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1.
A new chromone-substituted dihydrotriflavonol, (2S,3S)[6-{(3S) 3″,5″-dihydroxy-6″-methoxydihydrochromone}5,3′,4′,5′-tetrahydroxy-7-methoxy-3-O-8-dihydroflavone]2 3-O-8[6-{(3S) 3″,5″-dihydroxy-6″methoxydihydrochromone}3,5,3′,4′,5′-pentahydroxy-7-methoxydihydroflavonol] was isolated from the leaves
of Anogeissus pendula. The structure was determined by UV, 1H NMR, 13C NMR, HMBC, and CD data. 相似文献
2.
Vadim A. Pestunovich Nataliya F. Lazareva Alexander I. Albanov 《Monatshefte für Chemie / Chemical Monthly》2006,137(8):1005-1013
Summary. The first representative of the N-silylmethylamides of phosphoric acid O=P[NMe(CH2SiMe
n
(OEt)3-n
]3 have been synthesized by interaction of MeNHCH2SiMe
n
(OEt)3-n
(n = 2, 3) with POCl3. The interaction of the N,N′,N″-trimethyl-N,N′,N″-tris[(ethoxydimethyl- silyl)methyl]triamide phosphoric acid with BF3·Et2O or BCl3 results in the formation of the N,N′,N″-trimethyl-N,N′,N″-tris[(fluorodimethyl-silyl)methyl]triamide phosphoric acid or N,N′,N″-trimethyl-N,N′,N″-tris[(chlorodimethylsilyl)methyl]triamide phosphoric acid. NMR data show on the tetracoordinate state of silicon in these
products.
Professor Vadim Aleksandrovich Pestunovich, our chief, teacher and friend died on July 4th, 2004 相似文献
3.
Vadim A. Pestunovich Nataliya F. Lazareva Alexander I. Albanov 《Monatshefte für Chemie / Chemical Monthly》2006,57(7):1005-1013
The first representative of the N-silylmethylamides of phosphoric acid O=P[NMe(CH2SiMe
n
(OEt)3-n
]3 have been synthesized by interaction of MeNHCH2SiMe
n
(OEt)3-n
(n = 2, 3) with POCl3. The interaction of the N,N′,N″-trimethyl-N,N′,N″-tris[(ethoxydimethyl- silyl)methyl]triamide phosphoric acid with BF3·Et2O or BCl3 results in the formation of the N,N′,N″-trimethyl-N,N′,N″-tris[(fluorodimethyl-silyl)methyl]triamide phosphoric acid or N,N′,N″-trimethyl-N,N′,N″-tris[(chlorodimethylsilyl)methyl]triamide phosphoric acid. NMR data show on the tetracoordinate state of silicon in these
products. 相似文献
4.
The yellow parts of the flowers of Asystasia gangetica were extracted with 85% methanol under reflux. The alcoholic extract was concentrated in vacuo and the aqueous extract was fractionated with solvents of increasing polarity. The ethyl acetate fraction yielded a yellow
solid, which was characterized as apigenin 7-O-glucosyl(3′ → 6″)luteolin 7″-O-glucoside using UV, 1H, 1H–1H COSY, 13C NMR, and mass spectral studies. 相似文献
5.
A series of novel fluorinated poly(ether ketone amide)s (PEKAs) were prepared from an unsymmetrical aromatic diamine, (4′-(4″-amino-2″-trifluoromethylphenoxy)-3′,5′-dimethylphenyl)(4-aminophenyl)-methanone
(1), with various aromatic dicarboxylic acids using the phosphorylation polycondensation technique. The PEKAs had inherent viscosities
ranging from 0.43 to 0.65 dl/g. All the fluorinated PEKAs could be soluble in many polar organic solvents such as N-methyl-2-pyrrolidinone (NMP), N,N′-dimethylacetamide (DMAc), N,N′-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), and tetrahydrofuran (THF). Flexible and tough polymer films could be
prepared by casting from DMAc solvent. The PEKA films exhibited high optical transparency with a cutoff wavelength of 354–365 nm
and good mechanical properties with tensile strengths of 78–98 MPa and elongations at break of 11.5–18.5%. They showed glass-transition
temperatures in the range of 288−323 °C and the onset decomposition temperatures in the range of 450−461 °C in nitrogen atmosphere.
Meanwhile, the PEKA films possessed low dielectric constants of 1.98–2.71 at 1 MHz and low moisture absorption (<2%). Due
to their properties, the fluorinated PEKAs could be considered as photoelectric and microelectronic materials. 相似文献
6.
