首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
The crystal structure of ethylenediaminecadmium(II) tetracyanocadmate(II)-benzene(1/2),I, has been redetermined based on 1632 reflections collected anew for the crystal coated with epoxy resin, with a final conventionalR=0.038;I crystallizes in space groupP4222, witha=b=8.265(1) andc=15.512(3) Å, andZ=2. Ethylenediaminecadmium(II) tetracyanocadmate(II),II, is concluded to be identical with the residual metal complex host ofI, remaining after the liberation of the guest benzene molecules;II crystallizes from an aqueous solution containing bis- or tris-ethylenediaminecadmium(II) tetracyanocadmate(II) in space groupI41/acd, witha=b=14.366(1) andc=23.771(4) Å, andZ=16; refinement led to a conventionalR=0.043 for 1181 reflections. The bridging ethylenediamine ligand inI turns to a chelating one inII; dissociation and recombination should occur in the coordination sphere of the six-coordinate cadmium atom, whenII is derived fromI by the liberation of the guest molecules. Supplementary Data relating to this article are deposited with the British Library as Supplementary Publication No. SUP 82018 (30 pages).Dedicated to Professor H. M. Powell.  相似文献   

2.
Abstract

Two new cadmium(II) complexes with phenylthiourea (PTU), namely Cd(PTU)4Cl2 (1) and [Cd2(NCS)22-SCN)2(PTU)22-PTU)2] n (2), have been prepared and characterized structurally by X-ray diffaction. Complex 1 crystallizes in the monoclinic space group C2/c, with a = 27.057(13), b = 8.108(3), c = 16.751(8) Å, β = 114.46°, V = 3345(3) Å3, Z = 4. Complex 2 crystallizes in the triclinic space group P-1, with a = 9.336(3), b = 14.686(5), c = 16.911(5) Å, α = 71.36(2), β = 84.31(2), γ = 72.470(10)°, V = 2095.0(12) Å3 Z = 4. The structural analysis shows that each metal atom in both the mononuclear complex 1 and polynuclear complex 2 is octahedrally coordinated by four sulfur atoms and two chloro ligands or two nitrogen atoms from the thiocyanate groups, respectively. The PTU ligand can serve as either a monodentate ligand or a μ2-bridging ligand upon coordination to a metal atom.  相似文献   

3.
An efficient synthesis of enantiomerically pure (R)- and (S)-2-(aminomethyl)alanine ((R)- and (S)-Ama) 1a and (R)- and (S)-2-(aminomethyl)leucine ((R)- and (S)-Aml) 1b is described (Schemes 1 and 2). Resolution of the racemic amino acids was achieved using L -phenylalanine cyclohexylamide ( 2 ) as chiral auxiliary. The free amino acids 1a, b were converted to the Nα-Boc,Nγ-Z-protected derivatives 11a, b (Scheme 3) ready for incorporation into peptides. Based on the three crystal structures of the diastereoisomeric peptides 8a, 8b , and 9b , the absolute configurations in both series were determined. β-Turn type-I geometries were observed for structures 8b and 9b , whereas 8a crystallized in an extended backbone conformation.  相似文献   

4.
The structure of Ir(CO)2(acac) is determined by XRD at room temperature. Crystallographic data for C7H7IrO4 are: a = 6.4798(5) ?, b = 7.7288(5) ?, c = 9.1629(10) ?, α = 105.738(2)°, β = 90.467(3)°, γ = 100.658(2)°, space group 1, P , V= 433.24(6) ?3, Z = 2, d calc = 2.662 g/cm3, R = 0.0167. The structure is built of isolated mononuclear molecules. The central iridium atom has a square coordination environment formed by two oxygen atoms that belong to the acetylacetonate ligand and two carbon atoms of carbonyl groups. The average Ir-O and Ir-C bond lengths are 2.045(3) ? and 1.832(6) ? respectively. Molecules are stacked in such a way that the planes of coordination squares turn out to be parallel to the Ir...Ir distances between the nearest neighbors in the stack of 3.242 ? and 3.260 ?. Original Russian Text Copyright ? 2009 by K. V. Zherikova, N. V. Kuratieva, and N. B. Morozova __________ Translated from Zhurnal Strukturnoi Khimii, Vol. 50, No. 3, pp. 595–597, May–June, 2009.  相似文献   

5.
Abstract

Crystallization of (R)-(1-naphthyl)glycyl-(R)-phenyl-glycine [(R,R)-1] in the presence of oligo(ethylene glycol) dimethyl ethers 2(n) or poly(ethylene glycol)s (PEGs, 3(Mn )) afforded inclusion compounds. The ratio of (R,R)-1/the guest polymer (2 or 3) was proportional to the length of the polymer chain. The crystal structure of a hepta(ethylene glycol) dimethyl ether-included compound was disclosed by X-ray crystallography which showed that (R,R)-1 molecules form a sheet and the guest molecule penetrates the crystal lattice of (R,R)-1 through a one-dimensional channel on the sheet. Powder X-ray analysis revealed that, regardless of the length of the guest polymer, the distance between the neighboring sheets remains unchanged (12.0–12.3 Å) in these inclusion crystals. By thermal analysis, it was shown that the decomposition points of these inclusion compounds became higher with the longer PEG included. The inclusion phenomenon enabled the fractionation of PEGs with various molecular weights, among which longer PEG was preferably included.  相似文献   

6.
Abstract

The crystal structures of the two title tetracyanonickelate(II) salts of organic ammonium ions, (18-crown-6)-(2-hydroxyethylammonium) tetracyanonickelate(II), I, and 10-aminodecylammonium tetracyano nick-elate(II), II, have been analyzed. I crystallizes in the monoclinic space group P21/n with a = 10.458(2), b = 8.267(3), c = 24.045(2) Å, β = 94.09(1)°, V = 2074(1) Å3, Z = 2, R = 0.061 for 2274 reflections; II is triclinic P 1 with a = 9.437(3), b = 10.094(3), c = 9.205(3)Å,a = 110.16(2), β = 112.72(3), γ = 69.16(2)°, V = 733.7(5) Å3 2=1, R = 0.040 including all the hydrogen atoms refined for 2724 reflections. The square planar tetracyanonickelate(II) anion is in a favourable position to form hydrogen bonds via N with the hydroxyl group in I and the ammonio group in II, respectively.  相似文献   

7.
In the title compound, (2-chloro­benzyl)­tris­(pyridine-2-thiol­ato)-κ2N,S2N,SS-tin(IV), [Sn(C7H6Cl)(C5H4NS)3], two of the three pyridine-2-thiol­ato ligands (SPy) are bidentate and one is monodentate. The bonding C atom of the 2-chloro­benzyl group, the S atom of the monodentate SPy and the S and N atoms of the two bidentate SPy ligands form a distorted octahedron around the Sn atom. The three S atoms and the N atom of one of the bidentate SPy ligands occupy the equatorial positions, while the N atom of the second bidentate SPy ligand and the C(CH2) atom are axial. The axial N—Sn—C angle of 157.9 (1)° demonstrates the heavy distortion of the octahedron.  相似文献   

8.
Two new transition metal(II) complexes [M(hdpa)2(N(CN)2)2] (M = Mn ( 1 ), Co ( 2 ); hdpa = 2, 2'‐dipyridylamine) have been prepared and characterized structurally and magnetically. Both compounds crystallize in the monoclinic space group C2/c. 1 and 2 are isotypic with the unit cell parameters a = 8.634(9), b = 13.541(14), c = 21.99(2) Å, β = 94.806(18)°, and V = 2562(5) Å3 for 1 , a = 8.617(3) Å, b = 13.629(5)Å, c = 21.598(8)Å, β = 94.593(6)°, and V = 2528.4(15)Å3 for 2 , and Z = 4 for both. According to X‐ray crystallographic studies, each metal(II) ion was six‐coordinated with four nitrogen atoms from two bidentate hdpa ligand and two nitrogen atoms from two N(CN) anions to form slightly distorted octahedrons. Adjacent complex molecules are connected by hydrogen bonds or π···π interactions to form three‐dimensional network. The IR and UV spectroscopy were measured and the magnetic behaviors were investigated.  相似文献   

