Electronic structure and solution behavior of a tris(N,N′-diphenylhydrazido)manganese(iv) propeller complex

Abstract

The electronic structure and magnetic properties of the manganese(IV) trihydrazide propeller complex, Li₂Mn(κ₂-PhN–NPh)₃L₂ (1, L = tetrahydrofuran, diethyl ether), are explored. EPR and solid-state magnetometry studies are indicative of a high spin Mn(IV) with a S = 3/2 spin state. Solution-phase magnetic measurements result in a measured μ_eff less than that expected for a S = 3/2, indicating a solution-phase equilibrium with a lower-spin species. Concentration-dependent magnetic susceptibility measurements identify clustering of 1 to an antiferromagnetically coupled multinuclear complex as the most likely explanation for the solution behavior. Comparative infrared spectroscopy in solution and solid phase are described which support speciation in solution.