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1.
Bun‐Joo Kim Yong‐Min Lee Eun Hee Kim Sung Kwon Kang Sung‐Nak Choi 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(6):m361-m362
In the title complex, [Cu(N3)2(C15H26N2)], the Cu atom is surrounded by the two N atoms of the chelating (?)‐α‐isosparteine ligand and another two N atoms from the two azide anions, forming a distorted CuN4 tetrahedron. The two azide anions are terminally bound to the CuII atom, and the dihedral angle between the Nsparteine—Cu—Nsparteine and Nazide—Cu—Nazide planes is 50.0 (2)°. 相似文献
2.
A. Bagaria S. Ramakumar M. Gupta V. S. Chauhan 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(3):o174-o176
The title compound (systematic name: 3‐benzylidene‐6‐isobutylpiperazine‐2,5‐dione), C15H18N2O2, an α,β‐dehydrophenylalanine containing diketopiperazine, crystallizes in the space group P1 with two molecules in the asymmetric unit arranged antiparallel to one another. The α,β‐dehydrophenylalanine (ΔPhe) residue in this cyclic peptide retains its planarity but deviates from the standard conformations observed in its linear analogues. Each type of molecule forms a linear chain with molecules of the same type via pairwise N—H⋯O hydrogen bonds, while weaker C—H⋯O interactions link the chains together to form a three‐dimensional network. 相似文献
3.
Alexander V. Pestov Eugenia V. Peresypkina Alexander V. Virovets Nina V. Podberezskaya Yury G. Yatluk Yury A. Skorik 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(12):m510-m512
The CuII ion in the title complex, [Cu(C5H10NO3)2] or [Cu(He‐ala)2] [He‐ala = N‐(2‐hydroxyethyl)‐β‐alaninate], resides at the inversion centre of a square bipyramid comprised of two facially arranged tridentate He‐ala ligands. Each He‐ala ligand binds to a CuII ion by forming one six‐membered β‐alaninate chelate ring in a twist conformation and one five‐membered ethanolamine ring in an envelope conformation, with Cu—N = 2.017 (2) Å, Cu—OCOO = 1.968 (1) Å and Cu—OOH = 2.473 (2) Å. The [Cu(He‐ala)2] molecules are involved in a network of O—H⋯O and N—H⋯O hydrogen bonds, forming layers parallel to the (10) plane. The layers are connected into a three‐dimensional structure by van der Waals interactions, so that the molecular centres form pseudo‐face‐centered close packing. 相似文献
4.
D‐glucosamine Schiff base N‐(2‐deoxy‐β‐D‐glucopyranosyl‐2‐salicylaldimino) and its Cu(II) and Zn(II) complexes were synthesized and characterized. The hydrolysis of p‐nitrophenyl picolinate (PNPP) catalyzed by ligand and complexes was investigated kinetically by observing the rates of the release of p‐nitrophenol in the aqueous buffers at 25°C and different pHs. The scheme for reaction acting mode involving a ternary complex composed of ligand, metal ion, and substrate was established and the reaction mechanisms were discussed by metal–hydroxyl and Lewis acid mechanisms. The experimental results indicated that the complexes, especially the Cu(II) complex, efficiently catalyzed the hydrolysis of PNPP. The catalytic reactivity of the Zn(II) complex was much smaller than the Cu(II) complex. The rate constant kN showing the catalytic reactivity of the Cu(II) complex was determined to be 0.299 s?1 (at pH 8.02) in the buffer. The pKa of hydroxyl group of the ternary complex was determined to be 7.86 for the Cu(II) complex. © 2002 Wiley Periodicals, Inc. Int J Chem Kinet 34: 345–350, 2002 相似文献
5.
Lourdes Urpí Katia Jimnez Xavier Solans Alfonso Rodríguez‐Galn Jordi Puiggalí 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(1):o24-o26
The β‐alanine residue of the title compound, C5H8ClNO3, has a ggt folded conformation, which is mainly stabilized through intermolecular N—H⋯O=C (amide–acid) and O—H⋯O=C (acid–amide) hydrogen bonds. In addition, a cis conformation is found for the Cl—CH2—C(=O)—NH torsion angle, which is associated with the presence of an intramolecular hydrogen bond. 相似文献
6.
