On-surface synthesis under ultrahigh vacuum provides a promising strategy to control matter at the atomic level, with important implications for the design of new two-dimensional materials having remarkable electronic...On-surface synthesis under ultrahigh vacuum provides a promising strategy to control matter at the atomic level, with important implications for the design of new two-dimensional materials having remarkable electronic, magnetic, or catalytic properties. This strategy must address the problem of limited extension of the domains due to the irreversible nature of covalent bonds, which prevents the ripening of defects. We show here that extended materials can be produced by a controlled co-deposition process. In particular, co-deposition of quinoid zwitterion molecules with iron atoms on a Ag（111） surface held at 570 K allows the formation of micrometer-sized domains based on covalent coordination bonds. This work opens up the construction of micrometer-scale single-layer covalent coordination materials under vacuum conditions.展开更多
On-surface synthesis of semiconducting graphdiyne nanowires usually suffer severe side reactions owing to the high reactivity of the butadiynylene units at noble metal surfaces,limiting the production of isolated nano...On-surface synthesis of semiconducting graphdiyne nanowires usually suffer severe side reactions owing to the high reactivity of the butadiynylene units at noble metal surfaces,limiting the production of isolated nanowires. In this work, we report the high-yield synthesis of branchless graphdiyne nanowires [-C≡C-Ph2-C≡C-]nvia on-surface Ullmann coupling of 1,4-bis（4-bromophenyl）-1,3-butadiyne molecules with chemical vapor deposition method.Non-contact atomic force microscopy with single-bond resolution reveals that single gold adatoms act as effective protecting groups for butadiynylene units by forming Au-π ligand bonds, preventing unwanted branched coupling reactions and enabling the synthesis of ultralong isolated graphdiyne nanowires. This study will stimulate further investigation on the role of various surface adatoms in protecting on-surface reactions.展开更多
文摘On-surface synthesis under ultrahigh vacuum provides a promising strategy to control matter at the atomic level, with important implications for the design of new two-dimensional materials having remarkable electronic, magnetic, or catalytic properties. This strategy must address the problem of limited extension of the domains due to the irreversible nature of covalent bonds, which prevents the ripening of defects. We show here that extended materials can be produced by a controlled co-deposition process. In particular, co-deposition of quinoid zwitterion molecules with iron atoms on a Ag（111） surface held at 570 K allows the formation of micrometer-sized domains based on covalent coordination bonds. This work opens up the construction of micrometer-scale single-layer covalent coordination materials under vacuum conditions.
基金the National Key R&D Program of China(No.2016YFA0200603 No.2017YFA0205004)the Anhui Initiative in Quantum Information Technologies(AHY090300)+2 种基金the National Natural Science Foundation of China(No.21473174)the Fundamental Research Funds for the Central Universities(No.WK2060190084 and No.WK2340000082)Ai-di Zhao acknowledges a fellow-ship from the Youth Innovation Promotion Association of Chinese Academy of Science(2011322).
文摘On-surface synthesis of semiconducting graphdiyne nanowires usually suffer severe side reactions owing to the high reactivity of the butadiynylene units at noble metal surfaces,limiting the production of isolated nanowires. In this work, we report the high-yield synthesis of branchless graphdiyne nanowires [-C≡C-Ph2-C≡C-]nvia on-surface Ullmann coupling of 1,4-bis（4-bromophenyl）-1,3-butadiyne molecules with chemical vapor deposition method.Non-contact atomic force microscopy with single-bond resolution reveals that single gold adatoms act as effective protecting groups for butadiynylene units by forming Au-π ligand bonds, preventing unwanted branched coupling reactions and enabling the synthesis of ultralong isolated graphdiyne nanowires. This study will stimulate further investigation on the role of various surface adatoms in protecting on-surface reactions.
