Table 8. The second-order perturbation energies E(2) (kcal.mol-1), corresponding to the most important charge transfer interactions (donor→acceptor) in the conjugate bases of aldo-pentose sugars at B3LYP/6-311++G(d,p) level. Table 8. The second-order perturbation energies E(2) (kcal.mol-1), corresponding to the most important charge transfer interactions (donor→acceptor) in the conjugate bases of aldo-pentose sugars at B3LYP/6-311++G(d,p) level. Table 8. The second-order perturbation energies E(2) (kcal.mol-1), corresponding to the most important charge transfer interactions (donor→acceptor) in the conjugate bases of aldo-pentose sugars at B3LYP/6-311++G(d,p) level. Table 8. The second-order perturbation energies E(2) (kcal.mol-1), corresponding to the most important charge transfer interactions (donor→acceptor) in the conjugate bases of aldo-pentose sugars at B3LYP/6-311++G(d,p) level. Table 8. The second-order perturbation energies E(2) (kcal.mol-1), corresponding to the most important charge transfer interactions (donor→acceptor) in the conjugate bases of aldo-pentose sugars at B3LYP/6-311++G(d,p) level. Table 8. The second-order perturbation energies E(2) (kcal.mol-1), corresponding to the most important charge transfer interactions (donor→acceptor) in the conjugate bases of aldo-pentose sugars at B3LYP/6-311++G(d,p) level. Table 8. The second-order perturbation energies E(2) (kcal.mol-1), corresponding to the most important charge transfer interactions (donor→acceptor) in the conjugate bases of aldo-pentose sugars at B3LYP/6-311++G(d,p) level.
Aldo-pentose Conjugate base Charge transfer Charge transfer E(2) ∑ E(2) b Total ∑ E(2)
Donor (i) Acceptor ( j)
D-xylose C2-HO2 n (3)O2→σ*(HO3-O3) n (3)O2→σ*(HO3-O3) 4.06 4.06 4.06
C3-HO3 n (3)O3→σ*(HO2-O2) n (3)O3→σ*(HO2-O2) 4.58 4.58 4.58
C4-HO4 n (3)O4→σ*(HO3-O3) n (3)O4→σ*(HO3-O3) 6.72 6.72 6.72
D-lyxose C1-HO1 n (1)O1→σ*(HO2-O2) n (1)O1→σ*(HO2-O2) 1.96 18.18 19.61
n (2)O1→σ*(HO2-O2) n (2)O1→σ*(HO2-O2) 16.52
n (1)O2→σ*(HO3-O3) n (1)O2→σ*(HO3-O3) 1.13 1.13
C2-HO2 n (1) O2→σ*(HO1-O1) n (1) O2→σ*(HO1-O1) 2.36 16.26 28.2
n (3) O2→σ*(HO1-O1) n (3) O2→σ*(HO1-O1) 13.90
n (1)O2→σ*(HO3-O3) n (1)O2→σ*(HO3-O3) 1.85 12.3
n (1)O2→σ*(HO3-O3) n (1)O2→σ*(HO3-O3) 10.51
C3-HO3 n (1)O2→σ*(HO1-O1) n (1)O2→σ*(HO1-O1) 1.34 15.3 16.67
n (2)O2→σ*(HO1-O1) n (2)O2→σ*(HO1-O1) 14.00
n (1)O3→σ*(HO2-O2) n (1)O3→σ*(HO2-O2) 1.33 1.33
C4-HO4 n (3)O4→σ*(HO3-O3) n (3)O4→σ*(HO3-O3) 7.69 7.69 7.69
D-ribose C1-HO1 n (2) O2→σ*(HO3-O3) n (2) O2→σ*(HO3-O3) 1.82 2.68 2.68
n (1) O3→σ*(HO4-O4) n (1) O3→σ*(HO4-O4) 0.86
C2-HO2 n (1) O2→σ*(HO3-O3) n (1) O2→σ*(HO3-O3) 1.29 14.64 15.67
n (3) O2→σ*(HO3-O3) n (3) O2→σ*(HO3-O3) 13.35
n (1)O3→σ*(HO4-O4) n (1)O3→σ*(HO4-O4) 1.03 1.03
C3-HO3 n (1)O3→σ*(HO2-O2) n (1)O3→σ*(HO2-O2) 1.55 12.15 24.86
n (3)O3→σ*(HO2-O2) n (3)O3→σ*(HO2-O2) 10.60
n (1)O3→σ*(HO4-O4) n (1)O3→σ*(HO4-O4) 1.66 12.71
n (3)O3→σ*(HO4-O4) n (3)O3→σ*(HO4-O4) 11.05
C4-HO4 n (1)O4→σ*(HO2-O2) n (1)O4→σ*(HO2-O2) 4.17 33.68 38.65
n (2)O4→σ*(HO2-O2) n (2)O4→σ*(HO2-O2) 0.60
n (3)O4→σ*(HO2-O2) n (3)O4→σ*(HO2-O2) 28.91
n (2)O4→σ*(HO3-O3) n (2)O4→σ*(HO3-O3) 4.97 4.97
L-arabinose C2-HO2 n (2)O2→σ*(HO3-O3) n (2)O2→σ*(HO3-O3) 2.06 2.06 2.06
C3-HO3 n (1)O3→σ*(HO1-O1) n (1)O3→σ*(HO1-O1) 6.09 51.97 61.13
n (2)O3→σ*(HO1-O1) n (2)O3→σ*(HO1-O1) 0.86
n (3)O3→σ*(HO1-O1) n (3)O3→σ*(HO1-O1) 45.02
n (1)O3→σ*(HO4-O4) n (1)O3→σ*(HO4-O4) 1.04 9.16
n (2)O3→σ*(HO4-O4) n (2)O3→σ*(HO4-O4) 6.84
n (3)O3→σ*(HO4-O4) n (3)O3→σ*(HO4-O4) 1.28
C4-HO4 n (1)O4→σ*(HO3-O3) n (1)O4→σ*(HO3-O3) 2.84 29.36 41.68
n (3)O4→σ*(HO3-O3) n (3)O4→σ*(HO3-O3) 26.52
n (1)O3→σ*(HO1-O1) n (1)O3→σ*(HO1-O1) 1.33 12.32
n (3) O3→σ*(HO1-O1) n (3) O3→σ*(HO1-O1) 10.99
a For D-ribose in neutral:
a For D-ribose in neutral:
n (2)O4→σ*(HO2-O2)
n (2)O4→σ*(HO2-O2)
2.41 2.41 2.41
bThe total is the total charge transfer stabilization energies for each sugar. bThe total is the total charge transfer stabilization energies for each sugar. bThe total is the total charge transfer stabilization energies for each sugar. bThe total is the total charge transfer stabilization energies for each sugar. bThe total is the total charge transfer stabilization energies for each sugar. bThe total is the total charge transfer stabilization energies for each sugar. bThe total is the total charge transfer stabilization energies for each sugar.