Breaking Symmetry toward Nonspherical Janus Particles Based on Polyhedral Oligomeric Silsesquioxanes: Molecular Design, “Click” Synthesis, and Hierarchical Structure

• DOI: 10.1021/ja202906m
• Publication Date: 2011-06-17T19:36:00Z
• Authors: Yiwen Li; Wen-Bin Zhang; I-Fan Hsieh; Guoliang Zhang; Yan Cao; Xiaopeng Li; Chrys Wesdemiotis; Bernard Lotz; Huiming Xiong; Stephen Z. D. Cheng
• Keywords: Janus Particles; Silsesquioxane; Particle (ecology); Orthorhombic crystal system

The design, synthesis, and self-assembly of a series precisely defined, nonspherical, polyhedral oligomeric silsesquioxane (POSS)-based molecular Janus particles are reported. synthesis aims to fulfill the "click" philosophy by using thiol-ene chemistry efficiently install versatile functionalities on one POSS cages. In such way, both geometrical chemical symmetries were broken create feature. These self-organize into hierarchically ordered supramolecular structures in bulk. For example, particle with isobutyl groups carboxylic other self-assembles bilayered structure head-to-head, tail-to-tail arrangements each particle, which further organize three-dimensional orthorhombic lattice. While layers was lost upon heating via first-order transition, persisted throughout. This study provides model system well-defined for general understanding their hierarchical formation condensed state.