The self-assembly of two kinds of C2-symmetric aromatic carboxylic acids named 4,4′,4″,4‴-(1,4-phenylenebis­(azanetriyl))­tetrabenzoic acid (H4PTA) and 5′,5″-bis­(4-carboxyphenyl)-[1,1′:3′,1″:3″,1‴-quaterphenyl]-4,4‴-dicarboxylic acid (H4QDA) and the coadsorption with coronene (COR) molecules at different solution concentrations were investigated at the heptanoic acid (HA)/highly oriented pyrolytic graphite (HOPG) interface by scanning tunneling microscopy (STM). H4PTA molecules with nonplanar conformation self-assembled into a highly ordered rhombus structure at variational concentrations and subsequently could be regulated into a Kagomé network by the coadsorption of COR molecules. H4QDA molecules with planar conformation self-assembled into two various nanostructures (rhombus structure and Kagomé network) coexisting on the HOPG surface at different concentrations. The Kagomé architecture of H4QDA could act as a rigid host template to trap the COR molecules. Meanwhile, COR exhibited preferential adsorption in the porous template: COR only entered the hexagonal cavities at low concentrations and filled in all hexagonal and triangular cavities at high concentrations. Density functional theory (DFT) calculations and molecular dynamics (MD) simulations showed that the host–guest co-assembled structures were more thermodynamically and kinetically stable. The formation of different self-assembly and co-assembly processes of two molecules could be attributed to the dissimilar molecular conformation. Our work is of significance to further explore the formation mechanism of two-dimensional (2D) porous arrangements and provides an ideal way to regulate the adsorption of porous templates.

Fabricating tetraphenylethylene (TPE)-functionalized metal−organic frameworks (MOFs) with aggregation-induced emission on surfaces and understanding the growth mechanism have not yet been pursued. Herein, MOFs constructed via the Ullmanntype reaction of a C 2 -symmetry TPE derivative (p-BrTBE) on Au(111) and Cu(111) surfaces were thoroughly investigated using scanning tunneling microscopy. On a Au(111) surface, p-BrTBE molecules formed the self-assembled pattern at 298 K. Stepwise annealing led to a progressive evolution process, in which the stepwise debromination reaction led to organometallic intermediates, and surface-stabilized radicals and metal−organic networks were formed. By contrast, the relatively ordered MOFs were obtained by replacing the underlying substrate with the more catalytically active Cu(111) at 298 K. Density functional theory calculations demonstrated that the formation of different networks on Au(111) and Cu(111) was determined by the different conformations of the TBE unit on the different substrates due to the different adsorption energy.

A theoretically guided Zn2+ confining–anchoring strategy is proposed based on the different strengths between alpha-cyclodextrin (α-CD) additives and various crystallographic planes of zinc to achieve dendrite-free aqueous ZIB.

No abstract