NCAFM2023 Programme Booklet

Tuesday 1720-1740

CHEMIST INTUITED ATOMIC ROBOTIC PROBE FOR PRECISE SINGLE MOLECULE SURGERY OF QUANTUM π MAGNETS

Jie Su 1 , Jiali Li 2 , Na Guo 3,7, Xinnan Peng 1 , Jun Yin 2 , Jiahao Wang 4 , Pin Lyu 1 , Zhiyao Luo 2 , Koen Mouthaan 4 , Jishan Wu 1 , Chun Zhang 1,3,7* , Xiaonan Wang 5* , Jiong Lu 1,6* 1 Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore. 2 Department of Chemical and Biomolecular Engineering, College of Design and Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore 117585, Singapore. 3 National University of Singapore Chongqing Research Institute, Chongqing 401123, China. 4 Department of Electrical and Computer Engineering, College of Design and Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore 117583, Singapore. 5 Department of Chemical Engineering, Tsinghua University, Beijing 100084, China. 6 Institute for Functional Intelligent Materials, National University of Singapore, 4 Science Drive 2, Singapore 117544, Singapore. 7 Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117551, Singapore. Imprinting robust and correlated π-spins in magnetic nanographenes offers limitless opportunities for designing single-molecule quantum π-magnets (SMQMs) that exhibit non-trivial collective quantum behaviours and exotic quantum phases arising from the topological frustration or geometrical extension of π-network. The ability to precisely tailor both ingredients to achieve on-demand fabrication of SMQMs with tunable π-magnetism paves the way for future on-chip integration into spintronic devices and quantum information technologies. However, conventional surface-assisted synthesis or tip-assisted probe chemistry, while demonstrating huge potential in fabricating these SMQMs, are often impeded by the challenges of reaction selectivity control or severely restricted by scalability and production efficiency, respectively. Herein, we demonstrate a chemist-intuited atomic robotic probe concept by integrating artificial intelligence with a synchronous multi-bond surgery via probe chemistry, enabling on-demand site-selective fabrication of a series of SMQMs with precisely tailored topology and spin multiplicity. Our deep neural networks not only transform such a complex probe-chemistry issue into machine-understandable tasks but also provide valuable chemist-intuition into complex reaction mechanisms by extracting the critical chemical information within the data. A joint experimental and theoretical investigation demonstrates that a voltage-controlled two-electron-assisted electronic excitation enables synchronous six-bond transformations to extend the zigzag topology of SMQMs, triggered from the phenyl sp2 -CH bond activation, aligning with initial conjectures given by the deep neural models. Our work represents a significant leap from autonomous synthesis to intelligent fabrication with unparalleled levels of selectivity and precision beyond the current synthetic tools, thus creating a major paradigm shift in the on-demand manufacturing of novel organic quantum materials for on-chip integration.

Fig 1. Tip-assisted cyclodehydrogenationg of single-molecule π-magnets.

References [1] J. Su et al. To submit (2023)

45