Electronic Structure of 2,6-Bis{.N-(2-hydroxyphenyl)immoinethyl}-4-methylphenol

1999 ◽  
Vol 54 (7) ◽  
pp. 929-939 ◽  
Author(s):  
Miki Hasegawa ◽  
Yasunori Yamada ◽  
Ken-ichi Kumagai ◽  
Toshihiko Hoshi
Keyword(s):  
Diffraction Analysis ◽  
Electronic Absorption ◽  
Nmr Spectra ◽  
X Ray Diffraction ◽  
Mo Calculations ◽  
Absorption Bands ◽  
Polar Solvents ◽  
Additional Band ◽  
X Ray ◽  
H Nmr

The electronic and molecular structure of 2,6-bis{N-(2-hydroxyphenyl)iminomethyl}-4- methylphenol (hpimp) is clarified from the measurements of electronic absorption and 1H NMR spectra in various solvents and an X-ray diffraction analysis, together with MO calculations. Electronic absorption bands of hpimp are at 422, 397.9, 359, 341, 294.3, 265.8, and 224 nm in the non-polar solvent cyclohexane. In polar solvents, such as methanol, an additional band which is assigned to a partly formed keto-amine hpimp, is observed at 499 nm. From the 1H NMR spectra it is seen that hpimp exists in the enol-imine form in non-polar solvents, and as an equilibrium mixture of enol-imine and keto-amine forms in polar solvents. Each electronic absorption band of solid hpimp in a KBr disk is broadened compared with the solution state, and an additional band, again assigned to the keto-amine form, appears around 499 nm. An X-ray diffraction analysis shows that hpimp assumes a keto-amine structure in the solid state, and forms a column structure along the c-axis. MO calculations suggest that the enol-imine hpimp has a twist structure around the two C−C single bonds, the twist angle being 100° to 120°.

Degradation-insertion reactions of decaborane(14) with inorganic salts

1983 ◽  
Vol 48 (9) ◽  
pp. 2593-2603 ◽  
Author(s):  
Karel Baše
Keyword(s):  
Diffraction Analysis ◽  
Nmr Spectra ◽  
Inorganic Salts ◽  
Analogous Reaction ◽  
X Ray Diffraction ◽  
Insertion Reactions ◽  
X Ray ◽  
Lewis Bases ◽  
H Nmr

Decaborane(14) reacts with NaNO2 in tetrahydrofuran forming the [9-tetrahydrofuran-6-NO2B10H12]- salt which after protonization with concentrated H2SO4 or diluted HCl affords azaboranes 6-NB9H12 and 4-NB8H13, respectively. The 6-NB9H12 azaborane is hydrolyzed to the 4-NB8H13 azaborane and reacts with Lewis bases under the formation of the 9-L-6-NB9H12 ligand derivatives (L = (CH)S, CHCN, (CH)P). By the reduction of 9-CHCN-6-NBH with LiAlH4 in tetrahydrofuran the 6-NB9H13- anion was prepared. By an analogous reaction of decaborane(14) with KHSO3 in water and by a subsequent protonization of the formed intermediate with concentrated H2SO4 or diluted HCl the thiaboranes 6-SB9H11 and 4-SB8H12, respectively, were prepared. The reaction of decaborane(14) with Na2SeO3 in tetrahydrofuran followed by the protonization of the intermediate with diluted HCl afforded the 7,8-Se2B9H9 species. Structures of all compounds were proposed on the basis of the 11B and 1H NMR spectra; in the case of 4-NB8H13, the structure was determined by the X-ray diffraction analysis.

Reactions of PO(NCS)3 with 4-Hydroxy-1,3-dioxanes. Crystal Structure of rel-(2S,4R,5S,6S)-2,6-Diethyl-5-methyl-4-(N'-benzylthioureido)-1,3-dioxane

1992 ◽  
Vol 57 (6) ◽  
pp. 1299-1313 ◽  
Author(s):  
Juraj Bernát ◽  
Ladislav Kniežo ◽  
Gabriela Birošová ◽  
Miloš Buděšínský ◽  
Jaroslav Podlaha ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Diffraction Analysis ◽  
Nmr Spectra ◽  
Crystalline Form ◽  
The Other ◽  
Axial Position ◽  
X Ray Diffraction ◽  
X Ray ◽  
H Nmr ◽  
Alkyl Groups

Substituted 4-hydroxy-1,3-dioxanes II react rapidly with PO(NCS)3 to give 4-isothiocyanato-1,3-dioxanes III. The 1H NMR spectra showed that in the isothiocyanate IIIa the predominant stereoisomer has its NCS group in axial position. The addition of benzylamine to the isothiocyanates IIIa and IIIb gave uniform thioureas IVa and IVb with equatorial alkyl groups at 2 and 6 positions and axial thioureido group at 4 position. On the other hand, the isothiocyanate IIIc reacts with benzylamine to give a mixture of three stereoisomeric thioureas V,VI, and VIII. The structure of VI was proved by means of X-ray diffraction analysis; in crystalline form the molecules of VI are present as H-bonded dimers (N-H...O).

tert-Butylimino-cyclopentadienyIvanadiuni(V)-Verbindungen Darstellung, Struktur und NMR-spektroskopische Untersuchungen

1987 ◽  
Vol 42 (7) ◽  
pp. 881-888 ◽  
Author(s):  
Fritz Preuss ◽  
Harald Becker ◽  
Hans-Joachim Häusler
Keyword(s):  
Molecular Structure ◽  
Diffraction Analysis ◽  
Temperature Dependence ◽  
Metal Atom ◽  
Nmr Spectra ◽  
X Ray Diffraction ◽  
Nmr Spectrum ◽  
X Ray ◽  
H Nmr ◽  
Intramolecular Rearrangements

Abstract The cyclopentadienyl compounds tC4R9N = VCpCl2 (2). tC4H9N = VCp(OtC4H9)Cl, tC4H9N = VCp(OtC4H9)(R) (R = CH3, "C4H9, CH2SiMe3), tC4H9N = VCp2(OtC4H9) (5) and ,tC4H9N = VCp(OtC4H9)2 have been prepared starting from tC4H9N = VCl31H and 51V NMR spectra are discussed; except for 5, the C5H5 rings are η5-coordinated to the metal atom. The temperature dependence of the 1H NMR spectrum of 5 indicates two types o f intramolecular rearrangements: η1/η5-Interchange of the C5H5 rings and fluxional behavior of the η1-C5H5 ring. The molecular structure of 2 has been investigated by X-ray diffraction analysis.

Preparation, properties and structure of some intermediate nido- and arachno-monocarbaboranes

1981 ◽  
Vol 46 (10) ◽  
pp. 2345-2353 ◽  
Author(s):  
Karel Baše ◽  
Bohumil Štíbr ◽  
Jiří Dolanský ◽  
Josef Duben
Keyword(s):  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Nmr Spectra ◽  
Liquid Ammonia ◽  
X Ray Diffraction ◽  
X Ray ◽  
H Nmr ◽  
Starting Compound

The 6-N(CH3)3-6-CB9H11 carbaborane reacts with sodium in liquid ammonia with the formation of 6-CB9H12- which was used as a starting compound for preparing the 4-CB8H14, 9-L-6-CB9H13 (L = (CH3)2S, CH3CN and P(C6H5)3), 1-(η5-C5H5)-1,2-FeCB9H10-, and 2,3-(η5-C5H5)2-2,31-Co2CB9H10- carboranes. The 4-CB8H14 compound was dehydrogenated at 623 K to give 4-(7)-CB8H12 carborane. Base degradation of 6-N(CH3)3-6-CB9H11 in methanol resulted in the formation of 3,4-μ-N(CH3)3CH-B5H10. The structure of all compounds was proposed on the basis of their 11B and 1H NMR spectra and X-ray diffraction was used in the case of the transition metal complexes.

Liquid crystalline polyureas with oligo(ethylene glycol) sequences

e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Shahram Mehdipour-Ataei ◽  
Leila Akbarian-Feizi
Keyword(s):  
Liquid Crystalline ◽  
Spectroscopic Method ◽  
Polymerization Reaction ◽  
X Ray Diffraction ◽  
Subsequent Reaction ◽  
Scanning Calorimetry ◽  
Polar Solvents ◽  
X Ray ◽  
H Nmr ◽  
Ft Ir

AbstractA diamine monomer containing ester, amide and ether functional groups was prepared and its polymerization reaction with different diisocyanates to give main chain poly(ester amide ether urea)s was investigated. The monomer was synthesized via reaction of terephthaloyl chloride with 4-hydroxybenzoic acid and subsequent reaction of the resulted diacid with 1,8-diamino-3,6-dioxaoctane. The polymers were characterized by FT-IR and 1H-NMR spectroscopic method and elemental analysis. The resulting polymers exhibited excellent solubility in polar solvents. Crystallinity of the resulted polymers was evaluated by wide-angle X-ray diffraction (WXRD) method, and they exhibited semi-crystalline patterns. The glass transition temperatures (Tg) of the polymers determined by differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA) were in the range of 88-112 °C. The temperatures for 10% weight loss (T10) from their thermogravimetric analysis (TGA) curves were found to be in the range of 297-312 °C in air. Also the prepared polyureas showed liquid crystalline character.

Organometallic oxides: preparation of the cluster [(η-C5Me5)Mo]4O7 by reduction of [(η-C5Me5)MoCl(O)]2(μ-O) or (η-C5Me5)MoCl2(O)

2000 ◽  
Vol 78 (3) ◽  
pp. 383-394
Author(s):  
Frank Bottomley ◽  
Victor Sanchez ◽  
Robert C Thompson ◽  
Olusola O Womiloju ◽  
Zhiqiang Xu
Keyword(s):  
Nmr Spectra ◽  
Chloroform Solution ◽  
X Ray Diffraction ◽  
Broad Resonance ◽  
Nmr Spectrum ◽  
X Ray ◽  
Temperature Range ◽  
H Nmr ◽  
Tributyltin Hydride ◽  
Effective Moment

Reduction of [(η-C5Me5)MoCl(O)]2(μ-O) or (η-C5Me5)MoCl2(O) with sodium or magnesium amalgam, magnesium turnings, or tributyltin hydride produced [(η-C5Me5)Mo]4O7, with [(η-C5Me5)Mo(O)(μ-O)]2 as a co-product. [(η-C5Me5)Mo]4O7 was characterized by X-ray diffraction, mass spectrometry, 1H NMR and IR spectroscopies, and magnetism. Crystals of [(η-C5Me5)Mo]4O7 contained a tetrahedral [(η-C5Me5)Mo]4 unit (Mo-Mo = 2.909 (3) Å) with the Mo4O7 core having the structure Mo4(μ2-O(b))3(µ2-O(c))3(µ3-O(a)) (3). Microcrystalline samples of [(η-C5Me5)Mo]4O7 were paramagnetic over the temperature range 2-300 K, with an effective moment of 1.26 μB at 300 K. [(η-C5Me5)Mo]4O7 was also paramagnetic in chloroform solution, over the temperature range 223-298 K, with an effective moment of 1.43 µB at 298 K. The 1H NMR spectrum showed a broad resonance at 16.3 ppm (Δν 1/2 = 113 Hz) and two narrow resonances at 1.89 ppm and 1.69 ppm (Δν 1/2 = 5 Hz). The magnetism and NMR spectra showed that [(η-C5Me5)Mo]4O7 existed in two forms which were in equilibrium in solution. One form was paramagnetic (S = 1), with the Mo4O7 core having the geometry 3, and the other was diamagnetic (S = 0), with the Mo4O7 core having the geometry 4.Key words: cluster, cyclopentadienyl, molybdenum, oxide, paramagnetism.

Photoreaktionen von Dekacarbonyldirhenium mit Allen und unverzweigten Allenderivaten / Photoreactions of Decacarbonyldirhenium with Allene and Unbranched Derivatives of Allene

1995 ◽  
Vol 50 (4) ◽  
pp. 649-660 ◽  
Author(s):  
Cornelius G. Kreiter ◽  
Wolfgang Michels ◽  
Gerhard Heeb
Keyword(s):  
Nmr Spectra ◽  
Crystal And Molecular Structure ◽  
Reaction Products ◽  
X Ray Diffraction ◽  
X Ray ◽  
H Nmr ◽  
Oxidative Rearrangement ◽  
Dirhenium Complexes ◽  
Derivatives Of ◽  
By Products

