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1.
A. A. Abdoh M. B. Zughul J. Eric. D. Davies A. A. Badwan 《Journal of inclusion phenomena and macrocyclic chemistry》2007,57(1-4):503-510
Guest–host interactions were examined for neutral diclofenac (Diclo) and Diclofenac sodium (Diclo sodium) with each of the
cyclodextrin (CD) derivatives: α-CD, β-CD, γ-CD and 2-hydroxypropyl-β-cyclodextrin (HP-β-CD), all in 0.05 M aqueous phosphate
buffer solution adjusted to 0.2 M ionic strength with NaCl at 20 °C, and with β-CD at different pHs and temperatures. The
pH solubility profiles were measured to obtain the acid–base ionization constants (pK
as) for Diclo in the presence and absence of β-CD. Phase solubility diagrams (PSDs) were also measured and analyzed through
rigorous procedures to obtain estimates of the complex formation constants for Diclo/CD and Diclo sodium/CD complexation in
aqueous solutions. The results indicate that both Diclo and Diclo sodium form soluble 1:1 complexes with α-, β-, and HP-β-CD.
In contrast, Diclo forms soluble 1:1 Diclo/γ-CD complexes, while Diclo sodium forms 1:1 and 2:1 Diclo/γ-CD, but the 1:1 complex
saturates at 5.8 mM γ-CD with a solubility product constant (pK
sp = 5.5). Therefore, though overall complex stabilities were found to follow the decreasing order: γ-CD > HP-β-CD > β-CD > α-CD,
some complex precipitation problems may be faced with aqueous formulations of Diclo sodium with γ-CD, where the overall concentration
of the latter exceeds 5.8 mM γ-CD. Both 1H-NMR spectroscopic and molecular mechanical modeling (MM+) studies of Diclo/β-CD indicate the possible formation of soluble isomeric 1:1 complexes in water. 相似文献
2.
Sanyo Hamai 《Journal of inclusion phenomena and macrocyclic chemistry》2007,58(3-4):241-247
In pH 7.3 buffers, the interactions of a cationic porphyrin, tetrakis(4-N-methylpyridyl)porphyrin (TMPyP), with cyclodextrins (CDs) and disodium phthalate (DSP) have been examined by means of absorption,
fluorescence, and induced circular dichroism spectroscopy. α-CD, β-CD, and γ-CD form a 1:1 inclusion complex with a TMPyP
monomer, which dimerizes in solution without CD. TMPyP also forms a 1:1 organic cation–organic anion complex with DSP. The
1:1 TMPyP–DSP complex forms a ternary CD–TMPyP–DSP inclusion complex with α-, β-, and γ-CD, in which a DSP molecule is not
incorporated into the CD cavity. From the fluorescence intensity change, the␣equilibrium constants have been evaluated for
the formation of the inclusion complexes and the organic cation–anion complexes. 相似文献
3.
Cs. Novák Zsuzsanna Éhen Marietta Fodor L. Jicsinszky Judit Orgoványi 《Journal of Thermal Analysis and Calorimetry》2006,84(3):693-701
Citronellol
and citronellyl acetate have been entrapped with α-, β- and γ-cyclodextrin
(CD). Evolved gas detection and TG-MS coupling was applied to prove the actual
inclusion complex formation between monoterpens and CDs. The terpene content
was determined by UV-VIS specrophotometry and RP-HPLC and the effect of storage
time on the terpene content was also investigated. The α- and γ-cyclodextrin
inclusion complexes showed higher thermal stabilities vs.
dynamic heating compared to the β-CD complexes. On the contray, the retention
of guest using β-cyclodextrin even after 10 years of storage was much
more pronounced. Experimental data other than 1:1 complex compositions are
assumed. Molecular modeling experiments also suggested multiple complex compositions. 相似文献
4.
Arpansiree Wongmekiat Satoko Yoshimatsu Yuichi Tozuka Kunikazu Moribe Keiji Yamamoto 《Journal of inclusion phenomena and macrocyclic chemistry》2006,56(1-2):29-32
Drugs with poor water solubility were co-ground with cyclodextrins (CDs) to create nanoparticles with improved solubility characteristics. Indomethacin (IDM), furosemide (FRM) and naproxen (NAP) were co-ground with β-CD at the molar ratio of 2:1 (CD:drug). Co-grinding of a drug with CD resulted in not only the formation of drug nanoparticles but also the solubilization of the drug by inclusion complex formation with CD in aqueous media. The nanoparticle fraction of IDM, and FRM from ground mixtures prepared with β-CD was as high as 60–70% while the solubilization fraction was less than 10%. In contrast, β-CD–NAP ground mixture showed a large fraction, 48%, for drug solubilization and only 4% for nanoparticle formation. Furosemide ground mixtures prepared with α-CD, β-CD and γ-CD showed comparatively high nanoparticle fraction while the solubilization fraction was around 10%. Both the nanoparticle fraction and the solubilization fraction were greater in the IDM–β-CD system than those in γ-CD and α-CD systems. The nanoparticle formation of NAP depended on the types of CD used as a co-grinding additive. Naproxen nanoparticles could be prepared by co-grinding NAP and α-CD, while the solubilization of NAP tended to improve when β-CD or γ-CD was used. 相似文献
5.
M. I. El-Barghouthi N. A. Masoud J. K. Al-Kafawein M. B. Zughul A. A. Badwan 《Journal of inclusion phenomena and macrocyclic chemistry》2005,53(1-2):15-22
The solubility of risperidone (Risp) in aqueous buffered cyclodextrin (CD) solution was investigated for α-, β-, γ- and HP-β-CD. The effects of pH, ionic strength and temperature on complex stability were also explored. Neutral Risp tends to form
higher order complexes (1:2) with both β- and HP-β-CD, but only 1:1 type complexes with α-, and γ-CD. The tendency of Risp to complex with cyclodextrins is in the order β-CD > HP-β-CD > γ-CD > α-CD. The 1:1 complex formation constant of Risp/HP-β-CD increases with increasing ionic strength in an opposite trend to the inherent solubility (S
0) of Risp, thus indicating significant hydrophobic effect. The hydrophobic effect contributes to the extent of 72% towards
neutral Risp/HP-β-CD complex stability, while specific interactions contribute only 4.7 kJ/mol. Thermodynamic studies showed that 1:1 Risp/HP-β-CD complex formation is driven by a favorable enthalpy change (ΔH
0=−31.2 kJ/mol, ΔS
0=−7 J/mol.K) while the 1:2 complex is largely driven by entropy changes (ΔH
0=−5.0 kJ/mol, ΔS
0=42 J/mol.K). Complex stability was found to vary with pH, with a higher formation constant for neutral Risp. Molecular mechanical
computations using MM (atomic charges and bond dipole algorithms) and Amber force fields, which were carried out to explore
possible sites of interactions between Risp and CDs and to rationalize complex stoichiometry, produced similar results concerning
optimal inclusion complex geometries and stoichiometries. 相似文献
6.
De-zhi Sun Ling Li Xiao-mei Qiu Min Liu Bao-lin Yin 《Journal of solution chemistry》2006,35(11):1537-1549
Interactions between CDs with three substituted phenols, paeonol (Pae), acetovanillone (Ace) and 2-hydroxyl-5-methoxy-acetophone (Hma), which are isomers, have been determined by isothermal titration calorimetry (ITC) and 1H NMR in aqueous solution at 298.2 K. Both the binding thermodynamics and 1H NMR spectra show that the interaction between α-cyclodextrin (α-CD) molecule and each guest molecule is extremely weak. The thermodynamic parameters indicate that the binding processes of β-cyclodextrin (β-CD) with the isomers are mainly entropy driven and that β-CD binds with Pae or Ace in 1:1 stoichiometry, whereas with Hma binds in 1:1 and 2:1 stoichiometries. The thermodynamic parameters also suggest that γ-cyclodextrin (γ-CD) binds each isomer in the same 1:1 stoichiometry. The binding processes of Pae and Hma with γ-CD are enthalpy driven whereas Ace with γ-CD is predominantly driven by entropy. The 1H NMR spectra reveal that the three isomers were trapped into the torus cavity of the β-CD molecule from the narrow side during the binding process. Pae penetrates into the γ-CD cavity from the primary rim of the macrocycle whereas Ace does so from the secondary rim, but Hma appears not interact with the internal cavity of γ-CD at all. 相似文献
7.
P. Fini L. Catucci M. Castagnolo P. Cosma V. Pluchinotta A. Agostiano 《Journal of inclusion phenomena and macrocyclic chemistry》2007,57(1-4):663-668
The interaction of Rose Bengal (RB) with hydroxypropyl-α-cyclodextrin (HP-α-CD), hydroxypropyl-β-cyclodextrin (HP-β-CD) and
hydroxypropyl-γ-cyclodextrin (HP-γ-CD) has been studied in water and in acetate buffer at pH 4.5 by UV–Vis absorption, fluorescence
spectroscopy and Induced Circular Dichroism at 298 K. Evidence of the complex formation between the RB and all HP-CDs have
been obtained both in water and in buffer. Binding constants and stoichiometry of RB/HP-CD complexes in water have been determined
by applying the modified Benesi-Hildebrand equation to the fluorescence measurements. 相似文献
8.
H. Aki Y. Nakashima Y. Kawasaki T. Niiya 《Journal of Thermal Analysis and Calorimetry》2006,85(3):685-688
The antibacterial
action of amoxicillin (AMPC) and the inclusion complexes of AMPC with α-, β-
and γ-cyclodextrins (α-CD, β-CD and γ-CD, respectively)
to Escherichia coli B (E.
coli) was evaluated by isothermal titration microcalorimetry and
by petri-dish bioassay method. The effects of the compounds on produced heat
during the exponential phase of the E. coli
growing were measured and the growing rate constants of the cells was calculated
from the power-time (p-t) curve before
and after the treatment with AMPC. Results from the both methods showed that
the antibacterial activity became stronger in the following order: AMPC-βCD
> AMPC-γCD ≈ AMPC-αCD > AMPC only. 相似文献
9.
Mahmoud M. Al Omari Musa I. El-Barghouthi Mohammad B. Zughul J. Eric D. Davies Adnan A. Badwan 《Journal of solution chemistry》2008,37(2):249-264
The interaction of two benzocycloheptanes namely, pizotifen (Pizo) and ketotifen (Keto), with cyclodextrins (CDs: α-, β-, γ-, and HP-β-CDs) has been investigated by several techniques including phase solubility, X-ray powder diffractometry, 1H-nuclear magnetic resonance and molecular mechanical modeling. The effects of CD type, pH, ionic strength and temperature
on complex stability were also explored. The complex formation constant (K
11) values for the Pizo/CD system follows the decreasing order β-CD > γ-CD > HP-β-CD > α-CD. However, for the Keto/CD system it follows the decreasing order γ-CD > β-CD > HP-β-CD > α-CD. The tendency of Pizo and Keto to complex with β-CD is driven to the extent of 70% by the hydrophobic effect. Complex formation of Keto and Pizo was substantially driven
by entropy (>100 J⋅mol−1⋅K−1) but slightly retarded by enthalpy (3–8 kJ⋅mol−1). 1H-NMR and MM+ studies indicate multimodal inclusion of the methylpiperadine, thiophene and phenyl moieties into the β-CD cavity. 相似文献
10.
Yan-Min Yu Wensheng Cai Xueguang Shao 《Journal of inclusion phenomena and macrocyclic chemistry》2006,56(1-2):225-235
The inclusion complexes of α-, β- and γ-cyclodextrin (CD) with three isolated phospholipid (PI – phosphatidylinositol; PS – phosphatidylserine; and PE – phosphatidylethanolamine) headgroups were studied using a flexible docking algorithm FDOCK based on molecular mechanics (CFF91 force filed). In the three phospholipid headgroups, PI headgroup exhibits the strongest affinity for CD, and the affinity of PS headgroup is greater than that of PE headgroup. By investigating the energy distribution and the complex structure in the inclusion procedure, it can be found that the van der Waals force is the main driving force responsible for the complexation. For the α-CD complex of PI headgroup, more than one inclusion complex should coexist due to the steric hindrance, which is reasonably consistent with the experimental results. Furthermore, analyses of the complex of PS and PE headgroup with α-CD also show that two or three possible complexes may appear in the inclusion process, and the complex structure with full inclusion is of the lowest energy and should be the most stable structure in the mixture. For β-␣and γ-CD, the energies of the most stable complexes structures for the three phospholipids headgroups were also discussed. 相似文献
11.
Alexis Morales Jochem Struppe Enrique Meléndez 《Journal of inclusion phenomena and macrocyclic chemistry》2008,60(3-4):263-270
The possible inclusion complexes of Cp2NbCl2 into α-, β-, and γ-CD hosts have been investigated. The existence of a true inclusion complex in the solid state was confirmed
by a combination of thermogravimetric analysis, FTIR, PXRD, and 13C CP-MAS NMR spectroscopies. The solid-state results demonstrated that α-cyclodextrin does not form inclusion complexes with
Cp2NbCl2 whereas β- and γ-cyclodextrins do form such complexes. PXRD, NMR, and thermal analysis showed that the organometallic molecules
of Cp2NbCl2OH are included in the cavities of β- and γ-cyclodextrins, possibly adopting a symmetrical conformation in the complex, with
each glucose unit in a similar environment. In solution, 1H NMR experiments suggest that niobocene has a shallow penetration on the β-CD leading to upfield shift on H-3 signal with
a minor perturbation on the H-5 proton while for γ-CD, both H-3 and H-5 are shifted upfield substantially. This suggests that
niobocene penetrates deeper into the γ-CD cavity than in the β-CD cavity, as a result of the cavity size.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
12.
