title: Slow magnetic relaxation in mononuclear seven-coordinate cobalt(II) complexes with easy plane anisotropy.
abstract: Two mononuclear seven-coordinate cobalt(II) complexes [Co(L)3(NO3)2] (L = 4-tert-butylpyridine, 1; L = isoquinoline, 2) were prepared and structurally analyzed by single-crystal X-ray crystallography. The coordination spheres of 1 and 2 exhibit distorted pentagonal bipyramid geometry. Analysis of their direct-current magnetic data reveals the existence of easy plane anisotropy (D > 0) with a small transverse anisotropy (E), which was further confirmed by high-field electron paramagnetic resonance (HFEPR) spectroscopy. Field-induced slow magnetic relaxations were observed under the applied dc field in complexes 1 and 2 by alternating-current magnetic susceptibility measurements. Importantly, these complexes are new instances of mononuclear high-coordinate cobalt(II)-based single-molecule magnets.
authors.affiliation: State Key Laboratory of Coordination Chemistry, Nanjing National Laboratory of Microstructures, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China. xtchen@netra.nju.edu.cn.
authors.forename: Lei
authors.initials: L
authors.lastname: Chen
authors.forename: Shu-Yang
authors.initials: SY
authors.lastname: Chen
authors.forename: Yi-Chen
authors.initials: YC
authors.lastname: Sun
authors.forename: Yu-Mei
authors.initials: YM
authors.lastname: Guo
authors.forename: Lu
authors.initials: L
authors.lastname: Yu
authors.forename: Xue-Tai
authors.initials: XT
authors.lastname: Chen
authors.forename: Zhenxing
authors.initials: Z
authors.lastname: Wang
authors.forename: Z W
authors.initials: ZW
authors.lastname: Ouyang
authors.forename: You
authors.initials: Y
authors.lastname: Song
authors.forename: Zi-Ling
authors.initials: ZL
authors.lastname: Xue