摘要:

We predicted and confirmed experimentally that an ordinary wave may propagate through a very thick (∼5 mm) nematic liquid crystal (NLC) cell almost without distortions. The physical idea is that: 1) the polarizations of thee-ando-wave follow adiabatically the local orientation of optical axis and 2) phase velocity ofo-wave does not depend on orientation. Behavior of polarization around disclination line is studied.

ISSN:1058-725X    

DOI:10.1080/10587259208030763

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The search for the hexatic smectic F phase inN(p-n-alkoxybenzylidene)-p-n-alkylanilines, has revealed thatN(p-n-decyloxybenzylidene)-p-n-tetradecylaniline, 10O.14, exhibits a direct isotropic liquid to smectic F phase transition with a phase sequence variant FG, while both the compounds 10O.12 and 10O.16 exhibit the AFG phase sequence variant. This is the first observation of an isotropic liquid to smectic F phase transition innO.mcompounds.

ISSN:1058-725X    

DOI:10.1080/10587259208030764

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

We have found that at a sufficiently high concentration, diacetylenic phospholipid tubules form a nematic phase when suspended in water. As a consequence of their large size, the tubules were imaged with visible light and the nematic order parameter was extracted.

ISSN:1058-725X    

DOI:10.1080/10587259208030765

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The multilayers containing cyanobiphenyl liquid crystal (4-cyano-4-octybiphenyl) with stearic acid as a matrix have been fabricated by the Langmuir-Blodgett technique. The surface pressure-area isotherms and x-ray diffraction datas reveal that the multilayers have a close packed layer structure. Optical absorption spectra and morphological observations show that the aggregates of cyanobiphenyl liquid crystal are formed in the multilayers, and the aggregate size depend on the film thickness.

ISSN:1058-725X    

DOI:10.1080/10587259208030766

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Substituted phenylbenzoates of the typewhereX= R, RO; (Y= (CH2)nCOR′,n= 1, R′ = C8H17andn= 2, R′ = C7H15have been prepared to determine the effect of the spacer methylene groups on the mesomorphic properties of esters having a ketone chain on the phenolic side. The required precursor phenols were prepared by treatment of the protected acidswith an alkyllithium followed by hydrogenolysis of the benzyl group. The analogous cyclohexane diesterswere also synthesized to test the generality of trends observed in mesomorphic properties. Hot stage polarizing microscopy was used to determine mesomorphic properties. These were compared to those for the esters withY= C10H21, COR′ and (CH2)nCO2R′ (n= 1,2).

ISSN:1058-725X    

DOI:10.1080/10587259208030767

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The crystal structures of hexakis(dimethylsilyl)benzene (1) and its tricarbonyl tungsten (2), molybdenum (3) and chromium (4) complexes were determined by X-ray diffraction. Compound1crystallizes in the monoclinic system, space groupP21/cwitha= 11.196(5)A,b= 19.675(9)Å,c= 24.447(8)Å,Z= 8, at 175K. The metal complexes2,3,4are isomorphic; the compounds exhibit trigonal modifications (2t,3t,4t), space groupR3 orR3,Z= 6. Crystal data: (2t)a= 19.044(5)Å,c= 14.343(4)Å, at 193K; (3t)a= 19.056(4)Å,c= 14.633(5)Å, at 298K; (4t)a= 19.047(5)Å,c= 14.144(5)Å, at 193K.The metal complexes were dimorphic; compounds2and3exhibit monoclinic modifications (2m,3m), space groupP21,Z= 2. Crystal data: (2m)a= 11.059(4)Å,b= 13.885(4)Å,c= 11.140(3)Å, β = 114.79(3)°, at 225 K; (3m)a= 11.020(6)Å,b= 13.838(4)Å,c= 11.099(4)Å, β = 114.54(3)°, at 193K.Each of the five structures that were solved and refined (1,2m,2t,3m,4t) exhibit an orientational disorder. The extent of the disordering, measured as the refined occupancy of the minor species, varies for independent molecules within the same asymmetric unit in1, and between isomorphic structures in the trigonal and monoclinic series of2,3, and4.The disorder was accommodated differently in the trigonal and monoclinic modifications. The metal tricarbonyl units adopt a staggered conformation with respect to the side chains. Substantial out-of-plane deviations (>0.2 Å) of the dimethylsilyl groups were observed in all the structures and arene bond alternations were measured in the metal complexes.

ISSN:1058-725X    

DOI:10.1080/10587259208030768

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

This is a scanned image of the original Editorial Board page(s) for this issue.

ISSN:1058-725X    

DOI:10.1080/10587259208030752

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor