The effect of fluorine substituents on the crystal structure and spin crossover behavior of the cation [Mn-III (3,5-diHal-sal(2)323)](+) complex family with BPh4 anions

• Published in: New journal of chemistry Vol. 46; no. 35; pp. 16880 - 16888
• Main Authors: Tiunova, A., Kazakova, A., Korchagin, D., Shilov, G., Zakharov, K., Vasiliev, A. N., Yagubskii, E. B.
• Format: Journal Article
• Language: English
• Published: CAMBRIDGE Royal Soc Chemistry 12.09.2022; Royal Society of Chemistry
• Subjects: Anions; Bromine; Cations; Chemistry; Chemistry, Multidisciplinary; Crossovers; Crystal structure; Fluorine; Imines; Magnetic properties; Physical Sciences; Science & Technology; Spin transition; MONONUCLEAR MANGANESE(III) COMPLEXES; TRANSITION; STATE; PROFILE; MAGNETIC-PROPERTIES
• ISSN: 1144-0546; 1369-9261
• DOI: 10.1039/d2nj02872g

Mononuclear Mn(III) cation spin-crossover complexes with Schiff base ligands 3,5-diF-sal(2)323 and 3,5-Br,F-sal(2)323 have been synthesized: [Mn(3,5-diF-sal(2)323)]BPh4 (1) and two polymorphic modifications (2 and 3) of [Mn(3,5-Br,F-sal(2)323)]BPh4. Their crystal structure and magnetic properties have been studied. The complex [Mn(3,5-diF-sal(2)323)]BPh4 exhibits a gradual and complete spin conversion with T-1/2 = 141 K between high spin (S = 2) and low spin (S = 1) states. Two polymorphic modifications of the complex [Mn(3,5-Br,F-sal(2)323)]BPh4 have fundamentally different magnetic properties: one of the modifications (monoclinic, 2) shows a gradual and complete spin transition with T-1/2 = 137 K, while the other (triclinic, 3) suggests a more abrupt and not complete spin transition at 22 K which is difficult to diagnose due to the competition with the zero-field splitting effects. The magneto-structural relationships were traced in comparison with dichloro-, dibromo- and mixed Br,Cl-substituted [Mn(3,5-R,R'- sal(2)323)] complexes with tetraphenylborate anions.