%0 Journal Article %1 citeulike:579498 %A Blomberg, M. R. A. %A Siegbahn, P. E. M. %D 1997 %I Springer Berlin / Heidelberg %J Theor Chem Acc. %K manganese epr iron %N 1-4 %P 72--80 %T A comparative study of high-spin manganese and iron complexes %V 97 %X Different metal complexes of the general form M(OH)n(H2O)6-n have been studied for manganese and iron. Oxidation states considered for manganese are Mn(III), Mn(IV) and Mn(V) and for iron Fe(II), Fe(III) and Fe(IV). Oxygen containing ligands are used throughout with varying numbers of hydroxyl and water ligands. Some metal-oxo and some charged complexes were also studied. Large Jahn-Teller distortions were found for the Mn(III) and Fe(IV) complexes. Consequences of these distortions are that water ligands have to be placed along the weak JT-axis and that five-coordination by a loss of one of these water ligands is quite competitive with six-coordination in particular for manganese. For Fe(II) and Fe(III) lower coordinations than six are preferred due to the presence of two repulsive eg electrons. For the metal-oxo complexes five-coordination is also preferred due to the strong trans effect from the oxo ligand. All complexes studied have high-spin ground states. An interesting effect is that the spin is much more delocalized on the ligands for the iron complexes than for the manganese complexes. This effect, which is chemically important for certain iron enzymes, is rationalized by the large number of 3d electrons on iron. For manganese with only five 3d electrons no spin delocalization is needed to obtain the proper high-spin states.

@article{citeulike:579498, abstract = {Different metal complexes of the general form M(OH)n(H2O)6-n have been studied for manganese and iron. Oxidation states considered for manganese are Mn(III), Mn(IV) and Mn(V) and for iron Fe(II), Fe(III) and Fe(IV). Oxygen containing ligands are used throughout with varying numbers of hydroxyl and water ligands. Some metal-oxo and some charged complexes were also studied. Large Jahn-Teller distortions were found for the Mn(III) and Fe(IV) complexes. Consequences of these distortions are that water ligands have to be placed along the weak JT-axis and that five-coordination by a loss of one of these water ligands is quite competitive with six-coordination in particular for manganese. For Fe(II) and Fe(III) lower coordinations than six are preferred due to the presence of two repulsive eg electrons. For the metal-oxo complexes five-coordination is also preferred due to the strong trans effect from the oxo ligand. All complexes studied have high-spin ground states. An interesting effect is that the spin is much more delocalized on the ligands for the iron complexes than for the manganese complexes. This effect, which is chemically important for certain iron enzymes, is rationalized by the large number of 3d electrons on iron. For manganese with only five 3d electrons no spin delocalization is needed to obtain the proper high-spin states.}, added-at = {2007-02-02T11:54:15.000+0100}, author = {Blomberg, M. R. A. and Siegbahn, P. E. M.}, biburl = {https://www.bibsonomy.org/bibtex/2d3382760dce061d0a545e33b19fa5796/robert}, citeulike-article-id = {579498}, interhash = {303ce7f411201b73d1038020a8e8902e}, intrahash = {d3382760dce061d0a545e33b19fa5796}, journal = {Theor Chem Acc.}, keywords = {manganese epr iron}, month = {October}, number = {1-4}, pages = {72--80}, priority = {2}, publisher = {Springer Berlin / Heidelberg}, timestamp = {2007-02-02T11:54:15.000+0100}, title = {A comparative study of high-spin manganese and iron complexes}, volume = 97, year = 1997 }