Spin-Crossover and Slow Magnetic Relaxation Behavior in Hexachlororhenate(IV) Salts of Mn(III) Complexes [Mn(5-Hal-sal323)][ReCl] (Hal = Cl, Br).

The cationic complexes of Mn(III) with the 5-Hal-sal323 (Hal = Cl, Br) ligands and a paramagnetic doubly charged counterion [ReCl] have been synthesized: [Mn(5-Cl-sal323)][ReCl] () and [Mn(5-Br-sal323)][ReCl] (). Their crystal structures and magnetic properties have been studied. These isostructural two-component ionic compounds show a thermally induced spin transition at high temperature associated with the cationic subsystem and a field-induced slow magnetic relaxation of magnetization at cryogenic temperature, associated with the anionic subsystem.

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

Three tetraphenylborates of mononuclear Mn(III) cation complexes with hexadentate ligands, the products of the reaction between a N,N'-bis(3-aminopropyl)ethylenediamine and salicylaldehydes with the different haloid substitutions at the 5 or 3,5 positions, have been synthesized: [Mn(5-F-sal-N-1,5,8,12)]BPh (1), [Mn(3,5-diCl-sal-N-1,5,8,12)]BPh (2) and [Mn(3,5-Br,Cl-sal-N-1,5,8,12)]BPh (3). Their crystal structure, dielectric constant (ϵ) and magnetic properties have been studied. Ligand substituents have a dramatic effect on the structure and magnetic properties of the complexes.

The First Conducting Spin-Crossover Compound Combining a Mn Cation Complex with Electroactive TCNQ Demonstrating an Abrupt Spin Transition with a Hysteresis of 50 K.

We present herein the synthesis, crystal structure, and electric and magnetic properties of the spin-crossover salt [Mn(5-Cl-sal-N-1,5,8,12)]TCNQ ⋅2 CH CN (I), where 5-Cl-sal-N-1,5,8,12=N,N'-bis(3-(2-oxy-5-chlorobenzylideneamino)propyl)-ethylenediamine, containing distinct conductive and magnetic blocks along with acetonitrile solvent molecules. The Mn complex with a Schiff-base ligand, [Mn(5-Cl-sal-N-1,5,8,12)] , acts as the magnetic unit, and the π-electron acceptor 7,7,8,8-tetracyanoquinodimethane (TCNQ ) is the conducting unit. The title compound (I) exhibits semiconducting behavior with room temperature conductivity σ ≈1×10  ohm  cm and activation energy Δ ≈0.