B. Venkateswara Rao 《Journal of Thermal Analysis and Calorimetry》2010,100(2):577-587
Co(II), Ni(II), Cu(II) and Cd(II) chelates with 1-aminoethylidenediphosphonic acid (AEDP, H4L1), α-amino benzylidene diphosphonic acid (ABDP, H4L2), 1-amino-2-carboxyethane-1,1-diphosphonic acid (ACEDP, H5L3), 1,3-diaminopropane-1,1,3,3-tetraphosphonicacid (DAPTP, H8L4), ethylenediamine-N,N′-bis(dimethylmethylene phosphonic)acid (EDBDMPO, H4L5), O-phenylenediamine-N,N′-bis(dimethyl methylene phosphonic)acid (PDBDMPO, H4L6), diethylene triamine-N,N,N′,N′,N″N″-penta(methylene phosphonic)acid (DETAPMPO, H10L7) and diethylene triamine-N,N″-bis(dimethyl methylene phosphonic)acid (DETBDMPO, H4L8) have been synthesised and were characterised by elemental and thermal analyses as well as by IR, UV–VIS, EPR and magnetic
measurements. The first stage in the thermal decomposition process of these complexes shows the presence of water of hydration,
the second denotes the removal of the coordinated water molecules. After the loss of water molecules, the organic part starts
decomposing. The final decomposition product has been found to be the respective MO·P2O5. The data of the investigated complexes suggest octahedral geometry with respect to Co(II) and Ni(II) and tetragonally distorted
octahedral geometry with respect to Cu(II). Antiferromagnetism has been inferred from magnetic moment data. Infrared spectral
studies have been carried out to determine coordination sites. 相似文献
7.
Guido Kickelbick Dieter Rutzinger Thomas Gallauner 《Monatshefte für Chemie / Chemical Monthly》2002,133(8):1157-1164
Summary. Hexadentate ligands were formed by the reaction of primary dimethylaminoethyl- or methoxyethylamines with formaldehyde. The
resulting N, N′, N″-functionalized hexahydro-1,3,5-triazines contain pending amino or ether functionalities which are able to coordinate to
metals in addition to the ring nitrogen atoms. Both ligands were reacted with CuBr, and novel tricopper clusters were isolated
and characterized by X-ray structure analysis. In these compounds a ring nitrogen atom, the pending amino or ether functionality,
and two bridging bromine atoms coordinate each of the copper atoms.
Received January 22, 2002; accepted (revised) March 22, 2002 相似文献
8.
A. L. Kurlovich V. A. Tarasevich N. G. Kozlov 《Russian Journal of Organic Chemistry》2009,45(10):1503-1508
Condensation of 2′-hydroxy-1,1′: 3′,1″-terphenyl-5′-carbaldehyde with naphthalen-1-amine and cyclohexane-1,3-dione, methyl
2,2-dimethyl-4,6-dioxocyclohexane-1-carboxylate, or dimedone gave the corresponding 7-(2′-hydroxy-1,1′: 3′,1″-terphenyl-5′-yl)-7,8,9,10,11,12-hexahydro-12H-benzo[c]acridin-8-ones. The reaction of 2′-hydroxy-1,1′: 3′,1″-terphenyl-5′-carbaldehyde with naphthalen-1-amine and indan-1,3-dione
produced 7-(2′-hydroxy-1,1′: 3′,1″-terphenyl-5′-yl)-8H-benzo[h]indeno[1,2-b]quinolin-8-one. 7-(2′-Hydroxy-1,1′: 3′,1″-terphenyl-5′-yl)-7,8,9,10,11,12-hexahydrobenzo[b][1,10]phenanthrolin-8-ones were obtained by three-component condensation of 2′-hydroxy-1,1′: 3′,1″-terphenyl-5′-carbaldehyde
with quinolin-8-amine and cyclohexane-1,3-dione, methyl 2,2-dimethyl-4,6-dioxocyclohexane-1-carboxylate, or dimedone. 相似文献
9.