Decacarbonyldirhenium (1) reacts upon UV irradiation with allene (2), 1,2-butadiene (3) and 2,3-pentadiene (4) preferentially by CO substitution and oxidative rearrangement to the corresponding enneacarbonyl-μ-η1:3-endiyl-dirhenium complexes 5, 9, and 15 and to the octacarbonyl-μ-η2:2-allene-dirhenium complexes 6, the stereoisomers 10, 11, and 16. At elevated temperature 5, 9, and 15 loose CO and yield by a reductive rearrangement also the complexes 6, 10, 11, and 16. In addition to these main products, depending upon the allene derivative used, various by-products are obtained.By-products of the reaction o f 1 with 2 are octacarbonyl-μ-η3:3-(2,3-dimethylene-buta-1,4- diyl)dirhenium (7) and μ-η2:2-allene-hexacarbonyl-μ-η1:3-1-propene-1,3-diyl-dirheniurn (8). The photo reaction of 1 with 3 yields, in addition to 9-11, tetracarbonyl-η3-(E-5-ethylidene- 4-methyl-2-cyclopenten-1-yl)rhenium (12) and tetracarbonyl-η3-(Z-5-ethyliden-4- methyl-2-cyclopenten-1-yl)rhenium (13) as a mixture of isomers. 1 and 4 form the by-products tetracarbonyl-η3-(EZ-3-penten-2-yl)rhenium (17), tetracarbonyl-η3-(EE-3-penten-2-yl)rhenium (18) and heptacarbonyl-μ-η1:2:1:2-(4,5-dimethyl-2,6-octadiene-3,6-diyl)dirhenium (19) with an unusually bridging and chelating ligand. The constitutions of the reaction products have been concluded from the IR and 1H NMR spectra. For 19 the crystal and molecular structure has been determined by X-ray diffraction analysis.

Preparation and Crystal Structure of Genistein Benzenesulfonate Prodrugs

2008 ◽  
Vol 2008 (10) ◽  
pp. 555-558 ◽  
Author(s):  
You Peng ◽  
Zeyuan Deng ◽  
Shaojie Lang ◽  
Yawei Fan
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Sulfonic Acid ◽  
Nmr Spectra ◽  
High Yield ◽  
X Ray Diffraction ◽  
Aromatic Rings ◽  
X Ray ◽  
H Nmr ◽  
Ester Prodrugs

In order to improve bioavailability and anticancer activity of genistein, a series of novel sulfonic acid ester prodrugs of the isoflavone genistein were synthesised in high yield with excellent regioselectivity. Their structures were characterised by IR, MS, elemental analysis and 1H NMR spectra. The crystal structure was examined by X-ray diffraction. X-ray structure determination revealed that all the aromatic rings in the compound are not coplanar. In the crystal structure, molecules are linked through intermolecular C-H···O hydrogen bonds, forming layers parallel to the ab plane.

Structure of a pentacyclic triterpenyl angelate from Loeseliamexicana. 1H 2D-NMR data and stereochemistry

1989 ◽  
Vol 67 (12) ◽  
pp. 2071-2077 ◽  
Author(s):  
M. Jiménez E. ◽  
K. Velézquez ◽  
A. Lira-Rocha ◽  
A. Ortega ◽  
E. Díaz ◽  
...  
Keyword(s):  
Nmr Spectra ◽  
Parent Compound ◽  
2D Nmr ◽  
X Ray Diffraction ◽  
Pentacyclic Triterpene ◽  
Nmr Structure Determination ◽  
X Ray ◽  
H Nmr ◽  
Nmr Data ◽  
Unambiguous Assignment

The total assignment of 1H NMR spectra of a pentacyclic triterpene from Loeseliamexicana was performed using selected 2D-NMR experiments (COSY, NOE). X-ray diffraction data were obtained from the parent compound as supplemental information to the NMR investigations. The data allowed for the unambiguous assignment of the structure and the stereochemistry of the title compound. Keywords: pentacyclic triterpene NMR, 2D NMR of terpenes, X-ray of triterpenes, triterpenyl angelate NMR, X-ray -2D NMR structure determination.

Komplexbildung von Rhodium mit 6.6-Dimethylfulven / Complex Formation of Rhodium with 6.6-Dimethylfulvene

1983 ◽  
Vol 38 (11) ◽  
pp. 1454-1459 ◽  
Author(s):  
Jörn Müller ◽  
Rainer Stock ◽  
Joachim Pickardt
Keyword(s):  
Complex Formation ◽  
Diffraction Analysis ◽  
Nmr Spectra ◽  
X Ray Diffraction ◽  
X Ray

Abstract Reaction of [(nbd)RhCl]2 (nbd = nor bornadiene) with CH3Li and 6.6-dimethylfulvene yields (nbd)Rh(2-propenylcyclopentadienyl). (cod)Rh(Cl)P(CH3)3 (cod = 1.5-cyclooctadiene), obtained by cleavage of [(cod)RhCl]2 with P(CH3)3, reacts with 6.6-dimethyl-fulvene and CH3Li or i-C3H7MgBr with substitution of cod by dimeric fulvene ligands the nature of which depends on the alkyl reagent. The new complexes were characterized by NMR spectra and in one case by X-ray diffraction analysis.

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