Single crystal, spectral and electronic transition studies on (E)-N-(3-methoxy-4-hydroxybenzylidene)-4-nitrobenzohydrazide monohydrate

Article abstract of DOI:10.1016/j.molstruc.2018.12.029

The single crystal of (E)-N-(3-Methoxy-4-hydroxybenzylidene)-4-nitrobenzohydrazide monohydrate (MHBNB) was grown by a slow evaporation method. The crystal structure was determined by single crystal X-ray diffraction method. The electron density, Hirshfeld

Full text of DOI:10.1016/j.molstruc.2018.12.029

Accepted Manuscript
Single crystal, spectral and electronic transition studies on (E)-N-(3-methoxy-4-
hydroxybenzylidene)-4-nitrobenzohydrazide monohydrate
M. Manvizhi, S. Murugan, P. Sutharsan, J.S. Nirmal Ram, S. Subaschandrabose
PII:
S0022-2860(18)31450-9
DOI:
https://doi.org/10.1016/j.molstruc.2018.12.029
MOLSTR 25966
Reference:
To appear in: Journal of Molecular Structure
Received Date: 16 August 2018
Revised Date: 5 December 2018
Accepted Date: 7 December 2018
Please cite this article as: M. Manvizhi, S. Murugan, P. Sutharsan, J.S. Nirmal Ram, S.
Subaschandrabose, Single crystal, spectral and electronic transition studies on (E)-N-(3-methoxy-4-
hydroxybenzylidene)-4-nitrobenzohydrazide monohydrate, Journal of Molecular Structure (2019), doi:
https://doi.org/10.1016/j.molstruc.2018.12.029.
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ACCEPTED MANUSCRIPT
Single crystal, spectral and electronic transition studies on (E)-N-(3-Methoxy-4-
hydroxybenzylidene)-4-nitrobenzohydrazide monohydrate
M. Manvizhia, S. Muruganb*
,
P. Sutharsanc J.S. Nirmal Rame, S. Subaschandraboseef*
,
aDepartment of Science and Humanities, A.V.C College of Engineering, Mannampandal, Mayiladuthurai -609305, Tamil Nadu, India
bDepartment of Physics, A.V.C. College (Autonomous), Mannampandal, Mayiladuthurai – 609305, Tamil Nadu, India
cDepartment of Physics, Sir Theagaraya College,Old Washermenpet, Chennai – 600 021
eCentre for Research & Development, PRIST University, Vallam, Thanjavur-613403, Tamil Nadu, India
fCentre for Functionalized Magnetic materials (FunMagMa), Immanuel Kant Baltic Federal University-236000, Kaliningrad, Russia
Abstract
The single crystal of (E)-N-(3-MMethoxy-4-hydroxybenzylidene)-4-nitrobenzohydrazide monohydrate
(MHBNB) was grown by a slow evaporation method. The crystal structure was determined by single
crystal X-ray diffraction method. The electron density, Hirshfeld surface and fingerprint analysis reveals
that the crystal packing is governed by several weak O-H…C, O-H…O and O-H…N intermolecular
interactions. The analysis of bond critical points (BCP) and topology of the crystalline form of MHBNB
were analyzed. The intrusion of H2O molecule does not affect the aromaticity of the pheyl rings but
marginally distrurbs the aromaticity of hydrazide link. The FT-IR (4000-400cm-1) and FT-Raman (3500-
50 cm-1) spectra were recorded to study the vibrational behavior of MHBNB molecule. To explore the
electronic transition of MHBNB, the UV absorbance spectrum was recorded in the range of 200-800nm.
Furthermore, the Density functional theory (DFT) and Time-dependent DFT (TD-DFT) calculations were
performed to investigate the molecular geometry, vibrational behavior, electronic excitation and inter-
intramolecular charge transfers within the molecule. The singlet (S) and Triplet (T) electronic excited
states (n state=6) of MHBNB were examined, in which, the electron spin density (s), excitation energy
(ꢀE1-6), oscillator strength (f) and electric dipole moment (ꢁ) were examined. The frontier molecular
orbitals (FMOs) were studied to find the band gap of FMOs. The natural atomic orbitals (NAO) and
natural localized molecular orbitals (NLMO) of MHBNB were analyzed. The density of states (DOS) and
Total density of states (TDOS) of functional groups in MHBNB molecule were also evaluated. This
compound has very good first order hyperpolarizability (β0) coefficient.
Keywords: FT-IR; FT-Raman; FMOs; NAO; TD-DFT;
*corresponding author: sscbphysics@gmail.com
+91 9976853476

