Stepwise spin-state switching in a manganese(iii) complex

Abstract

A mononuclear manganese(III) complex containing flexible hexadentate chelating ligand has been prepared and characterised by variable temperature single-crystal X-ray diffraction analyses, magnetic, spectroscopic and electrochemical studies. The complex consists MnN4O2...

Abrupt Spin‐State Switching in Mn(III) Complexes with BPh4 Anion: Effect of Halide Substituents on Crystal Structure and Magnetic Properties.

“…The average bond lengths values MnÀ N amine and MnÀ N imine are 2.219(2) and 2.099 (13), respectively, while the average axial Mn-O phen bond length is 1.869(2) Å. They are close to the values observed in the [Mn(3,5-diBr-sal-N-1,5,8,12)] + BPh 4 À complex at 250 K. [19] The bond angles XÀ Mn-X deviate from ideal 90/180 °values showing significant distortion of the Mn III N 4 O 2 octahedron typical for the HS state. The octahedral distortion parameters (Σ, Θ and ζ) calculated using the OctaDist [4,23] tool are listed in Table 1.…”

“…Moreover, the study of the magnetic properties, crystal structure and spectra of resonant ultrasound spectroscopy of the SCO complex [Mn(3,5-diBr-sal-N-1,5,8,12)]BPh 4 in a wide temperature range showed the coexistence of ferroelastic and spin state ordered phase. [19] This observation opens up the prospect of further investigation of some spin-crossover Mn(III) complexes as potential ferroelectrics for magnetoelectric applications. [21] In our work, we synthesized new tetraphenylborates of cation Mn(III) complexes with 5-F-, 3,5-diCl-and 3,5-Br,Clderivatives of sal-N-1,5,8,12 ligand: [Mn(5-F-sal-N-1,5,8,12)]BPh 4 (1), [Mn(3,5-diCl-sal-N-1,5,8,12)]BPh 4 (2) and [Mn(3,5-Br,Cl-sal-N-1,5,8,12)]BPh 4 (3).…”

“…In contrast to our syntheses, sodium tetraphenylborate and manganese(II) chloride or nitrate tetrahydrates were used in the procedures described in works. [18][19][20] Crystals of complex 1 were obtained by slow evaporation of the mother liquor, while crystals of 2 and 3 were formed within week at standing solutions. It is noteworthy that the complexes 1-3 do not contain co-crystallized solvent molecules, which, firstly, increases their stability, since solvate solvents are often lost during storage of the SCO complexes, and secondly, it allows one to study the effects of ligand substitution on the magneto-structural relationships in SCO complexes without any additional influence associated with the co-crystallized solvent.…”

“…Compounds 2 and 3 are isostructural to each other and to the [Mn(3,5-diBr-sal-N-1,5,8,12)] + BPh 4 À complex (6). [19,20] They crystallize in the monoclinic acentric Cc space group at room temperature and show phase transitions with symmetry lowering upon cooling down to 100 K, the transition sequence is Cc!Pc!P1 in 2 and Cc!Pc in 3. Full data sets for each of the phases were collected at 240/160/100 K for 2 and 240/100 K for 3 (Table S2).…”

“…[16] More recently, advanced results in the SCO research of Mn(III) complexes have been achieved by two groups at once. [18][19][20] The tetraphenylborates of cation Mn(III) complexes with 5-Cl-, 5-Br-and 3,5-diBr-derivatives of sal-N-1,5,8,12 ligand were synthesized and showed an abrupt spin transitions. Moreover, the study of the magnetic properties, crystal structure and spectra of resonant ultrasound spectroscopy of the SCO complex [Mn(3,5-diBr-sal-N-1,5,8,12)]BPh 4 in a wide temperature range showed the coexistence of ferroelastic and spin state ordered phase.…”