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1.
Luciano Antolini Ledi Menabue Monica Saladini Luigi Pietro Battaglia Anna Bonamartini Corradi 《Inorganica chimica acta》1984,90(2):97-103
The compounds of formula [Cu(bipy)(acleuO)2] (1) and [Cu(bipy)(ts-β-alaO)2] (2) (bipy = 2,2′-bipyridil, acleuO = N-acetyl-DL-leucinate anion, ts-β-alaO = N-tosyl-β-alaninate anion) were synthesized and characterized by means of spectroscopic and structural measurements. Complex (1) crystallizes in the monoclinic space group C2/c with cell parameters a = 17.465(4), b = 19.740(5), c = 9.080(2) Å, β = 115.0(1)° with Z = 4; complex (2) crystallizes in the triclinic space group P, with cell parameters a = 14.489(3), b = 14.308(3), c = 8.659(1) Å, α = 75.0(1), β = 74.6(1), γ = 66.6(1)°, Z = 2. Both structures were solved by conventional Patterson and Fourier methods and refined to R factors of 4.10 and 3.8% respectively. In both crystals the Cu atom is four-coordinated by the nitrogen atoms of a bipy molecule and two carboxylate oxygens of two N-protected aminoacid anions acting as unidentate ligands. The only significant difference between the coordination geometry of (1) and (2) is in the tetrahedral distortion of the coordination plane. Complex (2) is strictly planar, while in complex (1) the distortion expressed by the dihedral angle between the (N)(1)CuN(1′) and O(1)CuO(1′) planes is 20.8°. The electronic and EPR results agree with these different coordination geometries. The infra-red data are consistent with a truly monodentate carboxylate group. The spectroscopic results on a series of previously investigated [Cu(bipy)(N-protected aminoacidato)2] complexes of unknown structures are discussed again in the light of the present structural reports. 相似文献
2.
Yuri N. Chirgadze Marina B. Garber Stanislav V. Nikonov 《Journal of molecular biology》1977,113(2):443-447
Crystals of plastocyanins from pea and corn leaves have been obtained. Both are suitable for X-ray structure analysis with a resolution up to 1.8 Å. The crystal form of plastocyanin from pea leaves belongs to the space group P212121 with unit cell dimensions: . The assumed number of protein molecules per asymmetric unit of the unit cell is two. Crystals of the oxidized (Cu2+) and reduced (Cu+) forms are isomorphic. No essential differences in spot intensities for the main zone with a resolution of 3 Å were revealed. The crystal form of plastocyanin from corn leaves belongs to the space group P1 with unit cell parameters: and α = 96° 10′, β = 87°08′, γ = 78°40′. The assumed number of protein molecules per asymmetric unit is two. 相似文献
3.
《Inorganica chimica acta》1986,113(1):81-85
Two compounds of empirical formula MCl3- (THF)3, M = V and Cr, have been characterized by single crystal X-ray studies. The VCl3(THF)3 molecule, which has a mer octahedral stereochemistry, crystallizes in the monoclinic space group P21/c with a= 8.847(2),b= 12.861(5),c= 15.134(3) Å, β = 91.94(2)°, V = 1721(1) Å3 and Z = 4. The V-Ci(1) and V-CI(2) distances have a mean value of 2.330 [3] Å while V-CI(3) = 2.297(2) Å, The VO(1) and VO(2) distances have a mean value of 2.061[8] Å while V-O(3) = 2.102(3) Å cis ClVCl angles average 92.0[5]° and cis OVO angles average 86.2[2]° . The isostmctural complex, CrCl3(THF)3, has a crystal structure made up of discrete octahedral mer-CrCl3(THF)3 molecules with the following unit cell dimensions (space group P21/c): a = 8.715(1), b= 12.786(3), c = 15.122(3) Å, β = 92.15(1)°, V = 1684(1) Å3 and Z = 4. The CrCl(1) and CrCl(2) distances have a mean value of 2.310131 Å while CrCl(3) = 2.283(2) Å. The CrO(1) and CrO(2) distances have a mean value of 2.0101171 Å while CrO(3) = 2.077(4) Å. cis ClCrCl angles average 90.9[4]° and cis OCrO angles average 86.1 [2]°. The structures of these two octahedral complexes and those previously reported for ScCl3(THF)3 and TiCl3(THF)3 are compared and certain general trends are discussed. 相似文献
4.
α-Aqua[N,N′-bis(2′-pyridinecarboxamido)-1,3-propane]copper(II) dihydrate, C15H20N4O5Cu, is monoclinic, space group P21/c, with a = 11.719(2), b = 13.092(2), c = 12.663(2) Å, β = 119.56(1)°, Z = 4. The structure was refined to R = 0.026 for 2398 diffractometer data using full-matrix least-squares methods. The copper atom is five-coordinate with the N4-tetradentate ligand encompassing the base of a distorted square-based pyramid which is appreciably distorted towards a trigonal bipyramid [average Cu-N(amide) 1.950(2), Cu-N(pyridine) 2.043(2) Å, N(amide)-Cu-N(amide) 94.5(1), N(pyridine)-Cu-N(pyridine) 100.2(1)°] and with the copper atom lying 0.27 Å above the N4 plane towards the apical water molecule [Cu-O 2.236(2) Å]. The central six-membered chelate ring adopts a skewed boat conformation and the enforced strain in the molecule results in non-planar distortions in the pyridine rings with only small distortions in the amide groups. The molecules pack in sheets parallel to (10) and the hydrogen-bonding network involves the water molecules and the amide oxygen atoms of the ligand. 相似文献
5.
Galactaric acid, C6H10O8, (CAS Reg. No. 526-99-8), is triclinic, P, with cell dimensions at ?147° [and 20°], a = 4.900(1) [4.918(1)], b = 5.728(1) [5.816(1)], c = 6.784(1) [6.849(1)] Å, α = 92.32(2) [92.31(2)], β = 93.74(2) [94.16(2)], γ = 93.08(2) [93.49(2)]°, V = 189.5 Å3, Z = 1, Dx = 1.831 [1.800], Dm = [1.790] g.cm?3, molecular symmetry . The structure was solved by the direct method, MULTAN, and refined to R = 0.034, Rw = 0.039 for 787 reflections with FObs > 3σ(Fobs). The crystal structure has a system of strong, intermolecular hydrogen-bonds, which accounts for the high crystal density and low solubility in water. 相似文献
6.
《Inorganica chimica acta》1988,142(1):43-50
The crystal and molecular structures of the ligand bpenH2 (N,N′-bis(2′-pyridinecarboxamide)-1,2-ethane) and its deprotonated dimeric cobalt(III) complex fac-[Co2(bpen)3]·12H2O have been determined by single-crystal X-ray diffraction methods. Crystal data: (a) bpenH2, C14H14N4O2, orthorhombic, space group Pccn, a=9.638(1), b= 15.288(1), c = 8.684(1) Å, Z=4; (b) Co2(bpen)3· 12H2O, C42H60N12O18Co2, triclinic, space group P, a = 11.128(3), b = 14.316(5), c = 16.466(4) Å, α= 92.02(2)°, β = 95.21(2)°, γ = 99.30(2)°, Z = 2.The structures were refined to R 0.034 and 0.053 for 1064 and 7748 independent reflexions, respectively. The bpenH2 molecule has a space group imposed centre of symmetry, with the amide group adopting a trans configuration in the closely planar picolinamide moiety. The cobalt complex is dimeric in which three bpen ligands, acting each as a bis(N2-bidentate), bridge the two metal atoms. Each cobalt atom is octahedral with CoNpy 1.944(3) and Co Nam 1.933(3) Å. The Co··Co separation is 5.493(1) Å. The symmetry of the dimeric molecule is D3 which is consistent with that indicated from solution NMR studies. 相似文献
7.
The “goose-type” lysozyme isolated from the egg-white of the black swan Cygnus atratus has been crystallized. The space group is P21 with one molecule of protein in the asymmetric unit. The cell parameters are , β = 110 °. The crystals diffract to a resolution of 2.25 Å and a set of diffraction data for the native protein has been collected photographically. 相似文献
8.
The crystal structure of chloro-(1-methyltyminato- N3)-cis-diammineplatinum(II) monohydrate, cis- (NH3)2Pt(C6H7N2O2)Cl·H2O, is reported. The compound crystallizes in space group P with a = 6.911(2) Å, b = 8.598(3) Å, c = 11.464(4) Å, α = 100.13(3)°, β = 120.03(3)°, γ = 93.16(3)°, Z = 2. The structure was refined to R = 0.048 and Rw = 0.057. The compound contains the deprotonated 1-methylthymine ligand coordinated to Pt through N3 (1.973(10) Å). This distance represents the shortest Pt-N3(pyrimidine-2.4-dione) bond reported so far. The two PtNH3 bond lengths differ significantly: PtNH3 (trans to Cl) is longer (2.052(10) Å) than PtNH3 (trans to N3 of 1-MeT) (2.002(11) Å). The PtCl distance (2.326(3) Å) is normal, as is the large dihedral angle between the Pt coordination plane and the nucleobase (76.5°). 相似文献
9.
In a further examination of the multiply bonded NbS group, the structure of NbS(S2CNEt2)3 has been determined. The compound crystallizes in triclinic space group P with a = 9.870(1), b = 15.743(2), c = 16.804(3) Å, α = 101.69(1)°, β = 93.51(1)°, γ = 91.12(1)°, and Z = 4. With use of 6709 unique data (FO2 > 3σ(FO2)) the structure was refined to R(Rw) = 3.1(3.5%). The crystal contains two inequivalent molecules with distorted pentagonal bipyramidal coordination in which a sulfide atom occupies an axial position. The molecules are differentiated by ethyl group orientations and significantly different NbS bond lengths of 2.122(1) and 2.168(1) Å. Full structural details are reported. The results fall within the ca. 2.09–2.20 Å interval established with other molecules and emphasize the variability in bond length of the NbS group. Stretching frequencies and bond lengths show a rough inverse dependence. For square pyramidal [NbSCl4]1?, with a relatively high NbS bond order, vNbS = 552 cm?1 is associated with a bond length of 2.085(5) Å and an overlap population of 0.64. 相似文献
10.
Yoshio Yamamoto Kazuo Torii Nakamura Yoichi Iitaka Yukio Mitsui Kaoru Miyamoto Hisayuki Matsuo Kozo Narita Nobuo Yoshida 《Journal of molecular biology》1981,145(1):285-287
The crystals of ribonuclease St, the extracellular ribonuclease from Streptomyces erythreus, have been obtained from (NH4)2SO4 solution with acetate buffer (pH 4.1). The crystals belong to a monoclinic space group C2 with dimensions . There are two protein molecules per asymmetric unit. The crystals diffract beyond 2.0 Å resolution. 相似文献
11.
Uteroglobin is a steroid-binding protein of 15,800 molecular weight, composed of two chemically identical subunits which, in the oxidized form, are covalently linked by disulphide bridges. Large crystals have been grown from ammonium sulphate solutions by vapour diffusion as well as by equilibrium dialysis. The crystals are very stable under X-rays, diffract to at least 2.2 Å resolution and belong to space group P21. The unit cell, with dimensions , contains two dimeric molecules. The crystals exhibit a prominent pseudo symmetry corresponding to space group P21212 which indicates that the two subunits should be structurally nearly identical. 相似文献
12.
Terrance B. Murphy Norman J. Rose Verner Schomaker Alejandro Aruffo 《Inorganica chimica acta》1985,108(3):183-194
Iron(III) complexes of three aroyl hydrazones, pyridoxal isonicotinoyl hydrazone (H2pih), pyridoxal benzoyl hydrazone (H2pbh), and salicylaldehyde benzoyl hydrazone (H2sbh), were synthesized and characterized. In aqueous medium at pH 7, [Fe(pih)(Hpih)]·3H2O is formed. In acidic methanol, a 1:1 ligand-to-metal complex is formed, [FeCl2(H2pih)]Cl (1), whereas in aqueous medium at low pH cis-[FeCl2(H2pih)(H2O)]Cl·H2O (2) is formed. Compounds 1 and 2 are high-spin d5 with μeff = 5.88 μB and 5.93 μB (298 K). The crystal structures of 1 and 2 show that H2pih acts as a tridentate neutral ligand in which the phenolic and hydrazidic protons have shifted to the pyridine nitrogen atoms. The co- ordination polyhedron of 1 is ‘square’ pyramidal, whereas that of 2 is pseudo-octahedral. Compound 1 is triclinic, space group P, with a = 12.704(2) Å, b = 8.655(2) Å, c = 8.820(2) Å, α = 105.42(1)°, β = 89.87(1)°, γ = 107.60(1)°, V = 888 Å3, and Z = 2; 2 is monoclinic, space group P21/c, with a = 15.358(4) Å, b = 7.304(3) Å, c = 17.442(4) Å, β = 101.00(2)°, V = 1921 Å3, and Z = 4. 相似文献
13.