D. V. Kuznetsov S. A. Andreev A. K. Tashmukhamedova 《Chemistry of Natural Compounds》2006,42(5):515-516
Diazonium salts were prepared by diazotization of 4′-amino-, 4′,4″-, and 4′,5″-diaminodibenzo-18-crown-6. Their coupling products
with kojic acid (5-hydroxy-2-hydroxymethyl-γ-pyrone) were synthesized for the first time: 4′-(6-aza-5-hydroxy-2-hydroxymethyl-γ-pyronyl)-, 4′,4″-di-(6-aza-5-hydroxy-2-hydroxymethyl-γ-pyronyl)-, and 4′,5″-di-(6-aza-5-hydroxy-2-hydroxymethyl-γ-pyronyl)-dibenzo-18-crown-6.
__________
Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 415–416, September–October, 2006. 相似文献
10.
Lutz Preu Wolfgang Kliegel Steven J. Rettig James Trotter 《Monatshefte für Chemie / Chemical Monthly》2001,132(10):1213-1224
Summary. The structure of the dehydrogenation product 1′,3a′-dihydro-3′-((1,3-dioxoindan-2-ylidene)-phenyl-methyl)-5′-phenyl-spiro-(indan-2,1′-pyrrolo[3,4-c]pyrrole)-1,3,4′,6′-(5′H, 6a′H)-tetrone derived from the cycloadducts (±)-(3a′S,6a′R)-1′,3a′-dihydro-3′-((R)-α-(1,3-dioxoindanyl)-benzyl)-5′-phenyl-spiro-(indan-2,1′-pyrrolo[3,4-c]pyrrole)-1,3,4′,6′(5H,6a′H)-tetrone and/or (±)-(3a′S,6a′R)-1′,3a′-dihydro-3′-((S)-α-(1,3-dioxoindanyl)-benzyl)-5′-phenyl-spiro-(indan-2,1′-pyrrolo[3,4-c]pyrrole)-1,3,4′,6′(5H,6a′H)-tetrone, which were synthesized by 1,3-dipolar cycloaddition of N-phenylmaleimide to 2-((2-(1,3-dioxoindan-2-yl)-2-phenyl-ethenyl)-imino)-indan-1,3-dione,
was determined by X-ray analysis. Crystal data (CCD, 180 K): rhombohedral, R&3macr;;, a = 34.0871(7), c = 13.9358(5) ?, Z = 18; the structure was solved by direct methods and refined by full-matrix least-squares procedures to R(F, I ≥ 3σ(I)) = 0.053. The molecule contains a central folded ring system of two cis-fused 5-membered heterocyclic rings; each ring is nearly planar, and the angle between the rings amounts to 59.0°. Dynamic
1H NMR spectroscopy of the product revealed an exchange process caused by restricted rotation of the double bonded 1,3-indandione
moiety and the phenyl group about the Csp2-Csp2 single-bonds. Molecular modeling and complete lineshape analysis indicated a four site exchange process for which free energies
of activation and free energies could be established. ΔG
‡ values for the barriers of rotation are in the range of 57–59 kJ · mol − 1 at 273 K, which is unusually high for an unsubstituted phenyl group.
Received May 3, 2001. Accepted (revised) June 8, 2001 相似文献
11.
Kukharev B. F. Stankevich V. K. Klimenko G. R. Lobanova N. A. Kovalyuk E. N. Negoda A. Yu. Stankevich V. V. Bragin E. V. 《Russian Journal of Applied Chemistry》2010,83(9):1666-1667
N-(2-Vinyloxyethyl)-N′-cyclohexylidene-1,2-ethylenediamine and N,N′,N″-tris-[2-(2-vinyloxyethyl)-aminoethyl]hexahydro-1,3,5-triazine were synthesized by reactions of N-(2-vinyloxyethyl)-1,2-ethylenediamine with cyclohexanone and formaldehyde with yields of 91 and 90%, respectively. The IR
and 1H and 13C NMR spectral data and the results of studying their anticorrosion properties are given. 相似文献
12.
E. L. Cavalieri E. C. Vauthier A. Cossé-Barbi S. Fliszár 《Theoretical chemistry accounts》2000,104(3-4):235-239
Self-consistent-field computations shed light on two relevant conformations of deoxyadenosine (dA) and deoxyguanosine (dG):
one with a pseudoequatorial C1′N9 glycosyl bond and the other, a slightly more stable one, with its C1′N9 bond in a bisectional orientation. In dA, both the N3 and N7 nitrogens are plausible sites for electrophilic attack, but only N7 is a plausible site in dG. The addition of H+, CH3
+, C2H5
+ or tert-C4H9
+ onto N7 does not provoke notable structural modifications and leaves the base of dA and dG in an antiperiplanar (or nearly antiperiplanar)
position with respect to the sugar C1′O4′ bond, but N3 additions cause the base to adopt a synperiplanar or strongly chiral position. This produces strong interactions between
the purine and deoxyribose moieties, whose relief could aid the eventual cleavage of the glycosyl bond of dA. Addition of
a radical cation onto N7 reduces the dissociation energy of the glycosyl bond by an estimated 8 kcal mol−1 in dA and 4 kcal mol−1 in dG – a bond weakening likely to concur to a depurination of DNA induced by radical cations.
