142
3 Fundamentals of the Analysis Tools
Conformer A
Conformer B
1 st layer (Model system)
Fig. 3.25 The employed first layer of soybean lipoxygenase-1 (SLO-1) in the present ONIOM2
method with the boundaries of the first layer indicated by wavy lines. The two conformers A and B
including the first layer have been obtained by energetical optimization. Reprinted with permission
from Hirao and Morokuma (2010). Copyright 2010 American Chemical Society
been concluded that the average of the Fe–O 694 distances in conformer A (2.39 Å)
and B (3.46 Å) well agrees with that of the crystal structure. As a whole, an averaged
geometry of A and B was in good agreement with the experimental result.
Microsolvated effects on the excitation energies of 2-aminopurine surrounded by
water molecules have been examined by using QM/QM ONIOM2 (TD-B3LYP/631++G*: PM3). In both of the ground and the first-excited states, six water molecules
interact with 2-aminopurine by hydrogen bonding as shown in Fig. 3.26 (Zhang et al.
2004). The first and the second lowest excitation energies obtained (4.29 and 4.43 eV
assigned for π → π* and n → π*, respectively) in aqueous medium well agree with
the experimental results (4.11 and 4.46 eV). Moreover, this ONIOM method has
predicted fluorescent emission energy for the S 1 → S 0 de-excitation as 3.87 eV
compared with the experimental value 3.70 eV based on the least square fitting for
the experimental transition.
(a)
(b)
Fig. 3.26 Geometries of 2-aminopurine surrounded by six water molecules in a the ground state and
b the lowest excited state obtained by the ONIOM2 method. The first layer contains a 2-aminopurine
and the second layer six water molecules. Reprinted from Zheng et al. (2004). Copyright 2004 with
permission from Elsevier
3 Fundamentals of the Analysis Tools
Conformer A
Conformer B
1 st layer (Model system)
Fig. 3.25 The employed first layer of soybean lipoxygenase-1 (SLO-1) in the present ONIOM2
method with the boundaries of the first layer indicated by wavy lines. The two conformers A and B
including the first layer have been obtained by energetical optimization. Reprinted with permission
from Hirao and Morokuma (2010). Copyright 2010 American Chemical Society
been concluded that the average of the Fe–O 694 distances in conformer A (2.39 Å)
and B (3.46 Å) well agrees with that of the crystal structure. As a whole, an averaged
geometry of A and B was in good agreement with the experimental result.
Microsolvated effects on the excitation energies of 2-aminopurine surrounded by
water molecules have been examined by using QM/QM ONIOM2 (TD-B3LYP/631++G*: PM3). In both of the ground and the first-excited states, six water molecules
interact with 2-aminopurine by hydrogen bonding as shown in Fig. 3.26 (Zhang et al.
2004). The first and the second lowest excitation energies obtained (4.29 and 4.43 eV
assigned for π → π* and n → π*, respectively) in aqueous medium well agree with
the experimental results (4.11 and 4.46 eV). Moreover, this ONIOM method has
predicted fluorescent emission energy for the S 1 → S 0 de-excitation as 3.87 eV
compared with the experimental value 3.70 eV based on the least square fitting for
the experimental transition.
(a)
(b)
Fig. 3.26 Geometries of 2-aminopurine surrounded by six water molecules in a the ground state and
b the lowest excited state obtained by the ONIOM2 method. The first layer contains a 2-aminopurine
and the second layer six water molecules. Reprinted from Zheng et al. (2004). Copyright 2004 with
permission from Elsevier