The preparation of three new N‐Fmoc‐protected (Fmoc=[(9H‐fluoren‐9‐yl)methoxy]carbonyl) β2‐homoamino acids with proteinogenic side chains (from Ile, Tyr, and Met) is described, the key step being a diastereoselective amidomethylation of the corresponding Ti‐enolates of 3‐acyl‐4‐isopropyl‐5,5‐diphenyloxazolidin‐2‐ones with CbzNHCH2OMe/TiCl4 (Cbz=(benzyloxy)carbonyl) in yields of 60–70% and with diastereoselectivities of >90%. Removal of the chiral auxiliary with LiOH or NaOH gives the N‐Cbz‐protected β‐amino acids, which were subjected to an N‐Cbz/N‐Fmoc (Fmoc=[(9H‐fluoren‐9‐yl)methoxy]carbonyl) protective‐group exchange. The method is suitable for large‐scale preparation of Fmoc‐β2hXaa‐OH for solid‐phase syntheses of β‐peptides. The Fmoc‐amino acids and all compounds leading to them have been fully characterized by melting points, optical rotations, IR, 1H‐ and 13C‐NMR, and mass spectra, as well as by elemental analyses. 相似文献
7.
Li‐Fang Jiang 《Acta Crystallographica. Section C, Structural Chemistry》2010,66(12):m375-m378
In the two title copper(II) complexes, [CuL(C5H7O2)]n, (I), and [CuL′(C5H7O2)], (II), respectively, where HL is 4‐hydroxy‐3‐methoxybenzaldehyde picoloylhydrazone, C14H12N3O3, and HL′ is 4‐methoxybenzaldehyde picoloylhydrazone, C14H12N3O2, the CuII ions display a highly Jahn–Teller‐distorted octahedral and a square‐planar coordination geometry, respectively. In complex (I), two neighbouring CuII atoms are bridged by L− and acetylacetonate, alternately, giving rise to a one‐dimensional chain of CuN2O4 octahedra interconnected by these two ligands along the a axis. In addition, the hydroxy H atom of the vanillin group connects to the carboxyl O atom of the adjacent chain via an O—H...O hydrogen bond, giving rise to a three‐dimensional supramolecular assembly. Complex (II) displays a discrete structure. 相似文献
8.
Stability constants of adducts of succinate copper(II) complexes with β‐cyclodextrin determined by capillary electrophoresis 下载免费PDF全文
《Electrophoresis》2018,39(8):1079-1085
Cyclodextrins (CD) form inclusion complexes with different “guests” owing to the fact that the shape of the CD molecule is a truncated cone with a hydrophobic cavity. The adducts of CD with metal complexes remain scantily explored. In this study, the stability constants of the adducts between succinate copper(II) complexes and β‐CD was determined using capillary electrophoresis. The β‐CD concentration in background electrolytes (BGE) was found to influence on the effective electrophoretic mobility of the copper(II) complexes in succinate BGEs. It was shown that succinic acid and its anions and copper(II) ions did not form a significant amount of the inclusion complexes with β‐CD and the mobility change was caused by the adduct formation between succinate copper(II) complexes and β‐CD. The stability constants of these adducts were determined at 25°С and ionic strength of 0.100 M: log β(CuL22−/β‐CD) = 1.76 ± 0.06, log β(CuL0/β‐CD) = 0.98 ± 0.09. The [CuHL]+ and [CuHL2]− species were found to do not form adducts with β‐CD. 相似文献
9.
D. R. Dakternieks I. W. Fraser J. L. Garnett I. K. Gregor 《Journal of mass spectrometry : JMS》1977,12(6):370-374
Electron capture processes in a series of copper (II) β-diketonate complexes of formula Cu[R1COCHCOR2]2 (where R1 is an alkyl, perfluoroalkyl or aryl group and R2 either an alkyl or aryl group) have been examined. Molecular anions, ligand ions and some novel rearrangement ions have been observed with these compounds. Relative intensities of fragment ions were dependent on the substituents R1, R2 as well as the electron energy and compound pressure in the ion source. By operating the mass spectrometer at compound pressures of c. 4×10?6 Torr and higher, reproducible negative ion mass spectra (free from any significant ion-molecule contributions) have been obtained for all compounds of the series. 相似文献
10.
