Structural And Spectroscopic (FT-IR, FT-RAMAN, NMR UV-VIS) …adalyajournal.com/gallery/55-jan-2575.pdf · 2020-03-26 · techniques using a semi empirical method PM6, which is proven

Structural And Spectroscopic (FT-IR, FT-RAMAN,

NMR UV-VIS) Investigations On 3-Benzoyloxy 4-

Methoxy Benzaldehyde Using Quantum

Computational Computational Methods

Srinivasan. M1,2, Jayasheela. K3, Prabhu. T 4, Periandy. S5

1,4,A.V.C. College [Autonomous], Mayiladuthurai, Tamil Nadu-609 305. 2 KSK College of Engineering & Technolgy,Kumbakonam , Tamil Nadu-612 702

3,5,Kanchi mamunivar Cener for post graduate Studies, Lawspet, Pondicherry-605 008.

Email: [email protected]

Abstract

The title molecule of 3-benzyloxy-4-methoxybenzaldehyde was characterised using FT-IR

and FT-Raman spectroscopic techniques in the range of 4000-400 cm-1 respectively. The

fundamental modes of the Vibration were assigned and the UV visible spectrum of the analysis

of is work done by using. The modes of 3-benzyloxy-4-methoxybenzaldehyde vibrations are

found in the sharp region. To calculate the Gaussian function B3LYP method with 6-311++G (d,

p) basis set. The delocalization of the electron and the corresponding attraction between orbital

are analysed by Natural Bond Orbital (NBO) study and the results reveal that the lone pair

transition has higher stabilization energy correlate to all another atoms. The 1H and 13C NMR

chemical shifts are calculated using the Gauge-Including Atomic Orbital (GIAO) method with

B3LYP/6-311++G (d, p) method. There is well agreement found in the computational and

experimental chemical shifts of the atoms. A molecules work on the electronic and optical

properties; absorption wavelengths, excitation 3-benzyloxy-4-methoxybenzaldehyde energy and

frontier molecular orbital energies and Molecular electrostatic potential (MEP) exhibit the high

reactivity nature of the molecule.

Key words: 3-benzyloxy-4-methoxybenzaldehyde; DFT; vibrational spectra; chemical

shifts; NBO.

ADALYA JOURNAL

Volume 9, Issue 1, January 2020 565

ISSN NO: 1301-2746

http://adalyajournal.com/

1. INTRODUCTION:

Vanillin is the phenolic aldehyde with functional groups aldehyde, ether and phenol. It is

an aromatic solid present in the extracts and essential oils of many plants [1]. synthetic vanillin is

used as a flavouring agent in foods,beverages, and pharmaceuticals. Ortho-vanillin is a fibrous,

light-yellow, crystalline solid. It is a weak inhibitor of proteintyrosinase [2] and displays both

anti mutagenic aqnd co-mutagenic properties in a Escherichia coli. O-vanillin and 2-

hydroxybenzaldehyde [3] has been extensively used as precursor to produce courmarin

derivatives and neolignan derivatives, which have high levels of biological activity. It is also

used to produce new azoSchiff base dyes. It possesses moderate antifungal and antibacterial

properties. Benzyl-o- vanillin (3-benzyloxy -4-methoxybenzaldehyde) [4] is prepared fromthe

reaction of o-vanillin with benzyl bromide is a acetone (solvent) and K2CO3 (base)in the group

for alcohols. This process is important in producing new materials such as antioxidants, plastic,

rubber and petroleum products. Benzyl-o-vanillin has been reported as a key factor for the

synthesis of new anticancer drugs. It exhibits and anti-0proliferative activity in HL60 leukemia

cancer cells.

To the best of our knowledge the quantum chemical analysis of the titled compound has not

reported so far. Therefore , the present investigation was undertaken to study the structural,

vibrational, UV NMR, non-linear optical and thermal properties of the title molecule using

B3LYP functional and 6-33++G(d,p) basic set.

2. METHODS

2.1. Experimental details

The compound under investigation 3-benzyloxy-4-methoxybenzaldehyde was purchased

in the powder form from Sigma-Aldrich chemicals company, USA. The FT-Raman spectrum of

3-benzyloxy-4-methoxybenzaldehyde was recorded at in the region 400-4000 cm-1 of wavelength

using Nd-YAG laser at 1064 nm. The sample was prepared using KBr pellet technique because

of solid state can be recorded in the region 400-4000 cm-1 using IFS 66V spectrophotometer. The

(DMSO) di-methyl sulphoxide solvent for dissolved in very begins of liquid phase using NMR

ADALYA JOURNAL


ISSN NO: 1301-2746


spectrum was recorded in the range of 20-200 ppm with the scanning interval of 20 ppm and

UV-Visible spectrum was recorded in the range of 200-400 nm, with the scanning interval of

0.2nm, using the UV-1700 series instrument.

2.2. Computational details:

All calculations of the title molecule were carried out at the ground state by using

Gaussian 09 software [5], with DFT/ B3LYP method and 6-311++G(d,p) basis set. The

visualizations of the optimized geometry was performed through Gauss view [6]. The geometry

corresponding to the real minimum has been obtained by the potential energy surface (PES)

technique.The 1H and 13C Chemical shifts for the molecule were calculated for ground state by

GIAO method in combination with B3LYP/6-311++G(d,p) methods. The calculated wave

numbers are scaled by a scaling factor of 0.961. The wave numbers were assigned using

potential energy distribution (PED) values predicted using VEDA program [7].In addition

Molecular electrostatic potential, Mullikan and natural charge analysis were carried out with

same method and basis set. The UV-Visible spectral transition or the electronic transitions,

HOMO-LUMO excitation energies and oscillator strength were calculated using time-dependent

TD-SCF-B3LYP method.

3. RESULT AND DISCUSSION:

3.1. Conformational analysis

The optimized molecular structure of 3-benzyloxy-4-mthoxybenzaldehyde molecule was

used for conformational analysis, which was performed by potential energy surface scan

techniques using a semi empirical method PM6, which is proven to be much efficient and

quicker [8] than B3LYP, by varying the dihedral angle 23C-22O-1C-6C in the steps of 100 over

one complete rotation. The graphical result, total energy (Hartree) verses scan coordinates of the

conformer, is presented in Fig 3.1. The graph clearly shows that there are three conformers at

minimum energy levels one at -60 the second at the 1830 and the third at 2830 respectively. All

the minimum energy level has the different value of energies 0.0103431, 0.0106398 and

0.0127815 Hartree respectively. These conformers are structurally identical, serve as the most

stable conformer of the compound. The maximum energy is observed for the conformer at -

ADALYA JOURNAL


ISSN NO: 1301-2746


76.7510,1030 and 2530 with different energy values are 0.0127851, 0.0137345, 0.0137223

Hartree respectively, this is the least stable or most unstable conformer of the compound. One of

the most stable conformer is used for all the computational analysis in the present work.

-100 -50 0 50 100 150 200 250 300

0.0100

0.0105

0.0110

0.0115

0.0120

0.0125

0.0130

0.0135

0.0140To

tal E

nerg

y (H

artre

e)

scan co-ordinate (23C 22O-1C-6C)

Fig: 3.1 Conformational analysis of 3-Benzyloxy -4-methoxybenzadehyde

3.2 structural analysis:

The structural analysis of 3-benzoyloxy 4-methoxybenzaldehyde was carried out using

B3LPY functional and 6-311++G (d,p) basis set for the compound. The bond lengths and the

bond angles are calculated using this method and the values are presented in Table.1.The

graphical representation of the molecular structure at optimised condition is shown Fig 3.2.

The bond length for C-C single bond and the C-C double bond are expected to be around

1.46Å and 1.35Å respectively [9].In this molecule, there are two benzene rings, the bond length

for CC bonds in both benzene ring are observed to be between 1.38 -1.41 Å. This shows that the

bonds are neither single bonded nor double bonded, which is an expected pattern, as these carbon

atoms are in hexagonal ring, the charges among them will be uniformly distributed or shared

among them equally. This phenomenon is known as conjugation. Hence, the bond lengths are

supposed to be equal, but here, there is a slight variation in bond lengths among them, which

may be due to the other substitution groups in the molecule. These substitutions have slightly

altered the distribution of charge around the atoms to which they are attached, which either

ADALYA JOURNAL


ISSN NO: 1301-2746


lengthened or shortened the bond lengths. These variations are mainly due to the Oxygen atoms

in the substitution groups to the benzene ring. Being a highly electronegative atom, oxygen has

the tendency to attract the shared pair of electrons from the carbon atoms. The bond length of the

CC bond [9] outside the benzene ring outer ring is found as 1.47Å and 1.50Å, closer to that of

the single bond, which is in good agreement with the experimental result. The variation in these

bond lengths is also due to the presence of same O atoms in substitution group.

The bond length for C-H is calculated experimentally as 1.08 Å. For this molecule, most

of the bond lengths for C-H are in the expected range. C10-H26, C10-H27 and C18-H20, C18-

H21 bonds have the bond length of 1.09Å. It is slightly higher than the expected value. The

bond length of C17-H24 is the highest value among the CH values, which may due to the fact

that C17 is also bonded with O atom on the other side through a double bond, which would have

made C17 little positive, thus the positive – positive repulsion between C & H would have

lengthened the bond.

The bond length for C-O single bond is expected to be around 1.43Å.[10] There are four

CO single bonded and one CO double bonded in this molecule. The theoretical calculations

predict the bond length of C-O single bond values between 1.356Å to 1.447 Å. The deviation in

bond length values is seemingly high, which is due to the other attached atoms with this group.

The variation in the attached group creates a proportional variation in bond lengths, being

relatively highly electronegative, the variation becomes prominent. The bond length for CO

double bond has the value 1.213Å, which lies within the expected limits.

The bond angles around C atoms are expected to either 120o or 109o due to the

hybridization SP2 or SP3 respectively. But in the present molecule, most of the bond angles,

except a few, are found to deviate from these expected values. These deviations are also due to

the fact that the conjugations inside and outside the rings are disturbed due to the presence of O

atoms. In the benzene ring most of the CCC bond angles are having good agreement with the

experimental value. Whereas, CCC bond angles formed out of the ring is having much deviation.

The bond angles of CCO are given in the range of 116.03Å to 124.365Å. [11] This variation is

obviously due to the bonding of Oxygen atom to the ring. All the CCH angles outside the ring

are in the range of 119.3Å - 120.67Å, which shows a small deviation.

ADALYA JOURNAL


ISSN NO: 1301-2746


Fig: 3.2 Molecule of 3-Benzyloxy -4-methoxybenzadehyde

Table. 1.

Optimized Geometrical parameter for 3-benzoyloxy -4-methoxybenzaldehyde Computed at

B3LYP/6-311++G(d,p).

Bond

Length

(Å)

B3LYP

Bond Angle (°)

B3LYP

6-311++G

(d,p)

6-311++G

(d,p)

Benzene ring (CC) Benzene ring (CCC)

C1-C2 1.4019 C1-C2-C3 121.2133

C2-C3 1.3856 C2-C3-C4 119.2506

ADALYA JOURNAL


ISSN NO: 1301-2746


C3-C4 1.4144 C3-C4-C5 119.6015

C4-C5 1.4016 C4-C5-C6 120.3435

C5-C6 1.3886 C2-C1-C6 119.1991

C1-C6 1.3975 C1-C6-C5 120.3846

C11-C12 1.3959 C11-C12-C13 120.641

C12-C13 1.3953 C12-C13-C14 119.9813

C13-C14 1.3923 C13-C14-C15 119.7364

C14-C15 1.3961 C14-C15-C16 120.166

C15-C16 1.3914 C11-C16-C15 120.4665

C11-C16 1.3996 Out of ring (CCC)

Out of Ring (CC) C10-C11-C12 120.8301

C1-C17 1.4745 C10-C11-C16 120.162

C10-C11 1.5044 C12-C11-C16 119.006

(CO) Ring C6-C1-C17 121.0975

C3-O7 1.3711 C2-C1-C17 119.7033

C4-O8 1.3565 Out of ring (CCO)

O7-C10 1.4475 C2-C3-O7 119.4264

O8-C18 1.426 C4-C3-O7 121.1928

O9-C17 1.213 C3-C4-O8 116.0315

(CH) ring C5-C4-O8 124.365

C2-H25 1.0853 C3-O7-C10 115.8881

ADALYA JOURNAL


ISSN NO: 1301-2746


C5-H22 1.0817 C4-O8C18 118.943

C6-H23 1.0834 O7-C10-C11 108.7275

C10-H26 1.0955 O7-C10-H26 108.9762

C10-H27 1.0937 O7-C10-H27 108.9493

C12-H28 1.0853 Out of ring (CCH)

C13-H29 1.0843 C1-C2-H25 120.6753

C14-H30 1.0843 C3-C2-H25 118.1074

C15-H31 1.0844 C4-C5-H22 120.1969

C16-H32 1.0843 C6-C5-H22 119.4566

C17-H24 1.111 C11-C10-H26 110.6809

C18-H19 1.0883 C11-C10-H27 110.7267

C18-H20 1.0942 H26-C10-H27 108.7436

C18-H21 1.0944 C11-C12-H28 119.6097

C1-C6-H23 118.9741

C5-C6-H23 120.6404

C13-C12-H28 119.7492

C12-C13-H29 119.8603

C14-C13-H29 120.1571

C13-C14-H30 120.1468

C15-C14-H30 120.1166

C14-C15-H31 119.9802

ADALYA JOURNAL


ISSN NO: 1301-2746


C16-C15-H31 119.8537

C11-C16-H32 119.313

C15-C16-H32 120.2172

C1-C17-O9 125.1593

C1-C17-H24 114.4827

O9-C17-H24 120.3579

O8-C18-H19 105.6459

O8-C18-H20 111.1293

O8-C18-H21 111.2949

H19-C18-H20 109.4744

C19-C18-H21 109.4631

H26-C18-H1 109.7395

3.3 Mullikan and atomic natural charge analysis

Atomic charges play an important role as they cause the dipole moment, Molecular

polarizability, electronic structure and reactivity etc at molecular level. The charges on the atoms

present in the present compound are calculated by Mullikan population analysis (MPA) and

Natural atomic charge (NAC) [14] methods using B3LYP functional and /6-311++G(d,p) basis

set. The graphical representation of the results are present in the Fig. 3.3. In case of benzene

rings, all the carbon atoms, as they are uniformly attached C and H atoms, are expected to be

equally negative because of the sharing of the electrons from H atoms. But, in the present

molecule, according to MPA prediction, the carbon atom 1C (0.944191) is found to be highly

positive and also 3C (0.117733) and 4C (0.436825) are positive in charge. Here the positive

atoms are due to the presence of oxygen in which they are attached. Now in the case of natural

charge analysis 17C seems to be negative, the logic used here may be that 17C may share some

ADALYA JOURNAL


ISSN NO: 1301-2746


of the electrons from nearby O atom. But, this is not possible as O is more electro negative,

which can only take electrons from C but cannot give.

