Journal of Spectroscopy

Research Article

Molecular Structure, NMR, HOMO, LUMO, and Vibrational Analysis of O-Anisic Acid and Anisic Acid Based on DFT Calculations

Table 3

Definition of internal coordinates of Anisic acid (AA).
No. (i)SymbolTypeDefinition
Stretching   
 1–4 C–HC2–H11, C3–H12, C5–H18, C6–H19
 5–10 C–CC1–C2, C2–C3, C3–C4, C4–C5, C5–C6,C6–C1
 11 C–CfnC1–C7
 12–14 C–OC7–O8, C7–O9, C4–O13
 15 O–CO13–C14
 16 O–HO9–H10
 17–19 C–H(methyl)C14–H15, C14–H16, C14–H17
Bending   
 20-21 C–CC2–C1–C7, C6–C1–C7
 22–29 C–C–HC1–C2–H11, C3–C2–H11,
C2–C3–H12, C4–C3–H12,
C4–C5–H18, C6–C5–H18,
C5–C6–H19, C1–C6–H19
 30–35 C–C–H(methyl)O13–C14–H15, O13–C14–H16, O13–C14–H17,
H17–C14–H15, H15–C14–H16, H17–C14–H16
 36-37 C–C–OC3–C4–O13, C5–C4–O13
 38 C–O–HC7–O9–H10
 39-40 C–C–OC1–C7–O8, C1–C7–O9
 41 C–O–CC4–O13–C14
 42–47 C–C–C (Ring)C1–C2–C3, C2–C3–C4, C3–C4–C5, C4–C5–C6,
C5–C6–C1, C6–C1–C2
Out-of-plane bending   
 48–51 C–HH11–C2–C3–C1, H12–C3–C4–C2, H18–C5–C6–C4, H19–C6–C1–C5
 52 C–CC7–C1–C6–C2
 53 C–OO13–C4–C5–C3
Torsion   
 54–55 C–OC2–C1–C7–O8, C2–C1–C7–O9
 56-57 C–O–CC3–C4–O13–C14, C5–C4–O13–C14
 58–60 C–H(methyl)C4–O13–C14–H15, C4–O13–C14–H16,
C4–O13–C14–H16
 61 O–HC1–C7–O9–H10
 62–67 tringC1–C2–C3–C4, C2–C3–C4–C5, C3–C4–C5–C6,
C4–C5–C6–C1, C5–C6–C1–C2, C6–C1–C2–C3
For numbering of atoms refer to Figure 1(b).