Chiral intertwined spirals and magnetic transition dipole moments dictated by cylinder helicity

Proc Natl Acad Sci U S A. 2017 Dec 12;114(50):13097-13101. doi: 10.1073/pnas.1717524114. Epub 2017 Nov 27.

Abstract

The presence of anomalous chirality in a roll of graphitic carbon sheets has been recognized since the discovery of carbon nanotubes, which are becoming available in higher quantities through the isolation of chiral single-wall congeners with high purity. Exploration of the properties arising from cylinder chirality is expected to expand the scope of tubular entities in the future. By studying molecular fragments of helical carbon nanotubes, we herein reveal interesting properties that arise from this chirality. The chirality of nanoscale cylinders resulted in chirality of larger dimensions in the form of a double-helix assembly. Cylinder chirality in solution gave rise to a large dissymmetry factor of metal-free entities in circular polarized luminescence. Theoretical investigations revealed the pivotal role of cylindrical shapes in enhancing magnetic dipole transition moments to yield extreme rotatory strength. Unique effects of cylinder chirality in this study may prompt the development of tubular entities, for instance, toward chiroptical applications.

Keywords: carbon nanotubes; chirality; circularly polarized luminescence; double helix; macrocycles.

Publication types

  • Research Support, Non-U.S. Gov't