Synthesis of Single‐Layer Two‐Dimensional Metal–Organic Frameworks M3(HAT)2 (M=Ni, Fe, Co, HAT=1,4,5,8,9,12‐hexaazatriphenylene) Using an On‐Surface Reaction

• Published in: Angewandte Chemie International Edition Vol. 61; no. 27; pp. e202204528 - n/a
• Main Authors: Lyu, Cheng‐Kun, Gao, Yi‐Fan, Gao, Zi‐Ang, Mo, Song‐Yu, Hua, Mu‐Qing, Li, En, Fu, Shu‐Qing, Chen, Jia‐Yan, Liu, Pei‐Nian, Huang, Li, Lin, Nian
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 04.07.2022
• Edition: International ed. in English
• Subjects: 2D Materials; Chelation; Cobalt; Conjugated Metal–Organic Frameworks; Density functional theory; Hexagonal lattice; Iron; Kagome lattice; Magnetic moments; Magnetic properties; Metal-organic frameworks; Nickel; On-Surface Synthesis; Scanning tunneling microscopy; Scanning Tunnelling Microscopy; Steric hindrance; Surface reactions; Synthesis; conjugated metal−organic frameworks; scanning tunnelling microscopy; on-surface synthesis; 2D materials
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.202204528

1,4,5,8,9,12‐Hexaazatriphenylene (HAT) is one of the smallest polyheterocyclic aromatic building blocks for forming conjugated metal–organic frameworks (cMOFs). However, the strong inter‐molecular steric hindrance impedes the growth of HAT‐based cMOFs. Here we employ on‐surface synthesis to grow single‐layer two‐dimensional cMOFs of M3(HAT)2 (M=Ni, Fe, Co). Using scanning tunnelling microscopy and density‐functional theory (DFT) analysis, we resolve that the frameworks comprise a hexagonal lattice of HAT molecules and a Kagome lattice of metal atoms. The DFT analysis indicates that Ni, Co and Fe carry a magnetic moment of 1.1, 2.5, and 3.7 μB, respectively. We anticipate that the small π‐conjugated core of HAT and strong bidentate chelating coordination give rise to appealing electronic and magnetic properties. 1,4,5,8,9,12‐Hexaazatriphenylene (HAT)‐based two‐dimensional conjugated metal–organic frameworks of M3(HAT)2 (M=Fe, Ni, Co) were synthesized by means of an on‐surface self‐assembly protocol which effectively overcomes the strong inter‐molecular steric hindrance.