Neodymium complex compound with glycine: Nd2(Gly)6·(ClO46·9H2O was synthesized and obtained in the form of monocrystals. Absorption spectra recorded in the region of 8000–35 000 cm-1 were measured along the crystallographic axes. Intensities of the f-f transitions were analysed on the basis of the Judd theory. The X-ray crystal structure determination of the complex is reported. Crystals are triclinic, space group P, with a = 11.554(4) Å, b = 14.108(1) Å, c = 15.660(3) Å, α = 97.14(1)°, β = 102.82(2)°, γ = 105.28(1)°, V = 2355.25 Å3 Z = 2, M.W. = 1495.4, Dc = 2.129)(3) g cm-3, Dm = 2.103(1) g cm-3. The structure was solved by Patterson's method and successive Fourier syntheses giving the locations of all nonhydrogen atoms. The final R factor was 0.062 and Rw = 0.073 for 12869 reflections with |Fo| > 5σ|(Fo)|. The asymmetric unit consists of a dimeric formula unit. The coordination polyhedron of Nd atoms comprises seven oxygen atoms from glycine and two from water molecules. The neodymium-glycine bonding mode is compared with that of the calcium-glycine complex. 相似文献
14.
The lectin from the seeds of Abrus precatorius has been crystallized and the crystals subjected to study by X-ray diffraction and electron microscopy. Three closely related crystal forms were obtained, of orthorhombic space group P212121 with , , and , of tetragonal space group P41212 with , , and a twinned intermediate of the first two. From electron microscopy and two-dimensional spatial filtering of electron micrographs of the crystals, the molecule appears to consist of four similar domains grouped in a roughly planar diamond-shaped arrangement having a local intramolecular dyad axis. The average diameter of the Abrus lectin molecule is 50 to 60 Å and the individual domains appear to have a diameter of about 25 Å. 相似文献
15.
16.
Isolation of a sequence-specific endonuclease (BamI) from Bacillus amyloliquefaciens H. 总被引:54,自引:0,他引:54
Flavodoxin isolated from the blue-green alga, Anacystis nidulans, crystallizes from ammonium sulfate in space group P212121, with . The diffraction patterns extend to a resolution of at least 1.8 Å. Reduction of the flavin mononucleotide in the crystalline protein, to either the semi-quinone or fully reduced (hydroquinone) state, results in minimal changes in cell dimensions and diffracted intensities. The higher molecular weight (19,000 to 20,000) and spectral properties of the A. nidulans protein, along with the near-isomorphism of crystals of the three oxidation states, distinguish this crystalline flavodoxin from the corresponding proteins of Clostaridium MP and Desulfovibrio vulgaris, whose three-dimensional structures are known. In contrast to Clostridium flavodoxins, but like the D. vulgaris protein, A. nidulans flavodoxin is capable of binding riboflavin in place of flavin mononucleotide (Ka = 2 × 106m−1). 相似文献
17.
Crystals of crambin, a plant seed protein of molecular weight 5000, diffract X-rays strongly to the interplanar spacing limit of 0.88 Å. These diffraction data should allow a definition of atomic structure that is on a par with that typically obtained from crystals of small organic molecules. The crystals are in space group P21 and have unit cell dimensions . The asymmetric unit contains one protein molecule. 相似文献
18.
J C Brochon P Wahl M Charlier J C Maurizot C Hélène 《Biochemical and biophysical research communications》1977,79(4):1261-1271
A new crystal form of a mitogenic lectin from pea seeds () has been obtained which is suitable for high resolution structural work. The crystals are orthorhombic, space group P212121, with unit cell dimensions: = 64.2Å, = 72. 7Å, = 108. 3Å. The asymmetric unit contains one protein molecule. 相似文献
19.
J.P. Mornon E. Surcouf J. Berthou P. Corvol S. Foote 《Journal of molecular biology》1982,155(4):539-540
Renin isolated from the mouse submaxillary gland has been crystallized and is being subjected to X-ray diffraction analysis.The observed crystalline form has the following unit cell dimensions: , space group P21, Z = 8 (4 protein molecules in the asymmetric unit).Native data have been recorded at 5 Å resolution with an automatic diffractometer. 相似文献
20.
EcoRI endonuclease crystallizes in space group C2 with unit cell parameters . Four 29,000 molecular weight subunits per asymmetric unit would give a reasonable Vm value of 2.87 Å3/dalton. EcoRI endonuclease is the first protein which recognizes a specific sequence of bases in DNA to be crystallized in a form suitable for high resolution structure analysis. 相似文献