Organic Nanosynthesis of Ancient Windmill-like Window Gridarenes at Molecular Scale

We focus on another kind of square-type unit nanogrids with starlike divergent extensibility. As a result, square windmill-like nanogrid WG4 have been successfully synthesized by two different kinds of fluorene-based nanosynthons, namely I-shape nanosynthon and L-shape nanosynthon synthesis method. Besides WG4, triangle and hexagon windmill-like nanogrids (WG3 and WG5) are also obtained via one-pot nanosynthesis of I-shape nanosynthon with WG3 as the main product. For the L-shape nanosynthon synthetic method, the cyclization process possesses higher selectivity, resulting to an excellent yield for WG4. In addition, two stereoisomers of the triangle nanogrids, cis-trans-WG3 and cis-cis-WG3, were separated and characterized from the single-crystal X-ray diffraction and ¹H NMR analyses for getting insight into the configuration of the triangle nanogrids with the skeleton planarization for the trans-configuration and deplanarization for the cis-configuration.