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1.
Elena Bermejo Alfonso Castieiras Teresa Prez Rosa Carballo Wolfgang Hiller 《无机化学与普通化学杂志》2001,627(10):2377-2385
The reactions of 4N‐ethyl‐2‐[1‐(pyrrol‐2‐yl)methylidene(hydrazine carbothioamide ( 4 EL1 ) and 4N‐ethyl‐2[1‐(pyrrol‐2‐yl)ethylidene(hydrazine carbothioamide ( 4 EL2 ) with Group 12 metal halides afforded complexes of types [M(L)2X2] (M = Zn, Cd; L = 4 EL1, 4 EL2; X = Cl, Br, I; 1 – 6 , 14 – 19 ) and [M(L)X2] (M = Hg; L = 4 EL1, 4 EL2; X = Cl, Br, I; 7 – 9 , 20 – 22 ). In addition, reaction of 4 EL1 with salts of CuII, NiII, PdII and PtII afforded compounds of type [M(4 EL1–H)2] ( 10 – 13 ). The new compounds were characterized by elemental analysis, FAB mass spectrometry, IR and electronic spectroscopy and, for sufficiently soluble compounds, 1H, 13C and, when appropriate, 113Cd or 199Hg NMR spectrometry. The spectral data suggest that in their complexes with Group 12 metal cations, both thiosemicarbazones are neutral and S‐monodentate; and for [Zn(4 EL1)2I2] ( 3 ), [Cd(4 EL1)2Br2] ( 5 ) and [Hg(4 EL1)Cl2]2 ( 7 ) this was confirmed by X‐ray diffractometry. By contrast, in its complexes with CuII and Group 10 metal cations, 4 EL1 is monodeprotonated and S,N‐bidentate, as was confirmed by X‐ray diffractometry for [Ni(4 EL1–H)2] ( 11 ) and [Pd(4 EL1–H)2] ( 12 ). 相似文献
2.
Elena Bermejo Alfonso Castieiras Ricardo Domínguez Rosa Carballo Ccilia Maichle‐Mssmer Joachim Strhle Douglas X. West 《无机化学与普通化学杂志》1999,625(6):961-968
Reaction of group 12 metal dihalides in ethanolic media with 2‐acetylpyridine 4N‐phenylthiosemicarbazone ( H4PL ) and 2‐acetylpyridine‐N‐oxide 4N‐phenylthiosemicarbazone ( H4PLO ) afforded the compounds [M(H4PL)X2] (X = Cl, Br, M = Zn, Cd, Hg; X = I, M = Zn, Cd) ( 1–8 ), [Hg(4PL)I]2 ( 9 ) and [M(H4PLO)X2] (X = Cl, Br, I, M = Zn, Cd, Hg) ( 10–18 ). H4PL , H4PLO and their complexes were characterized by elemental analysis and by IR and 1H and 13C NMR spectroscopy (and the cadmium complexes by 113Cd NMR spectroscopy), and H4PL , H4PLO , ( 5 · DMSO) and ( 9 ) were additionally studied by X‐ray diffraction. H4PL is N,N,S‐tridentate in all its complexes, including 9 , in which it is deprotonated, and H4PLO is in all cases O,N,S‐tridentate. In all the complexes, the metal atoms are pentacoordinate and the coordination polyhedra are redistorted tetragonal pyramids. In assays of antifungal activity against Aspergillus niger and Paecilomyces variotii, the only compound to show any activity was [Hg(H4PLO)I2] ( 18 ). 相似文献
3.
Tarlok S. Lobana Prof. Renu Sharma Rekha Sharma Razia Sultana R. J. Butcher 《无机化学与普通化学杂志》2008,634(4):718-723
Reactions of divalent Zn‐Hg metal ions with 1,3‐imidazolidine‐2‐thione (imdtH2) in 1 : 2 molar ratio have formed monomeric complexes, [Zn(η1‐S‐imdtH2)2(OAc)2] ( 1 ), [Cd((η1‐SimdtH2)2I2] ( 2 ), [Cd(η1‐S‐imdtH2)2Br2] ( 3 ), and [Hg(η1‐S‐imdtH2)2I2] ( 4 ). Complexes 1 – 4 , have been characterized by elemental analysis (C, H, N), spectroscopy (IR, 1H, NMR) and x‐ray crystallography ( 1 ‐ 4 ). Hydrogen bonding between oxygen of acetate and imino hydrogen of ligand, {N(2)–H(2C)···O(2)#} in 1 , ring CH and imino hydrogen, {C(2A)–H(2A)···Br(2)#} in 3 have formed H‐bonded dimers. Similarly, the interactions between molecular units of complexes 2 and 4 have yielded 2D polymers. The polymerization occurs via intermolecular interactions between thione sulfur and imino hydrogen, {N(2)–H(2)···S(1)#}, imino hydrogen and the iodine atom, {NH(1)···I(2)#} in 2 and imino hydrogen – iodine atom {N(2A)–H(2A)···I(2)} and I···I interaction in 4 . Crystal data: [Zn(η1‐S‐imdtH2)2(OAc)2] ( 1 ), C10H18N4O4S2Zn, orthorhombic, Pbcn, a = 9.3854(7) Å, b = 12.4647(10) Å, c = 13.2263(11) Å; V = 1547.3(2) Å3, Z = 4, R = 0.0280 [Cd((η1‐S‐imdtH2)2I2] ( 2 ), C6H12CdI2N4S2, orthorhombic, Pnma, a = 13.8487(10) Å, b = 14.4232(11) Å, c = 7.0659(5) Å; Z = 4, V = 1411.36(18) Å3, R = 0.0186. 相似文献
4.
Voltammetric studies of rabbit liver metallothioneins (MTs, containing both Zn and Cd ions) and Zn7‐MT were carried out at Nafion‐coated mercury film electrodes (NCMFEs). The accumulation of MT molecules into the NCMFEs enhances the voltammetric signals and the electrostatic interaction between the Nafion membrane and MT facilitates facile electron transfer reactions. Two well‐defined redox waves, with reduction potential (Epc) values at ?0.740 and ?1.173 V, respectively, were observed. The peak at Epc =?0.740 V is attributable to the reduction of the Cd‐MT complex, whereas that at Epc=?1.173 V was assigned to the reduction of the Zn‐MT complex. Zn7‐MT exhibits only one redox wave with Epc=?1.198 V. The NCMFE was found to be more advantageous than thin mercury film electrode (MFE), because the pristine metal ions in MTs (e.g., Cd2+ and/or Zn2+) are not significantly replaced by Hg2+. The NCMFE is also complementary to Nafion‐coated bismuth film electrode in that it has a greater hydrogen overpotential, which allows the reduction of the Zn‐MT complex to be clearly observed. Moreover, intermetallic compound formation between Cd and Zn appears to be less serious at NCMFEs. Consequently, the amounts of Cd and Zn deposited into the electrode upon the reduction reactions can be quantified more accurately. 相似文献
5.
Cisplatin is widely used to treat a number of cancers, and its covalent binding to DNA is believed to cause cell death; however, the roles of cisplatin–protein interactions in the mechanisms of action, toxicity, and resistance of the drug largely remain to be elucidated. Here, we investigate the interactions of cisplatin and a native rabbit metallothionein (MT), containing 1.4% zinc and 7.9% cadmium, using nanospray tandem quadrupole time‐of‐flight mass spectrometry (MS) and size‐exclusion high‐performance liquid chromatography with inductively coupled plasma MS. At near‐neutral pH conditions, reactions between cisplatin and MT resulted in the formation of complexes that contained Cd4–Ptn–MT (n = 1–7). While zinc was displaced by cisplatin, both platinum and cadmium were bound to the same MT molecule. This is the first report to provide direct evidence for the co‐binding of cadmium and platinum to MT, which suggests that the mechanism of the binding of cisplatin to the native MT may not be through the displacement of cadmium as previously proposed. A tandem MS investigation into the binding sites of the platinum and cadmium to MT showed platinum‐ and cadmium‐related fragments, such as (PtS2C2H7N)+ and (CdS3C5H17N2)+, demonstrating the platinum–cysteine and cadmium–cysteine binding. In addition, detection of Cd4–Pt7–MT demonstrated more than ten metals bound to a single MT molecule. This finding was extended to the binding of MT with a five‐fold excess of CdCl2. As many as 14 metal atoms (13 cadmium and one zinc) were detected bound to a single MT molecule, the complexes being Cdx–Zn–MT (x = 5–13). The high binding capacity of MT for cadmium and platinum is consistent with the role of MT in reduction of metal toxicity and its involvement in drug resistance. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
6.
Enantiomerization of octahedral tris(α‐diimine)–transition metal complexes was investigated by enantioselective dynamic MEKC. Varying both the transition metal ion (Fe2+, Fe3+, and Ni2+) and the bidentate diimine ligand (1,10‐phenanthroline and 2,2′‐bipyridyl), the enantiomer separations were performed either in a 100 mM sodium tetraborate buffer (pH 9.3) or in a 100 mM sodium tetraborate/sodium dihydrogenphosphate buffer (pH 8.0) both containing sodium cholate as chiral surfactant. The unified equation of dynamic chromatography was employed to determine apparent reaction rate constants from the electropherograms showing distinct plateau formation. Apparent activation parameters ΔH? and ΔS? were calculated from temperature‐dependent measurements between 10.0 and 35.0°C in 2.5 K steps. It was found that the nature of the central metal ion and the ligand strongly influence the enantiomerization barrier. Surprisingly, complexes containing the 2,2′‐bipyridyl ligand show highly negative activation entropies between ?103 and ?116 J (K mol)?1 while the activation entropy of tris(1,10‐phenanthroline) complexes is positive indicating a different mechanism of interconversion. Furthermore, it was found that the Ni2+ complexes are stereostable under the conditions investigated here making them a lucent target as enantioselective catalysts. 相似文献
7.
Roser Pons Cristina Ibez Ana B. Buades Antonio Franconetti Angel Garcia‐Raso Juan J. Fiol Angel Terrn Elies Molins Antonio Frontera 《应用有机金属化学》2019,33(6)
We report the synthesis and X‐ray characterization of the N6‐benzyl‐N6‐methyladenine ligand (L) and three metal complexes, namely [Zn(HL)Cl3]·H2O ( 1 ), [Cd(HL)2Cl4] ( 2 ) and [H2L]2[Cd3(μ‐L)2(μ‐Cl)4Cl6]·3H2O ( 3 ). Complex 1 consists of the 7H‐adenine tautomer protonated at N3 and coordinated to a tetrahedral Zn(II) metal centre through N9. The octahedral Cd(II) in complex 2 is N9‐coordinated to two N6‐benzyl‐N6‐methyladeninium ligands (7H‐tautomer protonated at N3) that occupy apical positions and four chlorido ligands form the basal plane. Compound 3 corresponds to a trinuclear Cd(II) complex, where the central Cd atom is six‐coordinated to two bridging μ‐L and four bridging μ‐Cl ligands. The other two Cd atoms are six‐coordinated to three terminal chlorido ligands, to two bridging μ‐Cl ligands and to the bridging μ‐L through N3. Essentially, the coordination patterns, degree of protonation and tautomeric forms of the nucleobase dominate the solid‐state architectures of 1 – 3 . Additionally, the hydrogen‐bonding interactions produced by the endocyclic N atoms and NH groups stabilize high‐dimensional‐order supramolecular assemblies. Moreover, energetically strong anion–π and lone pair (lp)–π interactions are important in constructing the final solid‐state architectures in 1 – 3 . We have studied the non‐covalent interactions energetically using density functional theory calculations and rationalized the interactions using molecular electrostatic potential surfaces and Bader's theory of atoms in molecules. We have particularly analysed cooperative lp–π and anion–π interactions in 1 and π+–π+ interactions in 3 . 相似文献
8.
The hydrothermal reaction of 2,3‐pyridinedicarboxylic acid (2,3‐H2pda) with a mixture of Cd(NO3)2 and Ni(NO3)2 afforded a coordination polymer, [CdNi(2,3‐pda)2(H2O)3]∞ ( 1 ); in contrast, that with a mixture of Cd(NO3)2 and Zn(NO3)2 surprisingly produced a discrete molecule, trans‐[Cd(3‐pa)2(H2O)4] ( 2 ) (3‐pa? = 3‐pyridinecarboxylate). Since a direct reaction between a single metal salt, Cd(NO3)2 or Zn(NO3)2, and 3‐pyridinecarboxylic acid (3‐Hpa) under similar hydrothermal conditions yielded different coordination polymers containing 3‐pa?, it appears that the apparently thermal decarboxylation from ligated 2,3‐pda2? to 3‐pa? occurs after complexation of both metal cations, Cd(II) and Zn(II). A new coordination mode, formed for 2,3‐pda2? in structure 1 , appears to help formation of microporous channels by piling up the observed 2D hydrogen‐bonded heteropolynuclear layers. Each channel apparently consists of two interpenetrating 63 Cd(II) and Ni(II) nets. 相似文献
9.
Yang Yang Tao Jia Ying‐Zi Han Zi‐Ang Nan Shang‐Fu Yuan Feng‐Lei Yang Di Sun 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(35):12408-12413
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
10.
Eugenijus Norkus Ernestas Gaidamauskas Irena Stalnionien Debbie C. Crans 《Heteroatom Chemistry》2005,16(4):285-291
Interactions between pyridine‐2,5‐dicarboxylic acid and Zn(II), Ni(II), Pb(II), Cd(II), and Cu(II) were characterized in aqueous solutions (20°C; I = 0.4 (KNO3)) by means of d.c.‐polarography, spectrophotometry, and 1H NMR spectroscopy. Polarography was used to determine the concentration of free metal ions in the presence of 10‐fold excess ligand in weakly alkaline solutions, and to determine stability constants for the Zn(II), Cd(II), and Cu(II) complexes with pyridine‐2,5‐dicarboxylic acid. 1H NMR spectroscopy was used to further characterize complex formation. © 2005 Wiley Periodicals, Inc. 16:285–291, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20123 相似文献
11.
Biologically active triazole Schiff bases ( L 1 L 3 ) derived from the reaction of 3‐amino‐1,2,4‐triazole with chloro‐, bromo‐ and nitro‐ substituted salicylaldehydes and their Zn(II) complexes (1–3) have been synthesized and characterized by their physical, spectral and analytical data. Triazole Schiff bases potentially act as tridentate ligands and coordinate with the Zn(II) metal atom through salicylidene‐O, azomethine‐N and triazole‐N. The complexes have the general formula [M(L‐H)2], where M = zinc(II) and L = ( L 1 – L 3 ), and observe an octahedral geometry. The Schiff bases and their Zn(II) complexes have been screened for in‐vitro antibacterial, antifungal and brine shrimp bioassay. The biological activity data show the Zn(II) complexes to be more potent antibacterial and antifungal than the parent simple Schiff bases. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
12.
Fei‐Long Li Pengtang Wang Xiaoqing Huang David James Young Hui‐Fang Wang Pierre Braunstein Jian‐Ping Lang 《Angewandte Chemie (International ed. in English)》2019,58(21):7051-7056
Ultrathin metal–organic framework (MOF) nanosheets (NSs) offer potential for many applications, but the synthetic strategies are largely limited to top‐down, low‐yield exfoliation methods. Herein, Ni–M–MOF (M=Fe, Al, Co, Mn, Zn, and Cd) NSs are reported with a thickness of only several atomic layers, prepared by a large‐scale, bottom‐up solvothermal method. The solvent mixture of N,N‐dimethylacetamide and water plays key role in controlling the formation of these two‐dimensional MOF NSs. The MOF NSs can be directly used as efficient electrocatalysts for the oxygen evolution reaction, in which the Ni–Fe–MOF NSs deliver a current density of 10 mA cm?2 at a low overpotential of 221 mV with a small Tafel slope of 56.0 mV dec?1, and exhibit excellent stability for at least 20 h without obvious activity decay. Density functional theory calculations on the energy barriers for OER occurring at different metal sites confirm that Fe is the active site for OER at Ni–Fe–MOF NSs. 相似文献
13.
Fei‐Long Li Pengtang Wang Xiaoqing Huang David James Young Hui‐Fang Wang Pierre Braunstein Jian‐Ping Lang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(21):7125-7130
Ultrathin metal–organic framework (MOF) nanosheets (NSs) offer potential for many applications, but the synthetic strategies are largely limited to top‐down, low‐yield exfoliation methods. Herein, Ni–M–MOF (M=Fe, Al, Co, Mn, Zn, and Cd) NSs are reported with a thickness of only several atomic layers, prepared by a large‐scale, bottom‐up solvothermal method. The solvent mixture of N,N‐dimethylacetamide and water plays key role in controlling the formation of these two‐dimensional MOF NSs. The MOF NSs can be directly used as efficient electrocatalysts for the oxygen evolution reaction, in which the Ni–Fe–MOF NSs deliver a current density of 10 mA cm?2 at a low overpotential of 221 mV with a small Tafel slope of 56.0 mV dec?1, and exhibit excellent stability for at least 20 h without obvious activity decay. Density functional theory calculations on the energy barriers for OER occurring at different metal sites confirm that Fe is the active site for OER at Ni–Fe–MOF NSs. 相似文献
14.
Larica Pathaw Themmila Khamrang Balasubramaniam Selvakumaran Mariappan Murali Pitchan Arul Prakash Mohamed Sultan Mohamed Jaabir Marappan Velusamy 《应用有机金属化学》2021,35(1)
Copper(I) complexes of the types [Cu(N–N)(PPh3)2]NO3 (LC41–LC44) and [Cu(N–N)(PPh3)(NO3)] (LC45) carrying 3‐substituted 1‐pyridine‐2‐ylimidazo[1,5‐a]pyridine (N–N) derivatives and triphenylphosphine (PPh3) ligands have been prepared. The synthesized copper(I)–phosphine complexes were fully characterized by NMR, IR, ESI‐MS and UV–visible spectroscopy as well as by cyclic voltammetry. Selected structures such as LC42, LC43 and LC45 were additionally analysed by single‐crystal X‐ray method, which show that copper(I) centre adopts a highly distorted tetrahedral geometry. The 1H and 13C NMR spectral data of the complexes throw light on the nature of metal–ligand bonding. They display dπ–π* metal‐to‐ligand charge transfer (MLCT) transition and show quasireversible CuI/CuII metal oxidation. Among the copper(I)–phosphine complexes, LC41–LC44 exhibit moderate cytotoxicity (IC50: 24 h, 67–74 μM; 48 h, 58–70 μM) against human lung epithelial adenocarcinoma A549 cells, whereas LC45 displays the best activity (IC50: 24 h, 42 μM; 48 h, 34 μM) for A549 cancer cell line, which is better than that of the commercial antitumor drug cisplatin. All the complexes also displayed excellent selectivity by being relatively inactive against the human lung epithelial L132 normal cell line with selectivity index (SI) values ranging from 3.4 to 7.4. The complexes block cell cycle progression of A549 cells in G0/G1 phase. FACSVerse analyses are suggestive of reactive oxygen species (ROS) generation and apoptotic cell death induced by the LC41, LC43 and LC45. The induction of apoptosis in A549 cells was shown by Annexin V with propidium iodide (PI) and 4′,6‐diamidino‐2‐phenylindole (DAPI) staining methods and established the ability of LC41, LC43 and LC45 to accumulate in the cell nuclei. 相似文献
15.
Dr. Jun Yoshida Prof. Dr. Shin‐ichi Nishikiori Prof. Dr. Reiko Kuroda Prof. Dr. Hidetaka Yuge 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(10):3451-3457
We previously reported that monomeric and polymeric metal complexes are obtained from solution and mechanochemical reactions of 3‐cyano‐pentane‐2,4‐dione (CNacacH) with 3d metal acetates (M=MnII, FeII, CoII, NiII, CuII, and ZnII). A common feature found in all complexes was that their structural base is trans‐[M(CNacac)2]. Here, we report that the reactions of CNacacH with CdII acetate in the solution and solid states afford different coordination polymers composed of trans‐[Cd(CNacac)2] and cis‐[Cd(CNacac)2] units, respectively. From a methanol solution containing CNacacH (L) and Cd(OAc)2 ? 2 H2O (M), a coordination polymer ( Cd‐1 ) in which trans‐[Cd(CNacac)2] units are three‐dimensionally linked was obtained. In contrast, two different coordination polymers, Cd‐2 and Cd‐3 , were obtained from mechanochemical reactions of CNacacH with Cd(OAc)2 ? 2 H2O at M/L ratios of 1:1 and 1:2, respectively. In Cd‐2 , cis‐[Cd(CNacac)2] units are two‐dimensionally linked, whereas the units are linked three‐dimensionally in Cd‐3 . Furthermore, Cd‐1 and Cd‐2 converted to Cd‐3 by applying an annealing treatment and grinding with a small amount of liquid, respectively, in spite of the polymeric structures. These phenomena, 1) different structures are formed from solution and mechanochemical reactions, 2) two polymorphs are formed depending on the M/L ratio, and 3) structural transformation of resulting polymeric structures, indicate the usability of mechanochemical method in the syntheses of coordination polymers as well as the peculiar structural flexibility of cadmium‐CNacac polymers. 相似文献
16.
Pseudohalide‐directed Assembly of Two Zinc(II) Coordination Polymers with a 3,4‐Bis(3‐pyridyl)‐5‐(4‐pyridyl)‐1,2,4‐triazole Tecton
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The zinc(II) pseudohalide complexes {[Zn(L334)(SCN)2(H2O)](H2O)2}n ( 1 ) and [Zn(L334)(dca)2]n ( 2 ) were synthesized and characterized using the ligand 3,4‐bis(3‐pyridyl)‐5‐(4‐pyridyl)‐1,2,4‐triazole (L334) and ZnCl2 in presence of thiocyanate (SCN–) and dicynamide [dca, N(CN)2–] respectively. Single‐crystal X‐ray structural analysis revealed that the central ZnII atoms in both complexes have similar octahedral arrangement. Compound 1 has a 2D sheet structure bridged by bidentate L334 and double μN,S‐thiocyanate anions, whereas complex 2 , incorporating with two monodentate dicynamide anions, displays a two‐dimensional coordination framework bridged by tetradentate L334 ligand. Structural analysis demonstrated that the influence of pseudohalide anions plays an important role in determining the resultant structure. Both complexes were characterized by IR spectroscopy, microanalysis, and powder X‐ray diffraction techniques. In addition, the solid fluorescence and thermal stability properties of both complexes were investigated. 相似文献
17.
Dr. Jing‐xin Ma Dr. Xiao‐feng Huang Dr. Xue‐qin Song Prof. Dr. Wei‐sheng Liu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(11):3590-3595
Framework‐isomeric three‐dimensional (3D) Cd–Ln heterometallic metal–organic frameworks (HMOFs), {[Ln2(ODA)6Cd3(H2O)6] ? 6 H2O}n (Ln=Gd ( 1 a ) and Tb ( 1 b ), ODA=oxydiacetic acid) and {[Cd(H2O)6] ? [Ln2(ODA)6Cd2] ? H2O}n (Ln=Gd ( 2 a ), Tb ( 2 b )), with neutral and anionic pores, respectively, were designed based on a lanthanide metalloligand strategy and synthesized by using a stepwise assembly and a hydrothermal method. Luminescence studies revealed that 1 b and 2 b can act as luminescent metal–organic frameworks and their light‐emitting properties can be modulated by small guest molecules and the manganese counterion, respectively. 相似文献
18.
