Eigenschaften, Theorien und Molekülbau flüssiger Kristalle

Demus, D.

doi:10.1002/zfch.19750150102

Cited by 30 publications

(1 citation statement)

References 117 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Previous comparative studies for two-ring benzene derivatives (3)(4)(5) considered the effect of up to eight different linking groups , whereas for the cyclohexane-benzene (3) and cyclohexane-cyclohexane derivatives (6) the variety of the group was smaller. It was concluded that aromatic rings typically prefer unsaturated linking groups that allow for the extension of electronic conjugation, whereas the saturated cyclohexane rings are more compatible with the saturated dimethylene linker and the ester group.…”

Section: Introductionmentioning

confidence: 98%

The effect of the linking group on mesogenic properties of three‐ring derivatives of p‐carborane and biphenyl

et al. 2008

View full text Add to dashboard Cite

Four series of mesogenic derivatives of p-carborane (series A[0] and A[1]) and their benzene analogues (series B[0] and B[1]) with variable linking groups were prepared and investigated for phase behaviour. The data allowed a comparison of the effect of the group on the mesophase stability as a function of the adjacent ring (carborane or benzene), the variable central ring (carborane or benzene), and the presence of an oxygen atom in the terminal chain. The results showed that substitution of carborane for a benzene ring in B[m] depresses the clearing point by 50 K to 208 K and eliminates all smectic behaviour in A[m]. The carborane derivatives A[m] are weakly dependent (effectiveness of : -CH5CHCOO-,-COO-,-CH5CH-.-CH5N-,-CH 2 CH 2 -.-CONH-), whereas the benzene analogues B[m] are strongly dependent (effectiveness of : -CONH-.-CH5CH-.-CH5N-, -CH5CHCOO-.-COO-.-CH 2 CH 2 -) on the structure of the linking group . The difference in the effectiveness of the amide group on mesophase stability (DT I 5208 K) has been attributed to the stabilizing intermolecular H-bonding in B[m], which is prevented in A[m] by steric and electronic effects of the carborane cage on the carbonyl group.

show abstract

Section: Introductionmentioning

confidence: 98%