journal article·1993-11

Gas phase molecular modeling of liquid crystals: Electro‐optical anisotropies

Matthias Bremer, Kazuaki Tarumi

Advanced Materials· Volume 5· Issue 11
Publisher page

Abstract

Molecular modeling of liquid crystals is important as it provides information without the need for chemical synthesis. The first ever quantitative correlation of semiempirically obtained quantities with electro‐optical parameters measured in 80 bulk liquid crystals is reported here. The Figure shows the calculated relative energy of an LC as a function of two torsion angles. magnified image
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Research context

OpenAlex topics: Molecular spectroscopy and chirality · Liquid Crystal Research Advancements · Spectroscopy and Quantum Chemical Studies

SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.

References (31)

Show source-provided references
1. 10.1007/BF0151671010.1007/BF01516710 ↗
2. DeJeu W. H. · 1980
3. deGennes P. G. · 1974
4. Demus D. · 1974 · 1984
5. Demus D. · 1978
6. 10.1080/0026894840808082710.1080/00268948408080827 ↗
7. P. S.Scheuble Kontakte (Darmstadt)1989 34.
8. 10.1016/0141-9382(92)90004-B10.1016/0141-9382(92)90004-B ↗
9. 10.1007/BF0153202010.1007/BF01532020 ↗
10. 10.1080/0026894910803342210.1080/00268949108033422 ↗
11. 10.1080/0267829890802640310.1080/02678298908026403 ↗
12. 10.1246/bcsj.66.63310.1246/bcsj.66.633 ↗
13. All structures were first optimized on an IBM compatible PC with the MMX force field as implemented in PCMODEL[16]. At this stage the rotational energy surface was briefly examined by using the rigid rotor approximation in order to ensure that a structure as close as possible to the global minimum was selected. In most cases possible intramolecular rotations have sufficiently high barriers so that the consideration of only one structure suffices. The structures obtained were then subjected to geometry optimization with MOPAC V6.0[17] using the AM1[18] Hamiltonian and the Eigenvector Following[19] algorithm. Polarizabilities were calculated by the Finite Field Method[20] as implemented in MOPAC V6.0 and the molecules were oriented so that their largest moment of inertia coincided with the x‐axis (default option in MOPAC V6.0). „Delta Alpha”︁ (δα) was obtained from the MOPAC output according to\documentclass{article}\pagestyle{empty}\begin{document}$ Dx = x - \sqrt {(\alpha ^2 yy + \alpha ^2 zz)} $\end{document}and is in atomic units (a.u.). The semiempirically (AM 1) obtained molecular dipole moments are in Debye (D). „Delta Dipole Squared”︁ is computed as Δμ2= μ‐ (μ+ μ). „Beta”︁ (β) is the angle of the total molecular dipole moment with the x‐axis in degrees. „Delta Eps”︁ is obtained according to δϵ = −μ2·(1−3 cos2β). Typical CPU times are of the order of a few hours per molecule on a VAX‐8550 computer.
14. Hehre W. J. · 1986
15. Clark T. · 1985
16. Finkenzeller U. · Kontakte (Darmstadt) · 1988 · 7
17. 10.1080/0267829890802637210.1080/02678298908026372 ↗
18. PCMODEL V4.0 Serena Software Bloomington. IN47402–3976.
19. MOPAC V6.0 QCPE 455 Indiana University. Bloomington IN 47405.
20. 10.1021/ja00299a02410.1021/ja00299a024 ↗
21. 10.1002/jcc.54007040210.1002/jcc.540070402 ↗
22. 10.1002/jcc.54011011010.1002/jcc.540110110 ↗
23. Blinov L. M. · 1983 · 45
24. 10.1002/jcc.54010020910.1002/jcc.540100209 ↗
25. Vuks M. F. · Opt. Spectrosc. · 1966 · 20 · 361
26. Madhusudana N. V. · J. Physique Colloq. · 1969 · 30 · C4124
27. 10.1021/j100626a02010.1021/j100626a020 ↗
28. Maier W. · Z. Naturforsch. · 1961 · 16 · 26210.1515/zna-1961-0309 ↗
29. 10.1080/0026894910803339510.1080/00268949108033395 ↗
30. 10.1063/1.167739610.1063/1.1677396 ↗
31. 10.1002/prop.1982030100210.1002/prop.19820301002 ↗