Self-assembling diacetylene molecules on atomically flat insulatorsElectronic supplementary information (ESI) available: XPS experimental details and spectra, I/V characteristics of diamond, droplet contact angle measurements, supplementary AFM data and secondary discussion on molecular stacking. See DOI: 10.1039/c6cp06749b

• Main Authors: Verveniotis, Elisseos, Okawa, Yuji, Makarova, Marina V, Koide, Yasuo, Liu, Jiangwei, Šmíd, B etislav, Watanabe, Kenji, Taniguchi, Takashi, Komatsu, Katsuyoshi, Minari, Takeo, Liu, Xuying, Joachim, Christian, Aono, Masakazu
• Format: Article
• Language: English
• ISSN: 1463-9076; 1463-9084
• DOI: 10.1039/c6cp06749b

Single crystal sapphire and diamond surfaces are used as planar, atomically flat insulating surfaces, for the deposition of the diacetylene compound 10,12-nonacosadiynoic acid. The surface assembly is compared with results on hexagonal boron nitride (h-BN), highly oriented pyrolytic graphite (HOPG) and MoS 2 surfaces. A perfectly flat-lying monolayer of 10,12-nonacosadiynoic acid self-assembles on h-BN like on HOPG and MoS 2 . On sapphire and oxidized diamond surfaces, we observed assemblies of standing-up molecular layers. Surface assembly is driven by surface electrostatic dipoles. Surface polarity is partially controlled using a hydrogenated diamond surface or totally screened by the deposition of a graphene layer on the sapphire surface. This results in a perfectly flat and organized SAM on graphene, which is ready for on-surface polymerization of long and isolated molecular wires under ambient conditions. The diacetylene self-assembly mechanism on atomically flat insulators is elucidated, towards using polydiacetylene wires in molecular electronic devices.