Spectroscopic (FT-IR, Raman, NMR) and DFT Quantum Chemical Studies on Phenoxyacetic Acid and Its Sodium Salt
Table 1
The bond lengths, angles, aromatic indices, values of dipole moment, and energy calculated (B3LYP/6-311++G**) for alkali metal phenoxyacetates.
Atoms
PAA
NaPA
Atomic numbers of PAA and NaPA molecules
Bond lengths (Å)a
C1–C2
1.3963
1.3992
C2–C3
1.3981
1.3977
C3–C4
1.3897
1.3901
C4–C5
1.3980
1.3984
C5–C6
1.3877
1.3873
C6–C1
1.3995
1.4024
C1–O7
1.3706
1.3617
O7–C8
1.4038
1.4162
C8–C9
1.5174
1.5290
C9–O10
1.1977
1.2559
C9–O11
1.3576
1.2689
O10–H(Na)11a
0.9689
2.2169
O11–H(Na)11a
2.3148
2.2199
Angles (°)
C1–C2–C3
119.34
119.55
C2–C3–C4
120.89
121.01
C3–C4–C5
119.24
119.07
C4–C5–C6
120.61
120.63
C5–C6–C1
119.84
120.14
C6–C1–C2
120.10
119.59
C6–C1–O7
115.28
115.55
C2–C1–O7
124.62
124.87
C1–O7–C8
118.49
118.64
O7–C8–C9
108.85
111.45
C8–C9–O10
127.23
120.84
C8–C9–O11
109.00
114.37
C9–O11–H(Na)11a
107.43
87.23
O10–C9–O11
123.78
124.79
H(Na)11a–O10–C9
107.43
87.41
Geometric aromaticity indices
0.982557
0.976809
0.99765
0.99672
0.93095
0.92338
96.21196
95.52024
Magnetic aromaticity indices
NICSf
−11.0192
−8.8957
Dipole moment ()
2.48
6.99
Energy (hartree)g
−535.5
−542.55
Å = m; babbreviation from Harmonic Oscillator Model of Aromaticity; cnormalized function of variance of bond lengths; dbond alternation coefficient; eBird’s index [5]; fnuclear independent chemical shifts; g1 hartree = 2625.5 kJ/mol.