Structural and electronic properties of M-MOF-74 (M = Mg, Co or Mn)

Highlights: • The furthest understanding of MOF-74 at molecular level was realized. • The best Hubbard parameters were determined to simulate M-MOF-74 (M = Co or Mn). • The ELF and QTAIM methods were used for deep analyses of the electronic density. • The catalytic activity is not dependent only of the metallic cation charge. • Non-conventional hydrogen bonds are identified for M-MOF-74 (M = Mg or Co). The Metal-Organic Frameworks M-MOF-74 (M = Mg, Co or Mn) were investigated through Density Functional Theory calculations. Structural parameters and band gap energies were determined in agreement with experimental data, with errors under 2%. The methods Electron Localization Function and Quantum Theory of Atoms in Molecules were applied to the analyses of the electronic density topology of the three solids. These methodologies indicated that the bonds between the metallic cations and the oxygen atoms are predominantly ionic while the other ones are predominantly covalent. Furthermore, non-conventional hydrogen bonds were identified to Mg-MOF-74 and Co-MOF-74, which were not observed to Mn-MOF-74.