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Popova, Elena L.; Rozenberg, V. I.; Starikova, Z. A.; Keuker‐Baumann, Susanne; Kitzerow, Heinz‐S.; Hopf, Henning

doi:10.1002/1521-3757(20020916)114:18<3561::aid-ange3561>3.0.co;2-r

Cited by 10 publications

(7 citation statements)

References 1 publication

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“…5 These molecules act as hosts for molecular guests,6 and have been utilized in polymer chemistry and material science 6c. 7 The close approach of two coplanar benzene rings gives unique electronic properties and leads to interesting applications in areas such as chemical sensors,8 liquid crystals,9 and light‐emitting polymers 10…”

Section: Introductionmentioning

confidence: 99%

Synthesis and Ring‐Opening Metathesis of Tetraalkoxy‐Substituted [2.2]Paracyclophane‐1,9‐dienes

Helliwell

Raftery

et al. 2011

Chemistry A European J

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Tetraalkoxy-substituted [2.2]paracyclophane-1,9-dienes can be prepared in three steps from dithia[3.3]paracyclophanes. A mixture of pseudo-geminal and pseudo-ortho diastereomers is produced and the pure compounds can be separated by fractional crystallization. The solid state structures of these diastereomers reveal strongly distorted aromatic rings consistent with high levels of ring strain. Reaction of these diastereomers with the second generation Grubbs catalyst shows that only the pseudo-geminal isomer can be ring opened to give cis,trans-distrylbenzenes. The origin of this selectivity is discussed and the photoisomerization of the as-formed cis,trans-product to the all trans isomer is demonstrated.

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Section: Introductionmentioning

confidence: 99%

Synthesis and Ring‐Opening Metathesis of Tetraalkoxy‐Substituted [2.2]Paracyclophane‐1,9‐dienes

Helliwell

Raftery

et al. 2011

Chemistry A European J

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“…Hopf and coworkers assessed the mesogenic potential of the PCP unit in the development of chiral liquid-crys-talline (LC) materials, [10] and established the characteristic features of [2.2]paracyclophane-containing compounds ( Figure 2) concerning meso-morphism. The peculiar geometry of these kinds of compounds, which possess planar chirality, may provide a rigid interaction between the origin of the symmetry-breaking chirality and the mesogenic unit, i.e., between the chiral and optical parts of the molecule, thus resulting in a definite fixing of a source of chirality into a LC matrix.…”

Section: [22]paracyclophane-derived Arylenesmentioning

confidence: 99%

“…A search for the structural features enabling an increased stability of the mesomorphic behavior of the PCP derivatives was performed. [10] Carboxylic acids were selected as the most appropriate starting PCP building blocks. It was found that [2.2]paracyclophane derivatives can be generated that exhibit stable mesomorphic behavior over a wide range of temperature and different types of mesophases, thus paving the way for a new class of chiral LC compounds.…”

Section: [22]paracyclophane-derived Arylenesmentioning

confidence: 99%

Organic Small Molecules for Photonics and Electronics from the [2.2]Paracyclophane Scaffold

Marrocchi

Tomasi

Vaccaro

2012

Israel Journal of Chemistry

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In the search for molecules for organic photonics and electronics, several strategies have been used to modulate physical and chemical properties of [2.2]paracyclophane derivatives by sequential functionalization of their three‐dimensional cores. This review summarizes the major design and synthetic strategies for tuning paracyclophane‐containing small molecules by introducing various moieties featuring (hetero)aromatic rings directly connected to each other, as well as alternating (hetero)aryl and ethylene or ethynylene units. Several examples are presented that elucidate the structural, optical, and electronic consequences of incorporating these fragments in the aromatic decks, particularly relating to applications in organic optoelectronics.

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“…A weak spontaneous polarization (Ps) value was obtained due to the fact that the two arms attached to the fer-rocene were not greatly different in length or polarity. It is important to note that planar chirality was rarely used to prepare optically active liquid-crystalline materials: only butadiene-tricarbonyliron complexes (S C* and N* phases) [28] and [2.2]paracyclophane derivatives (S C* , S A , and N* phases) [29] were reported in addition to our ferrocene compound. Planar chiral 1,3-disubstituted ferrocenes (Fig.…”

Section: Introductionmentioning

confidence: 99%

Ferrocene‐Containing Optically Active Liquid‐Crystalline Side‐Chain Polysiloxanes with Planar Chirality

Brettar

Bürgi

Donnio

et al. 2005

Adv Funct Materials

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Optically active liquid‐crystalline side‐chain polysiloxanes have been prepared by grafting planar chiral ferrocene‐based vinyl monomers onto commercially available polyhydrosiloxane. Two ferrocene monomers have been synthesized: a linear‐type monomer, which displays a monotropic chiral smectic C (SC*) phase and enantiotropic smectic A (SA) and chiral N (N*) phases, and a laterally branched monomer, which shows an enantiotropic N* phase. X‐ray diffraction analysis indicates a monomolecular organization of the monomeric units within the smectic layers. The polymers retain the liquid‐crystalline phases of their corresponding monomers. The UV‐vis and circular dichroism (CD) spectra are in agreement with the structure of the monomers and polymers. The molar absorption coefficient (ϵ) and molar circular dichroic absorption coefficient (Δϵ) values of the polymers are proportional to the number of monomeric units grafted onto them. The absolute configuration of the ferrocene carboxylic acid intermediate, used to synthesize the monomers, has been determined on the basis of CD spectra. The helical twisting power (HTP) of the nematogenic monomer and polymer have been determined in E7, and indicate that such materials could be used as chiral dopants. Finally, this study demonstrates that the nature of chiral phases can be controlled by structural engineering of the organic groups only, with ferrocene acting as the source of chirality.

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Untitled

Cited by 10 publications

References 1 publication

Synthesis and Ring‐Opening Metathesis of Tetraalkoxy‐Substituted [2.2]Paracyclophane‐1,9‐dienes

Synthesis and Ring‐Opening Metathesis of Tetraalkoxy‐Substituted [2.2]Paracyclophane‐1,9‐dienes

Organic Small Molecules for Photonics and Electronics from the [2.2]Paracyclophane Scaffold

Ferrocene‐Containing Optically Active Liquid‐Crystalline Side‐Chain Polysiloxanes with Planar Chirality

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