Synthesizing Cr‐Based Two‐Dimensional Conjugated Metal‐Organic Framework Through On‐Surface Substitution Reaction

Abstract

A single‐layer Cr3(HITP)2 (HITP = 2,3,6,7,10,11‐hexaiminotriphenylene) conjugated metal‐organic framework (c‐MOF) is synthesized under ultrahigh vacuum conditions by substituting Cr for Ni in Ni3(HITP)2 template. As revealed by low‐temperature scanning tunneling microscopy and scanning tunneling spectroscopy, while codeposition of Cr atoms and 2,3,6,7,10,11‐hexaaminotriphenylene precursors produces irregular branches, crystalline Cr3(HITP)2 frameworks are obtained by depositing Cr atoms to the Ni3(HITP)2 templates. The density functional theory calculations reveal that the binding energy between Cr and HITP ligands is much higher than that for Ni, which hampers the growth of crystalline Cr3(HITP)2 frameworks through direct coordination assembly but makes the substitution reaction energetically favorable. This work demonstrates a new strategy to prepare high‐quality early‐transition‐metal‐based c‐MOFs under ultrahigh vacuum conditions.

Identifying topological corner states in two-dimensional metal-organic frameworks

“…We found that the Type-I bands can be realized in monolayer Ni 3 (HITP) 2 grown on Au(111) substrate. Through the reported on-surface coordination assembly method 46 , 47 , monolayer Ni 3 (HITP) 2 frameworks are synthesized on Au(111) substrate from Ni atoms and 2,3,6,7,10,11-Hexaaminotriphenylene (HATP) molecules under ultrahigh vacuum conditions. The high quality of the synthesized Ni 3 (HITP) 2 frameworks are verified by STM image (Supplementary Fig.…”

A Highly Chemically Robust 3D Interpenetrated MOF Heterogeneous Catalyst for the Synthesis of Hantzsch 1,4‐Dihydropyridines and Drug Molecules

“…It is very inspirational that more than 10 000 products are being synthesized every year by employing various solid catalysts, which further trigger ≈15% of the world's GDP worth around $10 trillion per year. [ 1 ] In the contest of heterogeneous catalysis, Metal–organic frameworks (MOFs) have attracted immense attention over other solid catalysts having their unique structural features such as well‐defined pore structure and high porosity, [ 2–11 ] versatile functionality, [ 12–29 ] diverse composition, [ 30–46 ] tunable topography, [ 47–53 ] framework flexibility, [ 54–59 ] and improved stability. [ 60–62 ] Taking advantage of three different parts in MOFs, i) metal nodes, ii) employed organic ligands, and iii) the pore system , they have been explored in several multicomponent heterogeneous catalysis reactions such as condensations, oxidations, and C─C couplings, etc.…”

Transmetalation in Surface-Confined Single-Layer Organometallic Networks with Alkynyl–Metal–Alkynyl Linkages

“…Surprisingly, this option has been rarely studied within the field of metallosupramolecular surface networks, with the exception of a nitrogen−metal linked 2D conjugated system. 38 In particular, successful postsynthetic transformation of surface-confined 2D-OMNs with carbon−metal bonding, bearing significant prospects for appealing 2D graphyne-or graphdiyne-like materials with interesting electronic properties has not been reported so far.…”

“…In-vacuum surface-adsorbed macrocycles, e.g., metalloporphyrins, have been reported to undergo transmetalation, facilitating the creation of macrocycles and the tuning of their properties for heterogeneous catalysis. − Accordingly, in the context of surface-supported 2D OMNs, transmetalation appears as an appealing route for customizing the structure–property relationship of such attractive 2D materials in a controlled way. Surprisingly, this option has been rarely studied within the field of metallosupramolecular surface networks, with the exception of a nitrogen–metal linked 2D conjugated system . In particular, successful postsynthetic transformation of surface-confined 2D-OMNs with carbon–metal bonding, bearing significant prospects for appealing 2D graphyne- or graphdiyne-like materials with interesting electronic properties has not been reported so far.…”