Coupled molecular switching processes in ordered mono- and multilayers of stimuli-sesponsive rotaxanes on gold surfaces

Interfaces provide the structural basis for function as, for example, encountered in nature in the membrane-embedded photosystem or in technology in solar cells. Synthetic functional multilayers of molecules cooperating in a coupled manner can be fabricated on surfaces through layer-by-layer self-assembly. Ordered arrays of stimulus-responsive rotaxanes undergoing well-controlled axle shuttling are excellent candidates for coupled mechanical motion. Such stimulus-responsive surfaces may help integrate synthetic molecular machines in larger systems exhibiting even macroscopic effects or generating mechanical work from chemical energy through cooperative action. The present work demonstrates the successful deposition of ordered mono- and multilayers of chemically switchable rotaxanes on gold surfaces. Rotaxane mono- and multilayers are shown to reversibly switch in a coupled manner between two ordered states as revealed by linear dichroism effects in angle-resolved NEXAFS spectra. Such a concerted switching process is observed only when the surfaces are well packed, while less densely packed surfaces lacking lateral order do not exhibit such effect

C K edge NEXAFS spectra of graphene with physical and chemical defects a study based on density functional theory

We present density functional based simulations of NEXAFS spectra to model the effects of plasma treatment.</p

Innovative and Established Strategies for the Surface Analysis of Nitrogen and Oxygen Rich Plasma Polymer Films by XPS An Introductory Guide

Nitrogen- and oxygen-based plasma polymer films are materials with a complex and partially elusive surface chemistry. We present an overview of innovative and established X-ray photoelectron spectroscopy (XPS)-based analysis strategies developed to elucidate the surface chemistry of such films. We focus on both experimental methods and data analysis strategies and include the following topics: high-resolution spectra curve fitting, aging, chemical derivatization, and depth profiling by angle- and energy-resolved XPS

A detailed assignment of NEXAFS resonances of imidazolium based ionic liquids

Experimental and theoretical investigation of Near Edge Absorption Fine Structure (NEXAFS) resonances of two kinds of imidazolium based ionic Liquids.</p

A photoswitchable rotaxane operating in monolayers on solid support

A novel photoswitchable rotaxane was synthesised and its switching behaviour in solution and on solid support was studied.</p