) at ?125 °C. The first resonance Raman spectroscopic characterization of such a metal‐bound PN moiety supports a cis κ1‐(?OONO) geometry. PN1 transforms thermally into an isomeric form ( PN2 ) with κ2‐O,O′‐(?OONO) coordination, which undergoes O?O bond homolysis to generate a putative cupryl (LCuII?O.) intermediate and NO2.. These transient species do not recombine to give a nitrato (NO3?) product but instead proceed to effect oxidative chemistry and formation of a CuII–nitrito (NO2?) complex ( 2 ). 相似文献
7.
Akhilesh Kumar Gupta Jinkwon Kim 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(7):m262-m264
The title dinuclear CuII complex, [Cu2(C7H8NO2)2(C7H9NO2)2](CH3COO)2, has been synthesized by the reaction of Cu(CH3COO)2·H2O with pdmH2 (pdmH2 is pyridine‐2,6‐diyldimethanol) in the presence of tetrabutylammonium hydroxide. The title complex contains a centrosymmetric Cu2O2 core and each CuII atom has distorted octahedral geometry. Molecular [Cu2(pdmH)2(pdmH2)]2+ cations are connected by hydrogen bonds involving the CH3COO− anions, forming one‐dimensional chains along the a axis. 相似文献
8.
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
9.
Malika Ammam Bineta Keita Louis Nadjo Israel‐Martyr Mbomekalle Michelle D. Ritorto Travis M. Anderson Wade A. Neiwert Craig L. Hill Jan Fransaer 《Electroanalysis》2011,23(6):1427-1434
The electrochemical behavior of two manganese (Mn)‐substituted polyoxoanions, the dissymmetrical Dawson sandwich‐type [MnII4(H2O)2(H4AsW15O56)2]18? and the Keggin sandwich banana‐shaped [((MnIIOH2)MnII2PW9O34)2(PW6O26)]17? is investigated. At pH 5, the oxidation of the MnII‐centers results in one oxidation wave for [MnII4(H2O)2(H4AsW15O56)2]18? and two oxidation waves for [((MnIIOH2)MnII2PW9O34)2(PW6O26)]17?. To the best of our knowledge, presence of the second Mn‐based wave is rarely observed in the electrochemistry of Mn‐containing polyoxometalates. Deposition of Mn‐oxides electrocatalysts for dioxygen reduction is noticed by cyclic voltammetry, which can be distinguished by the significant positive shift in potentials of the dioxygen reduction reaction. 相似文献
10.
Clément Camp Victor Mougel Dr. Jacques Pécaut Prof. Laurent Maron Dr. Marinella Mazzanti 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(51):17528-17540
Two new arene inverted‐sandwich complexes of uranium supported by siloxide ancillary ligands [K{U(OSi(OtBu)3)3}2(μ‐η6:η6‐C7H8)] ( 3 ) and [K2{U(OSi(OtBu)3)3}2(μ‐η6:η6‐C7H8)] ( 4 ) were synthesized by the reduction of the parent arene‐bridged complex [{U(OSi(OtBu)3)3}2(μ‐η6:η6‐C7H8)] ( 2 ) with stoichiometric amounts of KC8 yielding a rare family of inverted‐sandwich complexes in three states of charge. The structural data and computational studies of the electronic structure are in agreement with the presence of high‐valent uranium centers bridged by a reduced tetra‐anionic toluene with the best formulation being UV–(arene4?)–UV, KUIV–(arene4?)–UV, and K2UIV–(arene4?)–UIV for complexes 2 , 3 , and 4 respectively. The potassium cations in complexes 3 and 4 are coordinated to the siloxide ligands both in the solid state and in solution. The addition of KOTf (OTf=triflate) to the neutral compound 2 promotes its disproportionation to yield complexes 3 and 4 (depending on the stoichiometry) and the UIV mononuclear complex [U(OSi(OtBu)3)3(OTf)(thf)2] ( 5 ). This unprecedented reactivity demonstrates the key role of potassium for the stability of these complexes. 相似文献
11.
