title: Effect of ligand substituent coordination on the geometry and the electronic structure of Cu(II)-diradical complexes.
abstract: Two organic moieties, known as ligands, having -OMe and -SePh as the ortho substituent attached to the aniline moiety of the parent 2-anilino-4,6-di-tert-butylphenol ligand, were synthesized. The ligands reacted with CuCl2·2H2O in a 2:1 ratio in CH3CN in the presence of Et3N and provided the corresponding mononuclear Cu(II)-diradical complexes 1 (-OMe) and 2 (-SePh). Complex 1 was square planar, while complex 2 was in distorted square planar geometry due to the secondary coordination between the Se atom and the central Cu(II) center. Both complexes were comprised of multi-paramagnetic centers and exhibited an St = 1/2 ground state as established by variable-temperature magnetic susceptibility measurements. X-band electron paramagnetic resonance measurements indicated the presence of an unpaired electron at the Cu(II) center in complex 1 and at the ligand center (π-radical) in complex 2. The extent of the secondary interaction was found to be dependent on the "softness" of the donor atom belonging to the ortho substituent.
authors.affiliation: Department of Chemistry, Indian Institute of Technology , Guwahati 781039, Assam, India.
authors.forename: Richa
authors.initials: R
authors.lastname: Rakshit
authors.forename: Samir
authors.initials: S
authors.lastname: Ghorai
authors.forename: Soumava
authors.initials: S
authors.lastname: Biswas
authors.forename: Chandan
authors.initials: C
authors.lastname: Mukherjee
mesh_terms: D000814:Aniline Compounds / Q000737:chemistry*; D003300:Copper / Q000737:chemistry*; D018360:Crystallography, X-Ray; D004583:Electrons; D005609:Free Radicals; D008024:Ligands; D008958:Models, Molecular; D008968:Molecular Conformation; D009942:Organometallic Compounds / Q000737:chemistry
chemical_list: D000814:Aniline Compounds; D005609:Free Radicals; D008024:Ligands; D009942:Organometallic Compounds; D003300:Copper