V. A. Livshits B. G. Dzikovski V. G. Avakyan E. A. Samardak E. Yu. Polyakova V. Yu. Rudyak M. V. Alfimov 《Russian Chemical Bulletin》2005,54(5):1169-1177
Guest-host complexes of β- and γ-cyclodextrins (CDs) with two spin-labeled indole derivatives having the same molecular weights
but different structures were studied by EPR spectroscopy in aqueous solutions and semiempirical quantum-chemical calculations
of these systems were carried out. In the presence of CD the polarity of the NO group environment decreases and the rotational
correlation time (τ) of guest molecules increases. Both indole derivatives form 1 : 1 complexes with γ-CD, the binding constants
of the complexes being different more than twice. Simulation of EPR spectra made it possible to determine the indole ring
orientation relative to the plane of the host molecule (at angles in the range 30–60°) and the rotational diffusion coefficients
of the complexes, which corresponded to the hydrodynamic volume of one γ-CD molecule. In contrast to the complexes with γ-CD
the rotational correlation times, τ, of the complexes with β-CD correspond to a hydrodynamic volume which much exceeds the
volume of a single β-CD molecule. The complexes with β-CD are also characterized by more hydrophobic environment for guest
molecules and absence of spin exchange with Ni2+ ions in the aqueous solution. There results are consistent with a dimeric structure of β-CD in the complex and with the orientation
of the long axis of the guest molecule along the dimer axis. The energies and geometric parameters were calculated for all
complexes by the PM3 method with a conventional set of parameters. The optimized energetically stable structures of the 1
: 1 complexes with γ-CD and of the 1 : 2 complexes with β-CD are consistent with experimental data.
__________
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1139–1147, May, 2005. 相似文献
13.
Xiu-Kui Qu Lan-Ying Zhu Ling Li Xi-Lian Wei Feng Liu De-Zhi Sun 《Journal of solution chemistry》2007,36(5):643-650
As a continuation of our previous investigation, interactions between cyclodextrin (β-CD), γ-cyclodextrin (γ-CD) and alkyl trimethylammonium bromides in aqueous solutions have been studied with titration calorimetry and 1H NMR at 298.15 K. The results are discussed in terms of the amphiphilic interaction of CD with surfactants and the iceberg
structure formed by water molecules existing around the hydrophobic tail of surfactant molecules. The stoichiometry of the β-CD–surfactant system is 1:1 whereas that of the γ-CD–surfactant system is 1:2. The corresponding formation enthalpy (negative) of the complexes of the two systems decreases
with an increase in the number of carbon atoms (n) in hydrophobic chain of surfactant molecule, C
n
H2n+1, whereas the entropy increases with the enlargement of n. 相似文献
14.
L. Omar M. I. El-Barghouthi N. A. Masoud A. A. Abdoh M. M. Al Omari M. B. Zughul A. A. Badwan 《Journal of solution chemistry》2007,36(5):605-616
The extent and mode of solubility enhancement exerted by the cyclodextrins (α-, β-, γ-, and HP-β-CDs) on loratadine (Lort) have been experimentally measured under controlled conditions in buffered aqueous solutions. Rigorous
nonlinear regression analysis of the phase solubility diagrams obtained in 0.1 mol⋅L−1 phosphate buffer at pH=7.0 and 25 °C revealed the following: neutral Lort (pK
a
=4.6) tends to form soluble 1:1 and 1:2 Lort/CD complexes with all four of the examined CDs, where complex stability follows
the decreasing order β-CD>HP-β-CD>γ-CD>α-CD. The hydrophobic character of Lort constitutes about 66% of the driving force for complex formation whereas specific interactions
contribute 11.2 kJ⋅mol−1 towards the stability of the complexes. Thermodynamic studies showed that Lort/CD complex formation was favored by large
enthalpic contributions but was impeded by negative entropic changes. Dissolution studies indicate that the dissolution rate
of Lort from the freeze-dried Lort/β-CD complex is significantly higher than that of the corresponding physical mixture. Both DSC studies and molecular mechanical
modeling of Lort/β-CD interactions were carried out to explore the possible formation of inclusion complexes. 相似文献
15.
