Insight into the SBU Condensation in Mg Coordination and Supramolecular Frameworks: A Combined Experimental and Theoretical Study

This work is to emphasize the influence of the synthetic
procedures
in the isolation of different coordination polymers that coexist under
hydro-/solvothermal conditions. An experimental and theoretical study
in the Mg2+:4,4′-(hexafluoroisopropylidene)­bis­(benzoic
acid):1,10-phenantroline system has been carried out. Computational
studies have determined the relative energies for those compounds
that coexist under certain hydrothermal conditions, and have helped
to identify the driving forces for the formation of the different
phases. The five new compounds belong to five different structural
types: AEPF-14, which presents two polymorphs (α- and β-) ([Mg­(H2O)4(phen)2]­L), AEPF-15 ([Mg­(HL)2(phen)]) and AEPF-16 ([Mg­(H2O)2(L)­(phen)]) are both 1D MOFs (AEPF-16 with a helical
structure), and AEPF-17 ([Mg­(H2O)­(L)­(phen)])
with a 2D structure. Hydrogen bond interactions found in the five
compounds have been taken into account to study the topology of their
supramolecular nets. Finally, dehydration studies performed on AEPF-14 (α- and β-)
and AEPF-16 have shown that the topological type of their
supramolecular networks determines the structural changes that take
place during the dehydration processes of these Mg compounds.