Substrate-Modulated Synthesis of Metal–Organic Hybrids by Tunable Multiple Aryl–Metal Bonds

Abstract

Assembly of semiconducting organic molecules with multiple aryl−metal covalent bonds into stable one-and two-dimensional (1D and 2D) metal−organic frameworks represents a promising route to the integration of single-molecule electronics in terms of structural robustness and charge transport efficiency. Although various metastable organometallic frameworks have been constructed by the extensive use of single aryl−metal bonds, it remains a great challenge to embed multiple aryl−metal bonds into these structures due to inadequate knowledge of harnessing such complex bonding motifs. Here, we demonstrate the substrate-modulated synthesis of 1D and 2D metal−organic hybrids (MOHs) with the organic building blocks (perylene) interlinked solely with multiple aryl−metal bonds via the stepwise thermal dehalogenation of 3,4,9,10-tetrabromo-1,6,7,12-tetrachloroperylene and subsequent metal−organic connection on metal surfaces. More importantly, the conversion from 1D to 2D MOHs is completely impeded on Au(111) but dominant on Ag(111). We comprehensively study the distinct reaction pathways on the two surfaces by visually tracking the structural evolution of the MOHs with high-resolution scanning tunneling and noncontact atomic force microscopy, supported by first-principles density functional theory calculations. The substrate-dependent structural control of the MOHs is attributed to the variation of the M−X (M = Au, Ag; X = C, Cl) bond strength regulated by the nature of the metal species.

High-Throughput Preparation of Supramolecular Nanostructures on Metal Surfaces

“…Supramolecular chemistry has been a subject of intense study for developing functional materials with various applications. , Molecular self-assembly at solid surfaces offers a promising strategy and unparalleled route for the large-scale construction of low-dimensional nanostructures, which have gained considerable attention in the past few decades. , The organized surface molecular nanostructures are driven by molecule–molecule and/or molecule–metal recognitions through dynamic noncovalent interactions including hydrogen and halogen bonding, van der Waals forces, and dipole–dipole and metal–organic coordinated interactions. − A spectrum of interesting, and in some cases peculiar, supramolecular nanostructures were successfully constructed on surfaces. ,− Another noteworthy factor to the popularity of surface-supported supramolecular chemistry lies in the expansion of the surface science community, particularly thanks to the advances of scanning probe microscopy (SPM), which enables the submolecular characterization of the surface-supported species. − …”

Unveiling the formation mechanism of the biphenylene network

“…Such high barrier can be ascribed to strong C-Au interactions which prohibit the C-C coupling. 34 Furthermore, the activation energy for the dehydrogenation in the intra-polymer mechanism is found to be significantly reduced due to the close proximity of the C-H bond to the surface. 35 As shown in Figure 3, the C-H activation exhibits a smaller barrier than that of the defluorination in the first step (E TS2 -E S1 = 1.59 eV < E TS1 -E S0 = 2.14 eV).…”

“…However, the intermolecular C-C coupling starting from S1 is not favored due to the relatively high energy barrier of 1.86 eV (FigureS6). Such high barrier can be ascribed to strong C-Au interactions which prohibit the C-C coupling 34. Furthermore, the activation energy for the dehydrogenation in the intra-polymer mechanism is found to be significantly reduced due to the close proximity of the C-H bond to the surface 35.…”

A Deep‐Learning Framework for the Automated Recognition of Molecules in Scanning‐Probe‐Microscopy Images

“…The most representative SPMs include scanning tunneling microscope (STM) and atomic force microscope (AFM) [5–8] . The developments and applications of SPMs have significantly advanced our understanding of nanostructures and materials due to their capability of providing ultrahigh resolution down to the level of individual atoms [9–18] . Generally, when analyzing SPM images, it is important to determine their statistical parameters such as the sizes, numbers and areas of the objects of interest.…”