Synthesis And STM Observation Of Functional Organic Molecules

A series of functional organic molecules have been designed and synthesized and STM was used to explore their assembly behaviors on HOPG surface. Based on the density functional theory, we summarized the characteristics and regularity of assembly for conjugated multi-alkyne aniline derivatives and found 8Y(CPN8) molecule can act as template molecules. The main contents are as follows:(1) The triangular 2,4,6-tris(3,5-di-methyl formate-4’-hydroxy azobenzene)-1,3,5-triazine molecule assembles into the petal-like stable structure. A novel compound TDHAT has been synthesized. STM results show that the star-shaped molecule self-assembles into the petal-like stable structure. Despite the similar molecule structure, the driving force may be different, resulting in diverse nanoarchitectures.(2)For the conjugated multi-alkyne aniline derivatives, the larger the system, the more difficult the assembly, and solvent dependent are observed.2JT2 and PLY-D can be observed both in 1-phenyloctane and in heptanoic acid with different structures. When the systems expanded from 4JT2 (4J) to 8JT2 (8J), the assembly structures can only be observed in heptanoic acid with the solvent molecules are coadsorbed, which has been confirmed by the density functional theory (DFT) calculations. Furthermore, both the expanded system and the introductions of bulky triisopropylsilyl will reduce the stability of the 2D network.(3)Ring-conjugated multi-alkyne aniline derivatives 6Y and 8Y can act as a template. Studies have shown that the cavity can host matched guest molecules, such as 8Y can accommodate cyclic peptide molecule and TMA.