Two fumarato-bridged Co(II) coordination polymers: syntheses, crystal structures and properties of Co(H2O)4L and [Co3(H2O)4(OH)2L2]·2H2O with H2LHOOCCHCHCOOH

Synthesis and properties of a few 1-D cobaltous fumarates

“…MOFs containing the fumarate ligand, trans-(O 2 CH¼ CHCO 2 ) 2 À (fum), are known to show interesting magnetic properties [4,5] and also highly selective gas sorption behaviour [6]. Examples of 1-D and 2-D coordination polymers involving 'fum' as a bridging ligand have also been reported in the literature [7][8][9]. It is noted that, in addition to coordination bonds, non-covalent forces such as hydrogen bonding, C-H Á Á Á p, and pÀp interactions may also be important in governing the formation of such supramolecular solids [8,[10][11][12][13][14].…”

Structural Invariance of a ZnII Coordination Polymer with 5-Aminoisophthalic Acid under Different Synthetic Conditions

“…Indeed, in our previous work, the 2:1 metal:ligand stoichiometry of the starter reactants resulted in 1D CPs with 1:1 metal:ligand ratio using method A, 14 and 3D CPs with 2:1 metal:ligand ratio using method B. 14,18 Contrary here, the same starter reactants, now having aip as ligand instead fum or dhbdc, result in a same product, characterized as [Zn(aip)(DMSO)] (1) (see single crystal X-ray results), regardless of whether the method is A or B (Figure 1). Therefore, establishing an analogy with our previous results, 14 compound 1 can be considered both the kinetic and the thermodynamically stable product.…”

“…14 The 2:1 metal:ligand ratio was the stoichiometry chosen to compare the influence of the methods in the expectation of obtaining higher dimensionality CPs (2D or 3D) as achieved by Dietzel et al 18 working with Zn II and dhbdc. Indeed, in our previous work, the 2:1 metal:ligand stoichiometry of the starter reactants resulted in 1D CPs with 1:1 metal:ligand ratio using method A, 14 and 3D CPs with 2:1 metal:ligand ratio using method B.…”

“…Over again, the bulk materials obtained from all stoichiometries result in 1 as pure crystal phase (see powder X-ray results), even for the 3:1 and 4:1 metal:ligand stoichiometries, that could favor the formation of CPs with other structures or higher dimensionalities. 14,18 Finally, since the use of temperature is an intrinsic variant in the hydrothermal via, this method was chosen to test the influence of this variable in the structure and dimensionality of the CPs obtained from the starter reactants used here. The tested reactional temperatures, 70 and 100 °C, results in bulk materials constituted by a mixture of compound 1 (majority phase) and a spurious unknown crystal phase (see PXRD discussion).…”

“…14 The use of diffusion method favors the formation of 1D CPs, 14 whereas the use of pH control method favors the formation of 3D CPs. 14,18 It was demonstrated that the synthetic method could play a crucial role in the structure and dimensionality of CPs since the same starter reactants provided distinct products.…”