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1.
Christoph Seger Thomas Pacher Harald Greger Ekarin Saifah Otmar Hofer 《Monatshefte für Chemie / Chemical Monthly》2002,133(1):97-100
Summary. The bisamide aglairubine was isolated from different Aglaia species. The original structure was revised on the basis of FDMS and 2D-NMR data. Since all isolates were obtained from species
belonging to the section Amoora of the genus Aglaia, aglairubine might serve as a taxonomic marker.
Received July 3, 2001. Accepted July 12, 2001 相似文献
2.
Juraj ?ernák Janusz Lipkowski Ivan Poto?ňák Alexander Hudák 《Monatshefte für Chemie / Chemical Monthly》2001,40(5):193-202
[Cu(tn)2Ni(CN)4]2ċ4H2O and Cu(tn)2Ni(CN)4 (tn = 1,3-diaminopropane) were prepared and characterized. The hydrate is unstable on air and readily dehydrates to Cu(tn)2Ni(CN)4. Crystal structure analysis of the hydrate at 150 K revealed a novel tetranuclear molecular structure of the tetracyanonickellate. The building elements are two [Cu(tn)2]2+ cations (coordination numbers of Cu: 5 and 6, respectively), two [Ni(CN)4)2− anions, and crystal water. The two cations are linked by one tetracyanonickellate anion via bridging cyano groups placed in cis positions. The second anion is bound weakly (Cu-N = 2.82 ?) via one μ2-bridging cyano ligand. The tetranuclear molecules and pairs of solvate water molecules are linked by strong hydrogen bonds, thus forming infinite planes which are linked in the third dimension by considerably weaker hydrogen bonds. 相似文献
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Kamal A. Kandeel Ali M. Youssef Hany M. El-Bestawy Mohamed T. Omar 《Monatshefte für Chemie / Chemical Monthly》2002,45(8):1211-1219
N,N-Disubstituted 5-arylmethylidene-2-aminothiazol-4(5H)-ones reacted with diethyl malonate, ethyl benzoylacetate, acetylacetone, or cyclopentadiene in refluxing toluene and in presence of powdered sodium to give the respective 5-arylmethylidene-2′-amino-2,5′-bithiazolylidene-4,4′-dione derivatives in moderate yields. 5-Benzylidene-2-morpholin-4-yl-2-thiazol-4(5H)-one reacted with malononitrile in toluene and in presence of powdered sodium under mild conditions to afford the 1:1 adduct, benzylmalononitrile, and 2-morpholin-4-yl-2-thiazol-4(5H)-one. However, similar treatment of 5-(4-methoxyphenylmethylidene)-2-morpholin-4-yl-2-thiazol-4(5H)-one with malononitrile yielded the 2,5′-bithiazolylidene-4,4′-dione derivative together with 4-methoxyphenylmethylidene malononitrile. Treatment of 5-benzylidene- and 5-(4-methoxyphenylmethylidene)-2-morpholin-4-yl-2-thiazol-4(5H)-ones with 3-phenyl-4-oxo-2-thioxo-1,3-thiazolidine in refluxing toluene and in presence of powdered sodium produced 5-arylmethylidene-3-phenyl-4-oxo-2-thioxo-1,3-thiazolidines in good yields. The structures of all products were deduced from microanalytical and spectroscopic data, mechanistic details are discussed. 相似文献
4.
A new pentadentate tripodal peptide ligand N,N,N′-tri(2-pyridylmethyl)glycinamide (L) has been synthesized. The crystal structure of its nickel(II) complex, [NiL(H2O)] · 1.17ClO4 · 0.17H3O · 0.03H2O (1), has been determined by X-ray diffraction. In the complex, the deprotonated ligand L acts in a pentadentate fashion
and coordinates to the nickel(II) ion through five nitrogen atoms, while the sixth position is occupied by a water molecule.
The units of the complex are connected as a 3D honeycomb network by intermolecular hydrogen bonds. The thermodynamic properties
of the ligand L with the first-series transition metal ions Co(II), Ni(II), Cu(II) and Zn(II) have been investigated by potentiometric
titration and the results show that the order of their stability constants does not conform to the Irving–Williams serial.
The reason why the stability constants of the Cu(II) complex are unconventionally small is proposed. 相似文献
5.