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1. Introduction
Investigation of organic optical materials is playing a major role in recent research. Organic optical
materials (OM) are widely used in optoelectronics, photonics, optical switching, telecommunications,
modulator, optical computing and integrated optical circuit applications [1-2] since most of the OM
materials constituted by weak Van der Waals and hydrogen bonds with conjugated
π-electrons [3]. The
compounds having hydrazide (CH-N-C=O) and -electrons possess enhanced optical activity [4].
π
Moreover, the organic single crystals exhibiting photoconductive, photovoltaic and photocatalytic
activities [5]. The conjugative electron systems in the compound display extremely larger second-order
optical nonlinearities [6]. The aim of the present study is, obtain the single crystal structure and study the
vibrational and electronic spectra; in addition, Density Functional Theory (DFT) and Time Dependant-
DFT calculations were performed to investigate the molecular orbitals, excited electronic states and
natural atomic-orbitals of the title compound. The novelty of this compound is it has lesser frontier
molecular orbital band gap and very good β0 coefficient.
2. Computational details
The quantum chemical calculations of MHBNB were performed using the B3LYP level of theory
supplemented with 6-31G(d,p) basis set, using Gaussian 09 program package invoking geometry
optimization [7]. Initial geometry generated from geometrical parameters was minimized without any
constraint in the potential energy surface at DFT level. The optimized minimum structure parameters
were used in the vibrational wavenumber calculations at the DFT level to characterize all stationary
points as minima. The Raman activities were transformed into Raman intensities using Raint program [8]
by the expression:
1
− 1 2
4
(1)
I
= 1 0
× (ν
−
ν
)
×
× R A
i
0
i
i
ν
i
Where Ii is the Raman intensity, Ai is the Raman scattering activities, νi is the wavenumber of the
normal modes and ν0 denotes the wavenumber of the excitation laser [9]. Hirshfeld surface maps and
fingerprint plots were generated from the crystallographic data using the CrystalExplorer 3.1 [10].

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3. Experimental details
3.1 Synthesis of (E)-N-(3-methoxy-4-hydroxybenzylidene)-4-nitrobenzohydrazide (MHBNB)
O
O
O
O
N
O
H
C2H5OH
4 Hrs
N
+
O
H2N
H
H
3-methoxy-4-
hydrozybenzaldehyde
4-nitrobenzohydrazide
The reaction scheme of (E)-N-(3-Methoxy-4-hydroxybenzylidene)-4-nitrobenzohydrazide
The ethanol solution of 3-methoxy-4-hydroxybenzaldehyde was added to the ethanol solution of 4-
nitrobenzohydrazide. The mixture was refluxed for 4hrs in a heating mantle. The resulting solution was
allowed to cool slowly at room temperature. After few days the suitable crystalline of the title compound
were separated. Finally the single crystals of the synthesized compound were grown by slow evaporation
technique using ethanol as solvent. The block like single crystals are harvested after two weeks (yield =
90%, Melting point = 195°C).
3.2 Characterization techniques
The single crystal X-ray diffraction structural analysis of MHBNB was carried out using Bruker
kappa Apex II CCD diffractometer. The FT-IR spectrum of the synthesized MHBNB was measured in the
4000–400 cm−1 region at the spectral resolution of 4 cm−1 using Shimadzu FT-IR affinity
spectrophotometer (KBr pellet technique). The FT-Raman spectrum was recorded using Bruker RFS 27
spectrometer operating at laser 100mW in the spectral range of 4000–50 cm−1.
4. Results and Discussion
4.1 Crystal Structure and geometry
Crystal of MHBNB was grown at room temperature and single crystal X-ray data were collected on a
Bruker AXS Kappa Apex II CCD diffraction with graphite monochromatic Mo K
Å). The crystals were coated with inert oil, mounted on a glass capillary, and crystal data were collected
at 298 K. The reflections with I>2 (I) were employed for structure solution and refinement. The shelxl
α radiation (λ=0.71073
σ
program was used to solve the structure by direct methods. The structure refined using full-matrix least
squares refinement on |F|2 using the SHELXL97 [11] software. Fourier synthesis led to the location of all
of the non-hydrogen atoms. For the refinement, all data were used including negative intensities. The
criterion of F2>2σ(F2) was employed for calculating R1, R factor based on F2 (wR2) are statistically

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about twice as large as based on F, and R factors based on all data will be even larger. Non-hydrogen
atoms were refined with anisotropic thermal parameters. All of the hydrogen atoms in the MHBNB
structure could be located in the difference Fourier map. However, the hydrogen atoms were
geometrically relocated at chemically meaningful positions and were given riding model refinement. The
refinement data are listed in Table 1.
The MHBNB crystal structure belongs to a monoclinic and P21/n space group. The lattice cell parameters
are a=7.9566, b=21.3735, c=9.7681(Å) and the symmetry code of the molecule in the crystal unit is (i) x-
1/2, -y+1/2, z+3/2; (ii) x+1/2, -y+1/2, z-1/2; (iii) x+1, y, z-1; (v) x-1, y, z+1; The bond parameter such as
the bond length (Å), bond angle (°), dihedral angle (°) and hydrogen bonding interactions were measured.
This water also involves in hydrogen bonding interaction, but it does not change the symmetry, there was
observed a negligible influence due to the water present. The determined structure was optimized by
Density functional theory (DFT) calculation. The structure parameters were calculated and compared with
X-ray diffraction bond parameters, for example, the carbonyl (C=O) bond length has observed as about
1.229Å, whereas the calculated value is about 1.23Å. Similarly, the observed C=N (1.276Å), C-N
(1.337Å), C-O (1.367Å) and C-C in ring (~1.41 & ~1.37Å) bond lengths are matches well with the
computed bond parameters. The hydrogen bonding (HB) interactions have been observed like D-H,
H…A, D…A, and D-H…A. among the closest molecule, The donor nitrogen (N1-H2…O25ii) makes the
intermolecular hydrogen bonding with closest neighboring oxygen (O25ii) in hydroxybenzylidene (in ring
2), its D…A hydrogen bonding distance is about 3.078 Å and bonding angle is about 151̊ . Similarly, HB
at the terminal like C10-H11…O25i and C10-H11…O26ii is about 3.281 and 3.080 Å (D…A),
respectively, its corresponding angles are 154° and 129°(D-H…A). The determined crystal structure and
optimized gases phase structure are shown in Figure 1 (a-b). The comparison of experimental and
computed bond parameters are listed in Table S1 (Supporting information).
4.2 Vibrational analysis:
The vibrational analysis for MHBNB has carried out using FT-IR (4000-400 cm-1) and FT-Raman (3500-
50 cm-1) spectra (as shown in Figure 2a and Figure 2b). In addition to that, the DFT calculation was also
performed to explore the characteristic vibration in BCOP. The calculated wavenumbers were scaled
down by the appropriate scale factor [12] to bring closer with observed wavenumbers. This molecule
consists of 39 atoms and possesses 111 normal modes of vibrations but experimentally unable to observe
all those modes however the observed wavenumbers have compared with the simulated wavenumbers.
The hydroxyl (OH) stretching is very sensitive to hydrogen bonding and this vibration usually appears at
3500-3700cm-1 [13]. In the present investigation, the O-H stretching vibration appears at 3673 cm-1 as a
weak band, it indicates that there is no hydrogen bonding interaction at this OH (since the peak appeared

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weak and no broad). The N-H stretching vibration in heterocyclic molecule appears in the range of 3500-
3300cm-1 [14], the N-H stretching in ENBNB observed at 3458 cm-1 as a medium band in FT-IR
spectrum. The aromatic CH stretching vibration normally occur in the characteristic region of 3100-3000
cm-1[15], this molecule indicates the C-H peak at 3057cm-1 as a medium band in FT-Raman. The
vibrational modes of methoxyl groups are highly influenced by interactions such as electronic effects,
Fermi resonance and intermolecular hydrogen bonding [12]. The symmetric and asymmetric stretching
vibration of aryl methoxyl groups often appears at 3000 and 2925 cm-1 [16] whereas, in the present work,
the -OCH3 stretching vibration appears at 3001 cm-1 as weak band in FT-IR. The C=O stretching
vibration is an important class of vibration in a molecule, which is generally expected in the region 1710-
1600 cm-1, herein the C=O stretching has observed as strong band at 1788 cm-1 in FT-Raman, here
seems a positive deviation from the literature, this positive deviation is due to a short-range hydrogen
bonding interaction with the neighboring H2O. The above mentioned observed wavenumber agrees well
the computed wavenumber as well as literature. The recorded and computed results are listed in Table 2.
4.3 Molecular orbital (MO) theory:
MO theory calculation was performed using the TD-DFT method, the results presented in Table 3(a-b), in
which the singlet and triplet excited states were interested (n states=6). The first excited lays between
HOMO (H) and LUMO (L), its energy gap has calculated about 2.62 eV, whereas, in the triplet state, the
first excited state lays over 86 - 89th MO, its calculated band gap is about 0.835eV. By comparing the
first singlet and triplet excited states, the band gap difference is 1.79eV. In addition to that, the electric
dipole moment is four times higher the first excited triplet state (7.926 Debye) than singlet excited state
(2.107 Debye). In second excited singlet state, the 86-88th (H-1-L) MO involves, its band gap is about
3.399 eV, whereas the oscillator strength (f) and electric dipole moment (
Similarly, the f and are very weak at ES3, ES5 and ES6 it is due to the lesser x, y and z components and
ꢁ) are very weak in S state.
ꢁ
weak transitions among the frontier H-L. On the other hand, at singlet ES4, the f and
ꢁ are higher than
triplet ES4 due to positive ꢁx (2.557a.u) component.
The frontier HOMO and LUMO play an important role in optical and electronic applications; in the
present investigation, the band gap has calculated about 2.982 eV (462nm). The HOMO majorly locates
over the 2pz, 3py, 3pz, 4pz, 5s orbitals of hydrazine and hydroxybenzylidene ring, whereas, the LUMO
locates over the 4pz, 5s, 5px, 5py, and 5pz orbitals of the nitrobenzohydrazide ring. The details of the
molecular orbital coefficient have shown in Figure S1 (a-b) and Figure S2 (a-c) (Supporting information).

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4.4 NBO analysis:
Natural atomic orbital (NAO) and Natural bond orbital (NBO) analysis were performed using Gaussian
NBO version 3.1. The obtained results are presented in Table 4. In which, the core level atomic orbital
population has calculated about 47.98e, and valence orbital population has calculated about 125.47e,
whereas the total minimal basis is about 173.46e and Rydberg basis (Non-Lewis- NL) has calculated
about 0.539e. In the natural bond orbital analysis, shows the core electrons as about 47.98e, valence
Lewis electrons 121.40e and total Lewis electrons is about 169.39e. In NBO investigation, we mainly
concentrate on Pi (
an inequivalent bond like
1.928e respectively. The stabilization energy over
~8.34kcal/mol. In the 3-Methoxy-4-hydroxybenzylidene ring, the maximum stabilization energy (21.57,
17.94 and 18.28 kcal/mol) appears due to C9-C29→π*N3-C10, C5-C7, C6-C13 (NBO19 NBO590,
595, 598) delocalization. Similarly, in the 4-nitrobenzohydrazide ring, the strong stabilization appears at
C12-C16, C18-C19 and C21-C23 valence Lewis orbitals with corresponding valence non-Lewis
π
) bond (donor (i)
→
Pi* (
π
*) acceptor (j)) interactions. The bond N3=C10 (
N3-C10 (NBO5) having occupancy about 1.986e and
N3-C10→π*C9-C29 has calculated about
σ/π) has
σ
N3-C10 (NBO4) and
π
π
π
→
π
π
π
orbitals. The significant contribution also revealed from lone pair (n) oxygen atoms, in which nO25 yields
more stabilization due to nO25→π*C6-C13 overlap. On the whole, the dominant stabilization energy
(303.86 and 208.84kcal/mol) obtained at the valence non-Lewis interaction due to
C29 and *C12-C16→ π*C21-C23 stabilization.
π*C6-C13→ π*C9-
π
4.5 Hirshfeld surface analysis
Hirshfeld surface (HSs) and 2D fingerprint plot were generated using Crystal Explorer 3.1 based on the
results of single crystal X-ray diffraction studies, in which the crystal packing builds through the O…H-C
(2.15Å) and O…H-N (2.35Å) hydrogen bonding interactions (between hydrazine and neighboring
methoxy benzohydroxyl). This packing unit is like a zigzag crystal building by means of square-shaped
intermolecular hydrogen bonding interactions as shown in Figure S3 (a-j) (Supporting information). The
function of dnorm is a ratio encompassing the distances of any surface point to the nearest interior (di)
atom and exterior (de) atom and the van der Waals radii of the atoms [17]. The negative value of dnorm
indicates the sum of di and de is shorter than the sum of the relevant van der Waals radii, which is
considered to be the closest contact and is visualized as red colored in the HSs. The white color denotes
intermolecular distances close to van der Waals contacts with dnorm equal to zero whereas contacts longer
than the sum of van der Waals radii with positive dnorm values are colored with blue. A plot of di versus
de is 2D fingerprint plots which recognize the existence of different types of intermolecular interactions.
For this crystal structure, the D-H…A hydrogen bonding interactions when the H…A distance is shorter