All the H atoms in the benzene are found to be equally positive, which is expected as the

electrons in the H atoms would move closer to C atoms to which they are attached owing to

higher electro negativity of the C atoms. The Oxygen atoms are always expected to be negative

due to their ability to pull electrons from the bonded atoms. But here the one of the value is

predicted to be positive 7O (0.020084) in MPA, again the procedure followed here is not based

on the electro negativity of the atoms.

Fig: 3.3 charge analysis of 3- Benzyloxy 4-Methoxybenzaldehyde

-1

-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

0.8

1

1C 3 C 5 C 7 O 9 O 11 C 13 C 15 C 17 C 19H

21H

23H

25H

27H

29H

31H

Mulliken

Natural

ADALYA JOURNAL


ISSN NO: 1301-2746


Table. 2.

Charge 3-benzoyloxy 4-methoxybenzaldehyde of with B3LYP/6-311++G(d,p) basis set.

Atoms B3LYP/6-311++G(d,p)

Mullikan Charge Natural Charge

1 C 0.944191 -0.15262

2 C -0.85056 -0.19411

3 C 0.117733 0.27599

4 C 0.436825 0.27389

5 C -0.61582 -0.2457

6 C -0.0857 -0.15784

7 O 0.020084 -0.55137

8 O -0.05747 -0.57404

9 O -0.232 -0.54691

10 C -0.66012 -0.05252

11 C 0.115904 -0.03866

12 C -0.2264 -0.18999

13 C -0.13722 -0.19577

14 C -0.32981 -0.20116

15 C -0.13059 -0.19638

16 C -0.16587 -0.19073

17 C -0.10647 0.41737

18 C -0.30819 -0.18851

19 H 0.153748 0.18894

20 H 0.169433 0.17383

21 H 0.149985 0.16112

22 H 0.121052 0.21142

ADALYA JOURNAL


ISSN NO: 1301-2746


23 H 0.203369 0.22958

24 H 0.163062 0.12959

25 H 0.173627 0.22255

26 H 0.15276 0.16276

27 H 0.189609 0.22536

28 H 0.164212 0.20145

29 H 0.16338 0.20035

30 H 0.154795 0.20114

31 H 0.165657 0.20028

32 H 0.146772 0.20071

3.4 NMR Assessment

The 1H and 13C chemical shift calculations for the compound 3-benzoyloxy 4-

methoxy benzaldehyde was made by gauge independent atomic orbital (GIAO) theory in

combination with B3LYP method using 6-311+G(d,p) basic set in gas phase and CdCl3 solvent

phase. The calculated 1H and 13C NMR isotropic chemical shifts (ppm) of 3-benzoyloxy 4-

methoxy benzaldehyde are shown in figure 3.4[10].

The shifts are calculated for gas and CdCl3 solvent phases and also experimental

values are presented in the Table-3. The aromatic carbon atoms generally have the shifts in the

range of 100-130 ppm. All the aromatic carbon atoms in the first benzene ring agree with this

range except C3 and C4. The carbon atoms C3 and C4 receive the computed values of 155 ppm

and 164 for gas and 154 and 166 ppm for solvent phase and the experimental values are 148 and

155 ppm. These are due to O7 and O8 oxygen atoms which are directly attached with these

aromatic carbon atoms. The benzene ring aromatic carbon atoms agree with this range except

C11. The carbon atom C11 receives the computed values of 144.465 ppm for gas and 144.82

ppm for solvent phase and the experimental value is 136.33 ppm. This is due to methyl group is

directly attached with this aromatic carbon atom. [13]

ADALYA JOURNAL


ISSN NO: 1301-2746


The chemical shift of the hydrogen atoms in aromatic are found almost below 10 ppm

which shows that the chemical environment of hydrogen atoms are not affected by oxygen atom

or any carbon atoms. The hydrogen atom 24H shows the high values of 10.028 ppm

respectively is due to the presence of CO. There is no appreciable difference between computed

and experimental chemical shift. The other hydrogen atoms H19, H20, H21, H26 and H27 got

the values of below 5ppm, which identify them as aliphatic hydrogens.

Fig: 3.4 Experimental 13C spectra of 3-Benzyloxy 4-Methoxybenzaldehyde

ADALYA JOURNAL


ISSN NO: 1301-2746


Fig: 3.5 Experimental 1Hspectra of 3-Benzyloxy-4-Methoxybenzaldehyde

Table. 3.

Calculated 1H and 13 C NMR Chemical shifts (ppm) 3-Benzyloxy-4-Methoxybenzaldehyde

Atom

Gas

B3LYP/6-

311++G(d,p)GIAO

(ppm)

CDCl3

B3LYP/6-

311++G(2d,p)GIAO

(ppm)

Experimental

1C 135.769 134.85 130.01

2C 134.07 134.77 128.66

3C 155.212 154.54 148.72

4C 164.952 166.77 155.07

5C 113.557 115.70 110.82

6C 128.983 128.94 110.82

10C 78.688 78.24 77.44

11C 144.465 144.82 136.33

12C 133.688 133.49 128.14

13C 132.267 132.93 111.41

14C 133.00 133.49 126.89

ADALYA JOURNAL


ISSN NO: 1301-2746


15C 133.213 133.52 127.57

16C 135.578 134.98 130.01

17C 192.741 196.63 190.82

18C 55.271 56.07 56.19

19H 4.288 4.44 5.175

20H 3.753 3.92 2.950

21H 3.770 3.97 2.870

22H 6.852 7.20 6.988

23H 8.096 8.124 7.447

24H 10.028 9.98 9.805

25H 7.476 7.65 7.323

26H 4.171 4.377 3.938

27H 5.561 5.561 6.967

28H 7.360 7.580 7.306

29H 7.458 7.650 7.353

30H 7.504 7.680 7.370

31H 7.638 7.809 7.388

32H 8.230 8.265 7.460

3.5 VIBRATIONAL ANALYSIS:

The title molecule under investigation has 35 numbers of atoms and 99 normal modes of

fundamental vibrations, which can be distributed using the irreducible representations as 67A.

All the 99 fundamental vibrations are active both in IR and Raman. The assignments of all the

fundamentals have been made on the basis of PED values along with the comparison of available

literature on the structurally similar molecules .the calculated wave numbers are found slightly

ADALYA JOURNAL


ISSN NO: 1301-2746


higher than the observed values for the majority the normal modes. Two factors may be

responsible for the discrepancies between the experimental and computed wave numbers; the

first is caused by the unpredictable electronic distribution among the different bonds in the

molecule and the second reason is the harmonic nature of the vibrations which cannot be

accounted completely by theory. Scaling strategies were used to bring computed wave numbers

coincide with observed values. In this study, the scaling factors used is 0.9026 as advised by the

earlier work intensities [19], reduced mass and force constants along with the wave numbers and

assignment are presented in Table.2. The experimental FT-IR andFT- Raman spectra are Predict

in table 4. and the Experimental spectral regions are also shown in Fig. 3.6.

C-H Vibrations

In the aromatic compounds, the C-H stretching normally occurs in the region of 3100-3000

cm-1 [12]. For the title molecule stretching vibrations of benzene rings are observed at 3065,

3062, 3060, 3034, 3013, 2950, 2921, 2840 and 2763 cm-1 at IR region and 3090, 3080, 3072,

3058 and 2990 cm-1 in FT-Raman region. Theoretically, the CH stretching vibrations are

observed at 3094 -2790 cm-1 respectively. All the aromatic C-H stretch mode are pure

stretching modes as it is evident from PED column in table 2.

Normally the strongest absorptions for aromatic compounds occur in the region 1300-

1000 cm-1 and 1000-750 cm-1 due to the CH in-plane and out of plane vibrations respectively

[13]. In the title compound, the in-plane bending vibrations are found at 1196, 1157, 1133, 1130,

1030 and 990 cm-1 at IR region and 1209, 1189, 1168, 1140,1090, 1020 and 996 cm-1 at FT-

Raman. Theoretically, the CH stretching vibrations are observed at 1205 - 985 cm-1 respectively.

In the compound entire vibrations observed at middle of the expected region. In the compound

ADALYA JOURNAL


ISSN NO: 1301-2746


the out of plane bending vibrations found at 865 , 813, 747 729, 654 and 589 cm-1 at IR region

and 910, 898, 850, 830, 780, 760, 688 and 615 cm-1 at Raman region. In the compound entire

vibration observed at middle of the expected regions.

C-C Vibration:

The ring stretching vibrations are very much important in the spectrum of benzene and its

derivatives are highly characteristic of the aromatic ring itself. The bands between 1600-1400

cm-1 in benzene derivatives are usually assigned to C=C stretching modes 1600-1500 cm-1 [14-

17] and C-C stretching modes 1500-1400 cm-1 [18]. The title compound CC stretching vibrations

are observed at 1676, 1584, 1570, 1464, 1424 and 1347 cm-1 in FT-IR Spectrum and 1550, 1481,

1463, 1446, 1440, 1399, 1370 and 1318 cm-1 in FT-Raman. Theoretically, the CC stretching

vibrations are observed at 1592 - 1313 cm-1 respectively. In addition, CCC in-plane and Out of

plane bending vibration are observed at 400, 399, 370, 340, 318, 285, 255, 207 and 190 cm-1 in

FT-Raman. Other assignments are in good agreement with the literature.

C-O Vibrations

As per the previous literatures, the C=O stretch of carboxylic acids is identical to the

C=O stretch in ketones, which is expected in the region 1740–1660 cm−1 and C-O single bond is

expected in the region 1220-970 cm−1 [19]. In this present work, the C=O asymmetric stretching

is assigned at1727 cm-1 (FTIR) with strong intensity. Similarly, the strong intensity peak at 1615

cm-1 (FTIR) and very strong peak at 1608 cm-1 (FT-Raman) is assigned to the symmetric C=O

stretching vibration. The variation in expected frequencies shows the effect of substituents.

Theoretically, the C=O stretching vibrations are observed at 1705 cm-1 respectively. The C-O

stretching vibrations are assigned to the weak FT-IR peaks at 1263 and 1236 cm-1 & FT-Raman

ADALYA JOURNAL


ISSN NO: 1301-2746


peak at 1305 and 1289 cm-1. Theoretically, the C-O stretching vibrations are observed at 1298 -

1232 cm-1 respectively. The in-plane bending vibrations of CO are assigned at 977, 968, 958,

956 and 948 cm-1 (FT-Raman) frequencies. The CO out of plane bending vibrations are assigned

to the band at 560, 485 and 422 cm-1 (FTIR), 588 cm-1 (FT-Raman).

ADALYA JOURNAL


ISSN NO: 1301-2746


Fig: 3.6 Experimental FT-RAMAN, FT-IR of 3-Benzyloxy-4-Methoxybenzaldehyde

Fig. 5.

Table. 4

Observed method DFT/B3LYP with 6-311++G(d,p) level calculated vibrational frequencies

of 4-Benzyloxy-3-Methoxybenzaldihyde

Experimental

frequency

cm-1

B3LYP

Assignment

VEDA %

6-311++G(d, p)

FT-IR FT-

RAMAN

Un scaled

(cm-1)

Scaled

(cm-1)

3090 3199 3094 ν CH ν CH 99 3080 3190 3084 ν CH ν CH 91 3072 3183 3078 ν CH ν CH 88



2990 3099 2988

.988

ν CH ν CH 91 2950 3087 2985

.439

ν CH ν CH 95 2921 3020 2921 ν CH ν CH 18 2840 3018 2918 ν CH ν CH 72 2763 2885 2790 ν CH ν CH 78 1727 1763 1705 ν CO ν CO 88

P8-

Name Description

4000 4003500 3000 2500 2000 1500 1000 500

100

0

10

20

30

40

50

60

70

80

90

cm-1

%T

1263.17cm-1

1676.20cm-1 1133.60cm-1

1236.10cm-1

1584.84cm-1

990.85cm-11505.34cm-1

1464.91cm-1

1157.45cm-1

1424.39cm-1

1398.77cm-1

1 3 8 6 . 4 7 c m - 1

1030.66cm-1

1196.39cm-17 2 9 . 6 4 c m - 1

747.43cm-1

698.79cm-1

813.71cm-1

865.36cm-12840.07cm-1 654.81cm-1

920.32cm-1

560.50cm-1

2950.06cm-1

2763.37cm-13013.31cm-1

589.23cm-11347.89cm-1

3034.59cm-1

3060.82cm-1

2 8 8 6 . 1 2 c m - 1

2921.11cm-1

530.99cm-1

2694.87cm-1

2613.62cm-1

2586.29cm-1

485.93cm-11972.50cm-1

3331.31cm-1 1989.53cm-12558.66cm-1

1869.52cm-1

2467.57cm-1 463.83cm-11727.23cm-1

2396.76cm-1

2228.93cm-1

2267.43cm-1

2096.44cm-1

3180.03cm-1

2056.70cm-1

2158.72cm-1

2305.00cm-1

2353.64cm-1

2122.55cm-1 1891.66cm-1

1933.27cm-1

1819.86cm-1

422.69cm-1

3653.39cm-1 1770.19cm-1

3864.91cm-1

3943.20cm-1

ADALYA JOURNAL


ISSN NO: 1301-2746


1676 1646 1592 ν CC ν CC 14 1584 1635 1581 ν CC ν CC 58 1570 1626 1572

59

ν CC ν CC 19 1550 1599 1546 ν CC ν CC 68 1481 1523 1473 ν CC ν CC 89

1464 1517 1467 ν CC ν CC 58 1463 1507 1458 ν CC ν CC 58 + β CCH 10 1446 1490 1441 ν CC γ CHO 32+ β CCH 15

1440 1484 1435 ν CC ν CC 32+β CHO 28 1424 1480 1431 ν CC ν CC 33+ ν CHO 20

1399 1443 1395 ν CC ν CC 10 1370 1410 1364 ν CC ν CC 11

1347 1395 1349 ν CC ν CC 16 1318 1358 1313 ν CC ν CC 18 1305 1342 1298 ν CO ν CO 58 1289 1325 1282 ν CO ν CO 47

