TY - JOUR
T1 - Characterization of synthetic oxomanganese complexes and the inorganic core of the O2-evolving complex in photosystem II
T2 - Evaluation of the DFT/B3LYP level of theory
AU - Sproviero, Eduardo M.
AU - Gascon, Jose A.
AU - McEvoy, James P.
AU - Brudvig, Gary W
AU - Batista, Victor S.
PY - 2006/4
Y1 - 2006/4
N2 - The capabilities and limitations of the Becke-3-Lee-Yang-Parr (B3LYP) hybrid density functional are investigated as applied to studies of mixed-valent multinuclear oxomanganese complexes. Benchmark calculations involve the analysis of structural, electronic and magnetic properties of di-, tri- and tetra-nuclear Mn complexes, previously characterized both chemically and spectroscopically, including the di-μ-oxo bridged dimers [MnIIIMnIV(μ-O)2(H2O)2(terpy)2]3+ (terpy = 2,2′:6,2″-terpyridine) and [MnIIIMnIV(μ-O)2(phen)4]3+ (phen = 1,10-phenanthroline), the Mn trimer [Mn3O4(bpy)4(H2O)2]4+ (bpy = 2,2′-bipyridine), and the tetramer [Mn4O4L6]+ with L = Ph2 PO2
-. Furthermore, the density functional theory (DFT) B3LYP level is applied to analyze the hydrated Mn3O4CaMn cluster completely ligated by water, OH-, Cl-, carboxylate and imidazole ligands, analogous to the '3+1 Mn tetramer' of the oxygen-evolving complex of photosystem II. It is found that DFT/B3LYP predicts structural and electronic properties of oxomanganese complexes in pre-selected spin-electronic states in very good agreement with X-ray and magnetic experimental data, even when applied in conjunction with rather modest basis sets. However, it is conjectured that the energetics of low-lying spin-states is beyond the capabilities of the DFT/B3LYP level, constituting a limitation to mechanistic studies of multinuclear oxomanganese complexes where until now the performance of DFT/B3LYP has raised little concern.
AB - The capabilities and limitations of the Becke-3-Lee-Yang-Parr (B3LYP) hybrid density functional are investigated as applied to studies of mixed-valent multinuclear oxomanganese complexes. Benchmark calculations involve the analysis of structural, electronic and magnetic properties of di-, tri- and tetra-nuclear Mn complexes, previously characterized both chemically and spectroscopically, including the di-μ-oxo bridged dimers [MnIIIMnIV(μ-O)2(H2O)2(terpy)2]3+ (terpy = 2,2′:6,2″-terpyridine) and [MnIIIMnIV(μ-O)2(phen)4]3+ (phen = 1,10-phenanthroline), the Mn trimer [Mn3O4(bpy)4(H2O)2]4+ (bpy = 2,2′-bipyridine), and the tetramer [Mn4O4L6]+ with L = Ph2 PO2
-. Furthermore, the density functional theory (DFT) B3LYP level is applied to analyze the hydrated Mn3O4CaMn cluster completely ligated by water, OH-, Cl-, carboxylate and imidazole ligands, analogous to the '3+1 Mn tetramer' of the oxygen-evolving complex of photosystem II. It is found that DFT/B3LYP predicts structural and electronic properties of oxomanganese complexes in pre-selected spin-electronic states in very good agreement with X-ray and magnetic experimental data, even when applied in conjunction with rather modest basis sets. However, it is conjectured that the energetics of low-lying spin-states is beyond the capabilities of the DFT/B3LYP level, constituting a limitation to mechanistic studies of multinuclear oxomanganese complexes where until now the performance of DFT/B3LYP has raised little concern.
KW - DFT/B3LYP
KW - Exchange coupling
KW - O-evolving complex
KW - Oxomanganese complex
KW - Photosystem II
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U2 - 10.1016/j.jinorgbio.2006.01.017
DO - 10.1016/j.jinorgbio.2006.01.017
M3 - Article
C2 - 16510187
AN - SCOPUS:33645885634
VL - 100
SP - 786
EP - 800
JO - Journal of Inorganic Biochemistry
JF - Journal of Inorganic Biochemistry
SN - 0162-0134
IS - 4
ER -