Ming‐Lin Guo Feng‐Qin Wang 《Acta Crystallographica. Section C, Structural Chemistry》2010,66(7):m184-m187
The title complex, [CaCu(C5H6O4)2(H2O)2]n, is the first heterobimetallic complex based on a substituted malonate dianion. The CuII cation and two independent 2,2‐dimethylmalonate (or 2,2‐dimethylpropanedioate) dianions build up a robust dianionic [Cu(C5H6O4)2]2− complex, which acts as a building block to coordinate to four Ca2+ cations. Each CuII centre is in a four‐coordinate square plane of dimethylmalonate O atoms, while each CaII atom is in an eight‐coordinate distorted bicapped trigonal–prismatic environment of six O atoms from four different dimethylmalonate groups and two water molecules. This arrangement creates a two‐dimensional layer connectivity of the structure. The dianionic [Cu(C5H6O4)2]2− units are involved in different intermolecular hydrogen‐bonding interactions with water molecules via the formation of hydrogen‐bonded rings of graph sets R12(8) and R(6) within this layer. The crystal was nonmerohedrally twinned by rotation about [011] with a major twin volume fraction of 0.513 (3). 相似文献
11.
Jaromír Marek Jn Van
o Oga vajlenov 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(12):m509-m511
The title polymeric compound, catena‐poly[dipotassium [bis[μ‐N‐salicylidene‐β‐alaninato(2−)]‐κ4O,N,O′:O′′;κ4O′′:O,N,O′‐dicopper(II)]‐di‐μ‐isothiocyanato‐κ2N:S;κ2S:N], {K[Cu(NCS)(C10H9NO3)]}n, consists of [isothiocyanato(N‐salicylidene‐β‐alaninato)copper(II)]− anions connected through the two three‐atom thiocyanate (μ‐NCS) and the two anti,anti‐μ‐carboxylate bridges into infinite one‐dimensional polymeric anions, with coulombically interacting K+ counter‐ions with coordination number 7 constrained between the chains. The CuII atoms adopt a distorted tetragonal–bipyramidal coordination, with three donor atoms of the tridentate Schiff base and one N atom of the bridging μ‐NCS ligand in the basal plane. The first axial position is occupied by a thiocyanate S atom of a symmetry‐related μ‐NCS ligand at an apical distance of 2.9770 (8) Å, and the second position is occupied by an O atom of a bridging carboxylate group from an adjacent coordination unit at a distance of 2.639 (2) Å. 相似文献
12.
Yue Feng Gang Liu Xiu‐Mei Tian Ji‐De Wang 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(12):m598-m600
In the title compound, [Cu(C9H5N2O2)2(H2O)2], the CuII ion lies on an inversion centre and has an elongated centrosymmetric octahedral environment, equatorially trans‐coordinated by two N,O‐bidentate quinoxaline‐2‐carboxylate ligands and axially coordinated by two water O atoms. Symmetry‐related molecules are linked by strong O—H...O hydrogen bonds, involving the uncoordinated carboxyl O atom of the carboxylate group and the coordinated water molecules, to form a two‐dimensional network. Weak intermolecular C—H...N interactions also stabilize the crystal structure. 相似文献
13.
Alexander J. Blake Vito Lippolis Tiziana Pivetta Gaetano Verani 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(8):m364-m367
In the first title salt, [Cu(C12H8N2)2(C5H10N2Se)](ClO4)2, the CuII centre occupies a distorted trigonal–bipyramidal environment defined by four N donors from two 1,10‐phenanthroline (phen) ligands and by the Se donor of a 1,3‐dimethylimidazolidine‐2‐selone ligand, with the equatorial plane defined by the Se and by two N donors from different phen ligands and the axial sites occupied by the two remaining N donors, one from each phen ligand. The Cu—N distances span the range 1.980 (10)–2.114 (11) Å and the Cu—Se distance is 2.491 (3) Å. Intermolecular π–π contacts between imidazolidine rings and the central rings of phen ligands generate chains of cations. In the second salt, [Cu(C10H8N2)2(C3H6N2S)](ClO4)2, the CuII centre occupies a similar distorted trigonal–bipyramidal environment comprising four N donors from two 2,2′‐bipyridyl (bipy) ligands and an S donor from an imidazolidine‐2‐thione ligand. The equatorial plane is defined by the S donor and two N donors from different bipy ligands. The Cu—N distances span the range 1.984 (6)–2.069 (7) Å and the Cu—S distance is 2.366 (3) Å. Intermolecular π–π contacts between imidazolidine and pyridyl rings form chains of cations. A major difference between the two structures is due to the presence in the second complex of two N—H...O hydrogen bonds linking the imidazolidine N—H hydrogen‐bond donors to perchlorate O‐atom acceptors. 相似文献
14.
Elena Bugella‐Altamirano Josefa María Gonzlez‐Prez Duane Choquesillo‐Lazarte Juan Nicls‐Gutirrez Alfonso Castieiras‐Campos 《无机化学与普通化学杂志》2000,626(4):930-936
The stoichiometric reaction of copper(II) hydroxycarbonate, iminodiacetic acid (H2IDA = HN(CH2CO2H)2) and α‐picolinamide (pya) in water yields crystalline samples of (α‐picolinamide)(iminodiacetato)copper(II) dihydrate, [Cu(IDA)(pya)] · 2 H2O ( 1 ). The compound was characterised by thermal (TG analysis with FT‐IR study of the evolved gasses), spectral (IR, electronic and ESR spectra), magnetic and single crystal X‐ray diffraction methods. It crystallises in the triclinic system, space group P1, a = 8.8737(4), b = 10.23203(5), c = 15.7167(11) Å, α = 77.61(1)°, β = 103.89(1)°, γ = 80.32(1)°, Z = 4, final R1 = 0.056. The asymmetric unit contains two crystallographic independent molecules but chemically very similar ones. The CuII atom exhibits a square base pyramidal coordination (type 4 + 1). pya acts as N,O‐bidentate ligand supplying two among the four closest donor atoms of the metal [averaged bond distances (Å): Cu–N = 1.982(2), Cu–O(amide) = 1.972(2)]. IDA plays a N,O,O′‐terdentate chelating role [averaged bond distances (Å): Cu–N = 2.004(3), Cu–O = 1.941(2) and Cu–O = 2.242(2)]. The coordinating behaviour of pya in 1 is discussed on the basis of its N,O‐bidentate chelating role and the preference of the ‘Cu‐iminodiacetato' moiety [Cu(IDA)] to link the N‐heterocyclic donor of pya in trans versus the Cu–N(IDA) bond. Consistently the ligand pya is able to impose a fac‐chelating configuration to IDA one around the copper(II) as previously has been reported to mixed‐ligand complexes having a 1/1/2 CuII/IDA/N(heterocyclic) donor ratio or a closely related 1/1/1/1 CuII/IDA/N(heterocyclic)/N(aliphatic) one. 相似文献
15.
Paul C. Kline Bruce C. Noll Hongqiu Zhao Anthony S. Serianni 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(2):o137-o140
1‐(β‐d ‐Erythrofuranosyl)cytidine, C8H11N3O4, (I), a derivative of β‐cytidine, (II), lacks an exocyclic hydroxymethyl (–CH2OH) substituent at C4′ and crystallizes in a global conformation different from that observed for (II). In (I), the β‐d ‐erythrofuranosyl ring assumes an E3 conformation (C3′‐exo; S, i.e. south), and the N‐glycoside bond conformation is syn. In contrast, (II) contains a β‐d ‐ribofuranosyl ring in a 3T2 conformation (N, i.e. north) and an anti‐N‐glycoside linkage. These crystallographic properties mimic those found in aqueous solution by NMR with respect to furanose conformation. Removal of the –CH2OH group thus affects the global conformation of the aldofuranosyl ring. These results provide further support for S/syn–anti and N/anti correlations in pyrimidine nucleosides. The crystal structure of (I) was determined at 200 K. 相似文献
16.
Magdalena Maecka Lilianna Chciska 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(4):m115-m117
In the title compound, [CuCl2(C9H8N2)4], there are two independent molecules in the asymmetric unit. The Cu2+ ions lie on inversion centres and are octahedrally coordinated by two Cl atoms and four pyrazole N atoms. All pyrazole N—H groups form intramolecular hydrogen bonds, giving rise to five‐membered hydrogen‐bonded rings incorporating the Cu atoms. 相似文献
17.
