title: Crystal structure and magnetic properties of an ionic C60 complex with decamethylcobaltocene: (Cp*2Co)2C60(C6H4Cl2, C6H5CN)2. Singlet-triplet transitions in the C60(2-) anion.
abstract: The C(60) complex with decamethylcobaltocene, (Cp(2)Co)(2)C(60)(C(6)H(4)Cl(2), C(6)H(5)CN)(2) (1) (C(6)H(4)Cl(2) = 1,2-dichlorobenzene; C(6)H(5)CN = benzonitrile), has been obtained as single crystals by the diffusion method. The IR and UV-vis-NIR spectra show the presence of the C(60)(2)(-) and the Cp(2)Co(+) ions, which form a three-dimensional framework with channels accommodating solvent molecules. EPR and SQUID measurements show that C(60)(2)(-) has a diamagnetic singlet (S = 0) state in the 2-140 K range. The appearance of a broad EPR signal and the increase in magnetic susceptibility of 1 above 140 K are assigned to a thermal population of a close lying triplet (S = 1) state. The singlet-triplet energy gap for C(60)(2)(-) in solid 1 is estimated to be 730+/-10 cm(-)(1).
authors.affiliation: Division of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan. konarev@icp.ac.ru
authors.forename: Dmitri V
authors.initials: DV
authors.lastname: Konarev
authors.forename: Salavat S
authors.initials: SS
authors.lastname: Khasanov
authors.forename: Gunzi
authors.initials: G
authors.lastname: Saito
authors.forename: Ivan I
authors.initials: II
authors.lastname: Vorontsov
authors.forename: Akihiro
authors.initials: A
authors.lastname: Otsuka
authors.forename: Rimma N
authors.initials: RN
authors.lastname: Lyubovskaya
authors.forename: Yury M
authors.initials: YM
authors.lastname: Antipin