On-Surface Crystallization Behaviors of H-Bond Donor-Acceptor Complexes at Liquid/Solid Interface

Two-dimensional (2D) crystallization behaviors of A-TPCn (n = 4, 6, 10), T3C4, and hydrogen-bonded complexes T3C4@TPCn (n = 4, 6, 10) are investigated by means of scanning tunneling microscope (STM) observations and density functional theory (DFT) calculations. The STM observations reveal that A-TPC4, A-TPC10, and T3C4 self-organize into dumbbell-shaped structures, well-ordered bright arrays, and zigzag structures, respectively. Interestingly, T3C4@TPC10 fails to form the cage-ball structure, whereas T3C4@TPC4 and T3C4@TPC6 co-assemble into cage-ball structures with the same lattice parameters. The filling rates of the balls of these two kinds of cage-ball structures depend heavily on the deposition sequence. As a result, the filling rates of the cages in T3C4/A-TPCn (n = 4, 6) with deposition of T3C4 anterior to A-TPCn are higher than those in A-TPCn/T3C4 (n = 4, 6) with the opposite deposition sequence. Furthermore, lattice defects formed by T3C4 coexist with the cage-ball structures. Moreover, the simi...