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 (alpha- and beta-) ([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 (alpha- and beta-) 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.