Remarkably stable metal–organic frameworks on an inert substrate: M-TCNQ on graphene (M = Ni, Fe, Mn)

Abstract

We present three isostructural substrate-decoupled 2D metal organic frameworks, which are stable in ambient environment and can be studied with atomic-scale precision.

Simple lattice model of surface-confined metal–organic networks consisting of linear nitrogen-bearing molecules and transition metals

“…In a first approximation, the type of functional group determines its size and type of electron donor atom that bonds with the coordinating metal center. [4][5][6][7][8][9][10][11][12][13][14][15] Bischoff et al compared the phase behavior of SMONs consisting of copper atoms coordinating the pyridyl and cyano groups of porphyrin derivatives. 4 The pyridyl derivatives of the porphyrin and copper atoms self-assemble into metal-organic networks where the copper coordinates two pyridyl groups (two-fold coordination motif).…”

“…In previous work 7 the authors observed similar SMONs with three-fold coordination motifs formed by linear molecules with nitrile and hydroxy groups. Linear molecules with deprotonated carboxyl 8,9 and dinitrile 10,12,13 groups are known to form metal-organic structures consisting of four-fold coordination motifs with various metal centers on different surfaces. In the case of a carboxyl group, complexes can also be observed in the structure of the metal-organic layer where the metal binds to three molecules.…”

How the Support Defines Properties of 2D Metal–Organic Frameworks: Fe-TCNQ on Graphene versus Au(111)

“…On both Fe-TCNQ systems, we have deposited >1ML of TCNQ at 25 °C and post-annealed the samples to 80 °C to desorb any TCNQ multilayers 44 and TCNQ molecules from areas of clean graphene/Ir. 27 The UPS work function measurements shown in Figure 6A reveal that upon this treatment, the work function of Fe-TCNQ/gr/Ir increases by more than 0.5 eV, whereas the Fe-TCNQ/Au work function only increases by 0.1 eV. This clearly indicates that the electrostatic surface dipole changes differently on the two supports, hinting on different structures and/or bonding mechanisms taking place.…”

A Cu2(C6O6) metal–organic framework monolayer assembled on silicon carbide grown graphene exhibiting a metallic band structure

“…Therefore, decoupling the 2D-MOFs from the metallic substrates or directly bottom-up synthesizing them on inert surfaces is highly desirable. [25][26][27][28][29][30][31] As illustrated in Scheme 1, BHO forms a Cu 3 (C 6 O 6 ) coordination framework on Cu(111) 22 and a Fe 3 (C 6 O 6 ) coordination framework on Au(111). 32 In this work, we synthesize a singlelayer 2D-MOF of Cu 2 (C 6 O 6 ) through the on-surface reaction of BHO and Cu on graphene grown epitaxially from 4H-SiC (0001) (G/SiC).…”

“…Therefore, decoupling the 2D-MOFs from the metallic substrates or directly bottom-up synthesizing them on inert surfaces is highly desirable. 25–31…”