An Independent 1D Single‐Walled Metal–Organic Nanotube Transformed from a 2D Layer Exhibits Highly Selective and Reversible Sensing of Nitroaromatic Compounds
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Prof. Dr. Qingfu Zhang Aijing Geng Haina Zhang Falu Hu Prof. Dr. Zhang‐Hui Lu Prof. Dr. Dezhi Sun Prof. Xilian Wei Prof. Dr. Chunlin Ma 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(17):4885-4890
The syntheses and structures of two new ZnII complexes, a 2D graphite‐like layer {[Zn(PIA)H2O] ? H2O}n ( 1 ) and an independent 1D single‐walled metal–organic nanotube (SWMONT) {[Zn2(PIA)2(bpy)2] ? 2.5 H2O ? DMA}n ( 2 ), have been reported based on a “Y”‐shaped 5‐(pyridine‐4‐yl)isophthalic acid ligand (H2PIA). Interestingly, the 2D graphite‐like layer in 1 can transform into the independent 1D SWMONT in 2 with addition of 2,2′‐bipyridine (bpy), which represents the first successfully experimental example of an independent 1D metal–organic nanotube generated from a 2D layer by a “rolling‐up” mechanism. 相似文献
19.
Dr. Jiyoung Jung Junyong Jo Moitree Laskar Prof. Dr. Dongwhan Lee 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(16):5156-5168
A series of C2‐symmetric chiral tetra‐dentate ligands were prepared by using [4,5]‐ or [5,6]‐pinene‐fused 2,2′‐bipyridyl units that are supported across a rigid arylene–ethynylene backbone. These conformationally pre‐organised chelates support stable 1:1 metal complexes, which were fully characterised by UV/Vis, fluorescence, circular dichroism (CD), and 1H NMR spectroscopy. A careful inspection of the exciton‐coupled circular dichroism (ECCD) and 1H NMR spectra of the reaction mixture in solution, however, revealed the evolution and decay of intermediate species en route to the final 1:1 metal–ligand adduct. Consistent with this model, mass spectrometric analysis revealed the presence of multiple metal complexes in solution at high ligand‐to‐metal ratios, which were essentially unobservable by UV/Vis or fluorescence spectroscopic techniques. Comparative studies with a bi‐dentate model system have fully established the functional role of the π‐conjugated ligand skeleton that dramatically enhances the thermodynamic stability of the 1:1 complex. In addition to serving as a useful spectroscopic handle to understand the otherwise “invisible” solution dynamics of this metal–ligand assembly process, temperature‐dependent changes in the proton resonances associated with the chiral ligands allowed us to determine the activation barrier (ΔG≠) for the chirality switching between the thermodynamically stable but kinetically labile (P)‐ and (M)‐stereoisomers. 相似文献
20.
Markus Albrecht Prof. Dr. Marcel Fiege Dr. Paul Kögerler Prof. Dr. Manfred Speldrich Dr. Roland Fröhlich Dr. Marianne Engeser Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(29):8797-8804
Based on chiral, enantiomerically pure 7‐[(S)‐phenylethylurea]‐8‐hydroxyquinoline ( 1 ‐H), trinuclear helicate‐type complexes 2 – 5 are formed with divalent transition‐metal cations. X‐ray structural analyses reveal the connection of two monomeric complex units [M( 1 )3]? (M=Zn, Mn, Co, Ni) by a central metal ion to form a “dimer”. Due to the enantiopurity of the ligand, the complexes are obtained as pure enantiomers, resulting in pronounced circular dichroism (CD) spectra. Single‐ion effects and intra‐ and intermolecular coupling are observed with dominating ferromagnetic coupling in the case of the cobalt(II) and nickel(II) and dominating antiferromagnetic coupling in the case of the manganese(II) complex. 相似文献