Extraordinary deformation capacity of smallest carbohelicene springs

Extraordinary deformation capacity of smallest carbohelicene springs

Článek WoS

The extraordinary deformation and loading capacity of nine different [N]carbohelicene springs under uniaxial tension up to their fracture were computed using the density functional theory. The simulations comprised either the experimentally synthetized springs of hexagonal rings or the hypothetical ones that contained irregularities (defects) as, for example, pentagons replacing the hexagons. The results revealed that the presence of such defects can significantly improve mechanical properties. The maximum reversible strain varied from 78% to 222%, the maximum tensile force varied in the range of 5 nN to 7 nN and, moreover, the replacement of hexagonal rings by pentagons or heptagons significantly changed the location of double bonds in the helicenes. The fracture analysis revealed two different fracture mechanisms that could be related to the configurations of double and single bonds located at the internal atomic chain. Simulations performed with and without van der Waals interactions between intramolecular atoms showed that these interactions played an important role only in the first deformation stage.

The extraordinary deformation and loading capacity of nine different [N]carbohelicene springs under uniaxial tension up to their fracture were computed using the density functional theory. The simulations comprised either the experimentally synthetized springs of hexagonal rings or the hypothetical ones that contained irregularities (defects) as, for example, pentagons replacing the hexagons. The results revealed that the presence of such defects can significantly improve mechanical properties. The maximum reversible strain varied from 78% to 222%, the maximum tensile force varied in the range of 5 nN to 7 nN and, moreover, the replacement of hexagonal rings by pentagons or heptagons significantly changed the location of double bonds in the helicenes. The fracture analysis revealed two different fracture mechanisms that could be related to the configurations of double and single bonds located at the internal atomic chain. Simulations performed with and without van der Waals interactions between intramolecular atoms showed that these interactions played an important role only in the first deformation stage.

ab initio, carbohelicene, deformation capacity

ab initio, carbohelicene, deformation capacity

ŠESTÁK, P.; WU, J.; HE, J.; POKLUDA, J.; ZHANG, Z.

2016

10.06.2015

Royal Society of Chemistry

1463-9076

PHYSICAL CHEMISTRY CHEMICAL PHYSICS

17

28

Spojené království Velké Británie a Severního Irska

18684

18690

7

http://pubs.rsc.org/en/Content/ArticleLanding/2015/CP/C5CP02043C#!divAbstract