Agata Biaoska Zbigniew Ciunik 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(4):o182-o185
Comparison of the structures of strychninium N‐phthaloyl‐β‐alaninate N‐phthaloyl‐β‐alanine, C21H23N2O2+·C11H8NO4−·C11H9NO4, and brucinium N‐phthaloyl‐β‐alaninate 5.67‐hydrate, C23H27N2O4+·C11H8NO4−·5.67H2O, reveals that, unlike strychninium cations, brucinium cations display a tendency to produce stacking interactions with cocrystallizing guests. 相似文献
18.
《Electroanalysis》2004,16(4):268-274
An amperometric method for the determination of the neurotoxic amino acid β‐N‐oxalyl‐L ‐α,β‐diaminopropionic acid (β‐ODAP) using a screen printed carbon electrode (SPCE) is reported. The electrode material was bulk‐modified with manganese dioxide and used as a detector in flow injection analysis (FIA). The enzyme glutamate oxidase (GlOx) was immobilized in a Nafion‐film on the electrode surface. The performance of the biosensor was optimized using glutamate as an analyte. Optimum parameters were found as: operational potential 440 mV (vs. Ag/AgCl), flow rate 0.2 mL min?1, and carrier composition 0.1 mol L?1 phosphate buffer (pH 7.75). The same conditions were used for the determination of β‐ODAP. The signal was linear within the concentration range 53–855 μmol L?1 glutamate and 195–1950 μmol L?1 β‐ODAP. Detection limits (as 3σ value) for both analytes were 9.12 and 111.0 μmol L?1, respectively, with corresponding relative standard deviations of 3.3 and 4.5%. The biosensor retained more than 73% of its activity after 40 days of on‐line use. 相似文献
19.
Yasunori Muranishi Yue Wang Mamiko Odoko Nobuo Okabe 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(6):m307-m310
In the three title complexes, namely (2,2′‐biquinoline‐κ2N,N′)dichloropalladium(II), [PdCl2(C18H12N2)], (I), and the corresponding copper(II), [CuCl2(C18H12N2)], (II), and zinc(II) complexes, [ZnCl2(C18H12N2)], (III), each metal atom is four‐coordinate and bonded by two N atoms of a 2,2′‐biquinoline molecule and two Cl atoms. The PdII atom has a distorted cis‐square‐planar coordination geometry, whereas the CuII and ZnII atoms both have a distorted tetrahedral geometry. The dihedral angles between the N—M—N and Cl—M—Cl planes are 14.53 (13), 65.42 (15) and 85.19 (9)° for (I), (II) and (III), respectively. The structure of (II) has twofold imposed symmetry. 相似文献
20.
Hsiao‐Fen Wang Kuang‐Hway Yih Weng‐Feng Zeng Shou.‐Ling Huang Gene‐Hsiang Lee 《中国化学会会志》2012,59(8):989-994
Reactions of the thiocarbamoyl‐molybdenum complex [Mo(CO)2(η2‐SCNMe2)(PPh3)2Cl] 1 , and ammonium diethyldithiophosphate, NH4S2P(OEt)2, and potassium tris(pyrazoyl‐1‐yl)borate, KTp, in dichloromethane at room temperature yielded the seven coordinated diethyldithiophosphate thiocarbamoyl‐molybdenum complexe [Mo(CO)2{η2‐S2P(OEt)2}(η2‐SCNMe2)(PPh3)] β‐3 , and tris(pyrazoyl‐1‐yl)borate thiocabamoyl‐molybdenum complex [Mo(CO)2(η3‐Tp)(η2‐SCNMe2)(PPh3)] 4 , respectively. The geometry around the metal atom of compounds β‐3 and 4 are capped octahedrons. The α‐ and β‐isomers are defined to the dithio‐ligand and one of the carbonyl ligands in the trans position in former and two carbonyl ligands in the trans position in later. The thiocabamoyl and diethyldithiophosphate or tris(pyrazoyl‐1‐yl)borate ligands coordinate to the molybdenum metal center through the carbon and sulfur and two sulfur atoms, or three nitrogen atoms, respectively. Complexes β‐3 and 4 are characterized by X‐ray diffraction analyses. 相似文献