摘要:

AbstractManganese(III) porphyrins were successfully incorporated into Nafion, wherein they are located in the ionic pockets of the polymer. The result of UV—visible spectroscopy indicate that at least one solvent molecule and the anion accompany the macrocycle into the membrane. The anion is only loosely associated with the porphyrin, but strongly coordinating solvents such as pyridine remain in the axial coordination sites. Dramatic changes which were observed in the electronic and resonance Raman spectra when THF and dioxane were used as incorporation solvents indicate that the geometry of the macrocyle also changes when in Nafion. Puckering of the porphyrin ring apparently occurs as it interacts with the restrictive environment in Nafio

ISSN:0377-0486    

DOI:10.1002/jrs.1250261102

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

摘要:

AbstractRaman spectra of avidin, biotin and the avidin‐biotin complex were recorded. The percentages of secondary structure of avidin and the avidin‐biotin complex were obtained from the Raman spectra. The vibrational results indicate that, as a consequence of the interaction of avidin with biotin, the β‐sheet conformation percentage decreases and the α‐helical conformation percentage increases. Moreover, the interaction of avidin with biotin is also able to change slightly the tertiary structure of the protein. In fact, as a consequence of the binding of biotin, the hydrophobicity of the environment of Trp increases slightly according to the intensity increase of the 1360 cm−1component. The intesity of all bands attributable to Trp residues increases with biotin binding, indicating that Trp is directly involved in the interaction. These results are in agreement with the results of UV measurements which indicate a red shift of the avidin Trp absorption bands as a consequence of the bindin

ISSN:0377-0486    

DOI:10.1002/jrs.1250261103

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

摘要:

AbstractThe polarized Raman spectra of Na4P2O7.10H2O and the infrared and Raman spectra in the polycrystalline state were recorded at room temperature. A normal coordinate analysis of Na4P2O7.10H2O and Raman and infrared intensity analyses in the P—O stretching region were carried out and the force field and the intensity parameters for the P2O 74−ion obtained. These results were transferred and used to analyse the P—O stretches in (VO)2P2O7, whose infrared spectrum depends largely on the preparation method. It is concluded that α‐(VO)2P2O7corresponds to the Gorbunova and Linde structure, while the γ‐form probably has disorder

ISSN:0377-0486    

DOI:10.1002/jrs.1250261104

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

摘要:

AbstractThe infrared and Raman spectra ofL‐asparagine and ND3+, ND2‐L‐asparagine as solid samples were recorded. The data obtained were used to propose a general assignment of the fundamental vibrational modes on the basis of the measured isotopic shifts and correlations with previous data reported for other amino acids and related mole

ISSN:0377-0486    

DOI:10.1002/jrs.1250261105

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

摘要:

AbstractSurface‐enhanced Raman spectra of the two thiazole orange derivatives, TO6 {1‐(N,N'‐tetramethyl‐1,3‐propanediaminopropyl)‐4‐[3‐methyl‐2,3‐dihydro(benzo‐1,3‐thiazole)‐2‐methyliden] quinolinium triiodide} and TOTO {1,1′‐(4,4,8,8‐tetramethyl‐4,8‐diazaundecamethylene)‐bis‐ 4‐[3‐methyl‐2,3‐dihydro(benzo‐1,3‐thiazole)‐ 2‐methylidene]quinoliniumtetraiodide}, were recorded with visible (457.9 and 514.5 nm) and near‐infrared (1064 nm) excitation on silver colloids. The spectra were compared with the corresponding non‐enhanced Raman spectra obtained in the near‐infrared region and the resonance Raman spectra obtained with visible excitation. The qualitative enhancement pattern is explained within the electromagnetic theories. Partial assignment of the vibrational wavenumbers was achieved by comparison of observed band positions and intensities in the IR and Raman spectra with wavenumbers and intensities from quantum chemical calculations. Information on the adsorption geometry at the silver surface can be obtained on basis of this assignment. The surface‐enhanced Raman spectrum of TOTO on gold colloids was recorded with 1064 nm excitati

ISSN:0377-0486    

DOI:10.1002/jrs.1250261106

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

摘要:

AbstractThe Raman non‐coincidence effect of the symmetric C=O stretching band was measured in liquid acetone andN,N‐dimethylformamide confined to porous silica glasses prepared by the sol—gel process. The experiments were carried out both on bulk liquids and liquids confined to glasses with pore radii from 17—76 Å at 293 K. The value of the non‐coincidence was decreased with decreasing pore radius (R) and scaled approximately as 1/R. Additional information about the role of pore surface effects was obtained by measurements on the polar liquids confined to surface‐modified glasses when the surface hydroxyl groups were replaced by OSi(CH3)3groups. The experimental data show that the non‐coincidence effect is independent of the pore size in surface‐

ISSN:0377-0486    

DOI:10.1002/jrs.1250261107

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

摘要:

AbstractChanges in the wavenumbers of the anisotropic and isotropic components of the C=O stretching band in the Raman spectrum of Ca(ClO4)2and benzene solutions in acetone were investigated. Non‐coincidence values defined as Δv=vaniso—visofor the C = O band in Ca(ClO4)2solutions were positive (+ 5 cm−1) for bulk acetone and negative (—25 cm−1) for acetone‐shared ion pairs. In acetone solutions diluted with benzene there is a decrease in C = O non‐coincidence from +5 cm−1down to about — 1 cm−1. The change of non‐coincidence sign appears at a benzene/acetone molar ratio of 10. The concept of third‐body mediation is applied to explain the observed changes of non‐coincidence in highly po

ISSN:0377-0486    

DOI:10.1002/jrs.1250261108

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

ISSN:0377-0486    

DOI:10.1002/jrs.1250261101

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY