Monomer and cyclic tetramer of copper(II) complexes: Synthesis, characterization and crystal structure determination of [Cu(dm4bt)Cl(Hipht)] and [{Cu(dm4bt)(H2O)(ipht)}4·2H2O]

catena-Poly[[[(di-2-pyridylamine-κ2N2,N2′)copper(II)]-μ-benzene-1,3-dicarboxylato-κ3O1,O1′:O3] monohydrate], a zigzag coordination polymer with strong π–π interactions

“…The dihedral angle between coordinated carboxylate groups is 82.73 (8) . The bond distances between the Cu II cation and atoms O1, O2 and O4 (Table 1) are within the usual ranges for complexes where monodentate and chelate carboxylate groups of ipht or substituted ipht are present (Li & Wei, 2007;Cui et al, 2009;Du et al, 2009;Su et al, 2009;Zeng et al, 2009;Al-Hashemi et al, 2010;Guo et al, 2010). The chelate O1-Cu1-O2 angle [56.76 (6) ] is also similar to those found in these related metal-organic compounds m230 # 2011 International Union of Crystallography doi:10.1107/S0108270111022451…”

“…Metal-organic polymers where ipht is coordinated as a bridging tridentate ligand with monodentate and chelate carboxylate groups are quite rare among the numerous ipht complexes. To the best of our knowledge, in total four such transition metal complexes have been described so far (Li & Wei, 2007;Cui et al, 2009;Su et al, 2009;Al-Hashemi et al, 2010), but two of them (Su et al, 2009;Al-Hashemi et al, 2010) contain two chemically different ipht anions, i.e. one anion is not a bridging tridentate ligand.…”

“…Accordingly, a general characteristic of (I) and related complexes containing ipht or its derivatives is that these kinds of ligands do not deviate very much from planarity. It seems that higher dihedral angles in several complexes (Table 3) are associated with the bulkiness of the second ligand (Al-Hashemi et al, 2010), the bulkiness of the substituent on the ipht ligand (Du et al, 2009) or the overall bulkiness of the complex unit (Guo et al, 2010). The same coordination mode for polycarboxylate ligands is presumably the main explanation for the minor deviations between the stated dihedral angles.…”

Amino Acid Complexes of Zirconium in a Carbon Composite for the Efficient Removal of Fluoride Ions from Water

“…The “∆ criterion”, which is based on the difference between the values of the ν as (COO) and ν s (COO) vibration modes from the carboxylate group, was used to determine the coordination mode of this functional group [ 54 , 55 ]. If the difference between the asymmetric and symmetric vibrational modes of the carboxyl-type ligands in the synthesized compounds is greater than that of their ionic salts, there may be two types of interactions: if the value of ∆ is very large (>200 cm −1 ), this corresponds to a monodentate-type bond, whereas if the value is close to that of the ionic bond, it will be of the bridge type [ 56 ].…”