Related Experiment Video
Updated: Jul 30, 2026

Preparation of a Corannulene-functionalized Hexahelicene by Copper(I)-catalyzed Alkyne-azide Cycloaddition of Nonplanar Polyaromatic Units
Published on: September 18, 2016
Molecular dynamic study of the odd-even effect in some 4-n-alkyl-4'-cyanobiphenyls
1Dokuz Eylül University, Faculty of Arts and Science, Department of Physics, Buca-Izmir, Turkey.
Abstract:
Using a united atom model, we performed molecular dynamics (MD) simulations on the 4-n-alkyl-4'-cyanobiphenyl (nCB) liquid crystal homologous series for at a constant reduced temperature in the nematic phase. To evaluate the rotational diffusion coefficient (RDC), the second- and fourth-rank order parameters (OP's) and correlation time were calculated from MD trajectories. We analyzed the rotational viscosity coefficient (RVC) by using the Nemtsov-Zakharov and Fialkowski methods based on statistical-mechanical approaches. The simulated RDC, RVC, and OP's were found to be reasonable when compared with previous theoretical and experimental data. These quantities were also calculated for the rigid core and alkyl chain segments separately for each mesogen, to take a closer look at the molecule tail-chain flexibility. The properties calculated for a rigid core were compared with those for an alkyl chain, and satisfactory results were obtained. Odd-even effects for RDF, RVC, and molecular ordering parameters were calculated for five mesogens.
Related Concept Videos
Stereoisomerism of Cyclic Compounds
¹H NMR: Complex Splitting
Splitting diagrams or splitting tree diagrams are routinely used to depict such complex couplings. While drawing splitting diagrams, the splitting with the larger coupling constant is usually applied first.
NMR Spectroscopy of Benzene Derivatives
π Electron Effects on Chemical Shift: Overview
π Electron Effects on Chemical Shift: Aromatic and Antiaromatic Compounds
¹H NMR: Long-Range Coupling
In alkenes, spin information is communicated via σ–π overlap, as seen in allylic (four-bond) and homoallylic (five-bond) couplings. These coupling interactions are stronger when the σ bond is parallel to the alkene π orbitals.