Hyunmyung Kim Karpjoo Jeong Hyungwoo Park Seunho Jung 《Journal of inclusion phenomena and macrocyclic chemistry》2006,54(3-4):165-170
Cyclodextrins (CDs) are useful functional excipients, which are being used to camouflage undesirable pharmaceutical characteristics, especially poor aqueous solubility, through the inclusion complexation process with insoluble drugs. The selection of more efficient cyclodextrin is important to improve the bioavailability of drugs. In this study, the complexing and solubilizing abilities toward poorly water-soluble monocyclic molecules of natural CDs (α-CD, β-CD, and γ-CD) were investigated using Monte Carlo (MC) docking simulations studies. These theoretical results closely agree with the experimental observation of the complex stability in water of the various guests–CD complexes. Host preferences, based on the experimentally determined stability constants between host CDs and guest molecules, show excellent correlation with the calculated interaction energies of corresponding complexes. The inclusion complex with the lower MC docking interaction energy shows a higher value of stability constant than that of the other complex, and the prediction accuracy of the preferred complex for 21 host–guest pairs is 100%. This result indicates that the MC docking interaction energy could be employed as a useful parameter to select more efficient cyclodextrin as a host for the bioavailability of insoluble drugs. In this study, β-CD shows greater solubilizing efficacies toward guest molecules than those of α-CD and γ-CD, with the exception of one case due to the structure of a guest molecule containing one lipophilic cyclic moiety. The surface area change of CDs and hydrogen bonding between the host and guest also work as major factors for the formation of the stable complex. 相似文献
16.
Shengkai Xing Qian Zhang Chong Zhang Qiang Zhao Hongqi Ai Dezhi Sun 《Journal of solution chemistry》2009,38(5):531-543
Thermodynamic parameters for formation of the inclusion complexes of α-, β- and γ-cyclodextrin (α-, β- and γ-CD) with ibuprofen (BF) in Tris-HCl buffer solutions (pH=7.0) have been determined by isothermal titration calorimetry (ITC)
with nanowatt sensitivity, and the inclusion structures have been investigated by using 1H-NMR spectra at 298.15 K. A theoretical study on the inclusion processes between BF and CDs has been performed with the B3LYP/6-31G*//PM3
method in order to investigate the formation mechanism of the inclusion complexes. An analysis of the thermodynamic data indicates
that the stoichiometries of α-, β- and γ-CD with BF are all 1:1 and formation of the inclusion complexes α-CD⋅BF and β-CD⋅BF are driven by enthalpy and entropy, whereas formation of γ-CD⋅BF is an entropy driven process. The 1H-NMR spectra provide clear evidence for the inclusion phenomenon, and show that the isobutyl group and aromatic ring of the
guest molecule are trapped inside the cavity of the CDs. Theoretical calculations suggest that the complex formed by the BF
molecule entering into the cavity of the CD molecule from the wide side is more stable than that from the narrow side. 相似文献
17.
Xiao-Xiang Li Jun-Wen Wang Yu-Jing Guo Ling-Hong Kong Jing-Hao Pan 《Journal of inclusion phenomena and macrocyclic chemistry》2007,58(3-4):307-315
In phosphate buffer solution of pH5.4, the interaction of meso-tetrakis(2-thienyl)porphyrin(H2TTP) and Cu-meso-tetrakis(2-thienyl)porphyrin(Cu-TTP) with α-cyclodextrin(α-CD), β-CD, γ-CD, heptakis(2,3,6-tri-O-methyl)-β-CD(TM-β-CD)
has been studied by means of UV-vis, fluorescence and 1HNMR spectroscopy, respectively. The H2TTP and Cu-TTP can form 1:2 inclusion complexes with TM-β-CD and 1:1 inclusion complexes with the other three cyclodextrins.
In this paper, the inclusion constants (K) of H2TTP and Cu-TTP for the formation of the inclusion complexes have been estimated from the changes of absorbance and fluorescence
intensity in phosphate buffer solution. The inclusive capabilities of different kinds of cyclodextrins are compared. The result
shows that the inclusion ability of α-CD with H2TTP and Cu-TTP is the strongest among the three native CDs. The inclusion ability of modified β-CD with H2TTP and Cu-TTP is stronger, compared to the native β-CD, which indicates that the capacity matching plays a crucial role in
the inclusion procedure except for the hydrophobic effect. In addition 1HNMR spectra supports the inclusion conformation of the TM-β-CD-Cu-TTP inclusion complex, indicating the interaction mechanism
of inclusion processes. 相似文献
18.
