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Maria Gdaniec Tomasz Bytner Monika Szyrszyng Tadeusz Połonski 《Journal of inclusion phenomena and macrocyclic chemistry》2001,40(3):243-247
The crystalline inclusion compounds of cholic acid (CA) and deoxycholic acid (DCA) with several nitrosobenzenes were prepared. The IR spectra and crystal structures of these compounds confirmed inclusion of the monomeric form of the C-nitroso compounds. The DCA compounds have 2 : 1 host:guest stoichiometry and P21 symmetry. Guest molecules are enclosed in channels and disordered. In the CA-nitrobenzene inclusion compound (1·CA) the host:guest stoichiometry is 1 : 1. The host molecules form typical CA bilayer aggregates and guest molecules are accommodated in helicoidal channels. The guest nitroso group is not coplanar with the phenyl ring; the torsion angle on the C–N bond is 8.6(8)°. The solid-state circular dichroism spectrum of 1·CA shows the negative Cotton effect at 780 nm corresponding to the n–* electronic transition that can be associated with the P helicity of the guest molecule. The extremely weak magnitude of the Cotton effects exhibited by the DCA complexes points to a nearly planar arrangement of the NO group and the phenyl ring in the guest molecules. 相似文献
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Judit Orgoványi L. Pöppl Klára H.-Otta G. A. Lovas 《Journal of Thermal Analysis and Calorimetry》2005,81(2):261-266
The interaction of cypermethrin with β-cyclodextrin was investigated using different (coprecipitation, suspension, kneading and ‘melting in solution’) complexation methods and qualifying the resulted complexes by UV-spectrophotometry, thermal methods (TG, DTG and DSC) and X-ray powder diffraction. The total guest content of complexes can be measured by UV-spectrophotometry in aqueous ethanol solution, while the uncomplexed guest fraction of samples can be determined by DSC based on a previous calibration curve, which was found between the melting enthalpy change of cypermethrin and the guest content of physical mixture samples. The combination of both analytical methods enables the determination of really complexed guest content. 相似文献
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David B. Hobart Jr. Michael A. G. Berg Hannah M. Rogers Joseph S. Merola 《Molecules (Basel, Switzerland)》2021,26(14)
The reaction of palladium(II) acetate with acyclic amino acids in acetone/water yields square planar bis-chelated palladium amino acid complexes that exhibit interesting non-covalent interactions. In all cases, complexes were examined by multiple spectroscopic techniques, especially HRMS (high resolution mass spectrometry), IR (infrared spectroscopy), and 1H NMR (nuclear magnetic resonance) spectroscopy. In some cases, suitable crystals for single crystal X-ray diffraction were able to be grown and the molecular structure was obtained. The molecular geometries of the products are discussed. Except for the alanine complex, all complexes incorporate water molecules into the extended lattice and exhibit N-H···O and/or O···(HOH)···O hydrogen bonding interactions. The non-covalent interactions are discussed in terms of the extended lattice structures exhibited by the structures. 相似文献
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M. Fodor Cs. Novák R. Ràkosa K. Tomor G. Pokol S. Gál 《Journal of Thermal Analysis and Calorimetry》1997,48(3):515-525
In the present study the solid and liquid phase behaviour of mandelic acid cyclodextrin systems were studied. The samples were prepared using dry grinding/kneading technique in the absence of any solvent. Thermoanalytical methods (TG, DSC, EGD) were used to characterise the solid compounds. In liquid phase the stoichiometry and the stability constants of the complexes formed were determined using UV spectrophotometry. Partial complex formation was found in case of all cyclodextrins used. The amount of uncomplexed mandelic acid varied between 10–20% of the total guest content. 相似文献
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Orm Hager AntonioL. Llamas-Saiz Concepcin Foces-Foces RosaM. Claramunt Concepcin Lpez Jos Elguero 《Helvetica chimica acta》1999,82(12):2213-2230