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than the sum of the van der Waals radii more than 0.13Å is observed, the intermolecular hydrogen
bonding appears between hydrazine link and Methoxy benzohydroxyl of neighbor like O-H…N
(0.5%),O-H…C (34.7%) and O-H…O (34.7%) as shown in the Figure S3 (e-h) (Supporting information).
In the shape index, the highlighted red and blue triangles shown by purple color ellipse indicate the π•••π
interactions identically present in the crystal structure and its 2D fingerprint shows the CꢂꢂꢂC contact
contributes 5.2% of the Hirshfeld surface. Red and blue triangles pattern explicitly how the molecules
overlap and contact with one another. Red triangle represents the carbon atoms present in the benzene
ring of the molecule outside the surface, while blue represents the carbon atoms of benzene ring inside the
surface. The curvedness surface indicates the electron density surface curves around the molecular
interactions [18]. Moreover, the flat green region separated by the blue edges in curvedness surface is
another characteristic of π•••π stacking. The deep red color spots in the de surface are responsible for
strong interaction of OꢂꢂꢂH (16.2%) and the red spots in di surface correspond to HꢂꢂꢂO (18.5%)
interactions.
4.6 Density of States
Using Multiwfn 3.4.1 version [19], the topology of MHBNB has as shown in Figure S4 (Supporting
information) and also the density of states of MHBNB were studied using the same software. Density of
states is an important concept of solid state physics, which represents the number of states in unit energy
interval. In an isolated system, the energy levels are discrete, though the concept of DOS valueless, if the
discrete energy levels are broadened to curve artificially, the DOS graph can be used as a valuable tool for
analyzing the nature of electron structure.The original total DOS (TDOS) of isolated system can be
written as
TDOS(E) =
δ (E −εi )
∑
(2)
i
Where {
ε
} is eigenvalue set of single-particle Hamilton,
δ
is Dirac delta function. If
δ
is replaced by
broadening function F(x), such as Gaussian, Lorentzian and pseudo-Voigt function, we get broadened
TDOS [19].
The title molecule under B3LYP/6-31G(d,p) wave function is ground state, the orbitals canonical MOs,
fragments 1-5 are defined as functional groups as shown in Figure 4. The vertical dashed line indicates
the position of the HOMO level. The original DOS graph (as shown in Figure 4) is discrete comb-like
lines and it is difficult to distinguish the discrete lines. However the discrete lines are broadened, the
black curve is TDOS, and it reveals the dense of energy levels are distributed. Besides that PDOS is
separated as fragments (f1-f5), in which, f1 (red curve) belongs to –C=O-N-N=C-group, it has the
considerable contribution in the HOMO level, and maximum contribution is by ring carbons (f5) denoted

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as the green line in DOS spectrum. Also, a meager contribution found by means of –OCH3 (blue line-f2)
and NO2 (pink line-f3) in HOMO level. Moreover, the fragments f1 and f5 also considerably contribute
to the LUMO level. The OPDOS magnitude is much smaller than TDOS and PDOS.
4.7 Nonlinear property analysis
Theoretical investigation plays a substantial role in understanding the quantitative structure–
property relationship (QSPR), which is able to assist in designing novel NLO materials. For a molecule to
be NLO active, it is important to have high hyperpolarizability (β0) values. The calculated values of β0 by
finite field approach method are given in Table 5, along with the corresponding components.
The first-order hyperpolarizability β0 is given by,
1 / 2
2
2
2
y
(3)
β 0
=
(
β x
+
β
+
β z
)
For MHBNB, we have obtained the high value of
βxxx,
β
xxy and
β
xyy components (Table 5)
thus indicating that there is a charge imbalance along the y-axis which is due to the high electronegative
oxygen atoms lying in the X–Y plane. The 0 value (78.65x10-30esu) also indicates that the compound
has very good nonlinear optical property. This compound has greater 0 coefficient than that of urea.
β
β
Urea is one of the prototypical molecules used in the study of the NLO properties of molecular systems.
Therefore, it was used frequently as a threshold value for comparative purposes [20].
5 Conclusions
The MHBNB crystallizes in monoclinic and P21/n space group with lattice parameters a=7.9561,
b=21.3735, and c=9.781. The packing of molecules in the crystal is governed by weak O-H…N, O-H…C
and O-H…O interactions. The simulated geometries of the compound agree well with the geometrical
parameters obtained through single crystal X-ray diffraction technique. The functional groups vibrational
assignments were made using experimental and computational data. In TD-DFT calculations, S and T
excited states were computed; the S first excited state denotes the H-L band gap of 2.62eV. On comparing
the S first excited state with the T first excited the f and
ꢁ are very weak in S states. The HOMO majorly
locates over the 2pz, 3py, 3pz, 4pz, 5s orbitals of hydrazine and hydroxybenzylidene ring atoms, whereas,
the LUMO locates over the 4pz, 5s, 5px, 5py, and 5pz orbitals of nitrobenzohydrazide ring atoms. The
more hyperconjugative energy (303.86 and 208.84kcal/mol) obtained at the Lewis and non-Lewis
interaction due to π*C6-C13→ π*C9-C29 and π*C12-C16→ π*C21-C23. DOS graph is discrete comb-
like lines are broadened, the black curve is TDOS. This reveals the dense of energy levels. Among the
fragments, ring carbon, has considerable distributed electron density. An appreciable First-order
hyperpolarizability of the molecule makes it an active NLO compound.

