Solvent-Induced Structural Diversity and Magnetic Research of Two Cobalt(II) Complexes

Xiong-Feng Ma; Hai-Ling Wang; Zhong-Hong Zhu; Hua-Hong Zou; Bin Liu; Zhenxing Wang; Zhong-Wen Ouyang; Fu-Pei Liang

doi:10.1021/acsomega.9b01781

Solvent-Induced Structural Diversity and Magnetic Research of Two Cobalt(II) Complexes

ACS Omega. 2019 Dec 4;4(25):20905-20910. doi: 10.1021/acsomega.9b01781. eCollection 2019 Dec 17.

Authors

Xiong-Feng Ma¹, Hai-Ling Wang¹, Zhong-Hong Zhu¹, Hua-Hong Zou¹, Bin Liu², Zhenxing Wang³, Zhong-Wen Ouyang³, Fu-Pei Liang^{1

4}

Affiliations

¹ State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, School of Chemistry & Pharmacy of Guangxi Normal University, Guilin 541004, P. R. China.
² Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Ministry of Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules, College of Chemistry and Chemical Engineering, Hubei University, Wuhan 430062, P. R. China.
³ Wuhan National High Magnetic Field Center & School of Physics, Huazhong University of Science and Technology, Wuhan 430074, P. R. China.
⁴ Guangxi Key Laboratory of Electrochemical and Magnetochemical Functional Materials, College of Chemistry and Bioengineering, Guilin University of Technology, Guilin 541004, P. R. China.

Abstract

The solvent-induced topological and structural diversities of two Co(II) complexes, namely, [Co(L)₂(SCN)₂] (Co1) and [Co₂(L)₂(SCN)(OAc)₃] (Co2) (L = 8-methoxyquinoline), were comparatively analyzed. Certain proportions of L, Co(OAc)₂·4H₂O, and NaSCN were mixed and dissolved in CH₃OH at 60 °C to obtain complex Co1. Complex Co2, an asymmetric dinuclear compound, was obtained by simply replacing CH₃OH with CH₃CN as the solvent. The Co(II) ion in complex Co1 was coordinated by the N₄O₂ mode provided by two L ligands and two SCN^- anions. The two Co(II) ions in Co2 were in the N₂O₄ and NO₅ coordination environment and were linked by two μ₂-OAc^- bridges and one rare μ₃-OAc^- bridge. Weak interaction analysis revealed that complexes Co1 and Co2 exhibited 6-connected shp and 14-connected fcu nets, respectively. Magnetic studies showed that Co1 demonstrated single-ion magnet behavior under 2000 Oe. These behaviors are indicative of clearly field-induced single-ion magnetic behavior with U _eff = 34.7(2) K and τ₀ = 2.7(2) × 10^-7 s under 2000 Oe dc field, respectively. By contrast, Co2 lacked frequency dependence under zero-field conditions. Electrospray ionization mass spectrometry indicated that two complexes were stable in N,N-dimethylformamide.