The crystal and molecular structure of two salts, I and III , and one molecular complex, II , formed by combining 1,1′-binaphthyl-2,2′-dicarboxylic acid (BNDA) with pyrazole ( 3 ) and 3,5-dimethylpyrazole ( 4 ) has been determined by X-ray crystallography. The most striking feature is the spontaneous resolution of the racemic BNDA host by co-crystallization with 4 , an achiral guest, to form the salt III . The absolute configuration of three manually selected crystals of III have been established by crystallographic methods. The two crystals formed by the (P)-enantiomer display a negative Cotton effect. 13C-CPMAS-NMR Spectroscopy has been used to compare the compounds obtained by crystallization with those prepared by mechanical grinding. 相似文献
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Mohamed A. S. Goher Franz A. Mautner Thomas C. W. Mak Morsy A. M. Abu-Youssef 《Monatshefte für Chemie / Chemical Monthly》2003,134(12):1519-1527
Summary. Three new complexes, namely [(nicotinic acid)2H]+I–, [(2-amino-6-methylpyridine)H]+ (NO3)–, and the 1:1 complex between 1-isoquinoline carboxylic acid (zwitter ion form) and L-ascorbic acid were synthesized. The IR spectra revealed different types of hydrogen bonds in these compounds. The X-ray structure determination has shown the first compound to consist of a packing of [(nicotinic acid)2H]+ cations and I– anions. In the dimeric cation the two nicotinic acid molecules (zwitter ions) are connected through hydrogen bonds (O–HO). Each dimer is further engaged in other hydrogen bonds with adjacent dimers giving 2D layers. The I– ion is located at the inversion center. In the second compound the cation and anion are connected via hydrogen bonds formed between oxygen atoms of the NO3
– anion and NH and NH2 of the cation generating a layer structure. All atoms are coplanar on mirror planes. In the 1:1 complex the two molecules are connected through hydrogen bonds formed between the two oxygen atoms of the carboxylate group of 1-isoquinoline carboxylic acid (zwitter ion) and the oxygen atoms of the two adjacent hydrogen groups of the L-ascorbic acid molecule. These complex molecules are engaged in other hydrogen bonds with each other forming a 2D system normal to the long b-axis of the unit cell. 相似文献
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En Ju Wang Guang Ying Chen 《中国化学快报》2011,22(7):847-850
The inclusion complex ofβ-cyclodextrin(β-CD) with 4-chlorobenzoic acid was synthesized and its crystal structure was determined by single crystal X-ray diffraction under cryogenic condition.The complex contains twoβ-CDs,two 4-chlorobenzoic acids and twenty-nine water molecules in the asymmetric unit,and can be formulated as 2(C42H70O35)·2(C7H5O2Cl)·29(H2O).In the crystal lattice,twoβ-CDs form a face-to-face dimer jointed together through hydrogen bonding between the secondary hydroxyl groups ofβ-CDs.Two 4-chlorobenzoic acid molecules which contact by C-Cl…πinteractions are included in theβ-CD dimer cavity.Theβ-CD dimers are arranged in brickwork-like pattern along the crystallographic a-axis.The effect of guest molecule length on the inclusion geometry was discussed by comparative study of someβ-CD complexes containing similar guests. 相似文献
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Summary Salicylic acid (SA) is a signaling compound in plants such as tobacco, cucumber, and tomato which can induce systemic acquired resistance. In the work discussed in this paper a simple, rapid, and sensitive method was developed for determination of salicylic acid in plant tissues by gas chromatography–mass spectrometry (GC–MS). SA from tomato leaves extracted with 9:1 (v/v) methanol–chloroform was derivatized by use of bis(trimethylsilyl)trifluoroacetamide (BSTFA) under the optimum reaction conditions (120 °C, 60 min). Quantitative analysis by GC–MS was performed in selected ion monitoring (SIM) mode using an internal standard. Procedures for sample preparation and reaction conditions were optimized. Analysis was completed within 2 h. A sensitivity of 10 ng g–1 fresh weight and a relative standard deviation less than 5.0% for SA in tomato leaves were achieved. The method could be used for investigation of SA in plant tissues to monitor fast responses of plant defense. 相似文献
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N-苯基亚氨基二乙酸镍二维网状配合物的合成及结构表征(英) 总被引:6,自引:0,他引:6