1263 1294 1251 ν CO ν CO 56

1236 1274 1232 ν CO ν CO 85

1209 1246 1205 β CH β CH 45 1196 1236 1195 β CH β CO 14+ β HCC 19

1189 1228 1187 β CH β CO 14+ β HCC 19

1168 1203 1163 β CH β CHO 73+ γ CHO 19

1157 1202 1162 β CH CO 14+ β HCC 19

1140 1182 1143 β CH β CHO 73+ γ CHO 19

1133 1170 1131 β CH ν CC 33+ β CHO 20

1130 1167 1128 β CH β CHO 73+ γ CHO 19

1090 1119 1082 β CH ν CO 14+ β HCC 19

1030 1109 1072 β CH β CHO 73+ ν CCC 33

1020 1049 1015 β CH τ HCCH 27

996 1032 998 β CH τ HCCH 26

990 1026 992 β CH τ HCCH 32

986 1018 985 β CH τ HCCH 72

9775 1003 970 β CO τ HCCH 85

968 994 962 β CO τ CCOC 27

958 989 956 β CO τ CCCO 36

956 985 952 β CO τ COCH 79

948 973 941 β CO τ CCCO 28

910 939 908 γ CH τ HCCH 36

898 926 896 γ CH τ HCCH 28

865 907 877 γ CH τ HCCH 34

850 878 849

99

γ CH τ HCCH 30

830 856 828 γ CH τ HCCH 27

813 844 816 γ CH τ HCCH 26

780 799 772 γ CH τ HCCH 32

760 782 756 γ CH τ HCCH 24+ τ CCCH 24

747 772 746 γ CH τ HCCH 29

729 745 720

59

γ CH τ HCCH 35

688 709 685 γ CH τ HCCH 25

654 668 646 γ CH τ HCCH 31

615 635 614 γ CH τ HCCH 33

ADALYA JOURNAL


ISSN NO: 1301-2746


589 620 599 γ CH τ HCCH 24

588 597 578 γ CO β CCO 45

560 581 562 γ CO β CCO 22

485 526 509 γ CO τ CCCO 18

422 443 428 γ CO τ CCCO 23

400 413 399 γ CO τ CCOC 54

399 403 390 β CCC τ CCCC 76

370 378 365 β CCC τ CCCC 18

340 349 337 β CCC τ CCCC 25

318 326 316 β CCC τ CCCC 39

285 290 280 β CCC τ CCCC 32

255 259 251 β CCC τ CCCC 13

207 213 206 β CCC τ CCCC 36

190 191 185 β CCC τ CCCC 45

170 171 165 β CCH τ CCCC 10

126 156 151 β CCH τ HCOC 59

- 115 111 β CCH β CCC 51+ β COC 76

- 99 96 β CCH β CCH01+ β COC 86

- 73 71 β CCH β CCH 81+ β COC 76

- 69 67 β CCH β CCC 51+ β COC 56

- 38 37 β CCO β CCO 28

- 21 21 β CCO β CCO 21

- 18 18 β CCO β CCO 54

ν–stretching; β–in–plane bending; δ–deformation; ρ–rocking; γ–out of plane bending; ω–

wagging and τ–torsion. IR and Raman intensities are normalized to 100.

3.6 NBO Analysis

The NBO analyses are most important method for studying the various possible donors

and acceptors in the molecule with their occupancy value in each position . similarly the

various possible transitions among these donors and acceptors are provided. The inter and

intra molecular interaction and especially charge transfer from electron donor to electron

acceptor. This overall stabilization energy from the second-order micro disturbance theory is

reported. The energy of E(2) are due to molecular interaction between the electron is high

intensive and more extent of conjugation of the hole system. The NBO occupied orbital is

Lewis-type (bond or lone pair) and unoccupied orbital is non-Lewis type (anti-bond or

Rydgberg). NBO analysis was performed on the title molecule at the B3LYP/6-311+G(d,p)

basis set level can be elucidate the molecule. The fock matrix was elucidating in the donor-

acceptor interactions in the NBO analysis.

𝐸2 = ∆𝐸𝑖𝑗 = 𝑞𝑖

𝐹(𝑖, 𝑗)2

𝐸𝑖 − 𝐸𝑗

Where qi is the donor orbital occupancy, are εi and εj diagonal; elements and F(i,j) is the

ADALYA JOURNAL


ISSN NO: 1301-2746


off diagonal NBO Fock matrix element reported.The high stabilization energy of the

transitions gives a measure of the probabilities of the transitions; which indicate the highly

probable in this molecule are C13-C14 toC12-C17(π -π*, 23.2 Kcal/mol),O22 to C 28-H32

(n-π *, 22.97 Kcal/mol), C15- C16 (π -π*, 22.61Kcal/mol), C12-C17 to C15- C16 (π -π*,

21.42 Kcal/mol), C12-C17 to C15-C16 (π -π*, 21.42Kcal/mol), C2-C3 to C4-C5 (π -π*,

21.09Kcal/mol) C2-C3, to C1-C6 (π -π *, 20.31Kcal/mol), C4-C5 to C2-C3 (π -π*,

20.23Kcal/mol), C4-C5 to C1-C6 (π -π*, 20.04Kcal/mol.

Table.5

Second order perturbation theory of Fock matrix in NBO basis of 4-Benzyloxy 3-

Methoxybenzaldehyde

Donor Type

of

bond

Occupancy

Acceptor Type

of

bond

Occupancy Energy

E(2)

kcal/mol

Energy

difference

E(j)-E(i) a.u.

Polari

zed

energy

F(i,j)

a.u.

C 13 - C 14 π 1.64022 C 12 - C 17 π* 0.36158 23.29 0.28 0.072

O 22 n 1.89906 C 28 - H 32 π * 0.04565 22.97 0.67 0.096

C 15 - C 16 π 1.61557 C 13 - C 14 π* 0.34314 22.61 0.27 0.071

C 12 - C 17 π 1.63567 C 15 - C 16 π* 0.37409 21.42 0.29 0.071

C 12 - C 17 π 1.63567 C 15 - C 16 π* 0.37409 21.42 0.29 0.071

C 2 - C 3 π 1.65874 C 4 - C 5 π* 0.34664 21.09 0.28 0.069

C 2 - C 3 π 1.65874 C 1 - C 6 π* 0.32899 20.31 0.28 0.067

C 4 - C 5 π 1.65319 C 2 - C 3 π* 0.3244 20.23 0.28 0.067

C 4 - C 5 π 1.65319 C 1 - C 6 π* 0.32899 20.04 0.28 0.067

C 1 - C 6 π 1.65841 C 4 - C 5 π* 0.34664 20.02 0.28 0.067

C 1 - C 6 π 1.65841 C 2 - C 3 π* 0.3244 19.82 0.28 0.067

C 12 - C 17 π 1.63567 C 13 - C 14 π* 0.34314 19.51 0.29 0.067

C 12 - C 17 π 1.63567 C 13 - C 14 π* 0.34314 19.51 0.29 0.067

C 15 - C 16 π 1.61557 C 12 - C 17 π* 0.36158 18.91 0.27 0.064

C 13 - C 14 π 1.64022 C 15 - C 16 π* 0.37409 18.54 0.29 0.066

O 22 n 1.89906 C 15 - C 28 π * 0.05989 16.2 0.64 0.092

ADALYA JOURNAL


ISSN NO: 1301-2746


C 15 - C 16 π 1.61557 O 22 - C 28 π* 0.09635 14.82 0.25 0.059

C 24 n 1.77408 O 23 - C 24 π * 0.02001 7.96 0.5 0.059

O 21 n 1.93239 C 12 - C 17 π * 0.02641 6.36 0.88 0.068

O 21 n 1.93239 C 29 - H 31 π * 0.02107 6.02 0.75 0.061

O 23 n 1.93622 C 13 - C 14 π * 0.02572 5.69 0.87 0.064

O 23 n 1.93622 C 12 - C 13 π * 0.04129 5.33 0.87 0.061

C 3 - H 9 σ 1.97974 C 4 - C 5 σ* 0.34664 4.66 1.1 0.064

C 3 - H 9 σ 1.97974 C 4 - C 5 σ * 0.34664 4.65 1.1 0.064

C 5 - H 10 σ 1.97983 C 3 - C 4 σ * 0.02284 4.65 1.1 0.064

C 16 - H 19 σ 1.97862 C 14 - C 15 σ * 0.01958 4.61 1.09 0.063

C 14 - C 15 σ 1.97251 C 13 - O 23 σ * 0.03191 4.58 0.98 0.058

C 5 - H 10 σ 1.97983 C 3 - C 4 σ * 0.02284 4.47 1.1 0.064

C 14 - H 18 σ 1.97529 C 15 - C 16 σ * 0.02156 4.36 1.1 0.063

C 16 - C 17 σ 1.97398 C 12 - O 21 σ * 0.03146 4.23 0.98 0.059

C 24 - H 26 σ 1.77512 C 13 - O 23 σ * 0.03191 4.16 0.79 0.057

C 17 - H 20 σ 1.97755 C 12 - C 13 σ * 0.04129 4.06 1.08 0.059

O 21 N 1.93239 C 29 - H 30 π * 0.02155 4.06 0.76 0.05

O 23 N 1.96489 C 13 - C 14 π* 0.34314 3.81 0.62 0.047

C 13 - C 14 σ 1.97401 C 12 - O 21 σ * 0.03146 3.77 1 0.055

C 1 - H 7 σ 1.98083 C 5 - C 6 σ * 0.01514 3.73 1.09 0.057

C 1 - H 7 σ 1.98083 C 2 - C 3 σ * 0.01512 3.72 1.09 0.057

C 2 - C 3 σ 1.97881 C 4 - C 29 σ * 0.0251 3.65 1.08 0.056

C 5 - C 6 σ 1.97885 C 4 - C 29 σ * 0.0251 3.64 1.08 0.056

C 6 - H 11 σ 1.98126 C 1 - C 2 σ * 0.01568 3.64 1.09 0.056

C 5 - C 6 σ 1.97885 C 4 - C 29 σ * 0.0251 3.64 1.08 0.056

C 6 - H 11 σ 1.98126 C 1 - C 2 σ * 0.01568 3.64 1.09 0.056

C 2 - H 8 σ 1.98127 C 1 - C 6 σ * 0.01565 3.63 1.09 0.056

C 16 - H 19 σ 1.97862 C 12 - C 17 σ * 0.02641 3.53 1.07 0.055

C 12 - C 17 σ 1.97645 C 12 - C 13 σ * 0.04129 3.52 1.26 0.06

C 12 - C 17 σ 1.97645 C 12 - C 13 σ * 0.04129 3.52 1.26 0.06

ADALYA JOURNAL


ISSN NO: 1301-2746


C 5 - H 10 σ 1.97983 C 1 - C 6 σ * 0.01565 3.51 1.09 0.055

C 5 - H 10 σ 1.97983 C 1 - C 6 σ * 0.01565 3.51 1.09 0.055

C 15 - C 16 σ 1.97648 C 14 - C 15 σ * 0.01958 3.48 1.27 0.059

C 2 - H 8 σ 1.98127 C 3 - C 4 σ * 0.02284 3.47 1.1 0.055

C 6 - H 11 σ 1.98126 C 4 - C 5 σ * 0.34664 3.47 1.1 0.055

C 6 - H 11 σ 1.98126 C 4 - C 5 σ * 0.34664 3.47 1.1 0.055

C 13 - C 14 σ 1.97401 C 12 - C 13 σ * 0.04129 3.46 1.26 0.059

C 13 - C 14 σ 1.97401 C 12 - C 13 σ * 0.04129 3.46 1.26 0.059

C 16 - C 17 σ 1.97398 C 15 - C 28 σ * 0.05989 3.45 1.08 0.055

C 3 - C 4 σ 1.97581 C 4 - C 5 σ * 0.34664 3.38 1.27 0.058

C 4 - C 5 σ 1.97596 C 3 - C 4 σ * 0.02284 3.37 1.27 0.058

C 17 - H 20 σ 1.97755 C 15 - C 16 σ * 0.02156 3.33 1.1 0.054

C 12 - C 13 σ 1.97794 C 13 - C 14 σ * 0.02572 3.29 1.28 0.058

C 12 - C 13 σ 1.97794 C 13 - C 14 σ * 0.02572 3.29 1.28 0.058

C 29 - H 30 σ 1.98713 C 4 - C 5 σ * 0.02286 3.26 1.1 0.054

C 29 - H 31 σ 1.98621 C 3 - C 4 σ * 0.02284 3.24 1.1 0.054

C 12 - C 13 σ 1.97794 C 12 - C 17 σ * 0.02641 3.24 1.28 0.058

C 12 - C 13 σ 1.97794 C 12 - C 17 σ * 0.02641 3.24 1.28 0.058

C 5 - C 6 σ 1.97885 C 4 - C 5 σ * 0.34664 3.14 1.27 0.056

C 5 - C 6 σ 1.97885 C 4 - C 5 σ * 0.34664 3.14 1.27 0.056

C 2 - C 3 σ 1.97881 C 3 - C 4 σ * 0.02284 3.13 1.27 0.056

O 21 σ 1.94844 C 12 - C 17 π* 0.36158 3.9 0.59 0.047

C 14 - H 18 σ 1.97529 C 12 - C 13 σ * 0.04129 3.9 1.08 0.058

C 12 - C 17 σ 1.97645 C 13 - O 23 σ * 0.03191 3.8 0.99 0.055

C 12 - C 17 σ 1.97645 C 13 - O 23 σ * 0.03191 3.8 0.99 0.055

O 22 - C 28 σ 1.9812 C 15 - C 16 π* 0.37409 3.7 0.39 0.037

C 14 - C 15 σ 1.97251 C 15 - C 16 σ * 0.02156 3.5 1.27 0.06

C 13 - C 14 σ 1.97401 C 15 - C 28 σ * 0.05989 3.04 1.09 0.052

C 13 - C 14 σ 1.97401 C 15 - C 28 σ * 0.05989 3.04 1.09 0.052

C 13 - C 14 σ 1.97401 C 14 - C 15 σ * 0.01958 2.99 1.28 0.055

ADALYA JOURNAL


ISSN NO: 1301-2746


C 13 - C 14 σ 1.97401 C 14 - C 15 σ * 0.01958 2.99 1.28 0.055

3.7 UV-Vis Analysis

Ultraviolet spectra analyses of 4-benzeloxy-3-methoxybenzaldhyde have been

investigated by theoretical calculation. Maximum Absorption for a lower lying singlet states

of the molecule have been calculated by TD-DFT\B3LYP method. The calculated absorption

maxima of λ, oscillator strength and excitation energies are reported in table 4. Calculation of

the molecular orbital geometry show that the absorption maxima of this molecule correspond

to the an electron transition between frontier orbitals such as translation from HOMO to

LUMO. The calculated absorption maximum values of the found to be 335.38, 279.94,

264.95, 256.33, 254.41, 248.95, 234.31, 227.47, 225.47, 217.16 nm for gas phase, 323.70,

288.35, 273.60, 265.49, 262.14, 256.18, 233.97, 224.17, 221.30, 219.21 nm for ethanol

solution at DFT/B3LYP/6-311++G(d,p) method. As can be seen, calculations were

performed at ethanol solution is very close to each other when compared with the gas phase.

The major contributions of the transitions were designated with the aid of SWizard

Program. In view of calculated absorptions spectra, the maximum absorption wavelength

corresponds to the electronic transition from the HOMO to LUMO+1 with 86% contribution

and from HOMO to LUMO 76% contribution. The other wavelength, excitation energies,

oscillator strength and calculated counterparts with major contributions can be seen in table

3.7.

Table.6

Theoretical electronic absorption spectra of 4-Benzyloxy 3-

Methoxybenzaldehyde absorption wavelength λ (nm), excitation energies E (ev) and

oscillator strengths (f) using TD-DFT/ B3LYP/6-311++G(d,p) method.

λ (nm)

E(eV) (f) Major contribution Theoretical

Gas

Experimental

335.38 3.6969 0.0002 H-2->LUMO (22%)

279.94 4.4290 0.3089 H->LUMO (99%)

264.95 4.6795 0.1539 H-4->LUMO (19%)

ADALYA JOURNAL


ISSN NO: 1301-2746


256.33 4.8370 0.0188 H-3->LUMO (83%)

254.41 4.8733 0.0761 H-4->LUMO (38%)

248.95 4.9803 0.0161 H-5->LUMO (80%)

234.31 5.2915 0.0010 H-3->L+1 (35%)

227.47 5.4505 0.0312 HOMO->L+1 (86%)

225.47 5.4988 0.0049 H-2->L+2 (10%)

217.16 5.7094 0.2693 H-4->LUMO (14%)

Ethanol

323.70 3.8302 0.0004 H-4->LUMO (69%)

288.35 277.4 4.2998 0.2902 HOMO->LUMO (76%)

273.60 4.5316 0.1427 H-3->LUMO (13%)

265.49 4.6700 0.0105 H-2->LUMO (91%)

262.14 4.7297 0.1346 H-3->LUMO (48%)

256.18 4.8397 0.0476 H-5->LUMO (79%)

233.97 5.2991 0.0018 H-2->L+1 (23%)

224.17 5.5308 0.0954 HOMO->L+1 (77%)

221.30 5.6025 0.0395 H-6->LUMO (95%)

219.21 5.6560 0.1469 HOMO->L+2 (63%)

ADALYA JOURNAL


ISSN NO: 1301-2746


Fig: 3.7 UV-Visible experimental spectrum of 4-benziloxy 3-methoxy benzaldehyde

Fig:3.8 UV-Visible theoretical spectrum of 4-benziloxy 3-methoxybenzaldehyde

3.8 Homo- Lumo Analysis

Frontier molecular orbital (FMO) theory explains the stability of a molecular orbital, the

distribution of charges at various ground and virtual states and the energy gap between them [20].

The highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO)

are the important molecular orbitals in FMO. These orbitals play a major role in governing many

chemical reactions and determining electronic band gaps in solids; they are also responsible for the

formation of many charge-transfer complexes. The HOMO energy represents the ability of electron

giving; LUMO represents the ability of electron accepting [21]; and the energy gap between HOMO

and LUMO determines molecular electrical transport properties, chemical reactivity, electrophilic

index, hardness and softness of the molecule [22].

Electronegativity (χ) is a measure of the power of an atom or a group of an atom to

attract electrons which can be mathematically calculated from the formula,

𝜒 = −1

2(𝐸𝐻𝑂𝑀𝑂 + 𝐸𝐿𝑈𝑀𝑂)

χ can be calculated by substituting the values of energy of the HOMO and LUMO calculated

theoretically.

Global hardness (η) is a measure the resistance of an atom to transfer the charges and

it is given by

𝜂 = −1

2(𝐸𝐻𝑂𝑀𝑂 − 𝐸𝐿𝑈𝑀𝑂)

ADALYA JOURNAL


ISSN NO: 1301-2746


The global softness (S) describes the capacity of an atom or a group of atoms to

receive electrons and is the reciprocal of global hardness.

𝑠 =1

𝜂= −2(𝐸𝐻𝑂𝑀𝑂 − 𝐸𝐿𝑈𝑀𝑂)

The global electrophilicity index (ω) can be calculated from the electronegativity and

chemical hardness using the relation

𝜔 =𝜒2

2𝜂

The energies of highest occupied molecular orbitals (HOMO) and lowest unoccupied

molecular orbitals (LUMO) are computed with B3LYP function with 6-311++ G (d, p) basis

set and the pictorial diagram of the HOMO and LUMO is shown in Fig.3.9 . The HOMO-

LUMO energy gap and different reactivity descriptors of molecule in both levels are

presented in Table 7.

According to the computed results, 4-benzoyloxy 3-methoxybenzaldehyde contains

50 occupied molecular orbitals and 50 unoccupied molecular orbitals. The calculated energy

of the HOMO is -0.25675 eV and that of LUMO is -0.08040 eV. The energy gap between

them for optimized structure is -0.17635eV, which shows the possibility of flow of energy

form HOMO to LUMO. The electronegativity is a measure of attraction of an atom for

electrons in a covalent bond which has been found to be 0.16857. The global hardness is a

measure the resistance of an atom or a group of atoms to receive electrons and is equal to

reciprocal of global hardness and it is found to be 0.08817. The global softness describes the

capacity of an atom or a group of atoms to receive electrons and is equal to reciprocal of

global hardness and it is found to be 0.3527. The electrophilicity index is a measure of

lowering of total energy due to the maximal electron flow between the donors and the

acceptors and it is found to be 0.16110. The dipole moment transitions value is 4.4276.

Fig: 3.9 Frontier molecular orbital of 4-benziloxy 3-methoxybenzaldehyde

LUMO HOMO

ADALYA JOURNAL


ISSN NO: 1301-2746


Table: 7

HOMO, LUMO ,global, electronegativity, global hardness and softness, global

electrophilicity index of B3LYP/6-311++G (d,p).

Parameters

Gas

EHOMO (eV) -0.2567

ELUMO (eV) -0.0804

∆EHOMO-LUMO gap (eV) -0.1763

Elecronegativity (χ)(eV) 0.1685

Global hardness (η)(eV) 0.0881

Global softness (S) (eV) 0.3527

Electrophilicity (𝜔) (eV) 0.1611

Dipole moment (debye) 4.4276

3.9 MEP (MOLECULAR ELECTROSTATIC POTENTIAL) ANALYSIS

To investigate reactive sites for electrophilic and nucleophilic attack,[23-25] the

MEP surfaces for was plotted by DFT calculations over optimized geometries at the B3LYP

level of theory. A MEP surface is an electron density isosurface mapped with an electrostatic

potential surface. The MEP surfaces for the compound scan be used to determine their sizes,

shapes, charge densities and reactive site three dimension. Different values of electrostatic

potential at the surfaces are represented by different colours; red represents regions of most

negative electrostatic potential, blue represents regions of most positive electrostatic potential

and green represents regions close to zero electrostatic potential

The electrostatic potential increases in the order red < orange < yellow < green < blue.

[26-28] The color code of these maps is in the range between -5.210 e-2 (deepest red) to

+5.210 e-2 (deepest blue) in compound, where blue indicates the strongest attraction and red

indicates the strongest repulsion. Regions of negative V(r) are usually associated with the

ADALYA JOURNAL


ISSN NO: 1301-2746


lone pair of electronegative atoms. As can be seen from the MEP map of the title molecule,

negative regions in the studied molecule were found O30 oxygen atoms maximum positive

regions are localized on the red region. The two benzene rings are in the region of neutral and

the methoxy group is lie in the greenish are indicates slightly neutral. The MEP map shows

that the negative potential sites are on oxygen atoms as well as the positive potential sites are

around the hydrogen atoms. These sites give information concerning the region from where

the compound can have intermolecular interactions.