Received: 13 September 1999 / Accepted: 3 February 2000 / Published online: 21 June 2000 相似文献
13.
I. V. Rudenko A. A. Kucherak A. A. Tolmachev O. V. Hordiyenko 《Chemistry of Heterocyclic Compounds》2011,47(8):964-969
An efficient method has been developed for the synthesis of 4,6-dimethylpyridine-2,3-dicarbonitrile. A study was carried out
on the reaction of this compound with N-acylhydrazines to give two structural isomers, namely, N′-(7-amino-2,4-dimethyl-5H-pyrrolo[3,4-b]pyridin-5-ylidene)carbohydrazides and N′-(5-amino-2,4-dimethyl-7H-pyrrolo[3,4-b]pyridin-7-ylidene)carbohydrazides as well as disubstituted N′,N″-(2,4-dimethyl-5H-pyrrolo[3,4-b]pyridine-5,7-diylidene)dicarbohydrazides. 相似文献
14.
Anna Kamecka Barbara Kurzak Julia Jezierska Agnieszka Wo?na Marcin Broda 《Structural chemistry》2010,21(2):347-355
Solution equilibrium studies on the Cu(II)-polyamine-(aminomethyl)phosphonic acid (glycinephosphonic acid) ternary systems
(polyamine: ethylenediamine (en), diethylenetriamine (dien), N,N,N′,N′,N″-pentamethyldiethylenetriamine (Me5dien)) have been performed by pH-potentiometry, UV–vis spectrophotometry and EPR methods. The obtained results suggest the
formation of the heteroligand complexes with [Cu(A)(Gly(P))] stoichiometry in all studied systems. Additionally, in the systems
with dien the protonated [Cu(dien)(H–Gly(P))]+ species also exists in acid solution and in the system with en the [Cu(en)(Gly(P))H-1]− species is formed in the basic solution. Our spectroscopic results indicate the tetragonal geometry for the [Cu(en)(Gly(P))]
species, the geometry slightly deviated from square pyramidal for the [Cu(dien)(Gly(P))] complex and strongly deviated from
square pyramidal towards trigonal bipyramidal for the [Cu(Me5dien)(Gly(P))] species. The coordination modes in these heteroligand complexes are discussed. 相似文献
15.
An Cu(II)-imprinted interpenetrating polymer network (IPN) gel of epoxy-diethylenetriamine and methacrylic acid-acrylamide-N,N′-methylene-bis-(acrylamide) was synthesized by the ionic imprint polymer (IIP) technique. The first polymer network is formed by epoxy gelation
with diethylenetriamine. The other is formed by copper methacrylate co- polymerization with acrylamide and cross-linker N,N′-methylene-bis-(acrylamide). The adsorption–desorption characteristics of the IPN gel as a highly selective solid-phase extraction (SPE)
and preconcentration adsorbent for Cu2+ from aqueous solution were investigated. The experimental results show that trace Cu2+ ions can be quantitatively enriched at pH 5 with recovery >95%. The maximum static adsorption capacity of the ion-imprinted
functionalized gel adsorbent was 76 mg g−1. Comparing with non-imprinted IPN gel, the imprinted IPN gel has higher adsorption capacity and selectivity for Cu2+ by the static adsorption–desorption experiment. Simultaneously, the times of adsorption equilibration and complete desorption
were remarkably short. The precision (RSD) for 11 replicate adsorbent extractions of 20 ng mL−1 Cu2+ was 3.4%. The established procedure was applied to two real water samples with satisfactory results. The prepared ion-imprinted
IPN gel adsorbent was shown to be promising for solid-phase extraction coupled with atomic absorption spectrometry (AAS) for
the determination of trace copper in real samples. In addition, the coordination interaction of Cu2+ and functional groups of the IPN gel adsorbent was primarily discussed by FT-IR spectra. 相似文献
16.
Two new steroidal glycosides (1 and 2) have been isolated from the ethanolic extract of the stem bark of Mimusops elengi L. and characterized as stigmasta-5,22-dien-3β-ol-3β-D-glucuropyranosyl-(6′β→1″)-D-glucopyranoside (1) and β-sitosterol-3β-(3″′,6″′,7″′-trihydroxynaphthyl-2″′-carboxyl)-4″-glucopyranosyl-(1″→4′)-glucopyranoside (2) along with the known compounds stigmasta-5-en-3β-ol, lup-20(29)-en-3β-ol, and stigmasta-5-en-3β-D-glucopyranoside. Their
structures have been elucidated on the basis of spectral data analysis and chemical reactions. 相似文献
17.
Agata Trzesowska-Kruszynska 《Structural chemistry》2011,22(3):525-535
The crystal and molecular structures of nicotinohydrazide-derived hydrazones, N′-(2-furfurylidene)pyridine-3-carbohydrazide and N′-(1-(2-thienyl)ethylidene)pyridine-3-carbohydrazide, have been determined. The compounds have been also characterized by
the solid state IR and UV–Vis spectroscopy. The hydrazones exist in the keto-amine form. According to the results of molecules
quantum–mechanical calculations, performed for isolated molecules, this tautomeric form is energetically unfavorable but in
the solid and solution states the observed intermolecular interactions support the presence of this form. The furan derivative
crystallizes in two polymorphic forms with two molecules in an asymmetric unit regardless of the crystallization method. 相似文献
18.
Euchrenone a2 (7) isolated from the roots ofEuchresta japonica has been synthesised from 3-prenylphloroacetophenone (1) by other workers. We carried out its cyclodehydrogenation with dichloro dicyano quinone (DDQ) to obtain 6-acetyl-5,7-dihydroxy-2,2-dimethylchromene
(2) which was ethoxymethylated in the 7-position to give 6-acetyl-7-ethoxymethoxy-5-hydroxychromene (3). Chalcone condensation of3 and 4-ethoxymethoxy-3-C-prenylbenzaldehyde (4) gave 4,6′-bisethoxymethoxy-2′-hydroxy-6″, 6″-dimethyl-3-C-prenylpyrano (2″, 3″–4,3) chalcone (5) which cyclised with methanolic sodium acetate to give protected 5,4′-bisethoxymethoxy-6″, 6″-dimethyl-3′-C-prenylpyrano (2″, 3″–7,8) flavanone (6). Deprotection of6 with 4% methanolic HCl yielded (7) with melting point and spectral data identical to that of the natural compound. 相似文献
19.
N. M. Kurochkina V. E. Baulin E. N. Pyatova I. S. Ivanova A. Yu. Tsivadze 《Russian Journal of Coordination Chemistry》2010,36(4):241-248
Sodium and potassium complexes with 4′-(4‴-benzo-15-crown-5)methyloxy-2,2′:6′,2″-terpyridine (L1) and 4′-(4′-benzo-15-crown-5)oxy-2,2′:6′,2″-terpyridine (L2) and heteronuclear Na, K, Ca, and transition metal complexes with L1 were synthesized. The structure of the complexes was proposed on the basis of elemental analysis data, IR spectra, and the
results of earlier X-ray diffraction studies of L2, [NaL1NCS], and [Na2{Cu(L1)2}(NCS)3]NCS · CH3CN. 相似文献
20.
Solution equilibrium studies on Cu2+–L1–L2 ternary systems have been performed by pH-potentiometry, UV–Vis spectrophotometry and EPR methods (L1 corresponds to polyamines such as ethylenediamine (en), diethylenetriamine (dien), or N,N,N′,N′,N″-pentamethyldiethylenetriamine (Me5dien) and L2 represents 1-aminoethylphosphonic acid (α-alaninephosphonic acid)). The obtained results suggest the formation of heteroligand complexes with [Cu(L1)(α-Ala(P))] stoichiometry in all studied systems. Additionally, in the system with en the [Cu(en)(α-Ala(P))H−1]− species is formed in basic solution. Our spectroscopic results indicate tetragonal geometry for the [Cu(en)(α-Ala(P))] species, geometry slightly deviated from square pyramidal for the [Cu(dien)(α-Ala(P))] complex and strongly deviated from square pyramidal towards trigonal bipyramidal for the [Cu(Me5dien)(α-Ala(P))] species. The coordination modes in these heteroligand complexes are discussed. 相似文献