Metathesis Cyclopolymerization Triggered Self-Assembly of Azobenzene-Containing Nanostructure

Abstract

Azobenzene (AB) units were successfully introduced into poly(1,6-heptadiyne)s in order to ensure smooth synthesis of double- and single-stranded poly(1,6-heptadiyne)s (P1 and P2) and simultaneously realize the self-assembly by Grubbs-III catalyst-mediated metathesis cyclopolymerization (CP) of AB-functionalized bis(1,6-heptadiyne) and 1,6-heptadiyne monomers (M1 and M2). Monomers and polymers were characterized by 1H NMR, mass spectroscopy, and GPC techniques. The double-stranded poly(1,6-heptadiyne)s exhibited a large scale of ordered ladder nanostructure. This result was attributed to the π−π attractions between end groups along the longitudinal axis of the polymers and van der Waals interactions between the neighboring polymeric backbones. While the Azo chromophore connected in the side chain of P2 induced conformation of micelles nanostructure during the CP process without any post-treatment. Furthermore, the photoisomerization of Azo units had an obviously different regulatory effect on the conjugated degree of the polymer backbone, especially for the single-stranded P2, which was attributed to the structural differences and the interaction between AB chromophores in the polymers.

Envision and Appraisal of Biomolecules and Their Interactions through Scanning Probe Microscopy

“…Subsequently, it allows the chemical identification of atoms; hence, today, the analysis of magnetic anisotropy energy is also an engrossing topic that is being studied with this ubiquitous machine. STM also offers electrochemical studies at the electrode/liquid interface, along with redox processes occurring at the interface, [23] metallic and semiconducting surfaces, [24][25][26] oligomers, polymer-like heptadiyne, [27,28] organic molecules or wires, [29] redox molecules, [30,31] and redox proteins. [32,33] Being a versatile machine, the use of STM in studying various biomolecules is increasing continuously.…”