A new nickel(Ⅱ) coordination compound [Ni(L2-)(2,2′-bipy)(H2O)]·2H2O (H2L=phenyliminodiacetic acid) was obtained by self-assembly of phenyliminodiacetic acid, 2,2′-bipy, and NiCl2·6H2O in the mixed solvent of water and ethanol (V∶V=1∶1). The complex was characterized by elemental analysis, IR spectra, and X-ray crystallography analysis. The crystal is monoclinic, space group P21 /c with a=0.867 4(2) nm, b=0.907 3(1) nm, c=2.643 5(5) nm, β=91.01(1)°, V=2.080 2(4) nm3, Z=4, F(000)=992, Dc=1.520 Mg·m-3, R1=0.027 0 and wR2=0.067 5. In the complex, nickel (Ⅱ) atom is coordinated with a distorted octahedral geometry and extensive hydrogen bonds link the complexes into a 2D network structure. CCDC: 244926. 相似文献
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Kramareva N. V. Koklin A. E. Finashina E. D. Telegina N. S. Stakheev A. Yu. Kustov L. M. 《Kinetics and Catalysis》2004,45(5):743-751
FTIR spectroscopy and XPS are used to study palladium complexes with various forms of chitosan: initial and modified by glutaric aldehyde. IR bands are identified that are related to the Pd–N and Pd–O bonds. A difference between the spectra of complexes obtained by the methods of adsorption and coprecipitation of chitosanium hydrochloride with the tetrachloropalladate ion is found. It is shown that the systems studied can be used as catalysts for terminal olefin oxidation by oxygen in the presence of H2O2. In the course of the reaction, the complexes undergo redox transformations without breaking the structure of the complex or metal transfer to the reaction mixture. The use of heterogenized Pd(II) complexes as catalysts in terminal olefin oxidation leads to the formation of oxidation and isomerization products, similarly to the case of homogeneous oxidation. 相似文献
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Oguchi T Tozuka Y Hanawa T Mizutani M Sasaki N Limmatvapirat S Yamamoto K 《Chemical & pharmaceutical bulletin》2002,50(7):887-891
The solid-state complexation between cholic acid (CA) and either methyl p-hydroxybenzoate (MPB) or ibuprofen (IBP) was investigated. Powder X-ray diffractometry, IR spectroscopy and thermal analysis suggested the complex formation between CA and MPB as well as between CA and IBP by co-grinding method. The stoichiometry of CA-MPB was 1 : 1 while that of CA-IBP was 2 : 1, reflecting the effect of guest size on complex formation. The guest compounds were assumed to be included in the channel of complexes formed by hydrogen bonds among CA molecules. 相似文献
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Ludvik Beneš Vitězslav Zima Klára Melánová Miroslava Trchová Pavel Matějka 《Journal of inclusion phenomena and macrocyclic chemistry》2003,45(3-4):235-239
Intercalates of vanadyl phosphate with aliphatic dinitriles (malononitrile, succinonitrile, glutaronitrile, adiponitrile, pimelonitrile and suberonitrile) were prepared and characterized by X-ray powder diffraction, thermogravimetric analysis, IR and Raman spectroscopies. The basal spacings of all the intercalates prepared are practically identical. The dinitrile content in the intercalates decreases with increasing chain length. The dinitrile molecules are anchored to the host layers by an N–V donor–acceptor bond and their aliphatic chains are parallel to the host layers. The dinitrile intercalates are generally more stable in air (at relative humidity 40–50%) than nitrile intercalates and the guest molecules are slowly replaced by the water molecules. 相似文献
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A cis-geometry was proposed for the green complex bis(β-mercaptoethylamine) nickel(II) on the basis of its reactivity, IR spectroscopy and orbital geometry considerations. The crystal and molecular structure of this complex has been determined by X-ray diffraction and shows that the complex has a trans geometry. The crystal structure consists of trans-NiL2 molecules strongly linked through NH-S hydrogen bonds. Electronic and IR spectroscopy, and powder X-ray analysis are in agreement with the same trans geometry for the complexes bis(β-mercaptoethylamine)palladium(II) and bis-(γ-mercaptopropylamine)nickel(II). As a result of the new assignment of the structure of these complexes some concepts, such as its reactivity with nickel(II), are reconsidered. 相似文献
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The preparation and characterization of the crystalline inclusion complexes between a polymeric guest, poly(1,3-dioxolane) (PDXL), and small-molecular hosts, cyclodextrins (CDs) are reported. It is observed that the polymer guest can form crystalline inclusion complexes with three kinds of cyclodextrins, which may be attributed to the high oxygen atom density in PDXL chain. The crystalline inclusion complexes were characterized with FTIR , TGA, X-ray diffraction, SEM, 1H NMR and 13C CP/MAS NMR spectroscopes. It was found that the crystalline inclusion complexes have higher temperature stability than the pure CDs. The X-ray powder diffraction patterns of the crystalline inclusion complexes proved that they have columnar structures. 13C CP/MAS NMR spectra of the crystalline inclusion complexes indicate that CDs adopt a more symmetrical conformation in the complexes, while pure CDs assume a less symmetrical conformation in the crystal without a guest inside their cavities. The morphology of the crystal was 相似文献
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Judit Orgovnyi Klra H.- Otta Lszl Pppl va Fenyvesi Gyula Zray 《Microchemical Journal》2005,79(1-2):77
Cypermethrin/β-CD complexes were prepared at 1:2 cypermethrin/β-CD molar ratio by different complexation methods: conventional coprecipitation, suspension and kneading methods as well as “melting in solution” technique, which was developed in our laboratory. The complexes were investigated by UV-spectrophotometry and thermal analysis. It was found that complexes made by coprecipitation, suspension and kneading methods contained cypermethrin not only in complexed but also in uncomplexed form. The guest molecule in the complex prepared by “melting in solution” technique showed to be completely complexed, so it was the most effective complexation method studied.Investigating the solubility of cypermethrin with different cyclodextrins (CDs), it was established that the increase of solubility of cypermethrin was the highest in case of methylated cyclodextrins. The equilibrium constants were calculated from solubility isotherms. On the basis of these results, the heptakis(2,6-di-O-methyl)-β-cyclodextrin (DIMEB) complex was the more stable. By UV-irradiation measurements it was found that the photodegradation of cypermethrin was inhibited by methylated β-CDs. 相似文献
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Akasaka H Endo T Nagase H Ueda H Kobayashi S 《Chemical & pharmaceutical bulletin》2000,48(12):1986-1989
The complex forming ability of delta-cyclodextrin delta-CD with 7 kinds of macrocyclic compounds (MCCs) with 8-15 carbon atoms in the ring as models of large guest molecules was studied in aqueous solution and compared with the complexation properties of alpha-, beta- and gamma-CD. Both alpha- and beta-CD formed relatively stable complexes with small MCCs, while gamma- and delta-CD were more efficient in binding larger MCCs. The solid MCC/delta-CD complexes were precipitated with the larger MCCs with 11-15 carbon atoms in the ring, while no such precipitates were obtained with smaller MCCs with only 8-10 carbon atoms in the ring. The formation of the solid complexes was confirmed by powder X-ray diffractometry and differential scanning calorimetry. The cell dimensions of cycloundecanone (11 carbon atoms in the ring)/delta-CD complex were determined by X-ray crystallography. The preliminary crystal data were: Monoclinic, P21, a=32.50 (2)A, b=19.02 (3)A, c=16.60 (1) A, beta3=98.37 (5)degrees, V=10148 (16) A3. 相似文献
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Olga Helmle Ingeborg Csöregh Edwin Weber Thomas Hens 《Journal of inclusion phenomena and macrocyclic chemistry》1998,30(1):45-57
The crystal structure of the inclusion compound formed between (11S,12S)-(-)-9,10-dihydro-9,10-ethanoanthracene-11,12-dicarboxylic acid, (1), and n-hexane (2:1) has been studied by X-ray diffraction. It crystallizes in the tetragonal space group P41 and represents a less common type of inclusion compound, which has helical and chiral structural elements. Helical chains, formed by hydrogen-bonded host molecules, wind around the 21 screw axes and encircle the guest molecules. Crystal data: a=b=17.478(1); c=12.021(1)Å, Z=4 host–guest 2:1 units, R=0.043, Rw=0.061 for 2225 observations with I > 3 (I). The general shape and conformational flexibility of 1 with respect to the requirements of inclusion formation and crystal packing are discussed. 相似文献