摘要:

The role of hydrogen bonding in the packing of a variety of carboxyl acid amides is investigated - p-amide-benzoic, phenylamido carboxylic, benzoylamino carboxylic, phthalamido carboxylic acids and carboxytrimellitimides. A variety of arrangements are observed with both amide-amide and acid-acid hydrogen bonds as well as acid-amide interactions. In certain cases alternative packing arrangements appear possible with the structure finally adopted being determined by the length of the alkyl chain in the molecule.

ISSN:1058-725X    

DOI:10.1080/10587259208025810

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

This paper discusses structural strategies for assembling bulk materials for nonlinear optics. In part one, we review a strategy, based on the concepts of guest-host inclusion complexation. We incorporate molecules into crystalline environments in which molecular dipoles are assembled into materials for second harmonic generation by polar alignment of the dipoles. In part two, we review the fabrication and properties of optical quality materials for third order nonlinear optics based on nanoscale particles of semiconductors included in polymer media.

ISSN:1058-725X    

DOI:10.1080/10587259208025811

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Structural systematics, programmability, and guest transport are discussed for a large class of lattice clathrates based on tetraarylporphyrins.

ISSN:1058-725X    

DOI:10.1080/10587259208025812

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Alicyclic oil 's of specific design crystallise with a lattice enclosing a series of parallel helical canals which trap a wide range of guest molecules. Typical structures of these helical tubulate compounds are presented. The canal sizes and geometries vary considerably depending on the actual diol utilised. Lattices with smaller canals retain the helical tubuland structure in the absence of guests, whereas those with larger canals collapse to a close-packed structure.

ISSN:1058-725X    

DOI:10.1080/10587259208025813

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Urea and thiourea inclusion complexes have been prepared containing conjugated polyene chromophores. Dialkylpolyenes with n-alkane tails form complexes with urea; carotenoids and diphenylpolyenes form complexes with thiourea. In some cases the chromophoric groups are diluted by incorporation of saturated hydrocarbons into the inclusion complexes. The resulting crystals are highly dichroic with their maximum absorption along the crystallographic hexagonal c-axis. Polarized fluorescence excitation studies (of the urea n-alkylpolyene complexes) and polarized single crystal resonance Raman studies (of the thiourea carotenoid and diphenylpolyene complexes) have been performed and are interpreted in terms of the orientation of the transition dipole of these polyenes with respect to the molecular axis.

ISSN:1058-725X    

DOI:10.1080/10587259208025814

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Raman spectroscopic investigations of urea inclusion compounds containing α,ω-dibromoalkane [Br(CH2)nBr; n=7–10] guest molecules are reported. Vibrational modes due to the urea confirm the structural identity of the inclusion compounds, and assignments of lattice modes due to the urea channel structure are also discussed. Investigations of the vibrational properties of the α,ω-dibromoalkane molecules included within this host structure have focused on the longitudinal acoustic mode and the C-Br stretching vibrations. The spectral bands due to the v(C-Br) mode have been used to assess the relative amounts of trans and gauche end-groups in the included α,ω-dibromoalkane molecules.

ISSN:1058-725X    

DOI:10.1080/10587259208025815

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Solid state13C CP/MAS and2H NMR are used to examine the tri-o-thymotide clathrates of 2-bromopropane, 2-propanol and dimethylsulfoxide. In all cases the enantiotopic methyl groups could be resolved.

ISSN:1058-725X    

DOI:10.1080/10587259208025816

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The incoherent inelastic neutron scattering spectra of Dianin 's compound and its ethanol and CC14adducts have been measured, and the resulting velocity spectra are reported. The results show the insensitivity of the lattice dynamics of this host lattice to the presence of guests in its cages.

ISSN:1058-725X    

DOI:10.1080/10587259208025817

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Aggregation of cinnamic acid and cinnamamide derivatives is studied at the air/aqueous interface. We study both the spontaneous surface aggregation of soluble molecules from their aqueous solution, and insoluble monolayers of long alkyl chain derivatives on various subphases. The interaction at the surface between soluble and insoluble species is also probed.

ISSN:1058-725X    

DOI:10.1080/10587259208025818

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Z-type Langmuir-Blodgett films are prepared from an amphiphilic diacetylene derivative which has been polymerized. The high structural fidelity of these films is verified by optical second and third harmonic generation.

ISSN:1058-725X    

DOI:10.1080/10587259208025819

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor