Pentacoordinated isothiocyanate iron(III) complexes supported by asymmetric tetradentate donor and acceptor Schiff base ligands: Spectral, Structural and Hirshfeld Surface Analyses

The present study aims to synthesis and full characterization of two new pentacoordinated isothiocyanate iron(III) mixed ligand complexes featuring dianionic (N2O2)2? tetradentate Schiff-base ligands unsymmetrically substituted by either a pair acceptor (4-fluorophenyl nitro) or donor (ferrocenyl methoxy) substituents. neutral complexes3 4 were prepared in very good yields (~90 %) upon reaction their respective chloro-iron(III) precursors 1 2 with sodium thiocyanate refluxing ethanol. paramagnetic compounds 3 characterized elemental analysis, FT-IR UV-vis spectroscopy, mass spectrometry. stretching frequencies the group observed at 2014 2062 cm?1, respectively, indicate N-bonded NCS? moiety, agreement HSAB principle. crystal structure revealed that five-coordinate monomer, iron atom adopts slightly distorted square-pyramidal geometry, N O atoms occupying basal sites nitrogen co-ligand located apex pyramid. Intermolecular interactions complex have been addressed aid Hirshfeld surface analysis as well fingerprint plots. Magnetic susceptibility measurements (2-300 K) showed high-spin configuration (S = 5/2) for thed5 Fe(III) ion 3.