The authors have declared that no competing interests exist.
A combined experimental and theoretical study on molecular and vibrational structure of E-N¢ (ICINH) had been carried out. The FTIR, FT-Raman and UV-Vis spectra of ICINH were recorded in the solid phase. The optimized geometry was calculated by B3LYP method with 6-311++G(d,p) level of basis set. The harmonic vibrational frequencies, IR intensities and Raman scattering activities of the title compound were calculated at same level of theory. The scaled theoretical wavenumber showed very good agreement with the experimental values. The mulliken charges and thermodynamic functions of the ICINH were also performed at same level of theory. NLO and a study on the electronic properties such as excitation energies and wavelength, were performed by TD-DFT approach. HOMO–LUMO energy gap was also calculated and interpreted.
Indole is an aromatic heterocyclic organic compound with a bicyclic structure. It consist of a six-member benzene ring fused with five-member nitrogen containing pyrrole ring. It is of interest as it can be compared with tryptophane residue
The new Donor-π-Acceptor type dyes D1-3 carrying 3-(1-hexyl-1H-indol-3-yl)-2-(thiophen-2-yl) acrylonitrile as backbone with three different acceptor units were designed and synthesized by Babu,
The stability of the syn and anti structures of the non-steroidal anti-inflammatory drug indomethacin were investigated by Hassan et al.,
The (E)-2-(2-hydroxybenzylidenamino)-3-(1H-indol-3yl) propionic acid was synthesized by Saleem et al.,
The molecular structure, complete vibrational spectra and the quantum mechanical calculations of the title compound were not yet reported. Therefore, the vibrational spectrum and the quantum mechanical calculations for the title compound in the ground state by DFT method with the standard 6-311++G(d,p) level of basis set were reported. Electronic absorption spectra of the title compound were predicted by using TD-DFT method. The excitation energies, wavelength and oscillator strengths were obtained at the same level of theory. Besides the molecular parameters, dipole moments, NLO, thermodynamic properties, linear polarizability and first hyperpolarizability, were calculated. The results obtained from theoretical calculations and experimental were compared.
1H-indole-3-carbaldehyde (1.45 g, 0.01 mol) and isonicotinic acid hydrazide (1.37 g, 0.01 mol) were added to ethanol (10 ml) and stirred for an hour in the presence of hydrochloric acid to form a white precipitate. The precipitate was washed with sodium bicarbonate solution and filtered and again washed with petroleum ether (40–60%) and dried in air. The compound was recrystallized from absolute ethanol.
The optimized structural parameters of E-N¢ are calculated using B3LYP/6-311++G(d,p) basis set and listed in
Bond Parameters | B3LYP/6-311++G(d,p) | XRDa |
Bond Lengths (Å) | ||
C1-C2 | 1.416 | |
C1-C6 | 1.396 | |
C1-N15 | 1.383 | 1.347 |
C2-C3 | 1.404 | |
C2-C8 | 1.451 | 1.445 |
C3-C4 | 1.387 | |
C3-H9 | 1.084 | |
C4-C5 | 1.408 | |
C4-H10 | 1.084 | |
C5-C6 | 1.388 | |
C5-H11 | 1.084 | |
C6-H12 | 1.084 | |
C7-C8 | 1.385 | |
C7-H14 | 1.078 | |
C7-N15 | 1.372 | |
C8-C16 | 1.455 | 1.437 |
H13-N15 | 1.007 | |
C16-H17 | 1.087 | |
C16-N18 | 1.288 | 1.278 |
N18-N19 | 1.368 | 1.392 |
N19-H20 | 1.019 | |
N19-C21 | 1.384 | 1.33 |
C21-C22 | 1.496 | 1.495 |
C21-O29 | 1.223 | 1.236 |
C22-C23 | 1.398 | |
C22-C24 | 1.401 | |
C23-C25 | 1.388 | |
C23-H26 | 1.083 | |
C24-H27 | 1.082 | |
C24-N31 | 1.335 | |
C25-C28 | 1.394 | |
C25-H29 | 1.084 | |
C28-H30 | 1.0867 | |
C28-N31 | 1.336 | |
Bond Angles (°) | ||
C2-C1-C6 | 122.55 | |
C2-C1-N15 | 107.12 | 109.56 |
C6-C1-N15 | 130.34 | |
C1-C2-C3 | 118.87 | |
C1-C2-C8 | 107.31 | |
C3-C2-C8 | 133.81 | |
C2-C3-C4 | 118.9 | |
C2-C3-H9 | 120.86 | |
C4-C3-H9 | 120.24 | |
C3-C4-C5 | 121.19 | |
C3-C4-H10 | 119.6 | |
C5-C4-H10 | 119.2 | |
C4-C5-C6 | 121.18 | |
C4-C5-H11 | 119.4 | |
C6-C5-H11 | 119.42 | |
C1-C6-C5 | 117.31 | |
C1-C6-H12 | 121.52 | |
C5-C6-H12 | 121.17 | |
C8-C7-H14 | 130.27 | |
C8-C7-N15 | 109.75 | |
H14-C7-N15 | 119.85 | 123.3 |
C2-C8-C7 | 106.01 | |
C2-C8-C16 | 123.89 | 130.5 |
C7-C8-C16 | 129.95 | |
C1-N15-C7 | 109.81 | |
C1-N15-H13 | 125.49 | |
C7-N15-H13 | 124.69 | |
C8-C16-H17 | 115.93 | |
C8-C16-N18 | 130.93 | |
H17-C16-N18 | 113.14 | |
C16-N18-N19 | 117.96 | 113.29 |
N18-N19-H20 | 119.23 | |
N18-N19-C21 | 123.39 | 120.33 |
H20-N19-C21 | 112.73 | |
N19-C21-C22 | 119.89 | 114.64 |
N19-C21-O29 | 118.6 | 124.7 |
C22-C21-O29 | 121.49 | 120.6 |
C21-C22-C23 | 117.13 | |
C21-C22-C24 | 124.87 | |
C23-C22-C24 | 117.85 | |
C22-C23-C25 | 119.05 | |
C22-C23-H26 | 119.22 | |
C25-C23-H26 | 121.73 | |
C22-C24-H27 | 120.51 | |
C22-C24-N31 | 123.46 | |
H27-C24-N31 | 116.03 | |
C23-C25-C28 | 118.39 | |
C23-C25-H29 | 121.19 | |
C28-C25-H29 | 120.41 | |
C25-C28-H30 | 120.46 | |
C25-C28-N31 | 123.5 | |
H30-C28-N31 | 116.05 | |
C24-N31-C28 | 117.73 | |
C6-C1-C2-C3 | -0.05 | |
C6-C1-C2-C8 | -179.54 | |
N15-C1-C2-C3 | 179.79 | |
N15-C1-C2-C8 | 0.29 | |
C2-C1-C6-C5 | -0.29 | |
C2-C1-C6-H12 | 179.72 | |
N15-C1-C6-C5 | 179.92 | |
N15-C1-C6-H12 | -0.07 | |
C2-C1-N15-C7 | -0.26 | |
C2-C1-N15-H13 | 179.33 | |
C6-C1-N15-C7 | 179.56 | |
C6-C1-N15-H13 | -0.85 | |
C1-C2-C3-C4 | 0.41 | |
C1-C2-C3-H9 | -179.24 | |
C8-C2-C3-C4 | 179.74 | |
C8-C2-C3-H9 | 0.09 | |
C1-C2-C8-C7 | -0.22 | |
C1-C2-C8-C16 | -176.16 | |
C3-C2-C8-C7 | -179.61 | |
C3-C2-C8-C16 | 4.45 | |
C2-C3-C4-C5 | -0.44 | |
C2-C3-C4-H10 | 179.88 | |
H9-C3-C4-C5 | 179.21 | |
H9-C3-C4-H10 | -0.47 | |
C3-C4-C5-C6 | 0.11 | |
C3-C4-C5-H11 | -179.77 | |
H10-C4-C5-C6 | 179.78 | |
H10-C4-C5-H11 | -0.09 | |
C4-C5-C6-C1 | 0.26 | |
C4-C5-C6-H12 | -179.75 | |
H11-C5-C6-C1 | -179.87 | |
H11-C5-C6-H12 | 0.12 | |
H14-C7-C8-C2 | -175.75 | |
H14-C7-C8-C16 | -0.14 | |
N15-C7-C8-C2 | 0.06 | |
N15-C7-C8-C16 | 175.67 | |
C8-C7-N15-C1 | 0.12 | |
C8-C7-N15-H13 | -179.48 | |
H14-C7-N15-C1 | 176.44 | |
H14-C7-N15-H13 | -3.16 | |
C2-C8-C16-H17 | 20.44 | |
C2-C8-C16-N18 | -158.81 | |
C8-C16-N18-N19 | -154.47 | |
H17-C16-N18-N19 | 26.29 | |
C16-N18-N19-H20 | 2.17 | |
C16-N18-N19-C21 | -177.1 | |
N18-N19-C21-C22 | 21.38 | |
N18-N19-C21-O32 | 175.42 | |
H20-N19-C21-C22 | 21.29 | |
H20-N19-C21-O32 | -160.76 | |
N19-N21-C22-C23 | 176.81 | |
N19-N21-C22-C24 | -5.23 | |
O32-C21-C22-C23 | -156.35 | |
O32-C21-C22-C24 | 28.1 | |
C21-C22-C23-C25 | 25.76 | |
C21-C22-C23-H26 | -149.79 | |
C24-C22-C23-C25 | -177.41 | |
C24-C22-C23-H26 | 2.29 | |
C21-C22-C24-H27 | -1.54 | |
C21-C22-C24-N31 | 178.16 | |
C23-C22-C24-H27 | -3.35 | |
C23-C22-C24-N31 | 175.99 | |
C22-C23-C25-C28 | -178.87 | |
C22-C23-C25-H29 | 0.47 | |
H26-C23-C25-C28 | 1.25 | |
H26-C23-C25-H29 | -179.2 | |
C22-C24-N31-C28 | -178.45 | |
H27-C24-N31-C28 | 1.1 | |
C23-C25-C28-H30 | 0.92 | |
C23-C25-C28-N31 | -179.72 | |
H29-C25-C28-H30 | 179.8 | |
H29-C25-C28-N31 | 0.18 | |
C25-C28-N31-C24 | 0.25 | |
H30-C28-N31-C24 | -179.37 |
The harmonic vibrational frequencies were calculated using B3LYP/6-311++G(d,p) basis set. The title molecule belongs to C1 point group symmetry and it had 90 vibrational normal modes of same symmetry species are listed in
S.No | Type | Fragment type | Definition |
8-Jan | C-C | Double ring | C1-C2, C2-C3, C3-C4, C4-C5, C5-C6, C6-C1, C2-C8, C7-C8 |
9,10 | C-N | C1-N15, C7-N15 | |
15-Nov | C-H | C3-H9, C4-H10, C5-H11, C6-H12, C7-H14 | |
16 | N-H | N15-H13 | |
17-20 | C-C | Pyridine ring | C22-C23, C22-C24, C23-C25, C25-C28 |
21,22 | C-N | C24-N31, C28-N31 | |
23-26 | C-H | C23-H26, C24-H27, C25-H29, C28-H30 | |
27,28 | C-C | Out-of the ring | C8-C16, C21-C22 |
29 | C=O | C21-O32 | |
30 | N-H | N19-H20 | |
31 | C-H | C16-H17 | |
32,33 | C-N | C16-N18, C21-N19 | |
34 | N-N | N18-N19 | |
In-plane bending | |||
35-45 | C-C(N)-C(N) | Double ring | C1-C2 -C3, C2-C3-C4, C3-C4 -C5, C4-C5 -C6, C5-C6 -C1, C6-C1-C2, C1-C2-C8, C2-C8-C7, C8-C7-N15, C7-N15-C1 |
N15-C1 -C2 | |||
46-55 | C(N)-C-H | C2-C3 -H9, C4-C3 -H9, C3-C4 -H10, C5-C4 -H10, C4-C5 -H11, C6-C5 -H11, C1-C6 -H12, C5-C6 -H12, C8-C7 -H14, N15-C7 -H14 | |
56,57 | C-N-H | C1-N15-H13, C7-N15-H13 | |
58,59 | C-C-C(N) | C6-C1-N15, C3-C2-C8 | |
60,61 | C-C-H | Out-of the ring | C8-C16-H17, N18-C16-H17 |
62,63 | C-C-N | C8-C16-N18, C22-C21-N19 | |
64,65 | C-N-N | C16-N18-N19, C21-N19-N18 | |
66,67 | C(N)-N-H | C21-N19-H20, N18-N19-H20 | |
68,69 | C(N)-C=O | C22-C21-O32, N19-C21-O32 | |
70-73 | C-C-C | C21-C22 -C23, C21-C22-C24, C2-C8 -C16, C7-C8-C16 | |
74-79 | C-C(N)-C(N) | Pyridine ring | C22-C23 -C25, C23-C25-C28, C25-C28 -N31, C28-N31-C24, N31-C24-C22, C24-C22-C23 |
80-87 | C(N)-C-H | C22-C23-H26, C25-C23-H26, C22-C24-H27, N31-C24-H27, C23-C25-H29, C28-C25-H29, C25-C28-H30, N31-C28-H30 | |
Out-of-plane bending | |||
88-98 | C(N)-C(N)-C(N)-C(N) | Double ring | C1-C2-C3-C4, C2-C3-C4-C5, C3-C4-C5-C6, C4-C5 -C6-C1, C5-C6-C1-C2, C6-C1-C2-C3, C1-C2 -C8-C7, C2-C8-C7-N15, C8-C7-N15-C1, C7-N15-C1-C2, N15-C1 -C2-C8 |
99-103 | H-C(N)-C-C(N) | H9-C3-C2-C4, H10-C4-C3-C5, H11-C5-C4-C6, H12-C6-C1-C5, H13-N15-C1-C7, H14-C7-C8-N15 | |
105,106 | C-C-C-C | Out-of the ring | C16-C8-C2-C7, C21-C22-C23-C24 |
107 | O-C-C-N | O32-C21-C22-N19 | |
108 | H-N-N-C | H20-N19-N18-C21 | |
109 | H-C-C-N | H17-C16-C8-N18 | |
110 | C-N-N-C | C16-N18-N19-C21 | |
111-114 | N-C-C-C | N19-C21-C22-C23, N19-C21-C22-C24, | |
C2- C8- C16-N18, C7-C8-C16-N18 | |||
115-120 | C(N)-C(N)-C(N)-C(N) | Pyridine | C22-C23-C25-C28, C23-C25-C28-N31, C25-C28-N31-C24, C28-N31-C24-C22, N31-C24-C22-C23, C24-C22-C23-C25 |
121-124 | H-C-C-C | H26-C23-C22-C25, H27-C24-C22-N31, H29-C25-C23-C28, H30-C28-C25-N31 | |
125,126 | C(N)-C-C-C | Torsion | C3-C2-C8-C16, N15-C7-C8-C16 |
127,128 | C-C-C-C(N) | Butterfly | C8-C2-C1-C6, C3-C2-C1-N15 |
S.No | Type | Fragment type | Definition | |
