Parameters

Theory level

Experimental^c

Experimental^d

HF/3-21G^a

HF/6-21G^a

HF/6-31G*^b

HF/6-31G**

(this work)

Bond lengths (Å)

O₁O₂

1.462

1.447

1.390

1.390

1.474 (4)

1.4.69 (2)

O₂C₃

1.441

1.435

1.396

1.396

1.418 (4)

1.416 (3)

C₃O₁₃

1.436

1.435

1.408

1.409

1.451 (4)

1.445 (3)

O₁₃C₁₂

1.407

1.403

1.376

1.376

1.388 (4)

1.380 (3)

C₁₂C_12a

1.529

1.533

1.532

1.532

1.528 (5)

1.523 (2)

C_12aO₁

1.477

1.469

1.429

1.429

1.450 (4)

1.462 (3)

Bond angles (degree)

O₁O₂C₃

107.1

108.8

109.5

109.5

107.7 (2)

108.1 (2)

O₂C₃O₁₃

107.3

106.8

107.8

107.8

107.0 (2)

106.6 (2)

C₃O₁₃C₁₂

115.7

117.3

115.3

115.3

113.6 (3)

114.2 (3)

O₁₃C₁₂C_12a

112.1

112.3

112.3

112.3

114.7 (2)

114.5 (2)

C₁₂C_12aO₁

111.6

110.9

110.5

110.5

111.1 (2)

110.7 (2)

C_12aO₁O₂

111.3

113.2

112.7

112.7

111.5 (2)

111.1 (2)

Torsion angles (degree)

O₁O₂C₃O₁₃

−74.7

−71.8

−73.4

−73.4

−75.5 (3)

−75.5 (2)

O₂C₃O₁₃C₁₂

32.4

33.4

31.1

31.1

36.3 (4)

36.0 (2)

C₃O₁₃C₁₂C₁₂a

28.3

25.3

27.4

27.4

24.7 (4)

25.3 (2)

O₁₃C₁₂C₁₂a O₁

−50.7

−49.4

−50.1

−50.2

−50.8 (4)

−51.3 (2)

C₁₂C₁₂aO₁O₂

9.9

12.5

10.9

10.9

12.2 (3)

12.6 (2)

C₁₂aO₁O₂C₃

50.4

46.7

48.7

48.7

47.7 (3)

47.8 (2)