Electronic spectra of pseudotetrahedralbis(bidentate)copper(II) complexes: Spectral assignment and effect of ligand asymmetry

✍ Scribed by M.A. Atanasov; G.St. Nikolov

• Book ID: 104139054
• Publisher: Elsevier Science
• Year: 1985
• Tongue: English
• Weight: 851 KB
• Volume: 96
• Category: Article
• ISSN: 0020-1693
• DOI: 10.1016/s0020-1693(00)93733-2

✦ Synopsis

The electronic spectra (d-d transitions) of the following pseudotetrahedral complexes, Cu(L-L)22+, L-L = 2,2'-dipyridylamine (HDPA); 3,3'-dimethyl-2,2'-dipyridylamine (HMPA); 2-pyridyl-2'-pyrimidylamine (HPPA); 2-pyridyl-2'-thiazolylamine (HPTA) were interpreted by the Angular Overlap Model (AOM) in D2 symmetry for symmetrically bonded ligands and C2 for asymmetrically bonded ligands. AOM expressions were found in which the bite angle ((u), the dihedral angle (2~) and the ligand pitch angle (G) were retained as variables. Such an approach permitted the use of experimental (Y, 2w and $ values in the spectral fit procedure so that the extracted AOM parameters were free from geometry contributions.

Neglect of the real $ values produces a large distortion as to the real n-bonding picture in the studied complexes.

The geometry-free AOM parameters were further substantiated by using them in calculating the non-coincidence between the molecular symmetry axes and the g-tensor axes, as well as the charge transfer transitions. Contributions to transition energies by s-d and p-d mixing in D2 symmetry were found to be negligible.