Direct Evidence for a [4+2] Cycloaddition Mechanism of Alkynes to Tantallacyclopentadiene on Dinuclear Tantalum Complexes as a Model of Alkyne Cyclotrimerization 下载免费PDF全文
Keishi Yamamoto Dr. Hayato Tsurugi Prof. Dr. Kazushi Mashima 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(32):11369-11377
A dinuclear tantalum complex, [Ta2Cl6(μ‐C4Et4)] ( 2 ), bearing a tantallacyclopentadiene moiety, was synthesized by treating [(η2‐EtC?CEt)TaCl3(DME)] ( 1 ) with AlCl3. Complex 2 and its Lewis base adducts, [Ta2Cl6(μ‐C4Et4)L] (L=THF ( 3 a ), pyridine ( 3 b ), THT ( 3 c )), served as more active catalysts for cyclotrimerization of internal alkynes than 1 . During the reaction of 3 a with 3‐hexyne, we isolated [Ta2Cl4(μ‐η4:η4‐C6Et6)(μ‐η2:η2‐EtC?CEt)] ( 4 ), sandwiched by a two‐electron reduced μ‐η4:η4‐hexaethylbenzene and a μ‐η2:η2‐3‐hexyne ligand, as a product of an intermolecular cyclization between the metallacyclopentadiene moiety and 3‐hexyne. The formation of arene complexes [Ta2Cl4(μ‐η4:η4‐C6Et4Me2)(μ‐η2:η2‐Me3SiC?CSiMe3)] ( 7 b ) and [Ta2Cl4(μ‐η4:η4‐C6Et4RH)(μ‐η2:η2‐Me3SiC?CSiMe3)] (R=nBu ( 8 a ), p‐tolyl ( 8 b )) by treating [Ta2Cl4(μ‐C4Et4)(μ‐η2:η2‐Me3SiC?CSiMe3)] ( 6 ) with 2‐butyne, 1‐hexyne, and p‐tolylacetylene without any isomers, at room temperature or low temperature were key for clarifying the [4+2] cycloaddition mechanism because of the restricted rotation behavior of the two‐electron reduced arene ligands without dissociation from the dinuclear tantalum center. 相似文献
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Selective Ortho‐Hydroxylation–Defluorination of 2‐Fluorophenolates with a Bis(μ‐oxo)dicopper(III) Species 下载免费PDF全文
Joan Serrano‐Plana Dr. Isaac Garcia‐Bosch Dr. Ryosuke Miyake Dr. Miquel Costas Dr. Anna Company 《Angewandte Chemie (International ed. in English)》2014,53(36):9608-9612
The bis(μ‐oxo)dicopper(III) species [CuIII2(μ‐O)2(m‐XYLMeAN)]2+ ( 1 ) promotes the electrophilic ortho‐hydroxylation–defluorination of 2‐fluorophenolates to give the corresponding catechols, a reaction that is not accomplishable with a (η2:η2‐O2)dicopper(II) complex. Isotopic labeling studies show that the incoming oxygen atom originates from the bis(μ‐oxo) unit. Ortho‐hydroxylation–defluorination occurs selectively in intramolecular competition with other ortho‐substituents such as chlorine or bromine. 相似文献
13.
Mark Bartholomä Dr. Sergej Gisbrecht Dipl.‐Chem. Stefan Stucky Dr. Christian Neis Dr. Bernd Morgenstern Dr. Kaspar Hegetschweiler Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(11):3326-3340
The hexadentate ligand all‐cis‐N1,N2‐bis(2,4,6‐trihydroxy‐3,5‐diaminocyclohexyl)ethane‐1,2‐diamine (Le) was synthesized in five steps with an overall yield of 39 % by using [Ni(taci)2]SO4?4 H2O as starting material (taci=1,3,5‐triamino‐1,3,5‐trideoxy‐cis‐inositol). Crystal structures of [Na0.5(H6Le)](BiCl6)2Cl0.5?4 H2O ( 1 ), [Ni(Le)]‐ Cl2?5 H2O ( 2 ), [Cu(Le)](ClO4)2?H2O ( 3 ), [Zn(Le)]CO3?7 H2O ( 4 ), [Co(Le)](ClO4)3 ( 5 c ), and [Ga(H?2Le)]‐ NO3?2 H2O ( 6 ) are reported. The Na complex 1 exhibited a chain structure with the Na+ cations bonded to three hydroxy groups of one taci subunit of the fully protonated H6(Le)6+ ligand. In 2 , 3 , 4 , and 5 c , a mononuclear hexaamine coordination was found. In the Ga complex 6 , a mononuclear hexadentate coordination was also observed, but the metal binding occurred through four amino groups and two alkoxo groups of the doubly deprotonated H?2(Le)2?. The steric strain within the molecular framework of various M(Le) isomers was analyzed by means of molecular mechanics calculations. The formation of complexes of Le with MnII, CuII, ZnII, and CdII was investigated in aqueous solution by using potentiometric and spectrophotometric titration experiments. Extended equilibrium systems comprising a large number of species were observed, such as [M(Le)]2+, protonated complexes [MHz(Le)]2+z and oligonuclear aggregates. The pKa values of H6(Le)6+ (25 °C, μ=0.10 m ) were found to be 2.99, 5.63, 6.72, 7.38, 8.37, and 9.07, and the determined formation constants (log β) of [M(Le)]2+ were 6.13(3) (MnII), 20.11(2) (CuII), 13.60(2) (ZnII), and 10.43(2) (CdII). The redox potentials (vs. NHE) of the [M(Le)]3+/2+ couples were elucidated for Co (?0.38 V) and Ni (+0.90 V) by cyclic voltammetry. 相似文献
14.
