Magneto-Structural Relationship of Tetragonally-Compressed Octahedral Iron(II) Complex Surrounded by a pseudo-S6 Symmetric Hexakis-Dimethylsulfoxide Environment

Since the octahedral high-spin iron(II) complex has 5T2g ground term, spin-orbit coupling should be considered in magnetic analysis; however, such treatment is rarely seen recent papers, although symmetry-sensitive property of interest to investigate detail. A method consider T-term magnetism was well constructed more than half a century ago. On other hand, been still improved years. In this study, [Fe(dmso)6][BPh4]2 (dmso: dimethylsulfoxide) newly prepared, and single-crystal X-ray diffraction revealed tetragonal compression D4-symmetric coordination geometry around ion pseudo-S6 hexakis-dmso environment. From data, sign axial splitting parameter, Δ, found negative, indicating 5E state D4 symmetry. The DFT computation showed electronic configuration (dxz)2(dx2−y2)1(dyz)1(dxy)1(dz2)1 due environment dmso π orbitals. corresponded which agreement with negative Δ value. Therefore, structurally predicted consistent estimation from measurements.