First Investigation of Single-Walled Carbon Nanotubes Handedness Chirality Utilized By Scanning Tunneling Microscopy

Abstract

(n,m) chirality of single-walled carbon nanotubes (SWNTs) has been extensively identified as well as investigated and/or characterized using many spectroscopic techniques [1]. On the other hand, the identification of the absolute handedness chirality of SWNTs still big challenge to be achieved even though there are some attempts [2]. Hereby, we have distinguished the absolute handedness chirality of SWNTs for the first time by using scanning tunneling microscopy (STM). This can be accomplished by using supramolecular structures of some porphyrin derivatives i.e. 5,15-bisdodecylporphyrin (C12P) on the chital SWNTs surface. Two types of chiral SWNTs have been used in this study, right-handed helix P (or plus) type and left-handed helix M (or Minus) type [3]. As an exclusive finding, two opposite chiral supramolecular structures of C12P molecules have been observed on the chiral SWNT surface; reflecting the considerable effectiveness of the handedness chirality of SWNT on the supramolecular structures of organic molecules on its surfaces. This pivotal results directly open the gates towards the determination of the absolute handedness chirality of SWNT, as well as a key point for further understanding and building new supramolecular architectures on curved surfaces which can be used for designing and fabricating more advanced porphyrin-SWNTs based devices.