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Supporting information’s
CCDC 1821369 contains the supplementary crystallography data for this title molecule. These
data can be obtained free of charge from the Cambridge Crystallography Data Centre via
www.ccdc.cam.ac.uk/data request/cif.
6 References
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Table 1 Crystallographic data and structure refinement parameters of MHBNB
C15H15N3O6
333.30
Chemical formula
Mr
Monoclinic, P21/n
P21/n
Crystal system
Space group
296
Temperatue (K)
a, b, c (Å)
7.9566(4), 21.3735(14), 9.7681(7)
107.269 (2)
1586.28 (17)
β (˚)
V(Å3)
4
Z
MoKα
0.11
Radiation Type
ꢀ (mm‒1)
0.15 × 0.15 × 0.10
Bruker kappa Apex II CCD Diffractometer
Multi-scan' SADABS (Sheldrick, 1996)
28649, 3070, 2077
0.041
0.615
0.045, 0.170, 0.81
3070
Crystal size (mm)
Diffractometer
Absorption correction
Reflections [I>2σ(I)]
Rint
(Sinθ/λ)max (Å−1)
Refinement R[F2>2σ(F2)], wR(F2), S
No. of reflections
No. of parameters
No. of restraints
228
3
H atoms treated by a mixture of independent and
constrained refinement
0.33, -0.26
H-atom treatment
∆ρmax, ∆ρmin (e Å-3)

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Table 2 FT-IR, FT-Raman and simulated Vibrational assignments on MHBNB using B3LYP/6-31G(d,p)
level of basis set.
Mode
no.
FT-
Raman
cm-1
Unscaled Scaled
FT-IR
cm-1
Intensity
KM/Mole
Vibrational Assignments
cm-1
cm-1
ν
ν
O25-H26
O25-H26
110
109
108
107
102
97
96
94
92
88
79
71
68
62
61
55
52
45
41
31
14
8
3819
3706
3515
3248
3183
3022
1765
1689
1655
1577
1399
1235
1192
1094
1069
920
3674
3565
3381
3124
3062
2908
1698
1625
1592
1517
1346
1188
1147
1052
1029
885
3673w
3524w
96.6417
287.1698
18.4295
1.6564
ν
N1-H2
C19-H20 R2
C19-H20 R2
CH3(C33-H43,35,36)
C=O
3458ms
3276m
ν
ν
3057m
1788w
64.737
ν
3001w
37.1952
344.9814
70.2102
120.4776
41.5001
314.3328
55.8104
104.4462
28.3654
33.6426
24.9959
10.6079
26.9112
61.6307
0.5175
ν
ν
ν
ν
C3=N10
C-C R1
C-C R2
1597vs
1519vs
1345ms
1591vs
1517w
1344ms
1199w
1141w
1059w
ν
C10-NO2
CH3
CCH in R1
N1-N3
ω
β
COH, β
ν
Trigonal bending R1
N-C=O
1035ms
β
895w
γ
γ
CCH opb R1
CCH opb R2
Water opb
894
860
850ms
713ms
625w
733
705
646
472
622
454
Ring 1 floating
463w
179w
81w
τ
CH3 rocking
R1 opb
189
182
8.2426
90
87
1.1157
ν-stretching; β-in-plane bending; τ-rocking; ω-wagging; γ-out-of plane bending; R-Ring; w-weak;
ms-medium strong; vs-very strong;

