Mesoscale Graphene-like Honeycomb Mono- and Multilayers Constructed via Self-Assembly of Coclusters

Hou, XS (Hou, Xue-Sen)^[ 1,2 ] ; Zhu, GL (Zhu, Guo-Long)^[ 4 ] ; Ren, LJ (Ren, Li-Jun)^[ 1,2 ] ; Huang, ZH (Huang, Zi-Han)^[ 4 ] ; Zhang, RB (Zhang, Rui-Bin)^[ 5,6 ] ; Ungar, G (Ungar, Goran)^[ 5,6 ] ; Yan, LT (Yan, Li-Tang)^[ 4 ] ; Wang, W (Wang, Wei)^[ 1,2,3 ]

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 2018, 140(5): 1805-1811

DOI: 10.1021/jacs.7b11324

  WOS:000424851500034

Abstract

Honeycomb structure endows graphene with extraordinary properties. But could a honeycomb monolayer superlattice also be generated via self-assembly of colloids or nanoparticles? Here we report the construction of mono- and multilayer molecular films with honeycomb structure that can be regarded as self-assembled artificial graphene (SAAG). We construct fan-shaped molecular building blocks by covalently connecting two kinds of clusters, one polyoxometalate and four polyhedral oligomeric silsesquioxanes. The precise shape control enables these complex molecules to self-assemble into a monolayer 2D honeycomb superlattice that mirrors that of graphene but on the mesoscale. The self-assembly of the SAAG was also reproduced via coarse-grained molecular simulations of a fan-shaped building block. It revealed a hierarchical key determining the honeycomb structure. Experimental images also show a diversity of bi- and trilayer stacking modes. The successful creation of SAAG and its stacks opens up prospects for the preparation of novel self-assembled nanomaterials with unique properties.