Understanding the Jahn–Teller Effect in Octahedral Transition-Metal Complexes: A Molecular Orbital View of the Mn(β-diketonato)₃ Complex

Abstract

Density functional theory calculations are utilized to calculate and visualize the compression and elongation Jahn–Teller distortion in selected Mn­(β-diketonato)3 complexes. Students often struggle to understand this effect, due to the lack of visualization of the repulsion effect between charges on the metal and the axial ligands. Here, a visualization of the molecular orbitals involved in the elongation and compression Jahn–Teller distortion provides a great understanding of the effect.

Electrochemical and Computational Chemistry Study of Mn(β-diketonato)3 complexes

“…Mn(b-diketonato) 3 complexes are high spin d 4 complexes [17] that exhibit Jahn-Teller distortion, due to the one vacancy in the e g orbital group, which could either be of d x2-y2 or d z2 character. The electron occupations t g 3 d 1 x2-y2 d 0 z2 and t g 3 d 0 x2-y2 d 1 z2 , are thus of comparable energy [28]. X-ray structures of Mn(b-diketonato) 3 complexes generally exhibit elongation Jahn-Teller distortion [18], implying (in agreement Redox reactions that take place during a cyclic voltammetric experiment of a 0.0005 mol dm À3 concentration of Mn(CH 3 COCHCOCH 3 ) 3 , (2), with 0.0005 mol dm À3 ferrocene as internal standard, solvent dichloromethane, supporting electrolyte tetrabutylammonium hexafluorophosphate, working electrode glassy carbon, at a scan rate of 0.100 V s À1 .…”

Intercalation of Layered Materials from Bulk to 2D

“…High‐spin d 4 complexes, like Mn 3+ , partially fill e g orbitals and cause an energy splitting. The distortion does not occur for Mn 4+ , Co 3+ , or Ni 2+ complexes because the e g orbitals are either empty or both partially filled for d 3 , d 6 , and d 8 complexes respectively …”

Synthesis of the first mixed ligand Mn (II) and Cd (II) complexes of 4‐methoxy‐pyridine‐2‐carboxylic acid, molecular docking studies and investigation of their anti‐tumor effects in vitro

“…When it comes to the other coordination bonds, the bond lengths of O2-Mn1 and O3-Mn1 were found to be 2.1307 (17) and 2.1573 (19) Å, respectively. This result is known as a compression Jahn−Teller distortion [62,63] (elongation of the Mn − N bond lengths along the equatorial plane, or shortening of the Mn − O bond lengths along the axial). Additionally, the bond angles of O3-Mn1-N1 is found to be 87.19 (8) , demonstrating that both of the 4mpic-ligands are almost perpendicular with the each other.…”