Karel Mach Jií Kubita Ivana Císaov Petr tpni
ka 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(2):m116-m118
Reacting stoichiometric amounts of 1‐(diphenylphosphino)ferrocenecarboxylic acid and [Ti(η5‐C5HMe4)2(η2‐Me3SiC[triple‐bond]CSiMe3)] produced the title carboxylatotitanocene complex, [{μ‐1κ2O,O′:2(η5)‐C5H4CO2}{2(η5)‐C5H4P(C6H5)2}{1(η5)‐C5H(CH3)4}2FeIITiIII] or [FeTi(C9H13)2(C6H4O2)(C17H14P)]. The angle subtended by the Ti/O/O′ plane, where O and O′ are the donor atoms of the κ2‐carboxylate group, and the plane of the carboxyl‐substituted ferrocene cyclopentadienyl is 24.93 (6)°. 相似文献
15.
Fangfang Jian Ying Wang Lude Lu Xujie Yang Xin Wang Suchada Chantrapromma Hoong‐Kun Fun Ibrahim Abdul Razak 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(6):714-716
The crystal structures of tris(2‐methylquinolin‐8‐olato‐N,O)iron(III), [Fe(C10H8NO)3], (I), and aquabis(2‐methylquinolin‐8‐olato‐N,O)copper(II), [Cu(C10H8NO)2(H2O)], (II), have been determined. Compound (I) has a distorted octahedral configuration, in which the central Fe atom is coordinated by three N atoms and three O atoms from three 2‐methylquinolin‐8‐olate ligands. The three Fe—O bond distances are in the range 1.934 (2)–1.947 (2) Å, while the three Fe—N bond distances range from 2.204 (2) to 2.405 (2) Å. In compound (II), the central CuII atom and H2O group lie on the crystallographic twofold axis and the coordination geometry of the CuII atom is close to trigonal bipyramidal, with the three O atoms in the basal plane and the two N atoms in apical positions. The Cu—N bond length is 2.018 (5) Å. The Cu—O bond length in the basal positions is 1.991 (4) Å, while the Cu—O bond length in the apical position is 2.273 (6) Å. There is an intermolecular OW—H?O hydrogen bond which links the molecules into a linear chain along the b axis. 相似文献
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Zora Popovi Gordana Pavlovi Boris‐Marko Kukovec 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(5):m181-m183
The title compound, [Cu(C9H5N2O3)2(C2H6OS)2], consists of octahedrally coordinated CuII ions, with the 3‐oxo‐3,4‐dihydroquinoxaline‐2‐carboxylate ligands acting in a bidentate manner [Cu—O = 1.9116 (14) Å and Cu—N = 2.1191 (16) Å] and a dimethyl sulfoxide (DMSO) molecule coordinated axially via the O atom [Cu—O = 2.336 (5) and 2.418 (7) Å for the major and minor disorder components, respectively]. The whole DMSO molecule exhibits positional disorder [0.62 (1):0.38 (1)]. The octahedron around the CuII atom, which lies on an inversion centre, is elongated in the axial direction, exhibiting a Jahn–Teller effect. The ligand exhibits tautomerization by H‐atom transfer from the hydroxyl group at position 3 to the N atom at position 4 of the quinoxaline ring of the ligand. The complex molecules are linked through an intermolecular N—H...O hydrogen bond [N...O = 2.838 (2) Å] formed between the quinoxaline NH group and a carboxylate O atom, and by a weak intermolecular C—H...O hydrogen bond [3.392 (11) Å] formed between a carboxylate O atom and a methyl C atom of the DMSO ligand. There is a weak intramolecular C—H...O hydrogen bond [3.065 (3) Å] formed between a benzene CH group and a carboxylate O atom. 相似文献
18.
