Solvent and Dihalide Substituent Effects on Crystal Structure, Spin‐Crossover Behavior and Conductivity of the Cationic Mn(III) Complexes with Electroactive TCNQ Counteranions

Abstract

Cationic Mn(III) complexes with 3,5‐Hal‐sal2323 (Hal = diCl, diBr, BrCl) ligands containing electroactive TCNQ anions as counterions have been synthesized: [Mn(3,5‐diCl‐sal2323)](TCNQ)2 (1), [Mn(3,5‐diBr‐sal2323)]2(TCNQ)3×6CH3CN (2), and [Mn(3,5‐Br,Cl‐sal2323)]2(TCNQ)3×6CH3CN (3). The crystal structures, magnetic and conducting properties of the obtained compounds have been investigated. In 1, an incomplete spin transition from the low‐spin (LS) state at 100 K to the high‐spin (HS) state upon heating to 400 K is observed. Isostructural complexes 2 and 3 contain 6 molecules of solvated acetonitrile, which is lost upon heating, accompanied by the crystal structure transformation. As a result, desolvated complexes jump to the HS state. The temperature dependences of resistivity 2 and 3 show resistivity jumps associated with the loss of lattice solvent.