Structure, magnetic anisotropy and relaxation behavior of seven-coordinate Co(ii) single-ion magnets perturbed by counter-anions. Issue 22 (20th May 2020)

• Record Type: Journal Article
• Authors: Yi, Gangji; Zhang, Chunyang; Zhao, Wen; Cui, Huihui; Chen, Lei; Wang, Zhenxing; Chen, Xue-Tai; Yuan, Aihua; Liu, Yuan-Zhong; Ouyang, Zhong-Wen
• Is Part Of: Dalton transactions. Volume 49:Issue 22(2020)
• Page Start: 7620
• Page End: 7627
• Publication Date: 2020-05-20
• Subjects: Chemistry, Inorganic -- Periodicals; Chemistry, Physical and theoretical -- Periodicals; Chemistry, Inorganic -- Periodicals; 546.05
• DOI: 10.1039/d0dt01232g
• Languages: English
• ISSNs: 1477-9226

Abstract

Abstract : A series of mononuclear seven-coordinate complexes with the same coordination unit [Co(BPA-TPA)] 2+ (BPA-TPA = pentapyidyldiamine) display the different slow magnetic relaxation processes perturbed by the variation of the counter anions. Abstract : A series of mononuclear seven-coordinate Co(ii ) complexes [Co II (BPA-TPA)](ClO4 )2 ·H2 O (2-ClO4 ), [Co II (BPA-TPA)](PF6 )2 (3-PF6 ) and [Co II (BPA-TPA)](BPh4 )2 (4-BPh4 ) have been synthesized based on the ligand 2, 6-bis(bis(2-pyridylmethyl)amino)methylpyridine (BPA-TPA), and their structures have been characterized by single-crystal X-ray diffraction. All these complexes feature an intermediate coordination polyhedron between a capped trigonal prism and a capped octahedron, which is perturbed by the variation of the counter anions. Easy-plane magnetic anisotropies for all complexes were revealed via the analyses of the direct-current magnetic data and high-field electron paramagnetic resonance (HFEPR) spectra. They show slow magnetic relaxation under applied direct current field, which is similar to the previously reported complex [Co II (BPA-TPA)](BF4 )2 (1-BF4 ) with a capped trigonal prism. This work provides a new example of modulating the properties of single-ion magnets (SIMs) by changing the counter anions.