Xiu‐Li Hao Yuan‐Yuan Ma Dr. Yong‐Hui Wang Long‐Yang Xu Dr. Fu‐Chen Liu Mao‐Mao Zhang Prof. Yang‐Guang Li 《化学:亚洲杂志》2014,9(3):819-829
Investigation into a hydrothermal reaction system with transition‐metal (TM) ions, 1,4‐bis(1,2,4‐triazol‐1‐lmethyl)benzene (BBTZ) and various charge‐tunable Keggin‐type polyoxometalates (POMs) led to the preparation of four new entangled coordination networks, [CoII(HBBTZ)(BBTZ)2.5][PMo12O40] ( 1 ), [CuI(BBTZ)]5[BW12O40] ? H2O ( 2 ), [CuII(BBTZ)]3[AsWV3WVI9O40] ? 10 H2O ( 3 ), and [CuII5(BBTZ)7(H2O)6][P2W22Cu2O77(OH)2] ? 6 H2O ( 4 ). All compounds were characterized by using elemental analysis, IR spectroscopy, thermogravimetric analysis, powder X‐ray diffraction, and single‐crystal X‐ray diffraction. The mixed valence of W centers in compound 3 was further confirmed by using XPS spectroscopy and bond‐valence sum calculations. In the structural analysis, the entangled networks of 1 – 4 demonstrate zipper‐closing packing, 3D polythreading, 3D polycatenation, and 3D self‐penetration, respectively. Moreover, with the enhancement of POM negative charges and the use of different TM types, the number of nodes in the coordination networks of 1 – 4 increased and the basic metal–organic building motifs changed from a 1D zipper‐type chain (in 1 ) to a 2D pseudorotaxane layer (in 2 ) to a 3D diamond‐like framework (in 3 ) and finally to a 3D self‐penetrating framework (in 4 ). The photocatalytic properties of compounds 1 – 4 for the degradation of methylene blue under UV light were also investigated; all compounds showed good catalytic activity and the photocatalytic activity order of Keggin‐type species was initially found to be {XMo12O40}>{XW12O40}>{XW12?nTMnO40}. 相似文献
19.
Polyol Metal Complexes. 491) μ‐Dulcitolato‐O2, 3;4, 5 Complexes with CuII(en) and NiII(tren) Metal Fragments The dinuclear ethylenediamine‐copper(II) complex of the tetra‐anion of the achiral alditol dulcitol (galactitol) is remarkable, since it was the first crystalline carbohydrate—metal complex ever reported (W. Traube, G. Glaubitt, V. Schenck, Ber. Dtsch. Chem. Ges. 1930 , 63, 2083—2093). Although its existence is recognized for many decades, its structure remained unknown due to a kind of crystal packing that promotes twinning. Crystal growth at low temperatures now yielded crystalline specimens of [(en)2Cu2(Dulc2, 3, 4, 5H—4)] · 7 H2O ( 1 ) that have allowed us to unravel both the crystal structure and the twinning law. Closely related molecular structures are adopted by [(tren)2Ni2(Dulc2, 3, 4, 5H—4)] · 20 H2O ( 2 ) and [(Me3tren)2Ni2(Dulc2, 3, 4, 5H—4)] · 16 H2O ( 3 ), the latter showing the shortest hydrogen bond towards a polyolate acceptor ever found (O···O distance: 2.422Å). 相似文献
20.
Ana María García Jorge Manzur Andrs Vega 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(7):m335-m337
The title compund, [Cu2(OH)2(C22H25N3)2](ClO4)2, is a copper(II) dimer, with two [CuL]2+ units [L is bis(6‐methyl‐2‐pyridylmethyl)(2‐phenylethyl)amine] bridged by hydroxide groups to define the {[CuL](μ‐OH)2[CuL]}2+ cation. Charge balance is provided by perchlorate counter‐anions. The cation has a crystallographic inversion centre halfway between the CuII ions, which are separated by 3.0161 (8) Å. The central core of the cation is an almost regular Cu2O2 parallelogram of sides 1.931 (2) and 1.935 (2) Å, with a Cu—O—Cu angle of 102.55 (11)°. The coordination geometry around each CuII centre can be best described as a square‐based pyramid, with three N atoms from L ligands and two hydroxide O atoms completing the coordination environment. Each cationic unit is hydrogen bonded to two perchlorate anions by means of hydroxide–perchlorate O—H...O interactions. 相似文献