9.
The redox behaviour of tetrakis(triphenylphosphine)-platinum(0) [Pt(TPP)4], tetrakis(triphenylphosphine)-palladium(0) [Pd(TPP)4] and tetrakis(triphenylphosphine)-nickel(0) [Ni(TPP)4] has been studied in N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), acetonitrile (AN), propanediol carbonate (PDC), N,N-dimethylthioformamide (DMTF) N-methylpyrrolidine-2-thione (NMTP) and nitromethane (NM). The platinum complex was found to undergo irreversible two electron oxidations with partial or complete loss of the ligands in all solvents but nitromethane. The palladium complex was also oxidized to the divalent form in the solvents studied except inPDC andNM where the complex was found to be polarographically inactive; Ni(TTP)4 was reversibly or almost reversibly oxidized to a movovalent form inDMF, AN andDMTF followed by an irreversible oxidation to a divalent complex. Direct oxidation to the divalent form occurred inDMSO, no oxidation was observable inNMTP andPDC, decomposition took place in nitromethane. The half-wave potentials were recorded versus bisbiphenylchromium iodide (BBCr)I as an internal standard. The influence of the solvents on the redox behaviour and the dissociation of ligands is discussed.

Mit 1 Abbildung  相似文献   

10.
Extraction of Am(III) and Ln(III) from NaClO4 medium with di(2-ethylhexyl)dithiophosphoric acid (DEHDTP), di(2-ethylhexyl)monothiophosphoric acid (DEHMTP), di(2-ethylhexyl)monothiophosphinic acid (DEHMTPI), dihexyldithiophosphinic acid (DHXDTPI), diheptyldithiophosphinic acid (DHPDTPI), dioctyldithiophosphinic acids (DODTPI), dinonyldithiophosphinic acid (DNDTPI), di(1-methylheptyl)dithiophosphinic acid (DMHDTPI) and di(2-ethylhexyl)dithiophosphinic acid (DEHDTPI) in xylene has been investigated. The order of the extraction selectivity for Am(III) is DEHDTPI > DEHDTP > DEHMTPI > DEHMTP, DHPDTPI > DODTPI > DHXDTPI > DNDTPI, DMHDTPI > DEHDTPI > DODTPI, for extractants with 2-ethylhexyl alkyl, straight chain alkyl, branch chain alkyl, respectively. Using 0.1 mol/l NaClO4 solution as aqueous phase, the slope values of the logD-pH and logD-logC curves are not integers, and the slope values for Am(III) are slightly higher than those for Eu(III), for all extractants. The relationship between the slope value and extraction conditions can be described as: logS = alg(C HA/C M S/4)+b. In the presence of macro Eu(ClO4)3, the formula, logSF Am/Ln = B-2log(C HL-D Ln/(D Ln + 1)C Eu), can well describe the relationship between separation factor and the extraction condition. A high separation factor (SF Am/Eu = 2500) is obtained by solvent extraction with 0.5 mol/1 DEHDTPI in toluene from 1 mol/l NaNO3 solution.  相似文献   

11.
C–H-Activation: Syntheses and Properties of Acetonato( C )-acidophthalocyaninato(2–)metallates(III) of Rhodium and Iridium; Crystal Structure of Tetra(n-butyl)ammonium Acetonato( C )azidophthalocyaninato(2–)iridate(III) Phthalocyaninato(2–)metallate(I) of rhodium and iridium reacts with carbonyl substrates like acetone or acetylacetone and halides or pseudohalides forming acetonato(C)- or acetylacetonato(C)acidophthalocyaninato(2–)metallates(III), that are isolated as tetra(n-butyl)ammonium complex salts (nBu4N)[M(R)(X)pc2–] (M = Rh, Ir; R = aC, acaC; X = Cl, I, N3, SCN/NCS). (nBu4N)[Ir(aC)(N3)pc2–] · 0,25(C2H5)2O · 0,5 CH2Cl2 crystallizes in the triclinic space group P1 with cell parameters a = 16.267(8) Å, b = 17.938(3) Å, c = 18.335(4) Å, α = 74.77(2)°, β = 73.73(3)°, γ = 84.25(3)°, V = 4954(3) Å3, Z = 4. There are two crystallographically independent anions, differing by the orientation of the azido ligand either towards an isoindole group or a Naza bridge of the phthalocyaninate, while the σ-C bonded acetonate is always oriented towards an isoindole group (gauche and ecliptical configuration). The Ir–C distances are 2.12(1) and 2.14(1) Å. Due to the trans influence of the acetonate-C atom the Ir-azide-N distances of 2.22(1)/2.24(1) Å are longer than expected. The electrochemical properties and the optical, vibrational, and 1H-NMR spectra are discussed.  相似文献   

12.
The crystal structure of [Cu (Im)4] (teph) (Im = imidazole, teph = terephthalate) has been determined by X‐ray crystallography. It crystallizes in the triclinic system, space group Pī with cell dimensions of a = 0.80356 (16) nm, b = 0.84269 (17) run, c = 0.88967 (18) nm, α = 76.90 (3)°, β = 68.95 (3)°, γ = 75.94 (3)°, and Z = 1. Its structure of the title compound is composed of discrete monomelic molecule of [Cu (Im)4]‐(teph). The copper (II) ions have a square plane geometry with the CuN4 chromophore.  相似文献   

13.
Formation constants of ternary complexes of CuII with (S)-amino-acid amides ((S)-phenylalaninamide, (S)-prolinamide, and (S)-tryptophanamide) and (R)- or (S)-histidine and (R)- or (S)-tyrosine were determined potentiometrically in aqueous solution. Significant stereoselectivity was presented by all three amides towards histidine, the diastereoisomeric complexes with ‘heterochiral’ ligands being more stable than those with ‘homochiral’ ligands (see Table 3). The stereoselectivity observed with (S)-phenylalaninamide and (S)-tryptophanamide may be explained on the basis of hydrophobic stacking interactions between 1H-imidazole and the aromatic side chain, favoured by the terdentate behaviour of histidine (see Fig.2), whereas repulsive effects seem to be prevalent with (S)-prolinamide. Only (S)-prolinamide and (S)-phenylalaninamide show appreciable stereoselectivity with tyrosine, which is bidentate, probably on account of repulsive interactions. The present results on the stability of ternary complexes in solution allow to draw some conclusions on the mechanism of chiral discrimination performed by CuII complexes of (S)-amino-acid amides added to the mobile phase in HPLC (reversed phase).  相似文献   

14.
Summary The crystal and molecular structure of bis(1-methylimidazole)bis(perchlorato)bis(pyridineN-oxide)copper(II) have been determined using three-dimensional x-ray diffraction data. The complex crystallizes in space group P21/c with Z=2. The cell dimensions area=9.355(3),b=14.363(4),c=9.698(4) Å, and =106.40(3)o. Least-squares refinement of the structure has yielded a final R value of 0.049 for 1235 independent reflections. The centrosymmetric structure consists oftrans pairs of 1-methylimidazole and pyridineN-oxide figands forming a square planar geometry with Cu–N and Cu–O bond lengths of 1.963(4) Å and 1.948(4) Å, respectively. The two perchlorate ions are located above and below the square plane with Cu–O distances of 2.590(5) Å. The uv-vis and i.r. spectra and bonding properties of the title compound are discussed with reference to the structure.  相似文献   

15.
New complexes of the formulae K3[RhL 3]·2 H2O, [PdL]·H2O and [M(LH2)Cl2] [whereM = Pd, Pt andLH2 = bis(o-aminobenzenesulfonyl)ethylenediamine] have been prepared and characterized by conductivity measurements, thermogravimetric analysis, X-ray powder patterns and IR, Ligand Field and1H-NMR spectroscopy.
Rhodium(III), Palladium(II)- und Platin(II)-Komplexe mit Bis(o-aminobenzolosulfonyl)ethylendiamin (Kurze Mitteilung)
Zusammenfassung Neue Komplexe der allgemeinen Formeln K3[RhL 3]·2H2O, [PdL]·H2O und [M(LH2)Cl2] mitM = Pd, Pt undLH2 = Bis(o-aminobenzolosulfonyl)ethylendiamin wurden dargestellt und mit Konduktionsmessungen, thermogravimetrischen Analysen, Röntgenstrukturanalysen, IR, Ligandfeld- und1H-NMR-Spektroskopie charakterisiert.
  相似文献   

16.
trans‐Bis(3‐isopropyl‐7‐oxocyclohepta‐1,3,5‐trien‐1‐olato)copper(II) trans‐bis(3‐isopropyl‐7‐oxocyclohepta‐1,3,5‐trien‐1‐olato)palladium(II) as the (5/1) and (3/2) composites [Cu(C10H11O2)2]·0.2[Pd(C10H11O2)2] and [Cu(C10H11O2)2]·0.67[Pd(C10H11O2)2], respectively, where 3‐isopropyl‐7‐oxocyclohepta‐1,3,5‐trien‐1‐olate is the systematic name for the hinokitiolate anion (hino), are the first mixed‐metal cocrystalline products isolated from the Mx(hino)y family of complexes. These cocrystals contain square‐planar trans‐Cu(hino)2 and trans‐Pd(hino)2 molecules possessing crystallographic inversion symmetry. The bulk formulation for these cocrystalline compounds is Cu1−xPdx(hino)2, where x is 0.166 (4) for the (5/1) product and 0.399 (4) for the (3/2) product. This bulk formulation is simply a convenient average expression of the whole‐molecule substitutional disorder present in these compounds. The M—O bonds are in the range 1.9210 (11)–1.9453 (10) Å, the O—M—O bite angles are in the range 82.94 (4)–83.36 (4)°, and all of the hinokitiolate O atoms are involved in C—H...O hydrogen‐bonding interactions.  相似文献   

17.
Summary Dichlorobis(methylsalicylato)titanium(IV) reacts with potassium or amine salts of dialkyl or diaryl dithiocarbamates in 11 and 12 molar ratios in anhydrous benzene (room temperature) or in boiling CH2Cl2 to yield mixed ligand complexes: (AcOC6H4O)2 Ti(S2CNR2)Cl (1) and (AcOC6H4O)2 Ti(S2CNR2)2 (2), R=Et, n-Pr, n-Bu, cyclo-C4H8 and cyclo-C5H10. These compounds are moisture sensitive and highly soluble in polar solvents. Molecular weight measurement in conjunction with i.r.,1H and13C n.m.r. spectral studies suggest coordination number 7 and 8 around titanium(IV) in (1) and (2) respectively.  相似文献   

18.

Abstract  

An efficient synthesis method for the preparation of a series of new (Z)- and (E)-3(5)-(2-hydroxyphenyl)-4-styrylpyrazoles was developed. The reaction of (Z)- and (E)-3-styrylchromones with hydrazine hydrate afforded the corresponding (Z)- and (E)-3(5)-(2-hydroxyphenyl)-4-styrylpyrazoles, except for nitro derivatives, where both (Z)- and (E)-4′-nitro-3-styrylchromones afforded (E)-3(5)-(2-hydroxyphenyl)-4-(4-nitrostyryl)pyrazoles. The reaction mechanism for these transformations is discussed and the stereochemistries of all products were established by NMR experiments.  相似文献   

19.
Zusammenfassung 2,2,5-Trisubstituierte Imidazolidin-thione-(4) lassen sich mittels Schwefels mit guten Ausbeuten zu Imidazolin-(3)-thionen-(5) dehydrieren. Hierüber sowie über einige Verbesserungen der bisher bekannten Synthesen für insbesondere 2,2,5-trisubstituierte Imidazolidin-thione-(4) wird berichtet.
Dehydration of 2.2.5-trisubstituted imidazolidine-(4)-thiones with elementary sulfur gives in good yields 3-imidazoline-(5)-thiones. This reaction and improved methods of the well known syntheses of especially 2.2.5-trisubstituted imidazolidine-(4)-thiones are described.


Mitt.:F. Asinger, W. Schäfer undH. Triem, Mh. Chem.97, 1510 (1966).

Teil der Dissertation vonH. Meisel, Techn. Hochschule Aachen, 1963.

Teil der Dipl.-Arbeit vonHilde Kersten, Techn. Hochschule Aachen, 1963, und Teil der Dissertation vonHilde Kersten, Techn. Hochschule Aachen, 1965.  相似文献   

20.
Investigation of the solubility behavior of para-substituted (H, Me, t-Bu, n-Bu) meso-tetraarylporphyrins as well as meso-tetraalkylporphyrins (Me, n-Pr, n-Bu) were performed. An increase of solubility in chloroform and benzene is detected according to the higher functionality in para position of the phenyl ring for meso-tetraarylporphyrins or in meso position on meso-tetraalkylporphyrins. Furthermore, the series of bis(chlorido)tin(IV) meso-tetraarylporphyrin and bis(chlorido)tin(IV) meso-tetraalkylporphyrin was investigated via UV/Vis spectroscopy, 119Sn-NMR and single crystal X-ray diffraction.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号