8-Jan | C-C | Double ring | R1, R2, R3, R4, R5, R6, R7, R8 | |
9,10 | C-N | R9, R10 | ||
15-Nov | C-H | R11, R12, R13, R14, R15 | ||
16 | N-H | R16 | ||
17-20 | C-C | Pyridine ring | R17, R18, R19, R20 | |
21,22 | C-N | R21, R22 | ||
23-26 | C-H | R23, R24, R25, R26 | ||
27,28 | C-C | Out-of the ring | R27, R28 | |
29 | C=O | R29 | ||
30 | N-H | R30 | ||
31 | C-H | R31 | ||
32,33 | C-N | R32, R33 | ||
34 | N-N | R34 | ||
In-plane bending | ||||
35 | C(N)-C(N)-C(N) | Double ring | ||
36 | ||||
37 | ||||
38 | ||||
39 | ||||
40-44 | C(N)-C-H | (β46-β47)/√2(β48-β49)/2(β50-β51)/2(β52-β53)/2(β54-β55)/2
|
||
45 | C-N-H | |||
46,47 | C(N)-C(N)-C(N) | b58, b59 | ||
48 | C-C-H | Out-of the ring |
|
|
49,50 | C-C-N | |||
51 | C-N-N |
|
||
52 | C(N)-N-H | |||
53 | C(N)-C=O | |||
54,55 | C-C-C | |||
56 | C-C(N)-C(N) | Pyridine ring | ||
57 | ||||
58 | ||||
59-62 | C(N)-C-H | (β80-β81)/√2(β82-β83)/2(β84-β85)/2
|
||
, | ||||
Out-of-plane bending | ||||
63 | C(N)-C(N)-C(N)-C(N) | Double ring | ||
64 | ||||
65 | ||||
66 | ||||
67 | ||||
68-73 | H-C(N)-C-C(N) | g99, g100, g101, g102, g103, g104 | ||
74,75 | C-C-C-C | Out-of the ring | g105, g106 | |
76 | O-C-C-N | g107 | ||
77 | H-N-N-C | g108 | ||
78 | H-C-C-N | g109 | ||
79 | C-N-N-C | g110 | ||
80,81 | N-C-C-C | (γ111-γ112)/2(γ113-γ114)/2 |
||
82 | C(N)-C(N)-C(N)-C(N) | Pyridine | ||
83 | ||||
84 | (γ127-γ128)/2 | |||
85-88 | H-C-C-C | g121, g122, g123, g124 | ||
89 | C(N)-C-C-C | Ring Torsion | (γ125-γ126)/2
|
|
90 | C-C-C-C(N) | Butterfly |
Mode No | Exp. IR | Exp. Raman | Frequencies | Scaled | Red. Masses | Force | IR | Raman Intensity | Vibrational Assignments |
frequencies | constants | Intensity | |||||||
1 | - | - | 23 | 22 | 5.6685 | 0.0017 | 0.05 | 41.46 | gring (90) |
2 | - | - | 31 | 30 | 6.2039 | 0.0035 | 0.26 | 47.75 | gring (93) |
3 | - | - | 38 | 37 | 4.7887 | 0.0041 | 0.29 | 50.62 | g(py)ring (97) |
4 | - | - | 73 | 70 | 6.1906 | 0.0192 | 0.52 | 0.88 | g(py)ring (98) |
5 | - | 89 | 93 | 90 | 6.2748 | 0.0318 | 0.06 | 10.04 | gring (89) |
6 | - | - | 132 | 128 | 6.7417 | 0.0692 | 0.31 | 3.54 | gC=O (69), gring (23) |
7 | - | - | 151 | 146 | 5.367 | 0.0716 | 0.35 | 3.71 | gring (66), gN−N (26) |
8 | - | - | 171 | 166 | 4.8316 | 0.0835 | 0.2 | 5 | gN−N(54), gring (37) |
9 | - | - | 196 | 190 | 5.1729 | 0.1176 | 0.19 | 3.45 | g(py)ring (67), Butterfly (21) |
10 | - | - | 223 | 216 | 4.1358 | 0.1213 | 2.07 | 1.51 | Butterfly (89) |
11 | - | - | 236 | 229 | 5.5815 | 0.1835 | 2.48 | 4.94 | β(py)ring (78) |
12 | - | - | 295 | 285 | 7.0353 | 0.3595 | 0.36 | 0.27 | tring (94) |
13 | - | 376 | 363 | 5.8348 | 0.4847 | 0.8 | 0.48 | gring (62), goutC−C(21) | |
14 | - | - | 402 | 389 | 3.5462 | 0.3379 | 0.58 | 1.55 | goutC−N(43), gN−N(18), gring(14) |
15 | - | - | 418 | 405 | 5.2085 | 0.5367 | 0.63 | 1.35 | gring (69), g(py)ring (24) |
16 | - | - | 426 | 412 | 2.5799 | 0.2753 | 6.89 | 0.44 | goutC−C(50), bC−N(22), bN−H(10) |
17 | 426 | - | 440 | 426 | 1.5194 | 0.1731 | 7.82 | 0.87 | gN−H(78) |
18 | - | - | 449 | 434 | 3.4966 | 0.415 | 3.38 | 0.38 | goutC−C(56), gC−H (22) |
19 | - | - | 498 | 482 | 5.8526 | 0.8561 | 0.62 | 1.6 | βring (49),goutC−C(19), gring (18) |
20 | - | - | 552 | 535 | 5.1322 | 0.9221 | 1.85 | 2.76 | gC=N(61), gring (26) |
21 | - | - | 563 | 545 | 5.496 | 1.0281 | 0.54 | 2.03 | βring (72) |
22 | - | - | 582 | 564 | 2.8828 | 0.5762 | 1.76 | 4.01 | βoutC-C (46), βN‒H (23) |
23 | - | - | 589 | 570 | 3.2755 | 0.6698 | 7.32 | 2.24 | goutN−H(63), βC−H (18) |
24 | 581 | - | 606 | 587 | 5.2868 | 1.1458 | 11.97 | 3.94 | β(py)ring (68), goutN−H(22) |
25 | 615 | - | 637 | 616 | 6.325 | 1.5108 | 2.52 | 1.88 | βoutC-C (58), βC‒H (20), βN‒H (14) |
26 | - | - | 643 | 623 | 2.7471 | 0.6694 | 0.95 | 1.01 | βring (52), gC−H (24) |
27 | - | - | 668 | 647 | 2.6474 | 0.6964 | 2.08 | 15.49 | βN-N (50), βC‒N (18), β(py)ring (14) |
28 | 682 | - | 702 | 679 | 4.4972 | 1.3055 | 1.36 | 2.28 | βring (51), β(py)ring (27) |
29 | - | - | 719 | 696 | 2.1818 | 0.6637 | 3.21 | 0.31 | βoutC-C (47), βoutC−H (20), βring (17) |
30 | - | - | 748 | 724 | 3.0533 | 1.0053 | 12.23 | 4.31 | βoutC-N (57), βpyring (18), βC=O (13) |
31 | - | - | 751 | 727 | 1.4353 | 0.477 | 18.39 | 0.67 | gC-H (79) |
32 | - | - | 754 | 730 | 4.3578 | 1.4603 | 3.85 | 4.77 | gC-H (74), β(py)ring (13) |
33 | 752 | - | 774 | 749 | 3.9285 | 1.3867 | 0.53 | 1.49 | βoutC-H (48), βring (21) |
34 | - | - | 784 | 759 | 4.6888 | 1.6972 | 4.98 | 9.52 | βring (56), β(py)ring (23) |
35 | 793 | 795 | 828 | 802 | 1.3744 | 0.5555 | 1.89 | 1.51 | gC-H (88) |
36 | - | - | 840 | 813 | 1.9452 | 0.808 | 2.26 | 1.91 | g(py)C-H (92) |
37 | 830 | - | 855 | 828 | 1.4952 | 0.6446 | 0.98 | 0.25 | βC=O (60), β(py)ring (19) |
38 | - | - | 877 | 849 | 3.9613 | 1.796 | 23.55 | 3.59 | βC=N (45), βring (24), β(py)ring (18) |
39 | - | - | 893 | 864 | 4.4426 | 2.0861 | 3.75 | 0.23 | βring (78) |
40 | - | - | 919 | 890 | 1.4668 | 0.7301 | 1.25 | 6.07 | gC-H (91) |
41 | 912 | - | 944 | 913 | 1.3666 | 0.717 | 0.23 | 0.11 | gC-H (87) |
42 | - | - | 949 | 919 | 1.3956 | 0.7404 | 0.86 | 0.11 | g(py)C-H (90) |
43 | - | - | 981 | 949 | 1.2808 | 0.7258 | 0.01 | 0.06 | bN-H (59), bC−H(21) |
44 | 953 | - | 986 | 955 | 1.4487 | 0.8303 | 0.17 | 0.01 | g(py)C-H (92) |
45 | - | - | 1006 | 974 | 1.3774 | 0.8218 | 0.47 | 0.09 | g(py)C-H (92) |
46 | - | - | 1035 | 1002 | 2.1293 | 1.3435 | 1.87 | 6.9 | υC-C (41), βC‒H (28) |
47 | 1006 | 1009 | 1040 | 1007 | 4.2574 | 2.715 | 2.2 | 2.57 | υ(py)C-C (52), β(py)C‒H (29) |
48 | - | - | 1059 | 1025 | 3.2592 | 2.1539 | 0.09 | 13.5 | υ(py)C-C (68), β(py)C‒H (24) |
49 | 1047 | 1041 | 1066 | 1032 | 4.5472 | 3.0425 | 4.45 | 1.84 | υoutC-C (45), βring (20), βC‒H (14) |
50 | - | - | 1109 | 1074 | 3.4326 | 2.4881 | 18.31 | 16.64 | υN-N(52), β(py)C‒H (18), βoutC‒H (13) |
51 | - | 1092 | 1129 | 1093 | 1.5981 | 1.2012 | 5.03 | 1.73 | β C-H (47), βN‒H (22), υC‒N(17) |
52 | - | - | 1139 | 1102 | 1.4616 | 1.1167 | 0.86 | 0.43 | β(py)C-H (50), υ(py)C‒C (27) |
53 | - | - | 1155 | 1118 | 1.4763 | 1.1596 | 8.68 | 0.69 | βC-H (69) |
54 | 1126 | 1125 | 1160 | 1123 | 2.4869 | 1.9719 | 14.1 | 1.24 | υoutC-C (42), υoutC‒N (28) β(py)C‒H (15), |
55 | - | - | 1178 | 1140 | 1.1543 | 0.9431 | 0.36 | 0.39 | υC-C (53), υC‒N (19), βC‒H (15) |
56 | - | - | 1225 | 1186 | 1.4787 | 1.3081 | 2.73 | 1.51 | β(py)C-H (72), υ(py)C‒N (20) |
57 | - | - | 1251 | 1211 | 2.7583 | 2.5422 | 12.8 | 0.79 | βC-H (52), υC‒N(18), βN‒H (14) |
58 | - | - | 1263 | 1222 | 1.8362 | 1.7252 | 7.35 | 10.89 | υC-N (54), βC‒H (31) |
59 | 1244 | 1254 | 1285 | 1244 | 7.2124 | 7.0219 | 2.07 | 1.25 | υ(py)C-N (59), β(py)C‒H (22) |
60 | - | 1284 | 1325 | 1282 | 2.4286 | 2.5111 | 0.37 | 5.82 | υC-C (62), βC‒H (20) |
61 | 1298 | - | 1339 | 1296 | 2.3836 | 2.5178 | 54.46 | 0.89 | β C‒H (49), υC‒N(19), βoutC‒H (17) |
62 | - | - | 1361 | 1318 | 3.0228 | 3.3 | 71.69 | 18.1 | υ(py) C‒C (50), βC‒H (21), υoutC‒C (12) |
63 | - | - | 1365 | 1322 | 1.2876 | 1.4144 | 0.5 | 0.8 | υoutC‒N (58), βC‒H (23) |
64 | 1336 | 1345 | 1371 | 1327 | 5.9533 | 6.5908 | 6.32 | 4.61 | υC‒C (72), βC‒H (21) |
65 | 1360 | 1368 | 1410 | 1364 | 1.5509 | 1.8154 | 16.15 | 8.86 | boutC‒H (59), υC‒N (15), βN‒H (12) |
66 | - | - | 1442 | 1396 | 2.1721 | 2.6626 | 6.54 | 4.66 | υC‒C (49), βC‒H (27) |
67 | 1408 | - | 1447 | 1401 | 2.2447 | 2.7699 | 2.37 | 1.22 | β(py)C‒H (65), υ(py) (24) |
68 | - | - | 1473 | 1426 | 1.7655 | 2.2568 | 30.11 | 9.65 | βoutN-H (60), υoutC-N (17), υoutC‒C (14) |
69 | - | - | 1483 | 1436 | 2.3645 | 3.064 | 4.89 | 0.81 | βC-H (54), υC-C (21), βoutN‒H (18) |
70 | 1447 | 1455 | 1508 | 1460 | 2.2353 | 2.9957 | 1.61 | 3.14 | β(py) C-H (48), υ(py) (23), υoutC-C (10) |
71 | - | - | 1524 | 1475 | 2.7967 | 3.8252 | 0.94 | 0.21 | υC−N (43), υC−C (24), βC−H (18) |
72 | 1501 | - | 1554 | 1505 | 4.4312 | 6.307 | 20.77 | 41.94 | υC=C (68), βC−H (19) |
73 | - | - | 1604 | 1553 | 5.2119 | 7.9032 | 1.13 | 0.34 | υ(py) C−C (69), βC−H (22) |
74 | - | 1563 | 1615 | 1563 | 5.7905 | 8.8973 | 0.09 | 6.24 | υC−C (53), βN−H (25) |
75 | - | - | 1628 | 1575 | 5.6711 | 8.851 | 11.33 | 13.99 | υ(py) C−N (56),υ(py)C−C (23),β(py)C−H(14) |
76 | - | - | 1657 | 1604 | 7.6432 | 12.3614 | 5.91 | 100 | υout.C=N (56), υC−C (23), βC−H (14) |
77 | 1608 | 1606 | 1658 | 1605 | 6.6961 | 10.8407 | 2.95 | 28.6 | υC−C (52), υC=N (28), βC−H (12) |
78 | 1677 | - | 1718 | 1663 | 7.9762 | 13.8766 | 100 | 14.72 | υC=O (71), βN−H (23) |
79 | - | - | 3147 | 3046 | 1.0879 | 6.3482 | 1.02 | 0.82 | υout.C−H (98) |
80 | - | - | 3150 | 3049 | 1.0892 | 6.366 | 4.06 | 2.6 | υas(py) C−H (95) |
81 | - | - | 3167 | 3066 | 1.0858 | 6.4172 | 0.15 | 0.55 | υasC−H (96) |
82 | 3078 | - | 3174 | 3073 | 1.0887 | 6.463 | 0.72 | 2.26 | υasC−H (96) |
83 | - | - | 3184 | 3082 | 1.0936 | 6.532 | 4.39 | 1.24 | υasC−H (95) |
84 | - | - | 3185 | 3083 | 1.0909 | 6.5186 | 2.94 | 2.8 | υas(py)C−H (92) |
85 | - | - | 3194 | 3092 | 1.0971 | 6.5933 | 3.03 | 5.67 | υsC−H (97) |
86 | - | - | 3201 | 3099 | 1.092 | 6.593 | 2.66 | 0.24 | υas(py)C−H (91) |
87 | 3107 | 3109 | 3202 | 3100 | 1.0948 | 6.6134 | 0.13 | 3.81 | υas(py)C−H (94) |
88 | 3159 | - | 3253 | 3149 | 1.097 | 6.8395 | 0.27 | 0.6 | υC−H (99) |
89 | - | - | 3471 | 3360 | 1.0748 | 7.6289 | 7.5 | 3.16 | υout.N−H (99) |
90 | 3531 | - | 3664 | 3540 | 1.0805 | 8.5473 | 21.55 | 1.77 | υN−H (100) |
The ring stretching vibrations are very prominent in the spectrum of pyridine and its derivatives and are highly characteristics of aromatic ring itself
According to PED results, the C−C stretching vibrations of six and five members are assigned. The C−C stretching vibrations are observed at 1608, 1501 and 1336 cm−1 in FT-IR and 1606, 1563, 1345 and 1284 cm−1 in FT-Raman spectrum. The theoretically predicted scaled values are in excellent correlation with that of the experimental values.
Four C−H bonds in the pyridine ring of the title molecule give rise to four C−H stretching vibrations. The hetero-aromatic structure shows the presence of C−H stretching vibrations in the region 3000−3100 cm−1
The characteristic IR absorption wavenumber of C=O is normally strong in intensity and found in the region 1600–1800 cm−1
In primary amines, usually the N–H stretching vibrations occur in the region 3600–3300 cm−1
The identification of C=N stretching vibrations are difficult task since these are usually coupled with ring stretching and C-H in-plane bending vibrations. A bond C21=N19 at out of the ring possesses three vibrational normal modes. Since all these vibrations are inactive in both the spectra, the theoretically predicted wavenumbers 1604, 849 and 535 cm−1 are ascribed to C=N stretching, in-plane bending and out-of-plane bending, respectively. Similarly, the N−N stretching and bending vibrations are not present in both IR and Raman. Hence, the theoretically scaled values of 1074, 647 and 166 cm−1 are attributed to N−N stretching, in-plane bending and out-of-plane bending vibrations, respectively.
Non linear effect arise from the interactions of electromagnetic fields in various media to produce new fields altered in phase, frequency, amplitude or other propagation characteristics from incident fields
Parameters | B3LYP/6-311++G(d,p) |
Dipole moment ( μ ) Debye | |
μx | 1.6403 |
μy | 0.4934 |
μz | 0.1242 |
Μ | 1.7174Debye |
Polarizability ( α0 ) x10-30esu | |
αxx | 351.00 |
αxy | -4.96 |
αyy | 194.94 |
αxz | 1.53 |
αyz | 4.90 |
αzz | 132.91 |
αo | 0.5902x10-30esu |
Hyperpolarizability ( β0 ) x10-30esu | |
βxxx | -1163.89 |
βxxy | 31.69 |
βxyy | 148.04 |
βyyy | -106.30 |
βxxz | -196.67 |
βxyz | -19.08 |
βyyz | 12.83 |
βxzz | 46.85 |
βyzz | -42.47 |
βzzz | -35.40 |
β0 | 8.6424x10-30esu |
Standard value for urea (μ=1.3732 Debye, β0=0.3728x10-30esu): esu-electrostatic unit
The NBO analysis is performed on ICINH using B3LYP/6-311++G(d,p) basis set and are listed in
Type | Donor NBO (i) | ED/e | Acceptor NBO (j) | ED/e | aE(2) | bE(j)-E(i) | cF(i,j) |
KJ/mol | a.u. | a.u. | |||||
σ -σ* | BD ( 1) C 1 - C 2 | 1.959 | BD*(1) C 1 - C 6 | 0.021 | 18.95 | 1.23 | 0.07 |
BD*(1) C 2 - C 3 | 0.022 | 14.06 | 1.24 | 0.06 | |||
BD*(1) C 2 - C 8 | 0.027 | 8.2 | 1.16 | 0.04 | |||
BD*(1) C 3 - H 9 | 0.014 | 10.59 | 1.11 | 0.05 | |||
BD*(1) C 6 - H 12 | 0.013 | 9.41 | 1.1 | 0.05 | |||
BD*(1) C 8 - C 16 | 0.036 | 17.95 | 1.15 | 0.06 | |||
BD*(1) H 13 - N 15 | 0.016 | 16.82 | 1.04 | 0.06 | |||
π -π* | BD ( 2) C 1 - C 2 | 1.596 | BD*(2) C 3 - C 4 | 0.301 | 79.16 | 0.29 | 0.07 |
BD*(2) C 5 - C 6 | 0.319 | 76.11 | 0.28 | 0.07 | |||
BD*(2) C 7 - C 8 | 0.349 | 78.7 | 0.26 | 0.06 | |||
σ -σ* | BD ( 1) C 1 - C 6 | 1.976 | BD*(1) C 1 - C 2 | 0.027 | 20.21 | 1.25 | 0.07 |
BD*(1) C 1 - N 15 | 0.027 | 8.91 | 1.15 | 0.04 | |||
BD*(1) C 2 - C 8 | 0.027 | 5.86 | 1.21 | 0.04 | |||
BD*(1) C 5 - C 6 | 0.013 | 11.59 | 1.3 | 0.05 | |||
BD*(1) C 5 - H 11 | 0.012 | 9.46 | 1.16 | 0.05 | |||
BD*(1) C 6 - H 12 | 0.014 | 4.18 | 1.14 | 0.03 | |||
BD*(1) C 7 - N 15 | 0.013 | 6.53 | 1.15 | 0.04 | |||
σ -σ* | BD ( 1) C 1 - N 15 | 1.986 | BD*(1) C 1 - C 2 | 0.027 | 4.44 | 1.36 | 0.03 |
BD*(1) C 1 - C 6 | 0.021 | 8.54 | 1.38 | 0.05 | |||
BD*(1) C 2 - C 3 | 0.022 | 9.87 | 1.38 | 0.05 | |||
BD*(1) C 7 - H 14 | 0.012 | 9.12 | 1.23 | 0.05 | |||
BD*(1) C 7 - N 15 | 0.013 | 6.4 | 1.26 | 0.04 | |||
σ -σ* | BD ( 1) C 2 - C 3 | 1.974 | BD*(1) C 1 - C 2 | 0.027 | 15.44 | 1.24 | 0.06 |
BD*(1) C 1 - N 15 | 0.027 | 7.11 | 1.13 | 0.04 | |||
BD*(1) C 2 - C 3 | 0.022 | 16.48 | 1.22 | 0.06 | |||
BD*(1) C 3 - C 4 | 0.013 | 5.1 | 1.25 | 0.04 | |||
BD*(1) C 7 - C 8 | 0.019 | 12.84 | 1.21 | 0.06 | |||
BD*(1) C 7 - H 14 | 0.012 | 18.95 | 1.07 | 0.06 | |||
BD*(1) C 7 - N 15 | 0.013 | 5.44 | 1.09 | 0.03 | |||
BD*(1) C 8 - C 16 | 0.036 | 10.08 | 1.13 | 0.05 | |||
BD*(1) C 16 - N 18 | 0.01 | 9.5 | 1.25 | 0.05 | |||
σ -σ* | BD ( 1) C 3 - C 4 | 1.978 | BD*(1) C 2 - C 3 | 0.023 | 13.77 | 1.27 | 0.06 |
BD*(1) C 2 - C 8 | 0.027 | 19.25 | 1.19 | 0.07 | |||
BD*(1) C 3 - H 9 | 0.014 | 4.69 | 1.14 | 0.03 | |||
BD*(1) C 4 - C 5 | 0.016 | 10.84 | 1.26 | 0.05 | |||
BD*(1) C 5 - H 11 | 0.012 | 8.49 | 1.15 | 0.04 | |||
π -π* | BD ( 2) C 3 - C 4 | 1.721 | BD*(2) C 1 - C 2 | 0.477 | 75.1 | 0.28 | 0.07 |
BD*(2) C 5 - C 6 | 0.319 | 82.34 | 0.28 | 0.07 | |||
σ -σ* | BD ( 1) C 3 - H 9 | 1.979 | BD*(1) C 1 - C 2 | 0.027 | 17.24 | 1.06 | 0.06 |
BD*(1) C 4 - C 5 | 0.016 | 16.07 | 1.08 | 0.06 | |||
σ -σ* | BD ( 1) C 4 - C 5 | 1.979 | BD*(1) C 3 - C 4 | 0.013 | 11.17 | 1.28 | 0.05 |