Yan Bai Gui-Ying Xu Xia Xin Hong-Yuan Sun Hong-Xing Zhang Ai-You Hao Xiao-Deng Yang Lin Yao 《Colloid and polymer science》2008,286(13):1475-1484
The interaction between cetyltrimethylammonium bromide (CTAB) and β-cyclodextrin (β-CD) was studied via surface tension and
dilational viscoelasticity methods. The effect of sodium bromide and sodium chloride on the interaction between CTAB and β-CD
were studied as well. The surface tension isotherms provided a series of parameters, including apparent critical micelle concentration
(cmc*), surface tension at the cmc* (γcmc), stoichiometry of the complex (R), and the efficiency of adsorption (pC
20
). The addition of NaBr and NaCl decreases the cmc* of CTAB/β-CD solution. CTAB molecules enter the cavities of β-CD molecules
thus formed both 1:1 and 1:2 inclusion complexes. From the change of γcmc, it can be seen that the CTAB/β-CD complexes (1:1) act as short-chain alcohol, which decrease γcmc, but the depression of cmc* is too small to be detected. R first decreases then increases as a function of NaBr and NaCl. Compared to NaCl, NaBr increases R more efficiently. The presence of NaBr and NaCl increases pC
20
of CTAB/β-CD solution. The results obtained from the dilational viscoelasticity measurements at low dilational frequencies
(0.005–0.1 Hz) reveal that the dilational modulus passes through a maxium value with increasing concentration of β-CD at a
given concentration of CTAB. The addition of both NaBr and NaCl decreases the dilational modulus of a given concentration
CTAB/β-CD solution.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
19.
YOSHINORI TAKASHIMA KAZUYA SAKAMOTO YOSHIFUMI OIZUMI HIROYASU YAMAGUCHI SHIGEHIRO KAMITORI AKIRA HARADA 《Journal of inclusion phenomena and macrocyclic chemistry》2006,56(1-2):45-53
Cyclodextrins (α-CD, β-CD and 2,6-di-O-dimethyl-β-CD (DM-β-CD)) were found to form inclusion compounds with thiophenes (thiophene (T), bithiophene (2T)) in water and in crystalline states. The structures of α-CD–T, β-CD–2T, and DM-β-CD–2T inclusion complexes were determined by X-ray crystallography. DM-β-CD forms a 1:1 cage type complex with 2T. In contrast, β-CD formed 2:3 (CD:guest) complexes with thiophene and α-CD formed 2:3 complexes, both of the channel type. These inclusion complexes were found to polymerize by FeCl3 in the inclusion compounds in water. The products were formed poly-pseudo-rotaxane between cyclodextrins and poly(thiophene) characterized by IR, 1H-NMR and 13C CP/MAS NMR. The molecular weights of the poly-pseudo-rotaxanes with poly(thiophene) were determined by the MALDI-TOF mass spectra to be 3000–5000. In comparison between poly-pseudo-rotaxane (DM-β-CD–poly(thiophene)), authentic poly(thiophene) and the washed DM-β-CD–poly(thiophene) which was washed with DMF to dethread DM-β-CD, these poly-pseudo-rotaxane was characterized by Raman, UV–vis and fluorescence spectra. The maximum emission band of DM-β-CD–poly(thiophene) shifted to a shorter wavelength. The hypsochromic shift was derived from poly-pseudo-rotaxane with DM-β-CD. 相似文献
20.
Felicia Dragan I. Bratu Gh. Borodi Mihaela Toma A. Hernanz S. Simon Gh. Cristea R. Peschar 《Journal of inclusion phenomena and macrocyclic chemistry》2007,59(1-2):125-130
Aqueous-solution complexes of β-cyclodextrin (β-CD) with metoprolol tartrate (MET) have been analysed with 1H NMR and UV–vis spectroscopy. With 1H NMR a [1:1] stoichiometry could be established for the β-CD-MET complex while its stability constant was determined with
UV–vis spectroscopy. Powder diffraction data of a polycrystalline sample of the β-CD-MET complex show that a novel product
has been formed, likely to be a β-CD-MET [1:1] inclusion complex. Also Hyperchem MM+ molecular-dynamics results suggest an
inclusion complex and from 1H NMR data it is inferred that probably the MET is docked in the CD with the formers methoxyethyl-benzene moiety in front.
Mihaela Toma is Socrates/Erasmus student at UNED Madrid 相似文献