Theoretical versus experimental geometries in S-bridged manganese carbonyl complexes

The experimental geometry obtained from single-crystal X-ray diffraction for a number of binuclear S-bridged manganese complexes is compared with the results of theoretical calculations made at the ab initio level by using Hartree-Fock and density functional theory methods with medium-size and large basis sets. The optimized geometries obtained were somewhat relaxed when compared with the experimental ones, with very similar bond and torsion angles but longer bond lengths. The mean square deviation for bond lengths (angles) was found to be between 0.046 Å (1.1°) and 0.004 Å (0.7°) depending on the theoretical model used.