BD*(1) C 3 - H 9 | 0.014 | 10.46 | 1.13 | 0.05 | |||
BD*(1) C 5 - C 6 | 0.013 | 10.92 | 1.27 | 0.05 | |||
BD*(1) C 6 - H 12 | 0.013 | 11.05 | 1.12 | 0.05 | |||
σ -σ* | BD ( 1) C 4 - H 10 | 1.98 | BD*(1) C 2 - C 3 | 0.022 | 15.98 | 1.08 | 0.06 |
BD*(1) C 5 - C 6 | 0.013 | 15.94 | 1.1 | 0.06 | |||
σ -σ* | BD ( 1) C 5 - C 6 | 1.976 | BD*(1) C 1 - C 6 | 0.021 | 13.97 | 1.27 | 0.06 |
BD*(1) C 1 - N 15 | 0.026 | 25.98 | 1.14 | 0.08 | |||
BD*(1) C 4 - C 5 | 0.015 | 10.54 | 1.27 | 0.05 | |||
BD*(1) C 4 - H 10 | 0.012 | 8.28 | 1.15 | 0.04 | |||
BD*(1) C 6 - H 12 | 0.013 | 5.27 | 1.13 | 0.03 | |||
π -π* | BD ( 2) C 5 - C 6 | 1.729 | BD*(2) C 1 - C 2 | 0.477 | 82.01 | 0.28 | 0.07 |
BD*(2) C 3 - C 4 | 0.301 | 72.63 | 0.29 | 0.06 | |||
σ -σ* | BD ( 1) C 5 - H 11 | 1.98 | BD*(1) C 1 - C 6 | 0.022 | 14.69 | 1.08 | 0.06 |
BD*(1) C 3 - C 4 | 0.014 | 15.69 | 1.11 | 0.06 | |||
σ -σ* | BD ( 1) C 6 - H 12 | 1.98 | BD*(1) C 1 - C 2 | 0.027 | 17.66 | 1.07 | 0.06 |
BD*(1) C 4 - C 5 | 0.016 | 15.06 | 1.09 | 0.06 | |||
σ -σ* | BD ( 1) C 7 - C 8 | 1.972 | BD*(1) C 2 - C 3 | 0.023 | 20.42 | 1.28 | 0.07 |
BD*(1) C 2 - C 8 | 0.027 | 12.18 | 1.21 | 0.05 | |||
BD*(1) C 7 - H 14 | 0.012 | 6.53 | 1.13 | 0.04 | |||
BD*(1) C 8 - C 16 | 0.036 | 12.34 | 1.2 | 0.05 | |||
BD*(1) H 13 - N 15 | 0.017 | 14.02 | 1.09 | 0.05 | |||
BD*(1) C 16 - H 17 | 0.022 | 4.23 | 1.13 | 0.03 | |||
π -π* | BD ( 2) C 7 - C 8 | 1.801 | BD*(2) C 1 - C 2 | 0.477 | 66.23 | 0.3 | 0.07 |
BD*(2) C 7 - C 8 | 0.349 | 8.87 | 0.29 | 0.02 | |||
BD*(2) C 16 - N 18 | 0.212 | 73.6 | 0.29 | 0.06 | |||
σ -σ* | BD ( 1) C 7 - H 14 | 1.984 | BD*(1) C 1 - N 15 | 0.026 | 12.26 | 1.01 | 0.05 |
BD*(1) C 2 - C 8 | 0.027 | 8.66 | 1.06 | 0.04 | |||
BD*(1) C 7 - C 8 | 0.019 | 6.07 | 1.13 | 0.04 | |||
σ -σ* | BD ( 1) C 7 - N 15 | 1.985 | BD*(1) C 1 - C 6 | 0.021 | 17.03 | 1.39 | 0.07 |
BD*(1) C 1 - N 15 | 0.026 | 7.32 | 1.26 | 0.04 | |||
BD*(1) C 7 - C 8 | 0.019 | 5.06 | 1.38 | 0.04 | |||
BD*(1) C 8 - C 16 | 0.036 | 16.07 | 1.3 | 0.06 | |||
σ -σ* | BD ( 1) C 8 - C 16 | 1.979 | BD*(1) C 1 - C 2 | 0.027 | 4.81 | 1.23 | 0.03 |
BD*(1) C 2 - C 8 | 0.027 | 14.31 | 1.18 | 0.06 | |||
BD*(1) C 7 - C 8 | 0.019 | 14.81 | 1.24 | 0.06 | |||
BD*(1) C 7 - N 15 | 0.013 | 4.48 | 1.13 | 0.03 | |||
BD*(1) C 16 - N 18 | 0.01 | 9.54 | 1.29 | 0.05 | |||
σ -σ* | BD ( 1) H 13 - N 15 | 1.99 | BD*(1) C 1 - C 2 | 0.027 | 7.41 | 1.24 | 0.04 |
BD*(1) C 7 - C 8 | 0.019 | 5.73 | 1.26 | 0.04 | |||
σ -σ* | BD ( 1) C 16 - H 17 | 1.969 | BD*(1) C 7 - C 8 | 0.019 | 20.08 | 1.07 | 0.06 |
BD*(1) N 18 - N 19 | 0.03 | 35.31 | 0.89 | 0.08 | |||
σ -σ* | BD ( 1) C 16 - N 18 | 1.988 | BD*(1) C 2 - C 8 | 0.027 | 4.98 | 1.39 | 0.04 |
BD*(1) C 8 - C 16 | 0.036 | 9.37 | 1.38 | 0.05 | |||
BD*(1) N 19 - C 21 | 0.073 | 10.33 | 1.33 | 0.05 | |||
π -π* | BD ( 2) C 16 - N 18 | 1.942 | BD*(2) C 7 - C 8 | 0.349 | 32.55 | 0.35 | 0.05 |
σ -σ* | BD ( 1) N 18 - N 19 | 1.986 | BD*(1) C 16 - H 17 | 0.022 | 8.62 | 1.27 | 0.05 |
BD*(1) C 21 - O 29 | 0.021 | 5.69 | 1.44 | 0.04 | |||
σ -σ* | BD ( 1) N 19 - H 20 | 1.983 | BD*(1) C 21 - C 22 | 0.066 | 15.1 | 1.09 | 0.06 |
σ -σ* | BD ( 1) N 19 - C 21 | 1.99 | BD*(1) C 16 - N 18 | 0.01 | 8.91 | 1.42 | 0.05 |
BD*(1) C 22 - C 23 | 0.021 | 4.39 | 1.39 | 0.03 | |||
BD*(1) C 25 - C 23 | 0.026 | 4.23 | 4.67 | 0.06 | |||
σ -σ* | BD ( 1) C 21 - C 22 | 1.974 | BD*(1) N 19 - H 20 | 0.042 | 10.96 | 1.03 | 0.05 |
BD*(1) C 21 - O 29 | 0.021 | 5.27 | 1.24 | 0.04 | |||
BD*(1) C 22 - C 23 | 0.021 | 7.07 | 1.23 | 0.04 | |||
BD*(1) C 22 - C 24 | 0.033 | 8.12 | 1.22 | 0.04 | |||
BD*(1) C 23 - C 25 | 0.015 | 9.08 | 1.25 | 0.05 | |||
BD*(1) C 25 - N 32 | 0.015 | 9.5 | 1.21 | 0.05 | |||
σ -σ* | BD ( 1) C 21 - O 29 | 1.992 | BD*(1) N 18 - N 19 | 0.03 | 7.28 | 1.39 | 0.04 |
BD*(1) C 21 - C 22 | 0.066 | 7.11 | 1.45 | 0.05 | |||
BD*(1) C 22 - C 24 | 0.033 | 5.61 | 1.59 | 0.04 | |||
π -π* | BD ( 2) C 21 - O 29 | 1.979 | BD*(2) C 22 - C 24 | 0.328 | 13.85 | 0.42 | 0.04 |
σ -σ* | BD ( 1) C 22 - C 23 | 1.973 | BD*(1) N 19 - C 21 | 0.073 | 8.49 | 1.13 | 0.04 |
BD*(1) C 21 - C 22 | 0.066 | 7.07 | 1.12 | 0.04 | |||
BD*(1) C 22 - C 24 | 0.033 | 14.85 | 1.26 | 0.06 | |||
BD*(1) C 23 - C 25 | 0.0148 | 10.84 | 1.29 | 0.05 | |||
BD*(1) C 24 - H 27 | 0.023 | 9.5 | 1.15 | 0.05 | |||
BD*(1) C 25 - H 28 | 0.013 | 10.59 | 1.14 | 0.05 | |||
σ -σ* | BD ( 1) C 22 - C 24 | 1.979 | BD*(1) C 21 - C 22 | 0.066 | 6.23 | 1.13 | 0.04 |
BD*(1) C 21 - O 29 | 0.021 | 6.65 | 1.29 | 0.04 | |||
BD*(1) C 22 - C 23 | 0.021 | 16.07 | 1.27 | 0.06 | |||
