NCAFM2023 Programme Booklet

Tuesday 1620 - 1640

SUBSTRATE-MODULATED SYNTHESIS OF METAL−ORGANIC HYBRIDS REVEALED BY CHEMICAL BOND IMAGING

Qigang Zhong, 1,2 Kaifeng Niu, 1,3 Long Chen, 4 Haiming Zhang, *,1 Daniel Ebeling, 2 Jonas Björk, 3 Klaus Müllen, 4,5 André Schirmeisen, *,2 Lifeng Chi *,1 1 Institute of Functional Nano & Soft Materials, Soochow University, 215123 Suzhou, China 2 Institute of Applied Physics, Justus-Liebig University Giessen, 35392 Giessen, Germany 3 Department of Physics, Chemistry and Biology, IFM, Linköping University, 58183 Linköping, Sweden 4 Max Planck Institute for Polymer Research, 55128 Mainz, Germany 5 Institute of Physical Chemistry, Johannes Gutenberg University Mainz, 55128 Mainz, Germany Email: qigang.zhong@outlook.com

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 [1]. 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 bond-resolved 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. In addition, we discuss the possibility of visual inspection of metal bonds within the MOHs using CO tip functionalization. Our findings pave the way for the on-surface synthesis of elusive MOHs with good control over their growth in two dimensions by tuning the covalent metal−organic interactions. The incorporation and engineering of multiple aryl−metal bonds expand the toolbox of on-surface organometallic chemistry and will significantly increase the diversity and versatility of lowdimensional MOHs.

Fig. 1: Substrate-modulated synthesis of 1D and 2D MOHs by tunable multiple aryl−metal bonds.

References [1] Q. Zhong, K. Niu, L. Chen, H. Zhang, D. Ebeling, J. Björk, K. Müllen, A. Schirmeisen, L. Chi, J. Am. Chem. Soc. 2022, 144 , 8214.

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