Effects of planar and tetrahedral distortions on the ESR parameters of bis(salicylaldiminato)copper(II) complexes

Novel Diazamesocyclic Ligands Functionalized with Pyridyl Donor Group(s) − Synthesis, Crystal Structures, and Properties of Their Copper(II) Complexes

“…The approximate ESR parameters obtained were: g iso ϭ 2.11 (A iso ϭ 74 G), g || ϭ 2.23 (A || ϭ 94 G), and g Ќ ϭ 2.05 (A Ќ ϭ 64 G), where g Ќ ϭ (3g iso Ϫ g || )/2 and A Ќ ϭ (3A iso Ϫ A || )/2. [18] The values again conform to the relationship g || Ͼ g Ќ Ͼ g e , with a smaller A || value, indicating some distortion of the coordination geometry about the Cu II center from square-pyramidal in solution, [19] which is similar to the geometry observed in the solid state.…”

EPR and ESE of CuS4 complex in Cu(dmit)2: g-Factor and hyperfine splitting correlation in tetrahedral Cu–sulfur complexes

“…This is well known for blue copper proteins, where a very strong CT transition at 600 nm having unusually large extinction coefficient dominates visible region [29]. The d-d transition energies in pseudotetrahedral complexes are strongly dependent on degree of deformation [16,31] and for x 2 -y 2 ground state the transitions are expected in the range: 6000-7000 cm À1 for x 2 -y 2 M xy, and 1000-14,000 cm À1 for x 2 -y 2 M xz, yz. Moreover, dmit molecules have its intermolecular orbital transitions in visible spectral region without a participation of the coordinated metal.…”

Chiral Supramolecular Assemblies Derived from the Insertion of a Segmental Ligand into a Copper-Tyrosine Framework

“…We believe that the presence of the 4,4-bipy ligand in 2 is responsible for the subtle tuning of the chiral chain structure, forming a square-planar geometry in the self-assembly process with amino acids. [15,19] The Cu II ion acts as a kind of Lewis acid [20] and can therefore bind Lewis bases, such as the oxygen atom of the bridging carboxyl group in complex 1 and a water molecule of crystallization in complex 2, in its free axial coordination site.…”