TY - JOUR
T1 - What is the difference between the manganese porphyrin and corrole analogues of cytochrome P450's compound I?
AU - De Visser, Sam P.
AU - Ogliaro, François
AU - Gross, Zeev
AU - Shaik, Sason
PY - 2001/11/19
Y1 - 2001/11/19
N2 - Density functional calculations on oxo-manganese complexes of corrole (1) and porphyrin (2 and 3) show a fundamental difference. The ground state of 1 is the singlet manganese(v) state, 1A(MnV), in which corrole is a closed shell. In contrast, 2 and 3 have high-spin manganese(IV) states, 3A1u and 3A2u, respectively. This difference and the state ordering for each system are rationalized based on the competition between the intrinsic tendency of manganese to prefer high-spin electronic configurations, vis-à-vis the general tendency to prefer double occupancy in the low-lying orbitals. The outcome of this competition is determined primarily by the identity of the macrocycle, corrole versus porphyrin. Corrole with a small cavity holds the MnO moiety with a high off-plane displacement, and thereby prefers the low-spin state. On the other hand, porphyrin with the wider cavity holds the MnO moiety closer to the plane, and thereby prefers high-spin states.
AB - Density functional calculations on oxo-manganese complexes of corrole (1) and porphyrin (2 and 3) show a fundamental difference. The ground state of 1 is the singlet manganese(v) state, 1A(MnV), in which corrole is a closed shell. In contrast, 2 and 3 have high-spin manganese(IV) states, 3A1u and 3A2u, respectively. This difference and the state ordering for each system are rationalized based on the competition between the intrinsic tendency of manganese to prefer high-spin electronic configurations, vis-à-vis the general tendency to prefer double occupancy in the low-lying orbitals. The outcome of this competition is determined primarily by the identity of the macrocycle, corrole versus porphyrin. Corrole with a small cavity holds the MnO moiety with a high off-plane displacement, and thereby prefers the low-spin state. On the other hand, porphyrin with the wider cavity holds the MnO moiety closer to the plane, and thereby prefers high-spin states.
KW - Density functional calculations
KW - Metalloenzymes
KW - Oxomanganese corrole
KW - Oxomanganese porphyrin
UR - http://www.scopus.com/inward/record.url?scp=0035914644&partnerID=8YFLogxK
U2 - 10.1002/1521-3765(20011119)7:22<4954::AID-CHEM4954>3.0.CO;2-U
DO - 10.1002/1521-3765(20011119)7:22<4954::AID-CHEM4954>3.0.CO;2-U
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C2 - 11763464
AN - SCOPUS:0035914644
SN - 0947-6539
VL - 7
SP - 4954
EP - 4960
JO - Chemistry - A European Journal
JF - Chemistry - A European Journal
IS - 22
ER -