Poster Presentation The 35th Biennial Conference of the Society of Crystallographers in Australia and New Zealand 2024 (Crystal 35)

Mixed-donor phenanthroline-heterocyclic carboxylate MOFs  (#212)

Caroline CL Liu 1 2 , Cameron CJK Kepert 2 , Lauren LKM Macreadie 3
  1. School of Chemistry , University of New South Wales, Sydney, New South Wales, Australia
  2. School of Chemistry , University of Sydney, Sydney, New South Wales, Australia
  3. School of Chemistry , University of New South Wales, Sydney, New South Wales, Australia

Metal-organic frameworks (MOFs) have become one of the most attractive classes of material under investigation for their applications due to their special properties. However, precisely tuning the shape and pores size in MOFs remains a challenge. Using mixed-donor ligands is one of the most comment methods to control the use of multiple metals and achieve the targeted topologies in a framework.

Previously, our group used the phenanthroline-carboxylate ligand system to form a mixed-metal photoactive Ru-Co MOF (1H-imidazo [4,5-f][1,10]-phenanthroline ligand) with large pore apertures and resulted in high CO2 sorption capacities and selectivity over N2 (Figure 1) .1 A few years later, our group used a longer phenanthroline-carboxylate ligand (2-(4-carboxy-1,1’-biphenyl)imidazo(4,5-f)(1,10)phenanthroline ligand) to form manganese (II) or Zn(II) MOFs (Figure 1b) which also photoactive and with favorable CO2 selectivity.2 Further investigations using the same ligand were performed using a mixed Eu-Ru system, which resulted in a photosensitizing MOF shows properties for selective CO2 reduction.3 With just a fine tune of the ligands length and metals choices, huge impacts in the framework CO2 capacity and applications can resul. Besides the choice of metals and lengths of the ligand, changing the angle in the system is also an interesting variable to investigate. Thus, the aim of this project is to employ a new strategy to modulate the angle of the phenanthroline-carboxylate ligand system using heterocyclic linkers which can offer a carboxylic acid coordination site in an adjusted positon. The new phenanthroline-carboxylate ligands are formed with furan, thiophene, or pyrrole. The resulting ligands form MOFs with single or mixed metal species (i.e RuII, CoII, MnII, ZnII, etc.) and here we share their properties and structure using single crystal X-ray diffraction, powder X-ray diffraction, and gas sorption analysis.

References

1 Martins L, Macreadie LK, Sensharma D, et al. Chem Commun., 2019, 55 (34), 5013-5016.
2 Setter CJ, Price MB, Conte L, et al. Chem Commun., 2020, 56 (87), 13377-13380.
3 Yan ZH, Du MH, Liu J, et al. Nat Commun., 2018, 3353 (2018).