A Spectroscopic Study of Xanthene Dyes on a Polystyrene Surface: an Investigation of Ion-π Interactions at Polymer Interfaces

This paper reports a UV-Vis spectroscopic study on the interactions of chloroquine with anionic, cationic and neutral tetra-arylporphyrins and their iron(III) complexes in aqueous buffer and in methanolic solution. This study reveals that in water at pH 6.4 cooperative ion-pair and π-π interactions lead to complex formation between the anionic porphyrin species and chloroquine. In methanolic solution no π-π complexation is observed. The neutral and cationic porphyrins and metalloporphyrins do not form complexes with chloroquine. On the basis of these results, the iron(III) porphyrins have been used as catalysts for the oxidation of chloroquine by iodosylbenzene. The main oxidation product in all systems is monodesethylchloroquine. The anionic iron(III) porphyrins are the most active catalysts; in aqueous solution they are selective for oxidative deethylation whereas in methanol they also give five other oxidation products. The cationic and neutral iron(III) porphyrins are poor or inactive catalysts for chloroquine oxidation by iodosylbenzene. The effect of iron(III) porphyrin/chloroquine interactions on the yields and selectivity of the oxidation is discussed.

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Infrared-Visible Sum Frequency Generation Spectroscopic Study of Molecular Orientation at Polystyrene/Comb-Polymer Interfaces

Journal of the American Chemical Society ◽

10.1021/ja035513v ◽

2003 ◽

Vol 125 (37) ◽

pp. 11283-11290 ◽

Cited By ~ 46

Author(s):

Gary P. Harp ◽

Hasnain Rangwalla ◽

Mohsen S. Yeganeh ◽

Ali Dhinojwala

Keyword(s):

Spectroscopic Study ◽

Molecular Orientation ◽

Sum Frequency Generation ◽

Polymer Interfaces ◽

Sum Frequency ◽

Comb Polymer ◽

Frequency Generation

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Some Results of the Spectroscopic Study of Four Close Binary Systems of Early Spectral Types

International Astronomical Union Colloquium ◽

10.1017/s025292110002755x ◽

1965 ◽

Vol 5 ◽

pp. 120-130

Author(s):

T. S. Galkina

Keyword(s):

Spectroscopic Study ◽

Spectral Type ◽

Spectroscopic Investigation ◽

Binary Systems ◽

Quantitative Information ◽

Close Binary ◽

Physical Parameters ◽

Absorption And Emission ◽

Close Binary Systems ◽

Quantitative Estimates

It is necessary to have quantitative estimates of the intensity of lines (both absorption and emission) to obtain the physical parameters of the atmosphere of components.Some years ago at the Crimean observatory we began the spectroscopic investigation of close binary systems of the early spectral type with components WR, Of, O, B to try and obtain more quantitative information from the study of the spectra of the components.

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