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‐sal 2 323 (Hal=diCl, diBr, BrCl) ligands containing electroactive TCNQ anions as counterions have been synthesized: Mn(3,5‐diCl‐sal 2 323)(TCNQ) 2 ( 1 ), Mn(3,5‐diBr‐sal 2 323) 2 (TCNQ) 3 ⋅6CH 3 CN ( 2 ), and Mn(3,5‐Br,Cl‐sal 2 323) 2 (TCNQ) 3 ⋅6CH 3 CN ( 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.