3 years ago

Effect of Pyridyl Orientation on the Molecular Conformation and Self-Assembled Morphology of Regioisomeric Diketopyrrolopyrrole Derivatives

Effect of Pyridyl Orientation on the Molecular Conformation and Self-Assembled Morphology of Regioisomeric Diketopyrrolopyrrole Derivatives
Xinrui Miao, Yong Cao, Lei Ying, Wenli Deng, Xiaojun Wang
We reported the synthesis, characterization, and self-assembly of two new regioisomeric π-conjugated chromophores (p-DBPy and d-DBPy) based on pyridyl-flanked diketopyrrolopyrrole (DPP), where the nitrogen atom in the pyridyl was proximal or distal to the central DPP unit. Their solid powders and solutions displayed different colors, especially for p-DBPy, which could be attributed to the conversion of molecular conformation and different intermolecular aggregations. UV–vis spectra demonstrated that the possible intermolecular hydrogen bonding existed in the solution of p-DBPy. Of particular interest is that the morphology of solid powders and thin films for each molecule investigated by SEM and AFM, respectively, were dramatically different owing to different intermolecular interactions and different crystal growth speed. Their spectroscopic and electrochemical properties turned out to be strongly dependent on the orientation of the pyridyl group. DFT calculations were performed to determine the optimized molecular conformation and molecular 3D charge density. At the liquid–solid interface, as visualized by STM, d-DBPy formed a 2D fishbone-like adlayer with linear molecular conformation by the molecule–substrate van der Waals force; however, p-DBPy self-assembled into a fish-scale-like pattern with flexed molecular conformation resulting from intra- and intermolecular hydrogen bonds. Compared with the 2D adlayers, the π–π stacking is another important driving force to determine the morphology of the films. The results demonstrated that understanding the effect of pyridyl orientation along the conjugated core on the molecular conformation and self-assembly is of critical importance for fabricating desired films with special morphology for high-performance organic electronic devices.

Publisher URL: http://dx.doi.org/10.1021/acs.jpcc.7b06511

DOI: 10.1021/acs.jpcc.7b06511

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.