Diana Uría Fernández Valérie Geoffroy Mathias Sch?fer Jean-Marie Meyer Herbert Budzikiewicz 《Monatshefte für Chemie / Chemical Monthly》2003,12(4):1421-1431
The structural revision on the basis of spectroscopic and degradation results of several pyoverdins from Pseudomonas spp. is reported. Siderotyping studies by the isoelectrofocusing technique and by ferri-pyoverdin uptake experiments had prompted a re-investigation of some structures proposed in the literature. 相似文献
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Ana B. Gaspar M. Carmen Mu?oz Nicolás Moliner Vadim Ksenofontov Georgii Levchenko Philipp Gütlich José Antonio Real 《Monatshefte für Chemie / Chemical Monthly》2003,134(2):285-294
Summary. The monomeric compounds [Fe(abpt)2(NCX)2] (X = S (1), Se (2) and abpt = 4-amino-3,5-bis(pyridin-2-yl)-1,2,4-triazole) have been synthesized and characterized. They crystallize in the monoclinic
P21/n space group with a = 11.637(2) ?, b = 9.8021(14) ?, c = 12.9838(12) ?, β = 101.126(14)°, and Z = 2 for 1, and a = 11.601(2) ?, b = 9.6666(14) ?, c = 12.883(2) ?, β = 101.449(10)°, and Z = 2 for 2. The unit cell contains a pair mononuclear [Fe(abpt)2(NCX)2] units related by a center of symmetry. Each iron atom, located at a molecular inversion center, is in a distorted octahedral
environment. Four of the six nitrogen atoms coordinated to the Fe(II) ion belong to the pyridine-N(1) and triazole-N(2) rings
of two abpt ligands. The remaining trans positions are occupied by two nitrogen atoms, N(3), belonging to the two pseudo-halide ligands. The magnetic susceptibility
measurements at ambient pressure have revealed that they are in the high-spin range in the 2 K–300 K temperature range. The
pressure study has revealed that compound 1 remains in high-spin as pressure is increased up to 4.4 kbar, where an incomplete thermal spin crossover appears at around
T
1/2 = 65 K. Quenching experiments at 4.4 kbar have shown that the incomplete character of the conversion is a consequence of
slow kinetics. Relatively sharp spin transition takes place at T
1/2 = 106, 152 and 179 K, as pressure attains 5.6, 8.6 and 10.5 kbar, respectively.
Corresponding author. E-mail: jose.a.real@uv.es
Received June 12, 2002; accepted July 1, 2002 相似文献
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11.
Othman Al-Flaijj Mohamed R. Shehata Mahmoud M. A. Mohamed Mohamed M. Shoukry 《Monatshefte für Chemie / Chemical Monthly》2001,39(1):349-366
The interaction of dimethyltin(IV) (DMT) with some selected DNA constituents was investigated potentiometrically. The stepwise formation constants of the complexes were determined, and
the concentration distribution of the various complex species was evaluated as a function of pH. The effect of dioxane on the protonation constants of the ligands and the formation constants of dimethyltin(IV) complexes
are discussed. The thermodynamic parameters Δ H° and ΔS° were calculated from the temperature dependence of the equilibrium
constants. 相似文献
12.
Huda A. R. Farid Olaf Kunert Ernst Haslinger Christoph Seger 《Monatshefte für Chemie / Chemical Monthly》2002,53(2):1453-1458
Besides a known coumarin derivative, scopoletin, the iridoids gardenoside, α- and β-gardiol were isolated for the first time from a Xeromphis species, namely Xeromphis nilotica. Their structures were established on the basis of their spectroscopic data. 相似文献
13.
Dalia R. Imam Ahmed A. El-Barbary Claus Nielsen Erik B. Pedersen 《Monatshefte für Chemie / Chemical Monthly》2002,30(6):723-734
5-Isopropyl-6-naphthyl uracil and 5-isopropyl-6-naphthyl-2-thiouracil were alkylated to give N-1-(ethoxymethyl and methylthiomethyl) uracil and S2-cyclohexyl-thiouracil, respectively. 5-Ethyl-6-naphthyl uracil and 5-ethyl-6-naphthyl-2-thiouracil afforded N-1-(ethoxymethyl, methoxy-methyl, methylthiomethyl, acetoxyethoxy methyl and hydroxyethoxy methyl) uracil and S2-((2,2- diethoxyethyl), methoxycarbonylmethyl, ethoxycarbonylpropyl, methylthiomethyl, ethoxymethyl, methyl and cyclohexyl)-thiouracil upon alkylation. 相似文献
14.
