Investigation of triptycene-based surface-mounted rotors

Abstract

We have used computer simulations to investigate the potential of triptycene-based rotors mounted on the Si(100)-2 × 1 surface. Two concepts are explored for attaching the triptycene to the Si surface: –COOH and –OH groups. We find the –COOH produces an axle with too many degrees of freedom, creating too flexible a coupling to the substrate. By contrast, the calculations suggest that the –OH coupling should provide a useful stiff axle.

High Performance Polyimide with High Internal Free Volume Elements

“…[14] In addition, triptycene has a high energy barrier to molecular twisting or deformation, keeping the angle between aromatic rings nearly 1208. [15] These unique This paper reports a new polyimide design with high internal free volume elements for fast mass transport simultaneously with high selectivity. Here, we show that the polymer design using a three-dimensional rigid molecular structure having internal void space can lead to the formation of high fractional free volume with proper cavity size to separate small gas molecules with high selectivities as high permeabilities.…”

Dynamics in Self-assembled Organic Monolayers at the Liquid/Solid Interface Revealed by Scanning Tunneling Microscopy

“…Going beyond self-assembly, a number of recent reports stress the importance of 'reversibility' to obtain high-quality 2D surfacesupported covalent organic frameworks, combining molecular self-assembly and organic chemistry, on substrates such as graphite or iodide-covered Au(111). [13,14] Several exciting dynamic phenomena were discovered and discussed such as translational, [15][16][17][18][19][20][21][22] rotational, [23][24][25] and conformational dynamics [26][27][28][29][30][31] or a combination thereof, of single molecules or clusters on atomically flat metallic surfaces. Sometimes, these dynamics were intentionally provoked by the interaction with the STM-tip.…”

Dynamics of Single-Molecule Rotations on Surfaces that Depend on Symmetry, Interactions, and Molecular Sizes

“…Rotational dynamics of surface-mounted molecules has been studied by several experimental methods that include scanning tunneling microscopy (STM),29–32,38,39 inelastic electron tunneling (IET),40–44 and single-molecule fluorescence imaging 4531,46,47 and molecular mechanics (MM)48,49 computer simulations, quantum-chemical density-functional studies33,50 and fundamental thermodynamic approaches 51,52…”