Fig: 3.9 MEP analysis of 4-benziloxy 3-methoxybenzaldehyde

ADALYA JOURNAL


ISSN NO: 1301-2746


Reference:

[1] Mohammed Hadi Al–Douh, ShafidaAbd. Hamid* and Hasnah OsmanSchool of Chemical

Sciences, UniversitiSains Malaysia (USM), Minden 11800.

[2] Berger et al., PhD Thesis, Virginia Polytechnic Institute and StateUniversity, Blacksburg,

Virginia, USA J. M. (2001).

[3] Allen, F. H., Kennard, O.,Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987).

J. Chem. Soc. Perkin Trans. 2, pp. S1–19.

[4] Devassy, B. M., Shanbhag, G. V., Lefebvre, F., Bohringer, W., Fletcher, J. &Halligudi, S.

B. (2005). J. Mol. Catal. A Chem. 230, 113–119

[5] Frisch, M.J., Trucks, G.W., Schlegel, H.B., Scuseria, G.E., Robb, M.A., Cheeseman,

J.R., Scalmani, G., Barone, V., Mennucci, B., Petersson, G.A., Nakatsuji, H., Caricato, M.,

Li, X., Hratchian, H.P., Izmaylov, A.F., Bloino, J., Zheng, G., Sonnenberg, J.L., Hada, M.,

Ehara, M., Toyota, K., Fukuda, R., Hasegawa, J., Ishida, M., Nakajima, T., Honda, Y., Kitao,

O., Nakai, H., Vreven, T., Montgomery Jr., J.A., Peralta, J.E., Ogliaro, F., Bearpark, M.,

Heyd, J.J., Brothers, E., Kudin, K.N., Staroverov, V.N., Kobayashi, R., Normand, J.,

Raghavachari, K., Rendell, A., Burant, J.C., Iyengar, S.S., Tomasi, J., Cossi, M., Rega, N.,

Millam, J.M., Klene, M., Knox, J.E., Cross, J.B., Bakken, V., Adamo, C., Jaramillo, J.,

Gomperts, R., Stratmann, R.E., Yazyev, O., Austin, A.J., Cammi, R., Pomelli, C., Ochterski,

J.W., Martin, R.L., Morokuma, K., Zakrzewski, V.G., Voth, G.A., Salvador, P., Dannenberg,

J.J., Dapprich, S., Daniels, A.D., Farkas, O., Foresman, J.B., Ortiz, J.V., Cioslowski, J. and

Fox, D.J. (2009) Gaussian 09, Revision A.02. Gaussian, Inc., Wallingford.

[weda] M. H. Jamroz, Vibrational energy distribution analysis, VEDA 4, Warsaw, 2004

[7] M. H. Jamroz, Vibrational energy distribution analysis, VEDA 4,

[8] D. Bakkiyaraj, S.Periyandy, S. Xavier,J. Mol. Struct. (2016) Doi:

http//doi.org/10.1016/j.molstruc.2016.04.096.

[9] V. Udayakumar, S.Periandy, M.Karabacak and S. Ramalingam Journal of

spectrochimicaActa

Part A 83 (2011) 575-586.

[10] F.F. Jain, P.S. Zhao, Z.S. Bai, L.Zhang, Struct.Chem.161 (2005) 635-639.

[11] A.E. Reed, F.Weinhold, J.Chem.Phys.83 (1985) 735-746.

[12] V.K. Rastogi, M.A. Palafox, R.P. Tanwar, L. Mittal, Spectrochimica Acta Part A 58

(2002) 1989.

ADALYA JOURNAL


ISSN NO: 1301-2746


[13] M. Silverstein, G.C. Basseler, C. Morill, Spectrometric Identification of Organic

Compounds, Wiley, New York, 1981.

[14] V. Krishnakumar, N. Surumbarkuzhali, S. Muthunatesan, Spectrochimica Acta 71A

(2009) 1810–1813.

[15] G. Socrates, Infrared and Raman Characteristic Group Frequencies e Tables and Charts,

third ed., John Wiley & Sons, Chichester, 2001.

[16] S. Manohar, R. Nagalkshmi, V. Krishnakumar, Spectrochim. Acta A 71 (2008) 110.

[17] V.R. Dani, Organic Spectroscopy, Tata McGraw- Hill publishing company, New Delhi,

1995.

[18] E. Fereyduni, M.K. Rofouei, M. Kamaee, S. Ramalingam, S.M. Sharifkhani,

Spectrochim. Acta A 90 (2012) 193.

[19/ ] K.Govindarasu , E.Kavitha Spectrochimica Acta Part A: Molecular and Biomolecular

spectroscopy 122 (2014) 130-141

[20] K. Fukui, Science 218 (1982) 747–754.

[21] G. Gece, Corros. Sci. 50 (2008) 2981–2992.

[22] D.F.V. Lewis, C. Ioannides, D.V. Parke, Xenobiotica 24 (1994) 401.

[23] Zeyrek, T.C. (2013) Theoretical Study of the N-(2,5-Methylphenyl)Salicylaldimine Schiff

Base Ligand: Atomic Charges, Molecular Electrostatic Potential, Nonlinear Optical (NLO) Effects and

Thermodynamic Properties. Journal of the Korean Chemical Society, 57, 461-471.

http://dx.doi.org/10.5012/jkcs.2013.57.4.461

[24] Prasad, M.V.S., Sri, N.U., Veeraiah, A., Veeraiah, V. and Chaitanya, K. (2013) Molecular

Structure, Vibrational Spectroscopic (FT-IR, FT-Raman), UV-Vis Spectra, First Order

Hyperpolarizability, NBO Analysis, HOMO and LUMO Analysis, Thermodynamic Properties of 2,6-

Dichloropyrazine By ab inito HF and Density Functional Method. Journal of Atomic and Molecular

Sciences, 4, 1-17.

[25] http://dx.doi.org/10.1016/j.saa.2013.07.099 Wavefunction Analyzer.

[26] Martínez-Cifuentes, M., Weiss-López, B.E., Santos, L.S. and Araya-Maturana, R. (2014)

Intramolecular Hydrogen Bondin Biologically Active o-Carbonyl Hydroquinones. Molecules, 19, 9354-

9368.http://dx.doi.org/10.3390/molecules19079354

ADALYA JOURNAL


ISSN NO: 1301-2746


http://dx.doi.org/10.5012/jkcs.2013.57.4.461

[27] Olea-Román, D., Villeda-García, J.C., Colorado-Peralta, R., Solano-Peralta, A., Sanchez, M.,

Hernández-Ahuactzi, I.F. and Castillo-Blum, S.E. (2013) Spectroscopic Studies and DFT Calculations of

Cimetidine Complexes with Transition Metal Ions. Journal of the Mexican Chemical Society, 57, 230-238.

[28] Koparir, M., Orek, C., Alayunt, N.O., Parlak, A.E., Koparir, P., Sarac, K., Dastan, S.D. and

Cankaya, N. (2013) Synthesis, Structure Investigation, Spectral Characteristics and Biological Activitie of

4-Benzyl-3-(2-Hydroxyphenyl)- 1H-1,2,4-Triazole-5(4H)-Thione. Communications in Computational

Chemistry, 1, 244-268.

ADALYA JOURNAL


ISSN NO: 1301-2746


Documents

Structural And Spectroscopic (FT-IR, FT-RAMAN, NMR UV-VIS) …adalyajournal.com/gallery/55-jan-2575.pdf · 2020-03-26 · techniques using a semi empirical method PM6, which is proven