ACCEPTED MANUSCRIPT
Table 3a Singlet (S) state transitions, Band gap and oscillator strength between HOMO and LUMO
MO of MHBNB
S.No. Singlet excited electronic transitions
Band gap (eV/nm)
Oscillator strength
2.6232 /472.65
3.3986 /364.81
3.6508 /339.61
3.8183 /324.71
3.9212 /316.19
4.1550 /298.40
1
2
3
4
5
6
H
→
L
L
0.1354
0.0320
0.0005
0.6265
0.0018
0.0014
H-1
H-7
H-2
H-6
H-9
→
→
→
→
→
L, H-7
→ L+1, H-7→ L+3
L, H-1+L
L, H-2→
→
L, H-2→
L+1, H
→L+1
→ L
L, H-9
L+1, H-6→
L, H-4
Table 3b Triplet (T) state transitions, Band gap and oscillator strength between HOMO and
LUMO MO of MHBNB
S.No.
1
2
Triplet excited state transitions
L1, H-1 H, L L1,
L3, L L7, H-6
L+2, L L+7, H-6
Band gap
Oscillator strength
0.1622
L
L
L
→
→
→
→
→
→
→
→
→
0.8352 eV/ 1484.46 nm
1.0255 eV /1209.01 nm
1.4906 eV /831.76 nm
L1, L
L1, L
→
→
H, H-1
H, H-2
→
→
H
0.1232
0.0385
H,
3
4
5
6
H-1
→
H,
L+2, L
H, H-2
L1, L L+2, L
H, H-6 H, H-5
H, H-7 H, H-4
L→
→
→H,
L3, H-10
→
H, H-7
→
H, H-4
→
H,
1.6255 eV /762.73 nm
1.7323 eV /715.72 nm
1.9252 eV /644.02 nm
0.0004
0.0474
0.0130
H-3
→
L→
→
→
→
→
L3, L
H, H-3
→
L5, L→L7, H-
→
7
→
H, H-2
→
H
H-10
→
→
→
H, H-3
→
H, H-
→
2
H
Table 3c Singlet and Triplet excited state (n states=6) energy, oscillator strength and electric dipole
moment of MHBNB using TD-DFT calculation.
Singlet excited state (S, E1-6)
S,
Triplet excited state (T, E1-6)
T,
Excited
Energy states
(E1-6)
∆
E(S-T), eV
Energy,
eV
f
ꢀ
, D
Energy,
eV
f
ꢀ, D
E1
E2
E3
E4
E5
E6
2.62
3.40
3.65
3.82
3.92
4.16
0.1354 2.1071
0.0320 0.3840
0.0005 0.0059
0.6265 6.6974
0.0018 0.0191
0.0014 0.0135
0.84
1.03
1.49
1.63
1.73
1.93
0.1622
0.1232
0.0385
0.0004
0.0474
0.0130
7.9260
4.9042
1.0547
0.0093
1.1158
0.2764
1.79
2.37
2.16
2.19
2.19
2.23
f-oscillator strength, ꢀ-electric dipole moment, D-Debye

