摘要:

Variable-temperature Mössbauer spectra were measured for biferrocenium+F4TCNQ−(2) and 1′,1′′′-diethylbiferrocenium+F4TCNQ−(3) in order to elucidate their mixed-valence states, where F4TCNQ = 2,3,5,6-tetrafluoro-7,7,8,8-tetracyano-quinodimethane. A valence-delocalization between Fe(II) and Fe(III) sites on elevating the temperature was observed for2; The Mössbauer spectra of2below 298 K consisted of two quadrupole doubets corresponding to the Fe(II) and Fe(III) atoms in2, and the spectrum at 320 K consisted of only one quadrupole doublet showing a single valence state of iron averaged over Fe(II) and Fe(III). On the other hand, compound3showed trapped-valence type spectra in the whole temperature range of 4.2 - 320 K.

ISSN:1058-725X    

DOI:10.1080/10587259808030203

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

Deposition mechanism and a diameter dependence of the conductivity of polythiophene derivative fibrils polymerized in pores of a membrane filter having submicrometer-sized pores aperture were discussed. Deposition process of the fibrils was able to be divided in the following three stages from SEM observation and polymerization current measurements. The first stage is the generation of deposition growth nucleus on the pore-inside wall and the filter surface, the second is growth of thickness of a thin-layer-deposit, and the third is the accumulation of a spherical deposit. And, when the pore size became big, the second stage shortened remarkably, and thickness of the thin-layer-deposit became thinner, and the spherical deposition began earlier. From the simulated conductivity of the fibrils with each diameter, at the smaller pore aperture than a specific value, the thickness of the thin-layer-deposit having high-conductivity increases. When the pore aperture becomes smaller, the thin-layer-deposition is remarkably easy to occur.

ISSN:1058-725X    

DOI:10.1080/10587259808030204

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

Langmuir-Blodgett (LB) films containing various inorganic complexes were prepared using the so-called semi-amphiphilic approach where ions are adsorbed along a charged monolayer. The metal complexes are organized generally in monolayers within the LB films. The magnetic properties of such LB films are related to that of the inorganic molecules and present an anisotropic behavior in some cases. Those results emphasize the interest to control perfectly the molecular organization in order to build up new magnetic hybrid materials.

ISSN:1058-725X    

DOI:10.1080/10587259808030205

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

We report the conducting properties of Langmuir-Blodgett films obtained by mixing BEDO-TTF with various molecules. Conductivity was observed when BEDO-TTF was mixed with fatty acids and a phosphate. On the other hand, the association of BEDO-TTF and docosanol led to insulating properties. This suggests that the polar head group of the amphiphilic molecules contributes to the partial charge-transfer process of BEDO-TTF.

ISSN:1058-725X    

DOI:10.1080/10587259808030206

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

Structure and electrical properties of conductive LB films based on dioctadecyldimethylammonium-Au(dmit)2(2C18-Au) are studied. UV/visible polarized absorption spectra suggest that the longer axis of Au(dmit)2is appreciably tilted against the film plane. Both of the as-deposited and electrochemically oxidized LB films give sharp X-ray diffraction peaks at 2θ = 3.15° indicating a d-spacing of 2.8 nm. The in-plane conductivity of the film is semiconductor-like with an activation energy of 0.05 eV.

ISSN:1058-725X    

DOI:10.1080/10587259808030207

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

A blue-shifted band has been formed in the merocyanine dye -arachidic acid mixed LB films by adding octadecane molecule of various molar mixing ratios. The polarizing UV-visible absorption spectrum measurements revealed that the formation of molecular aggregates is sensitive to the mixing ratio of octadecane as a third component. The surface pressure - area isotherms indicated that a certain amount of octadecane molecule does not exist in the empty space of merocyanine dye even if mixing ratio of octadecane is small.

ISSN:1058-725X    

DOI:10.1080/10587259808030208

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

Some experiments for fundamental understanding of micro-phase separated structures formed in mixed monolayers ofn-alkyltrichlorosilanes and a partially fluorinated amphiphile are presented. The surface morphology of the mixed monolayers is varied by changing some parameters, such as chain length of alkyltrichlorosilanes, temperature of the water surface, and solvents of spreading solutions. It is demonstrated that the surface structures are mainly governed by the dynamic molecular process during spreading. The most likely mechanism of the micro-phase separation is proposed.

ISSN:1058-725X    

DOI:10.1080/10587259808030209

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

The thermodynamic concept was introduced in order to elucidate the dynamic flexibility of the amide derivative of p-phenylenediacrylic acid “1” for the formation of its monolayer. The phase transition region appeared in the surface pressure - area isotherms was interpreted in terms of molecular comformational changes between two extreme forms; bent comformation and erect comformation. The LB films prepared at higher temperatures possessed highly oriented and closely packed molecular assembly, as revealed by means of spectroscopy. Even though, the LB films prepared at lower temperatures exhibited a higher photoreactivity.

ISSN:1058-725X    

DOI:10.1080/10587259808030210

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

The manipulation of the LB film was investigated by using poly(vinyl alcohol) bearingp-phenylenediacrylate moiety. Its property was characterized with comparison of the monomeric LB film made from correspondingp-phenylenediacrylic acid monoester of the side chain. The spectroscopic data showed that the polymer LB film with high photoreactivity was obtained successfully. The result of measurement dynamic contact angle of the polymer LB film revealed its unique surface property, which was shown by a high advancing contact angle (108°) and a low receding contact angle (15°).

ISSN:1058-725X    

DOI:10.1080/10587259808030211

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

Novel functional polysilane homopolymers bearing ethereal groups were prepared by Wurtz coupling method. The polysilane monolayers demonstrated a unique chromic effect induced by a specific conformational and orientational change of polymer backbones at the air/water interface.

ISSN:1058-725X    

DOI:10.1080/10587259808030212

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor