Related Experiment Video
Updated: Apr 25, 2026

Construction and Systematical Symmetric Studies of a Series of Supramolecular Clusters with Binary or Ternary Ammonium Triphenylacetates
Published on: February 15, 2016
Density-Energy Balanced Selection of Chiral Honeycomb Superstructures from Deprotonated Carboxylate Molecules on
Shenwei Chen1, Haiwei Wang1, Xiang Zhang1
1State Key Laboratory of Green Chemical Synthesis and Conversion, College of Chemical Engineering, Zhejiang University of Technology, Hangzhou, Zhejiang 310014, China.
Abstract:
Here, we investigate the self-assembly of 4,4',4″-(1,3,3a1,4,6,7,9-heptaazaphenalene-2,5,8-triyl) tribenzoic acid on Ag(111) by scanning tunneling microscopy. Upon annealing, complete deprotonation drives the formation of a family of periodic honeycomb superstructures, denoted as HCN (N = 1-8), which are composed of triangular molecular sublattices and exhibit pronounced organizational chirality. By controlling the molecular coverage and annealing conditions, we identify the coexistence of HC4 and HC5 as the thermodynamically favored state near equilibrium. An analytical model incorporating the coupled contributions of molecular density and average intermolecular binding energy, supported by a rigorous convexity-based analysis, demonstrates that the ground state under a fixed density constraint corresponds to the coexistence of two adjacent HCN and HCN+1 phases. These results provide a unified thermodynamic framework for understanding and controlling surface-confined supramolecular networks.
Related Concept Videos
Prochirality
Regioselectivity and Stereochemistry of Acid-Catalyzed Hydration
Molecules with Multiple Chiral Centers
Ionic Crystal Structures
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
Crystal Field Theory - Tetrahedral and Square Planar Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than...
Radicals: Electronic Structure and Geometry
Accordingly, the structure of a trivalent radical lies between the geometries of carbocations and carbanions. An sp2-hybridized carbocation is trigonal planar, while an sp3-hybridized carbanion is trigonal pyramidal. Here, the difference in geometry is...