BD*(1) C 23 - H 26 | 0.014 | 10.42 | 1.16 | 0.05 | |||
BD*(1) C 24 - H 27 | 0.023 | 4.35 | 1.15 | 0.03 | |||
BD*(1) C 24 - C 30 | 0.015 | 5.9 | 1.26 | 0.04 | |||
π -π* | BD ( 2) C 22 - C 24 | 1.61 | BD*(2) C 21 - O 29 | 0.274 | 74.39 | 0.29 | 0.07 |
BD*(2) C 23 - C 25 | 0.287 | 97.53 | 0.28 | 0.07 | |||
BD*(2) C 28 - N 31 | 0.372 | 68.03 | 0.27 | 0.06 | |||
σ -σ* | BD ( 1) C 23 - C 25 | 1.979 | BD*(1) C 21 - C 22 | 0.066 | 12.01 | 1.13 | 0.05 |
BD*(1) C 22 - C 23 | 0.021 | 12.22 | 1.27 | 0.05 | |||
BD*(1) C 25 - H 28 | 0.014 | 4.35 | 1.15 | 0.03 | |||
BD*(1) C 30 - H 31 | 0.024 | 9.25 | 1.14 | 0.05 | |||
π -π* | BD ( 2) C 23 - C 25 | 1.639 | BD*(2) C 22 - C 24 | 0.329 | 69.33 | 0.29 | 0.06 |
BD*(2) C 30 - N 32 | 0.373 | 123.22 | 0.27 | 0.08 | |||
σ -σ* | BD ( 1) C 23 - H 26 | 1.979 | BD*(1) C 22 - C 24 | 0.033 | 16.99 | 1.08 | 0.06 |
σ -σ* | BD ( 1) C 24 - H 27 | 1.979 | BD*(1) C 22 - C 23 | 0.021 | 17.45 | 1.08 | 0.06 |
BD*(1) C 30 - N 32 | 0.016 | 20.33 | 1.06 | 0.06 | |||
σ -σ* | BD ( 1) C 24 - N 31 | 1.986 | BD*(1) C 21 - C 22 | 0.066 | 9.41 | 1.25 | 0.05 |
BD*(1) C 22 - C 24 | 0.033 | 8.12 | 1.38 | 0.05 | |||
BD*(1) C 28 - H 30 | 0.024 | 8.74 | 1.25 | 0.05 | |||
σ -σ* | BD ( 1) C 25 - C 23 | 1.985 | BD*(1) C 23 - C 25 | 0.015 | 10.59 | 1.3 | 0.05 |
BD*(1) C 23 - H 26 | 0.014 | 11.63 | 1.16 | 0.05 | |||
BD*(1) C 30 - N 32 | 0.016 | 5.86 | 1.26 | 0.04 | |||
σ -σ* | BD ( 1) C 25 - H 23 | 1.979 | BD*(1) C 22 - C 23 | 0.021 | 14.52 | 1.09 | 0.06 |
BD*(1) C 30 - N 32 | 0.016 | 17.87 | 1.07 | 0.06 | |||
σ -σ* | BD ( 1) C 30 - H 31 | 1.982 | BD*(1) C 23 - C 25 | 0.015 | 14.73 | 1.11 | 0.06 |
BD*(1) C 25 - N 32 | 0.015 | 20.17 | 1.07 | 0.06 | |||
σ -σ* | BD ( 1) C 30 - N 32 | 1.987 | BD*(1) C 24 - H 27 | 0.023 | 8.79 | 1.27 | 0.05 |
BD*(1) C 25 - H 29 | 0.013 | 6.11 | 1.26 | 0.04 | |||
π -π* | BD ( 2) C 30 - N 32 | 1.705 | BD*(2) C 22 - C 24 | 0.328 | 116.4 | 0.32 | 0.09 |
BD*(2) C 23 - C 25 | 0.287 | 52.38 | 0.32 | 0.06 | |||
n -π* | LP ( 1) N 15 | 1.613 | BD*(2) C 1 - C 2 | 0.476 | 140.71 | 0.3 | 0.09 |
BD*(2) C 7 - C 8 | 0.349 | 160.41 | 0.29 | 0.1 | |||
n -σ* | LP ( 1) N 18 | 1.921 | BD*(1) C 8 - C 16 | 0.036 | 42.76 | 0.87 | 0.09 |
BD*(1) C 16 - H 17 | 0.022 | 16.74 | 0.8 | 0.05 | |||
BD*(1) N 19 - H 20 | 0.042 | 33.05 | 0.75 | 0.07 | |||
n -π* | LP ( 1) N 19 | 1.679 | BD*(2) C 16 - N 18 | 0.212 | 102.42 | 0.3 | 0.08 |
BD*(1) C 21 - O 29 | 0.021 | 5.4 | 0.87 | 0.03 | |||
BD*(2) C 21 - O 29 | 0.274 | 170.41 | 0.33 | 0.1 | |||
n -σ* | LP ( 1) N 32 | 1.917 | BD*(1) C 22 - C 24 | 0.033 | 39.46 | 0.89 | 0.08 |
BD*(1) C 24 - H 27 | 0.023 | 16.57 | 0.78 | 0.05 | |||
BD*(1) C 25 - C 23 | 0.026 | 8.16 | 4.18 | 0.08 | |||
BD*(1) C 30 - H 31 | 0.023 | 17.11 | 0.77 | 0.05 | |||
n -σ* | LP ( 1) O 29 | 1.979 | BD*(1) C 21 - C 22 | 0.066 | 8.24 | 1.12 | 0.04 |
n -σ* | LP ( 2) O 29 | 1.868 | BD*(1) N 19 - C 21 | 0.073 | 99.66 | 0.68 | 0.12 |
BD*(1) C 21 - C 22 | 0.066 | 73.35 | 0.68 | 0.1 | |||
BD*(1) C 25 - C 23 | 0.026 | 6.9 | 4.1 | 0.08 | |||
π*-π* | BD*( 2) C 1 - C 2 | 0.477 | BD*(2) C 3 - C 4 | 0.301 | 1195.8 | 0.01 | 0.08 |
π*-π* | BD*( 2) C 7 - C 8 | 0.349 | BD*(2) C 1 - C 2 | 0.477 | 711.11 | 0.01 | 0.06 |
π*-σ* | BD*( 2) C 21 - O 29 | 0.274 | BD*(1) C 21 - O 29 | 0.021 | 18.24 | 0.54 | 0.11 |
π*-π* | BD*( 2) C 30 - N 32 | 0.373 | BD*(2) C 22 - C 24 | 0.328 | 604.96 | 0.02 | 0.08 |
BD*(2) C 23 - C 25 | 0.287 | 714.04 | 0.02 | 0.08 |
The HOMO–LUMO plot of ICINH molecule is shown in
By using HOMO and LUMO energy value ICINH, the global chemical reactivity descriptors such as hardness (η), chemical potential (μ), softness (S), electronegativity (χ) and electrophilicity index (ω) have been calculated and are listed in
Parameters | Values |
HOMO | -6.125 eV |
LUMO | -1.784 eV |
Energy gap | 4.341 eV |
Ionization potential (IP) | 6.125 eV |
Electron affinity (EA) | 1.784 eV |
Electrophilicity Index (ω) | 1.801 |
Chemical Potential (µ) | 3.954 |
Electronegativity (χ) | -3.954 |
Hardness (η) | -4.341 |
Softness (S) | 8.682 |
Occupancy | Orbital energies(a.u) | Orbital energies(eV) | Kinetic energies(a.u) |
O52 | -0.269 | -7.319 | 1.267 |
O53 | -0.267 | -7.265 | 1.605 |
O54 | -0.262 | -7.129 | 1.871 |
O55 | -0.254 | -6. 911 | 1.250 |
O56 | -0.228 | -6.203 | 1.576 |
V57 | -0.071 | -1.931 | 1.664 |
V58 | -0.055 | -1.496 | 1.519 |
V59 | -0.034 | 0. 925 | 1.367 |
V60 | 0.025 | 0.680 | 0.381 |
V61 | 0.023 | 0.625 | 1.250 |