Ab initio HF/6-31G* and MP2/6-31G*//HF/6-31G* methods were used to calculate the structure optimization and conformational interconversion pathways for all-(Z )-cyclododeca-1,4,7,10-tetraene. This compound adopts the symmetrical crown (C 4v) conformation. Ring inversion takes place via symmetrical intermediates, such as boat-chair (BC, C s) and twist (C 2h) conformers and requires about 22.3 kJ · mol−1. The calculated strain energies for BC and twist conformers are 5.9 and 13.5 kJ · mol−1. The results of semiempirical AM1 calculations for structural parameters and relative energies of the important geometries of the title compound are in good agreement with the results of ab initio methods. 相似文献
15.
《Monatshefte für Chemie / Chemical Monthly》2002,165(2):1177-1185
Novel N-(3-oxobutyl)-hydroxy- and acetoxypyrido[2,3-d]pyridazinones were synthesized and tested in vivo for their sedative and anticonvulsant activity. The Michael-type reaction of quinolinic acid hydrazide and methyl vinyl ketone afforded a mixture of two isomers, 5-hydroxy-N 7-(3-oxobutyl)-pyrido[2,3-d]pyridazin-8(7H)-one and 8-hydroxy-N 6-(3-oxobutyl)-pyrido[2,3,-d]pyridazin-5-(6H)-one, in a ratio of 2:1 which were separated by crystallization. Subsequent acetylation of both isomers yielded the corresponding 5- and 8-acetoxy compounds. The structures of the compounds were proven and completely assigned on the basis of 1H, 13C, 15N NMR, and 1D NOE difference spectra as well as 2D C,H-correlation experiments. Preliminary pharmacological tests showed low acute toxicity with a LD 50 > 1000 mg/kg in the mouse and sedative activity for the title compounds. 5-Acetoxy-N 7- (3-oxobutyl)-pyrido[2,3-d]pyridazin-8(7H)-one displayed a borderline anticonvulsant activity in the metrazole test model. 相似文献
16.
This article describes the synthesis of a new (2E,3E,6R,9E,11E)-6-isopropenyl-3,6,10-trimethyl-5,8-dioxa-4,9-diazadodeca-3,9-diene-2,11-dione dioxime (H2hmdm), and its mono-, homo, and heterodinuclear copper(II)/nickel(II) complexes. Elemental analyses, stoichiometric and spectroscopic
data of the metal complexes indicated that the metal ions are coordinated to the oxime and imine nitrogen atoms (C=N). The
Cu(H2hmdm), molecule coordinates to the second copper(II) ion through the oximate oxygens to afford a binuclear structure doubly
bridged by the oximate groups in the cis arrangement. In the dinuclear complexes, in which the first CuII ion was complexed with nitrogen atoms of the oxime and imine groups, the second CuII ion is ligated with the 1,10-phenanthroline nitrogen atoms. Ligand and its mononuclear copper(II), homo and heterodinuclear
copper(II)–nickel(II) complexes of (H2hmdm) were characterized by elemental analyses, magnetic moments, 1H-n.m.r. and 13C-n.m.r., i.r., and mass spectral studies. The data support the proposed structure of H2hmdm and its complexes. 相似文献
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Roland A. Obermüller Thomas G. Dax Heinz Falk 《Monatshefte für Chemie / Chemical Monthly》2001,5(2):1057-1062
When 1-methoxy-2-naphthalene carboxylic acid diethylamide was reacted with tert-butyl lithium in presence of TMEDA and 3,5-dimethoxybenzaldehyde was subsequently added to the reaction mixture, (P, S/M, R)- and (P, R/M, S)-1-tert-butyl-3-((3,5-dimethoxyphenyl)-hydroxymethyl)-naphthalene-2-carboxylic acid diethylamide were formed instead of the corresponding 1-methoxy derivative. The diastereomeric relationship of the products is due to a sterically severely hindered rotation around the amide-aryl bond. 相似文献
19.
Christoph Seger Otmar Hofer Harald Greger 《Monatshefte für Chemie / Chemical Monthly》2000,131(11):1161-1165
Summary. The structure of aglalactone, a dihydrobenzofuranone from Aglaia elaeagnoidea, was revised on the basis of 2D NMR data and lanthanide induced shifts (LIS).
Received June 29, 2000. Accepted July 11, 2000 相似文献
20.
Christoph Seger Otmar Hofer Harald Greger 《Monatshefte für Chemie / Chemical Monthly》2000,119(Z3):1161-1165
The structure of aglalactone, a dihydrobenzofuranone from Aglaia elaeagnoidea, was revised on the basis of 2D NMR data and lanthanide induced shifts (LIS). 相似文献