Synthesis, Crystallographic Structure, Hirshfeld Surface Analysis, and DFT Calculations of Two Salen-Type Hetero-Halogenated Schiff Base Mn(IV)/(III) Complexes

Abstract

Two new supramolecular compounds [MnIV(μ-3-Br-5-Cl-Salpn)(μ-O)]2 · 2[DMF] (I) and [MnIII(3-Br-5Cl-Salmen)(3-bromo-5-chlorosalicylaldehyde)]2 (II) (3-Br-5Cl-Salpn = N,N'-bis(3-bromo-5-chlorosalicylidene)-1,3-diamine and 3-Br-5Cl-Salmen = N,N'-bis(3-bromo-5-chlorosalicylidene)-1,2-diamine) have been synthesized via conventional solution method and characterized by single crystal (CIF files CCDC nos. 1855961 (I), 1900154 (II) and powder X-ray diffraction, IR spectroscopy and elemental analysis. The unconventional C–H···X (X = Cl and Br) supramolecular interaction within the compounds were qualitatively and quantitatively studied by Hirshfeld surface analysis. Additionally, in order to gain a deep insight into the electronic features of I, density functional theory was used for the calculations of the HOMO and LUMO energies and molecular electrostatic potential surface.