title: EPR study of intramolecular dynamics in o-semiquinonic nickel complexes with PCP-pincer ligand in solution.
abstract: A number of square pyramidal o-semiquinonic nickel complexes with 2,6-bis(diphenylphosphinomethyl)phenyl were investigated by EPR spectroscopy in solution. The complexes have flexible coordination spheres and can exist in solution as two isomers rapidly (on the EPR timescale) interconverting one to another at room temperature. The equilibrium is entropy driven and does not significantly depend on the substituents in the semiquinone ring. The spin density distribution depends on mesomeric properties and bulkiness of substituents in ortho-position to oxygen atoms.
authors.affiliation: G.A. Razuvaev Institute of organometallic chemistry of Russian Academy of Sciences, 49, Tropinina str., 603950, Nizhny Novgorod, Russian Federation.
authors.forename: Konstantin A
authors.initials: KA
authors.lastname: Kozhanov
authors.forename: Michael P
authors.initials: MP
authors.lastname: Bubnov
authors.forename: Vladimir K
authors.initials: VK
authors.lastname: Cherkasov
authors.forename: Georgy K
authors.initials: GK
authors.lastname: Fukin
authors.forename: Gleb A
authors.initials: GA
authors.lastname: Abakumov