Revealing the structural detail of individual polymers using a combination of electrospray deposition and UHV-STM

Abstract

A phenylene vinylene polymer derivative is deposited onto a Au(111) surface under Ultra-High Vacuum (UHV) conditions using electrospray ionisation deposition and characterised using Scanning Tunnelling Microscopy (STM). High resolution STM images reveal the polymer structure on the monomeric scale, allowing the identification of regioisomerism, the intricate isomerisations of the polymer side-chains, as well as the larger-scale topologies of the polymer strands.

Halogen-Bond-Controlled Self-Assembly of Regioisomeric Phenanthridine Derivatives into Nanowires and Nanosheets

“…All other commercially available reagents and solvents to prepare the assemblies were reagent grade and used without further purification. 1 H NMR spectra were collected on Bruker AV500 spectrometers in deuterated chloroform solution using tetramethylsilane as the reference. UV−vis spectra were recorded on a JASCO V660 spectrophotometer.…”

“…The slight difference in the molecular chemical structure could fabricate distinct self-organizations. Thus, exploring the molecular assembled nanostructures could provide important evidence to optimize the functionality in the system. − We have recently reported the self-organization of regioisomeric diketopyrrolopyrrole-based π-conjugated semiconductors. , It has been evidenced that scanning tunneling microscopy (STM) is a powerful approach to reveal the intermolecular interaction and gives a deep insight to explore the formation mechanism of the morphology for the films. − …”

Sequencing conjugated polymers by eye

“…To fully harness the analytical power of STM and to image individual molecular species with subnanometer resolution, it is essential that the molecules are deposited in vacuum onto atomically clean and flat surfaces and that the measurements are performed in situ. We achieve this by exploiting recent advances in the soft landing of thermolabile molecules (11,12), thereby demonstrating a significant development in vacuum electrospray deposition (ESD) (13)(14)(15)(16)(17). Here, we report the combination of ESD with submolecularresolution STM to analyze diketopyrrolopyrrole (DPP)-based polymers.…”

Revealing the Influences of Solvent Boiling Point and Alkyl Chains on the Adlayer Crystallinity of Furan-Diketopyrrolopyrrole-Thienylene Copolymer at Molecular Level

“…Scanning tunneling microscopy (STM) is a powerful tool for investigating the structures of adsorbing layers because of its submolecular resolutions. , Surface patterns of small molecules in different solvents have been studied intensively on the basis of STM analysis . Solvent-directed polymorphism was mostly reported, in which stacking styles and density, chirality, and the interactions between assembling units may vary largely from pattern to pattern. − Also, in many systems, solvent molecules are co-adsorbed on the surface with assembling blocks. − In contrast to the extensive studies on the small molecular systems, solvent effect on the adsorbing layers of functional polymers has not been paid enough attention, although general adsorbing structures of several kinds of polymers have been reported in some studies. − On the other hand, stacking of small molecules is usually rather flexible and could lead to a few surface patterns in different conditions, which makes the rationalization of the physicochemical basis behind diverse solvent effects very challenging. For polymers, the room left for adjusting their assemblies is reduced heavily because their covalent-bonded backbones make the available conformations and stacking styles for ordered structures very limited.…”