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Table 4 Second order perturbation theory analysis of fock matrix in NBO basis for MHBNB
Donor
NBO (i)
Acceptor
NBO (j)
aE(2)
kcal/mol
Type
Occupancy
Occupancy
bε(j)-
ε(i)
cf(i,j)
1.92848
1.98098
1.70452
0.39869
0.36646
0.37200
0.39869
0.34018
0.39869
0.20089
0.34018
0.37200
0.30037
0.37497
0.26437
0.36646
0.26437
0.61942
0.36646
0.37497
0.07626
0.06462
0.37200
0.34018
0.01831
0.01833
0.10396
0.05544
0.10396
0.05466
0.61942
0.39869
0.02733
0.39869
0.30037
0.26437
0.26437
0.37497
π
π
π
-
-
-
π
π
π
*
*
*
πN3-C10
πO4-C15
πC5-C7
π
*
8.34
3.17
0.37
0.42
0.28
0.29
0.3
0.054
0.036
0.066
0.067
0.062
0.071
0.069
0.064
0.064
0.061
0.07
C9-C29
π*
C12-C16
π*
18.49
18.25
15.9
C6-C13
C9-C29
π*
1.68589
1.66880
π-
π
π
*
*
πC6-C13
πC9-C29
π
*
C5-C7
C9-C29
N3-C10
π*
10.21
21.57
17.94
18.28
14.95
22.03
17.34
18.57
18.74
27.64
21.99
22.28
26.18
16.96
29.46
30.78
5.5
0.3
π-
π*
0.26
0.28
0.27
0.31
0.28
0.3
π
*
C5-C7
C6-C13
O4-C15
π*
1.63825
1.63748
π-
π
π
*
*
πC12-C16
π*
π
*
*
*
*
C18-C19
C21-C23
C12-C16
C21-C23
N27-O31
π
π
π
0.065
0.066
0.069
0.06
π-
πC18-C19
0.29
0.3
π*
0.14
0.27
0.27
0.69
0.67
0.35
0.34
0.69
0.69
0.56
0.71
0.57
0.72
0.14
0.03
0.52
0.01
0.02
0.01
0.02
0.14
1.61419
1.86482
π
π
π
π
π
-
-
-
π
π
π
*
*
*
*
*
πC21-C23
π*
0.069
0.069
0.122
0.097
0.096
0.095
0.057
0.057
0.073
0.105
0.073
0.104
0.137
0.068
0.131
0.079
0.069
0.082
0.081
0.058
C12-C16
C18-C19
π
*
*
nO4
π
π
*
N1-C15
C12-C15
1.86286
1.83509
nO25
nO28
π*
C6-C13
π
*
C5-C7
-
σ
σ
σ
σ
σ
σ
σ
σ
*
*
*
*
C33-H34
C33-H36
C18-N27
5.49
1.90001
1.90085
-
nO31
nO32
11.92
18.87
11.81
18.69
161.21
63.94
6.77
303.86
80.67
208.84
161.83
14.9
N27-O32
*
C18-N27
N27-O31
N27-O31
*
π
π
π
π
π
-
π
π
*
*
*
*
*
π*
0.20089
0.30037
0.37200
0.36646
-
π*
π*
π*
π*
N3-C10
O4-C15
C6-C13
C9-C29
O4-C15
C9-C29
O4-C15
-
-
σ
π
π
σ
π
*
*
-
π
*
*
*
π*
C12-C16
C12-C16
C18-C19
N27-O31
π
π
π
π
π
*
*
*
C21-C23
C21-C23
C18-C19
0.37497
0.61942
π-
π
π
*
*
π-
π*
aE(2) means energy of hyper conjugative interaction (stabilization energy).
bEnergy difference between donor(i) and acceptor(j) NBO orbitals.
cF(i,j) is the fork matrix element between i and j NBO orbitals.

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Table 5 The β0 components of MHBNB molecule.
Parameter
βxxx
Values
8924.07
676.38
βxxy
βxyy
171.02
βyyy
-199.61
150.75
βxxz
βxyz
36.78
βyyz
-58.36
βxzz
-4.12
βyzz
3.12
βzzz
2.48
78.653x10-30 esu
β0
*Standard Urea = 0.3728 X10-30 esu.

ACCEPTED MANUSCRIPT
Figure 1a Ortep diagram of (E)-N'-(3-methoxy-4-hydroxybenzylidene)-4-nitrobenzohydrazide
(MHBNB)
Figure 1b (E)-N'-(3-methoxy-4-hydroxybenzylidene)-4-nitrobenzohydrazide (MHBNB)

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1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.0
FT-IR
3960 3520 3080 2640 2200 1760 1320
880
440
0
Wavenumber (cm-1)
IR/B3LYP/6-31G(d,p)
Figure 2a The recorded FT-IR and computed IR spectrum of MHBNB

ACCEPTED MANUSCRIPT
0.012
0.010
0.008
0.006
0.004
0.002
0.000
FT-Raman
4000
3500
3000
2500
2000
1500
1000
500
0
Raman/B3LYP/6-31G(d,p)
Figure 2b The observed FT-Raman and computed Raman spectra of MHBNB

ACCEPTED MANUSCRIPT
LUMO (-3.2888 eV)
Band gap = 2.9288 eV
HOMO (-6.2176 eV)
Figure 3 Frontier molecular orbitals of MHBNB

ACCEPTED MANUSCRIPT
Figure 4 Density of states in MHBNB with respect to functional groups.

ACCEPTED MANUSCRIPT
Highlights
ꢀ Spectral (IR / Raman, UV) and Single crystal structure determination
ꢀ Singlet and Triplet state transitions
ꢀ Contribution of 2Pxyz orbitals in occupied MOs.
ꢀ Density of states of functional groups
ꢀ Natural atomic orbital (NAO) analysis
ꢀ Bond critical points and topology analysis