Field induced single ion magnet behavior in CoII complexes in a distorted square pyramidal geometry

Atanu Dey; Junaid Ali; Shruti Moorthy; Jessica Flores Gonzalez; Fabrice Pointillart; Saurabh Kumar Singh; Vadapalli Chandrasekhar

doi:10.1039/d3dt01769a

Field induced single ion magnet behavior in Co^II complexes in a distorted square pyramidal geometry

Dalton Trans. 2023 Oct 24;52(41):14807-14821. doi: 10.1039/d3dt01769a.

Authors

Atanu Dey^{1

2}, Junaid Ali², Shruti Moorthy³, Jessica Flores Gonzalez⁴, Fabrice Pointillart⁴, Saurabh Kumar Singh³, Vadapalli Chandrasekhar^{2

5}

Affiliations

¹ Department of Chemistry, Gandhi Institute of Technology and Management (GITAM), NH 207, Nagadenehalli, Doddaballapur Taluk, Bengaluru 561203, India. atanu130@gmail.com.
² Tata Institute of Fundamental Research Hyderabad, Gopanpally, Hyderabad, 500 046, India. vc@tifrh.res.in.
³ Department of Chemistry, Indian Institute of Technology Hyderabad, Kandi, Sangareddy, 502285, Telangana, India. sksingh@chy.iith.ac.in.
⁴ Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes) - UMR 6226, 35000 Rennes, France. fabrice.pointillart@univ-rennes1.fr.
⁵ Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, 208016, India.

PMID: 37791680
DOI: 10.1039/d3dt01769a

Abstract

We report three Co^II-based complexes with the general formula [Co^II(L)(X)₂] by changing the halide/pseudo-halide ions [X = NCSe (1SeCN); Cl (2Cl) and Br (3Br)]. The obtained τ⁵ and CShM values confirm a distorted square pyramidal geometry around the Co^II ion in all these complexes. In these three complexes, the central Co^II ion is situated above the basal plane of the square pyramidal geometry. The extent of distortion from the ideal SPY-5 geometry differs upon changing the coordinating halide/pseudo-halide ion in these complexes. This essentially results in the alteration of the anisotropic parameter D and hence impacts the magnetic properties in these complexes. This phenomenon has been corroborated with the aid of theoretical investigations. All these complexes display field-induced SIM behaviour with magnetic relaxation occurring through a combination of processes depending on the applied dc magnetic field values and dilution.