The UV absorption spectrum for ICINH is recorded in the range 200-800 nm. All the structures allow strong π-π* and σ-σ* transition in the UV-Vis region with high extinction coefficients. The calculated results involving in the vertical excitation energies, oscillator strength (f) and wavelength are carried out and compare with measured experimental wavelength. Typically, according to Frank-Condon principle, the maximum absorption peaks (λmax) in a UV-Vis spectrum correspond to vertical excitation. The λmax of ICINH molecule are calculated using TD-DFT/6-311++G(d,p) basis set. It is evident from the
Calculated at B3LYP/6-311++G(d,p) | Oscillator strength | CalculatedBand gap (ev/nm) | ExperimentalBand gap (ev/nm) | Type |
Excited State-1 | Singlet-A (f=0.0009) | 3.0010 eV/413.14 nm | ||
69 -> 70 | 0.6908 | |||
Excited State-2 | Singlet-A (f=0.0136) | 3.1849 eV/389.29 nm | ||
66 -> 70 | -0.1059 | |||
68 -> 70 | 0.6587 | |||
68 -> 71 | 0.1308 | |||
Excited State-3 | Singlet-A (f=0.0296) | 3.4698 eV/357.32 nm | 342.42 | π-π* |
66 -> 70 | 0.1243 | |||
66 -> 71 | 0.1564 | |||
68 -> 70 | -0.1275 | |||
68 -> 71 | 0.4689 | |||
69 -> 71 | -0.4067 |
In the present study, MEP surface map of ICINH is calculated using B3LYP/6-311++G(d,p) basis set and illustrated in
It is well known that the atomic charges are very much dependent on how the atoms are defined. It also plays an important role in the application of quantum chemical calculation to molecular system because of atomic charges affect the dipole moment, molecular polarizability, electronic structure and a lot of properties of molecular systems. The mulliken charges calculated at B3LYP/6-311++G(d,p) basis set for the molecule under study are given in
The C2 atom has high positive charge which is due to the indole group. Similarly the C16 atom has high negative charge due to the attachment of C16=N18 group. All the hydrogen atoms have positive charge.
Atoms | Charges | Atoms | Charges |
1C | -0.2987 | 17H | 0.1624 |
2C | 1.3144 | 18N | 0.0896 |
3C | -0.6692 | 19N | -0.0922 |
4C | -0.5107 | 20H | 0.2843 |
5C | -0.0917 | 21C | -0.5353 |
6C | -0.6358 | 22C | 0.7243 |
7C | -0.2138 | 23C | 0.0949 |
8C | 0.8639 | 24C | -0.5605 |
9H | 0.1424 | 25C | -0.1468 |
10H | 0.1605 | 26H | 0.2244 |
11H | 0.1674 | 27H | 0.2180 |
12H | 0.1439 | 28C | -0.2971 |
13H | 0.3039 | 29H | 0.1812 |
14H | 0.2100 | 30H | 0.1860 |
15N | -0.0449 | 31N | -0.0054 |
16C | -1.1123 | 32O | -0.2591 |
On the basis of vibrational analysis, the standard statistical thermodynamic functions: heat capacity (C), entropy (S) and enthalpy changes (H) for the title molecule are obtained from the theoretical harmonic frequencies and are listed in
Parameters | B3LYP/6-311++G(d,p) |
Total Energies | -873.259 |
Zero-point Energy | 154. 930 (Kcal/Mol) |
Rotational constants (GHZ) | 1.119 |
0.128 | |
0.120 | |
Entropy | |
Total | 131.409 |
Translational | 42.613 |
Rotational | 34.185 |
Vibrational | 54.610 |
T (K) | S (J/mol.K) | Cp (J/mol.K) | ddH (kJ/mol) |
100.00 | 362.62 | 109.42 | 7.39 |
200.00 | 460.26 | 183.91 | 21.90 |
298.15 | 549.35 | 268.44 | 44.07 |
300.00 | 551.01 | 270.03 | 44.57 |
400.00 | 640.10 | 351.39 | 75.73 |
500.00 | 726.10 | 419.62 | 114.40 |
600.00 | 807.63 | 474.29 | 159.20 |
700.00 | 884.14 | 517.90 | 208.89 |
800.00 | 955.68 | 553.15 | 262.50 |
900.00 | 1022.55 | 582.09 | 319.31 |
1000.00 | 1085.17 | 606.19 | 378.76 |
They can be used to compute the other thermodynamic energies according to relationships of thermodynamic functions and estimate directions of chemical reactions according to the second law of thermodynamics in thermo chemical field
C0p,m = 6.76926 + 0.02858T + 2.52495x10-5 T2 (R2 = 0.99905)
S0m = 1.40875 + 0.00595T + 5.25468x10-5 T2 (R2 = 0.99998)
ΔH0m = 4.06057 + 0.01714T + 1.51461x10-5 T2 (R2 = 0.9994)
The FT-IR, FT-Raman and UV-Vis spectra of the compound ICINH had been recorded and analyzed. The detailed interpretations of the vibrational spectra had been carried out. The optimized geometrical parameters were calculated and compared with the reported XRD data. The vibrational assignments were further justified with help of the PED analysis. The HOMO-LUMO energy gap indicated the stability and reactivity of the title compound. The good correlation between the UV-Vis, absorption maxima and calculated electronic absorption maxima were found. The donor-acceptor interaction, as obtained from NBO analysis could fairly explains the decrease of occupancies of σ bonding orbital and the increase of occupancy of π* anti-bonding orbitals. In addition, mulliken atomic charges, MEP, Thermodynamic parameters, first order hyperpolarizabilities and dipole moment of the title compound were also calculated.