Electronic torsional sound in linear atomic chains: Chemical energy transport at 1000 km/s

Abstract

We investigate entirely electronic torsional vibrational modes in linear cumulene chains. The carbon nuclei of a cumulene are positioned along the primary axis so they can participate only in transverse and longitudinal motions. However, the interatomic electronic clouds behave as a torsion spring with remarkable torsional stiffness. The collective dynamics of these clouds can be described in terms of electronic vibrational quanta, which we name torsitons. It is shown that the group velocity of the wavepacket of torsitons is much higher than the typical speed of sound, because of the small mass of participating electrons compared to the atomic mass. For the same reason the maximum energy of the torsitons in cumulenes is as high as a few electronvolts, while the minimum possible energy is evaluated as a few hundred wavenumbers and this minimum is associated with asymmetry of zero point atomic vibrations. Molecular systems for experimental evaluation of the predictions are proposed.

Extraction of One-Handed Helical Frontier Orbital in Even [n]Cumulenes by Breaking Mirror Images of Right- and Left-Handed Helical Orbitals: Theoretical Study

“…Carbon-based linear-chain molecules, cumulenes (H 2 CC···CCH 2 ), and their derivatives have attracted intense attention not only as interstellar space matter but also as promising nanomaterials in the fields of energy, electronics, , magnetics, and (non-) linear optics. , Cumulenes are also used as precursors for cycloaddition . Moreover, their fundamental properties are relevant to electronic structures, , rotational barriers, and reactivity .…”