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Fluorophobic effect

The Influence of Fluorophobic Effect and Size Effects on Self-Assembly... [Pg.25]

LC phases usually corresponds to at least the number of attached chains [258]. Moreover, no SmA phases were observed for non-fluorinated polycatenar mesogens, whereas chain fluorination obviously enables the formation of SmA phases, which are most probably of the de Vries type. It seems that non-fluorinated polycatenars are mainly stabilized by core-core interactions, whereas the mesophase stabilization by the fluorophobic effect retains the layer structure even if core-core interactions are relatively weak. [Pg.53]

Diels-Alder reactions have been performed in most alternative reaction media. For certain substrates this reaction is significantly accelerated in fluorous solvents (Figure 1.9) This has been ascribed to a fluorophobic effect, analogous to the better-known hydrophobic effect where there is an inverse relationship between reaction rate and the solubility of reagents. However, it should be noted that in general cycloaddition reactions (including Diels-Alder reactions) are faster in water and this can be attributed to additional hydrogen bond stabilization of the transition state. [Pg.152]

Thiophene (30) does not usually undergo Diels-Alder reaction under thermal and Lewis acid catalysed conditions but it has been reported that under high pressure (2.0 GPa) it reacts with maleic anhydride (31) in reasonable yield (47%) (Scheme 7.8). It was recently observed that the reaction yield is strongly improved (77%) if the cycloaddition reaction is carried out in perfluorohexane at 0.8 GPa the fluorophobic effect plays a crucial role in rate enhancement... [Pg.242]

X. Zhou, S. Kang, S. Kumar, Q. Li, Self-assembly of discotic liquid crystal porphyrin into more controllable ordered nanostructure mediated by fluorophobic effect. Liq. Ciyst. 36, 267-274 (2009)... [Pg.251]

Percec V, Johansson G, Ungar G, Zhou JP (1996) Fluorophobic effect induces the self-assembly of semifluorinated tapered mtmodendrons containing crown ethers into supramolecular columnar dendrimers which exhibit a hraneotropic hexagonal columnar liquid crystalline phase. J Am Chem Soc 118(41) 9855-9866... [Pg.390]

See other pages where Fluorophobic effect is mentioned: [Pg.393]    [Pg.7]    [Pg.14]    [Pg.15]    [Pg.25]    [Pg.55]    [Pg.63]    [Pg.79]    [Pg.147]    [Pg.216]    [Pg.61]    [Pg.63]    [Pg.171]    [Pg.224]    [Pg.421]    [Pg.393]    [Pg.7]    [Pg.14]    [Pg.15]    [Pg.25]    [Pg.55]    [Pg.63]    [Pg.79]    [Pg.147]    [Pg.216]    [Pg.61]    [Pg.63]    [Pg.171]    [Pg.224]    [Pg.421]    [Pg.28]    [Pg.56]    [Pg.88]    [Pg.148]    [Pg.1971]    [Pg.192]    [Pg.136]    [Pg.370]   
See also in sourсe #XX -- [ Pg.15 ]

See also in sourсe #XX -- [ Pg.152 ]



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