Darstellung und Strukturelle Charakterisierung von cis-und trans- Dicyclohexyl-3,3′,4,4′-tetracarbonsäure-tetramethylestern / Preparation and Structural Characterization of cis- and trans-Tetramethyl Dicyclohexyl-3,3′,4,4′-tetracarboxylates

2001 ◽  
Vol 56 (2) ◽  
pp. 189-201
Author(s):  
Akinori Shiotani
Keyword(s):  
Catalytic Hydrogenation ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
Trans Isomers ◽  
X Ray ◽  
Nmr Data ◽  
Methoxycarbonyl Group ◽  
Cis And Trans ◽  
C Nmr

Abstract In the catalytic hydrogenation of tetramethyl biphenyl-3,3′,4,4′-tetracarboxylate, tetramethyl dicyclohexyl-3,3′,4,4′-tetracarboxylates were obtained, from which we have isolated cis isomers as crystals. The base-catalyzed isomerization afforded the trans isomers. The structure of the products isolated was determined by single-crystal x-ray diffraction, which clearly reveals the axial and equatorial positions of the methoxycarbonyl group. The structures in solution are supported by 1H and 13C NMR data, and also by two-dimensional COSY techniques.

One Step Synthesis and Characterization of Zirconia-Graphene Composites

2012 ◽  
Vol 600 ◽  
pp. 174-177 ◽  
Author(s):  
Jian Fei Xia ◽  
Zong Hua Wang ◽  
Yan Zhi Xia ◽  
Fei Fei Zhang ◽  
Fu Qiang Zhu ◽  
...  
Keyword(s):  
Synthesis And Characterization ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
X Ray ◽  
Graphene Composite ◽  
Transmission Electron ◽  
One Step ◽  
Ft Ir ◽  
Xrd Techniques

Zirconia-graphene composite (ZrO2-G) has been successfully synthesized via decomposition of ZrOCl2•6H2O in a water-isopropanol system with dispersed graphene oxide (GO) utilizing Na2S as a precursor could enable the occurrence of the deposition of Zr4+ and the deoxygenation of GO at the same time. Transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) techniques were used to characterize the samples. It was found that graphene were fully coated with ZrO2, and the ZrO2 existing in tetragonal phase, which resulted in the formation of two-dimensional composite.

Spectroscopic and X-Ray Investigation of Cobalt(III) Complexes with 2-Oximinocarboxylic Acids

1993 ◽  
Vol 48 (4) ◽  
pp. 409-417 ◽  
Author(s):  
Rostislav D. Lampeka ◽  
Zamira D. Uzakbergenova ◽  
Victor V. Skopenko
Keyword(s):  
Electronic Absorption Spectra ◽  
Molecular Structures ◽  
X Ray Diffraction ◽  
Octahedral Structure ◽  
Space Group ◽  
X Ray ◽  
H Nmr ◽  
Nmr Data ◽  
R Factors

Mixed complexes of Co(III) with 2-oximinopropionic (H2A) or 2-oximino-3-phenylpropionic (H2B) acid and different amine (imidazole, benzimidazole, pyridine, β-picoline, γ-picoline) are reported. Characterization of the complexes was based upon elemental analysis, conductivity and JR, 1H NMR, and electronic absorption spectra, and X-ray diffraction analysis. The organic ligands behave as O,N donors via the carboxyl oxygen and the oxime nitrogen atoms. A trans-octahedral structure has been assigned to the bis(2-oximinocarboxylato)bis(amine)cobalt(III) on the basis of 1H NMR data.The crystal and molecular structures of the complexes trans-[bis(2-oximinopropionato)bis-(imidazole)]- (I) and trans-[bis(2-oximinopropionato)bis(pyridine)]cobalt(III) (II) were determined. I crystallizes in space group P2/n with a = 14.1 67(2), b = 8.774(1), c = 14.785(2) Å,β = 113.37(1)°, Z = 4, Dcalc = 1.568 g · cm-3. II crystallizes in space group P1̄ with a = 9.122(2), b = 10.038(2), c = 11.759(2) Å, α = 69.95(1)°, β = 67.47(2)°, γ = 69.49(2)°, Ζ = 2, Dcalc = 1.547 g cm-3. The structures were refined to unweighted R factors of 0.036 and 0.028, respectively. The coordination sphere around Co is pseudo-octahedral with the 2-oximinopropionato ligands occupying four equatorial positions, and the amines in axial positions.

Synthesis, Structure and Characterization of a Novel Two-Dimensional Supramolecular Mn(II) Coordination Polymer Constructed from a 1,10-Phenanthroline Derivative and a Flexible Dicarboxylate

2010 ◽  
Vol 65 (9) ◽  
pp. 1173-1176 ◽  
Author(s):  
Zhi-Guo Kong ◽  
Xiao-Yuan Ma ◽  
Zhan-Lin Xu
Keyword(s):  
Ir Spectroscopy ◽  
Glutaric Acid ◽  
Title Complex ◽  
Two Dimensional ◽  
Crystal Data ◽  
X Ray Diffraction ◽  
Triclinic Space Group ◽  
X Ray ◽  
1D Chains

The title complex, [Mn2(glu)(L)2(HL)2]・0.5H2O (H2glu = glutaric acid, HL = 2-(2-chloro-6-fluorophenyl)-1Himidazo[ 4,5-f][1,10]phenanthroline) has been synthesized using a hydrothermal method and characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction. Crystal data: C162H88Cl8F8Mn4N32O9, triclinic, space group P1¯, a = 14.932(5), b = 16.414(5), c = 17.891(5) Å , α = 115.851(5), β = 91.288(5), γ = 112.894(5)◦, V = 3536.4(19) Å3, Z = 1. Compound 1 exhibits 1D chains which are further stacked by C-H...π interactions to give two-dimensional supramolecular layers.

Pseudozoanthoxanthins from gold coral

1979 ◽  
Vol 57 (13) ◽  
pp. 1707-1711 ◽  
Author(s):  
Robert E. Schwartz ◽  
Mark B. Yunker ◽  
Paul J. Scheuer ◽  
Tor Ottersen
Keyword(s):  
Deep Water ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nmr Data ◽  
Derivatives Of ◽  
C Nmr

From a deep water Pacific zoanthid, Gerardia sp., we have isolated two new fluorescent nitrogenous pigments, derivatives of tetrazacyclopentazulene. The first was characterized by uv, 1H and 13C nmr data, and by X-ray diffraction; the second by interconversion.

One- and two-dimensional PbII compounds resulting from reaction of PbBr2 and Pb(SCN)2 with pyrimidine-2-thione

2021 ◽  
Vol 77 (7) ◽  
Author(s):  
Vânia Denise Schwade ◽  
Bárbara Tirloni
Keyword(s):  
Structural Characterization ◽  
Diffuse Reflectance ◽  
Tautomeric Form ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
One Dimensional ◽  
X Ray ◽  
Ft Ir ◽  
Compound Ii

Pyrimidine-2-thione (HSpym) reacts with lead(II) thiocyanate and lead(II) bromide in N,N-dimethylformamide (DMF) to form poly[(μ-isothiocyanato-κ2 N:S)(μ4-pyrimidine-2-thiolato-κ6 N 1,S:S:S:S,N 3)lead(II)], [Pb(C4H3N2S)(NCS)] n or [Pb(Spym)(NCS)] n , (I), and the polymeric one-dimensional (1D) compound catena-poly[[μ4-bromido-di-μ-bromido-(μ-pyrimidine-2-thiolato-κ3 N 1,S:S)(μ-pyrimidine-2-thione-κ3 N 1,S:S)dilead(II)] N,N-dimethylformamide monosolvate], {[Pb2Br3(C4H3N2S)(C4H4N2S)]·C3H7NO} n or {[Pb2Br3(Spym)(HSpym)]·DMF} n , (IIa), respectively. Poly[μ4-bromido-di-μ3-bromido-(μ-pyrimidine-2-thiolato-κ3 N 1,S:S)(μ-pyrimidine-2-thione-κ3 N 1,S:S)dilead(II)], [Pb2Br3(C4H3N2S)(C4H4N2S)] n or [Pb2Br3(Spym)(HSpym)] n , (IIb), could be obtained as a mixture with (IIa) when using a lesser amount of solvent. In the crystal structures of the pseudohalide/halide PbII stable compounds, coordination of anionic and neutral HSpym has been observed. Both Spym− (in the thiolate tautomeric form) and NCS− ligands were responsible for the two-dimensional (2D) arrangement in (I). The Br− ligands establish the 1D polymeric arrangement in (IIa). Eight-coordinated metal centres have been observed in both compounds, when considering the Pb...S and Pb...Br interactions. Both compounds were characterized by FT–IR and diffuse reflectance spectroscopies, as well as by powder X-ray diffraction. Compound (IIa) and its desolvated version (IIb) represent the first structurally characterized PbII compounds containing neutral HSpym and anionic Spym− ligands. After a prolonged time in solution, (IIa) is converted to another compound due to complete deprotonation of HSpym. The structural characterization of (I) and (II) suggests HSpym as a good candidate for the removal of PbII ions from solutions containing thiocyanate or bromide ions.

Synthesis and characterization of cis and trans isomers of [NiL2(NCS)2] [L=1-(2-aminoethyl)pyrrolidine]: X-ray single-crystal structures

Polyhedron ◽  
2000 ◽  
Vol 19 (15) ◽  
pp. 1803-1807 ◽  
Author(s):  
Inamur Rahaman Laskar ◽  
Tapas Kumar Maji ◽  
Siddhartha Chaudhuri ◽  
Ashutosh Ghosh ◽  
Nirmalendu Ray Chaudhuri
Keyword(s):  
Single Crystal ◽  
Crystal Structures ◽  
Synthesis And Characterization ◽  
Trans Isomers ◽  
X Ray ◽  
Single Crystal Structures ◽  
Cis And Trans Isomers ◽  
Cis And Trans

Synthesis and structural characterization of substituted phenols with a m-terphenyl backbone 2,4,6-R3C6H2OH (R=2,4,6-Me3C6H2, Me5C6)

2015 ◽  
Vol 70 (1) ◽  
pp. 77-81 ◽  
Author(s):  
Atena B. Şolea ◽  
Marian Olaru ◽  
Cristian Silvestru ◽  
Ciprian I. Raţ
Keyword(s):  
Grignard Reagent ◽  
Cross Coupling ◽  
Molecular Structures ◽  
Coupling Reactions ◽  
X Ray Diffraction ◽  
Substituted Phenols ◽  
X Ray ◽  
Cross Coupling Reactions ◽  
C Nmr

AbstractSubstituted phenols with a m-terphenyl backbone 2,4,6-R3C6H2OH [R=2,4,6-Me3C6H2 (1), Me5C6 (2)] were synthesized using Kumada cross-coupling reactions between 2,4,6-I3C6H2OH and the corresponding Grignard reagent. Both compounds were structurally characterized in solution by 1H and 13C NMR spectroscopy and HRMS. The molecular structures of 1 and 2 were determined by single-crystal X-ray diffraction.

Syntheses, electrochemistry and photophysical properties of a series ofmeso-pyridylpentafluorophenylporphyrins

2010 ◽  
Vol 14 (11) ◽  
pp. 975-984 ◽  
Author(s):  
Emmanuel Z. Moreira ◽  
Alba D.Q. Ferreira ◽  
Cláudio Roberto Neri ◽  
Sumitra Mukhopadhyay ◽  
Sérgio Dovidauskas ◽  
...  
Keyword(s):  
Electrochemical Properties ◽  
Photophysical Properties ◽  
Synthesis And Characterization ◽  
Redox Potentials ◽  
Trans Isomers ◽  
X Ray ◽  
X Ray Crystallography ◽  
Cis And Trans Isomers ◽  
Cis And Trans

This work presents the synthesis and characterization of a series of substituted pyridylpentafluroporphyrins, including the separation of the cis- and trans-isomers, the latter being characterized by X-ray crystallography. The spectroscopic and electrochemical properties of the series are dependent on the number of electron withdrawing pentafluorophenyl substituent, but they do not depend on the symmetry of the molecule. Ongoing from the monosubstituted to the more substituted pentafluorophenyl porphyrin H2(MPyTFPP) derivative, the Soret bands are slightly red-shifted and their quantum fluorescence yields range from 0.035 to 0.046, consistent with the value of 0.045 for the fully substituted 5,10,15,20-tetrapentafluorophenylporphyrin (dichloromethane solutions). The redox potentials of the reductive processes of monoanion and dianion formation are also sensitive to the number of pentafluoro substituents, shifting 180 mV to more positive values for the P0/P-1process ongoing from the monopentafluoro to the tris-pentafluorophenyl substituted derivative.

Synthesis and characterization of a series of 4-methyl-1-[2-aryl-1-diazenyl]-1,4-diazepanes and 1,4-di-[2-aryl-1-diazenyl]-1,4-diazepanes

2004 ◽  
Vol 82 (12) ◽  
pp. 1725-1735 ◽  
Author(s):  
Shasta Lee Moser ◽  
Keith Vaughan
Keyword(s):  
Nmr Assignments ◽  
Diazonium Salt ◽  
Variable Temperature ◽  
2D Nmr ◽  
Diazonium Salts ◽  
X Ray Diffraction ◽  
X Ray ◽  
New Compounds ◽  
C Nmr

1-Methylhomopiperazine was coupled with a series of diazonium salts to afford the 4-methyl-1-[2-aryl-1-diazenyl]-1,4-diazepanes (6), a new series of triazenes. These compounds are, in the main, stable crystalline solids (some of the series are stable oils), and they have been characterized by 1H and 13C NMR spectroscopy, IR spectroscopy, and mass spectrometry. NMR assignments were determined by 2D NMR and variable-temperature NMR experiments and by comparison with model compounds. A second series of new compounds, namely, 1,4-di-[2-aryl-1-diazenyl]-1,4-diazepanes (5), were prepared by coupling unsubstituted homopiperazine (1,4-diazepane) with 2 molar equivalents of the diazonium salt and were similarly characterized. The crystal and molecular structure of the parent member of this bis-triazene series (5, X = H) has been determined by single-crystal X-ray diffraction analysis.Key words: triazene, bis-triazene, diazenyl, bis-diazenyl, diazonium salt, NMR, diazepane.

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