摘要:

Designed supermolecular assemblies can be built up by the Langmuir-Blodgett technique, through the vectorial control of chemical interactions occurring at the air/water interface between adjacent amphiphilic molecules.

ISSN:1058-725X    

DOI:10.1080/10587259208025820

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

It has been shown that the recombination probabilities of radicals generated from photolysis of ketone precursors in pentasil zeolites can be controlled by the distribution of ketones on the internal and external zeolite surfaces as well as by the adsorption siting and sieving attributes of the radical fragments. Here we report the use of magnetic resonance techniques in the elucidation of the adsorption sites of ketone reactants. The techniques employed include solid state29Si and13C MAS-NMR to characterize the zeolite frame-work and the ketone adsorbates respectively. EPR spectroscopy of the stable free radical Tempo was also used as a complementary technique to obtain information about the environment of the radical including its interactions with the surface and with the ketones. The latter interactions, when present, result in the broadening and shifting of the13C NMR signals of the ketone.

ISSN:1058-725X    

DOI:10.1080/10587259208025821

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Results of photophysical studies of organic molecules included in zeolites are presented. Influence of cations through heavy atom effect and Iight atom effect on the photophysical properties of organic molecules is emphasized. Use of photophysical probes to understand the interior features of zeolites has been demonstrated.

ISSN:1058-725X    

DOI:10.1080/10587259208025822

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The interaction of Eu3+and tributylphosphate in the montmorillonite clay SAZ1 has been investigated by NMR spectroscopy. The13C-NMR spectrum of TBP sorbed onto SAZ1 partially exchanged with Eu3+shows two sets of four peaks differing by 2–3ppm. Longitudinal relaxation times for13C -TBP sorbed to SAZ1 and Eu3+-SAZ1 (as D2O slurries) are ˙9s and 4s, respectively. The T1′s determined by13C-CPMAS on the solid samples are 24s and ˙28s, respectively. Linewidths of the CPMAS spectra of13C-TBP sorbed to SAZ1 and Eu3+-SAZ1 are 204 Hz and 305 Hz.

ISSN:1058-725X    

DOI:10.1080/10587259208025823

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Five crystalline phases of magnesium hydrogen phthalate are described. The structures contain two, six or eight molecules of water per cation. Full crystal structures of two of the series (di-aquomagnesium hydrogen phthalate and hexa-aquomagnesium hydrogen phthalate) are reported and some general features of all the hydrogen phthalates are discussed.

ISSN:1058-725X    

DOI:10.1080/10587259208025824

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

An attempt was made, using lattice energy minimisation, to model guest orientation within layered double hydroxide intercalates, without explicit consideration of interlayer water. This was found to be unsuccessful, for which an explanation is advanced.

ISSN:1058-725X    

DOI:10.1080/10587259208025825

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The synthesis of photoactive (cinnamate) intercalates of layered double hydroxides is described. Corresponding single-crystal data on pure sodium salts enables information concerning the arrangement of the guest molecules within the hydroxide to be obtained.

ISSN:1058-725X    

DOI:10.1080/10587259208025826

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

New synthetic routes to bis(ethylenedithio)tetraselenafulvalene (BETS) were explored, starting from tetraselenafulvalene (TSF). Several radical cation salts of TSF and BETS were prepared by electrocrystallization. A new kappa phase salt of BETS, K-(BETS)2GaCl4,displayed an interesting resistance-temperature profile from 300-35K.

ISSN:1058-725X    

DOI:10.1080/10587259208025827

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Solutions of tris(2, 6-dimethoxyphenyl)methyl radical (1) and lithium salts form solids showing unusual magnetic behavior. The propeller-shaped radicals, with their tripods of nucleophilic oxygens, are preorganized polydentate ligands. By coordination with small alkali metal cations the radicals may stack, enforcing spin-spin interactions in extended chains of paramagnets.Ab initiocalculations on a linear H3C-Li+-CH3model shows that high-spin (ferromagnetic) electron coupling is favored for a wide range of radical-Li+distances.

ISSN:1058-725X    

DOI:10.1080/10587259208025828

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

We present here a comparative study of the electrical properties of two series of Cu / TCNQ composites, respectively with, and without, significant charge-transfer between Cu and TCNQ.

ISSN:1058-725X    

DOI:10.1080/10587259208025829

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor