title: Light Lanthanide Complexes with Crown Ether and Its Aza Derivative Which Show Slow Magnetic Relaxation Behaviors.
abstract: Two sets of isostructural Ln(III) mononuclear complexes, [Ln(NO3)3(18-crown-6)] (Ln = Ce (1), Pr (2), and Nd (3)) and [Ln(NO3)3(1,10-diaza-18-crown-6)] (Ln = Ce (4), Pr (5), and Nd (6)), were synthesized, and their slow magnetic relaxation behavior was investigated. Since Ln(III) ions are located in an axially stressed ligand field in both sets of complexes, they can exhibit single-molecule magnet (SMM) behavior owing to the oblate-type electronic distributions of the ground sublevels found in Ce(III), Pr(III), and Nd(III). Field-induced slow magnetic relaxation was observed for Ce(III) and Nd(III) complexes 1, 3, 4, and 6 under an applied bias dc field of 1000 Oe, whereas no slow relaxation was observed for Pr(III) complexes 2 and 5. The slow magnetic relaxation behavior of 1, 3, 4, and 6 was correlated with the even-numbered Jzsublevels of Ce(III) and Nd(III) ions, known as the Kramers system.
authors.affiliation: Department of Chemistry, Faculty of Science, Nara Women's University , Nara 630-8506, Japan.
authors.forename: Hisami
authors.initials: H
authors.lastname: Wada
authors.affiliation: Department of Chemistry, Faculty of Science, Nara Women's University , Nara 630-8506, Japan.
authors.forename: Sayaka
authors.initials: S
authors.lastname: Ooka
authors.affiliation: Institute for Materials Research, Tohoku University , Aoba-ku, Sendai 980-8577, Japan.
authors.forename: Tomoo
authors.initials: T
authors.lastname: Yamamura
authors.affiliation: Department of Chemistry, Faculty of Science, Nara Women's University , Nara 630-8506, Japan.
authors.forename: Takashi
authors.identifier: http://orcid.org/0000-0002-3814-7687
authors.initials: T
authors.lastname: Kajiwara