Isoreticular two-dimensional magnetic coordination polymers prepared through pre-synthetic ligand functionalization

Abstract

Chemical functionalization is a powerful approach to tailor the physical and chemical properties of two-dimensional (2D) materials, increase their processability and stability, tune their functionalities and, even, create new 2D materials. This is typically achieved through post-synthetic functionalization by anchoring molecules on the surface of an exfoliated 2D crystal, but it inevitably alters the long-range structural order of the material. Here we present a pre-synthetic approach that allows the isolation of crystalline, robust and magnetic functionalized monolayers of coordination polymers. A series of five isostructural layered magnetic coordination polymers based on Fe(II) centres and different benzimidazole derivatives (bearing a Cl, H, CH, Br or NH side group) were first prepared. On mechanical exfoliation, 2D materials are obtained that retain their long-range structural order and exhibit good mechanical and magnetic properties. This combination, together with the possibility to functionalize their surface at will, makes them good candidates to explore magnetism in the 2D limit and to fabricate mechanical resonators for selective gas sensing.

Two-dimensional polymers with versatile functionalities via gemini monomers

“…Functionalization of 2D net-poly(MA-11-2-11-MA) Despite the progress made to date toward 2DSPs, effective functionalization of 2DSPs remains a formidable challenge with a highly rewarding solution due to the range of properties anticipated in these polymers (24,25). The observed self-adaptability of gemini MA-11-2-11-MA during polymerizations makes it an excellent precursor to functionalized 2DSPs, where 2DSPs with tunable properties can be synthesized with varying functional groups by copolymerization.…”

Coordination assembly of 2D ordered organic metal chalcogenides with widely tunable electronic band gaps

“…Other OMCs are isostructural with Cu(SPh-OH), and this was confirmed by their powder X-ray diffraction (PXRD) measurements (Supplementary Table 4). Although synthesized with organic ligands and metal ions by coordination, OMCs have unique 2D inorganic structures, which are different from the typical coordination polymers 45 . In Cu(SPh-OH), each metal atom adopts a slightly distorted trigonal planar geometry coordinated with three μ 3 -bridging S atoms of the ligands.…”

“…In fact, many functional MOF and COF materials have been produced for different applications ranging from gas separation, gas storage, heterogenous catalysis, photonics and drug delivery [40][41][42][43] . Such significant progress in material design and synthesis will certainly facilitate the discovery of other types of materials 44,45 .…”

2D magnetic MOFs with micron-lateral size by liquid exfoliation

“…19-20 K. MUV-1-X single crystals (X = H, Cl, Br, or CH 3 ) were prepared following the solvent-free methodology previously used by our group. 11,23 Crystals of MUV-1-Cl were used as model compound of this family in order to assess the best conditions for the liquid exfoliation, analysing the effect of different parameters such as source of energy, solvent, time, temperature, concentration, and centrifugation. The exfoliation process is illustrated in Figure 1.…”