Effect of intermolecular anionic interactions on spin crossover of two triple-stranded dinuclear Fe(II) complexes showing above room temperature spin transition

S Athira; Dibya Jyoti Mondal; Shraoshee Shome; Bijoy Dey; Sanjit Konar

doi:10.1039/d2dt02115c

Effect of intermolecular anionic interactions on spin crossover of two triple-stranded dinuclear Fe(II) complexes showing above room temperature spin transition

Dalton Trans. 2022 Nov 8;51(43):16706-16713. doi: 10.1039/d2dt02115c.

Authors

S Athira¹, Dibya Jyoti Mondal¹, Shraoshee Shome¹, Bijoy Dey¹, Sanjit Konar¹

Affiliation

¹ Department of Chemistry, Indian Institute of Science Education and Research Bhopal (IISERB), Bhopal By-pass Road, Bhauri, Madhya Pradesh-462066, India. skonar@iiserb.ac.in.

PMID: 36282039
DOI: 10.1039/d2dt02115c

Abstract

Two new Fe(II)-based dinuclear triple helicates having the formula {[Fe₂(L)₃]·(CF₃SO₃)₄·6.5H₂O·CH₃OH} (complex 1) and {[Fe₂(L)₃]·(ClO₄)₄·7H₂O·1.35CH₃OH} (complex 2), displaying near room temperature spin transition have been synthesized and the effect of intermolecular interactions and co-operativity between metal centers on the spin crossover (SCO) has been studied. Picolinimidamide-based ligand system is chosen to provide maximum intermolecular interactions. Variable-temperature single crystal X-ray diffraction (SCXRD), magnetic study, and Hirshfeld analysis reveal that complex 1 shows a multistep spin transition, whereas, complex 2 shows an abrupt spin transition from [LS-LS] ↔ [HS-HS]. In complex 2 the presence of perchlorate anion induces high intermolecular O-H interaction that enhances the cooperativity resulting in high T_1/2 of 330 K. This study accentuates the interplay between anion effect, crystal packing, and supramolecular interactions in tuning the magnetic properties of SCO compounds.