title: Dihedral-Angle-Controlled Crossover from Static Hole Delocalization to Dynamic Hopping in Biaryl Cation Radicals.
abstract: In cases of coherent charge-transfer mechanism in biaryl compounds the rates follow a squared cosine trend with varying dihedral angle. Herein we demonstrate using a series of biaryl cation radicals with varying dihedral angles that the hole stabilization shows two different regimes where the mechanism of the hole stabilization switches over from (static) delocalization over both aryl rings to (dynamic) hopping. The experimental data and DFT calculations of biaryls with different dihedral angles unequivocally support that a crossover from delocalization to hopping occurs at a unique dihedral angle where the electronic coupling (Hab) is one half of reorganization (λ), that is, Hab=λ/2. The implication of this finding in non-coherent charge-transfer rates is being investigated.
authors.affiliation: Department of Chemistry, Marquette University, Milwaukee, WI, 53201-1881, USA.
authors.forename: Marat R
authors.initials: MR
authors.lastname: Talipov
authors.affiliation: Department of Chemistry, Marquette University, Milwaukee, WI, 53201-1881, USA.
authors.forename: Tushar S
authors.initials: TS
authors.lastname: Navale
authors.affiliation: Department of Chemistry, Marquette University, Milwaukee, WI, 53201-1881, USA.
authors.forename: Mohammad M
authors.initials: MM
authors.lastname: Hossain
authors.affiliation: Department of Chemistry, Marquette University, Milwaukee, WI, 53201-1881, USA.
authors.forename: Ruchi
authors.initials: R
authors.lastname: Shukla
authors.affiliation: Department of Chemistry, Marquette University, Milwaukee, WI, 53201-1881, USA.
authors.forename: Maxim V
authors.initials: MV
authors.lastname: Ivanov
authors.affiliation: Department of Chemistry, Marquette University, Milwaukee, WI, 53201-1881, USA.
authors.forename: Rajendra
authors.initials: R
authors.lastname: Rathore
mesh_terms: D002412:Cations / Q000737:chemistry; D005609:Free Radicals / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000592:standards; D015394:Molecular Structure; D011789:Quantum Theory; D012015:Reference Standards
chemical_list: D002412:Cations; D005609:Free Radicals
keywords: charge transfer; delocalization; electronic coupling; incoherent hopping; radical cations