On the potential as nonlinear optical material of a new chalcone derivative and its crystal and topological analysis

Article abstract of DOI:10.1016/j.molstruc.2019.127131

We report a study of the structural and the linear and nonlinear optical and electrical properties of a new chalcone. Using the M?ller-Plesset Perturbation and the Density Functional approaches, the dipole moment, linear polarizability and second hyperpol

Full text of DOI:10.1016/j.molstruc.2019.127131

Journal Pre-proof
On the potential as nonlinear optical material of a new chalcone derivative and its
crystal and topological analysis
Jean M.F. Custodio, Wesley F. Vaz, Eduardo C.M. Faria, Murilo M. Anjos, Carlos
E.M. Campos, Guilherme R. Oliveira, Felipe T. Martins, Cameron C. da Silva,
Clodoaldo Valverde, Francisco A.P. Osório, Basílio Baseia, Hamilton B. Napolitano
PII:
S0022-2860(19)31240-2
DOI:
https://doi.org/10.1016/j.molstruc.2019.127131
MOLSTR 127131
Reference:
To appear in: Journal of Molecular Structure
Received Date: 22 August 2019
Revised Date: 24 September 2019
Accepted Date: 25 September 2019
Please cite this article as: J.M.F. Custodio, W.F. Vaz, E.C.M. Faria, M.M. Anjos, C.E.M. Campos, G.R.
Oliveira, F.T. Martins, C.C. da Silva, C. Valverde, F.A.P. Osório, Basí. Baseia, H.B. Napolitano, On
the potential as nonlinear optical material of a new chalcone derivative and its crystal and topological
analysis, Journal of Molecular Structure (2019), doi: https://doi.org/10.1016/j.molstruc.2019.127131.
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On the Potential as Nonlinear Optical Material of a New Chalcone
Derivative and its Crystal and Topological Analysis
Jean M. F. Custodio1,2*, Wesley F. Vaz2,3, Eduardo C. M. Faria2,8, Murilo M. Anjos1, Carlos E. M. Campos4,
Guilherme R. Oliveira1, Felipe T. Martins1, Cameron C. da Silva1, Clodoaldo Valverde 2,5*, Francisco A. P.
Osório1,6, Basílio Baseia1,7 and Hamilton B. Napolitano2*
1
Universidade Federal de Goiás, Goiânia, GO, Brazil.
2
Universidade Estadual de Goiás, Anápolis, GO, Brazil.
3
Instituto Federal de Educação, Ciência e Tecnologia de Mato Grosso, Lucas do Rio Verde, MT, Brazil.
4
Departamento de Fisica, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
5
Universidade Paulista, Goiânia, GO, Brazil
6
Pontifícia Universidade Católica de Goiás, Goiânia, GO, Brazil
7
Universidade Federal da Paraíba, João Pessoa, PB, Brazil.
8
CAOA Montadora de Veículos LTDA – Centro de Pesquisas e Eficiência Enérgetica, Anápolis, GO, Brazil.
* Corresponding author
E-mail: jeanmfcustodio@gmail.com; valverde@ueg.br; hbnapolitano@gmail.com

Abstract
We report a study of the structural, optical and electrical properties of a new chalcone. Using the
Møller-Plesset Perturbation and the Density Functional approaches, the dipole moment, linear
polarizability and second hyperpolarizabilities were calculated in static and dynamic electric fields. The
supermolecule approach was used to simulate the crystalline environment of our crystal and the linear
refractive index. Lorentz local field correction factor and third order macroscopic susceptibility were
calculated, and the effects of solvent media on the non-linear optical properties are also taken into account
through the Polarizable Continuum Model. This chalcone is almost planar, except for slight rotations in
its open-chain which allows electron delocalization. This is also confirmed by an intramolecular hydrogen
bond formed between the carbonyl and amine groups. Interestingly, a good third order macroscopic
susceptibility value of 13.31×10-22ꢀ2ꢁ-2 was calculated, which is even higher than those reported for
related chalcone derivatives.
Keywords: NLO properties; Hirshfeld surfaces; Chalcone
Introduction
Chalcone is a class of compound obtained from natural or synthetic sources that can be considered
as a precursor agent of flavonoids and isoflavonoids1–4. The chalcones’ synthetic production process
normally occurs by Claisen Schmidt condensation, in which aromatic aldehydes are condensed with
acetophenones5–7. This compound class presents two aromatic rings connected through a three-carbon
bridge with a keto carbonyl group and one α,β-unsaturation3. Studies have showed some biological
activities associated with chalcones, such as antimicrobial, analgesic, antiplatelet, anti-inflammatory, anti-
ulcerative, antimalarial, antiviral, anticancer, antihyperglycemic, antioxidant and antitubercular1,8–12
.
In addition, chalcones can be applied for other purposes, such as new materials, environmental
demands and biological functions. Regarding materials, some chalcones have showed potential properties

of nonlinear optics, contributing to new material developments associated mainly with electronic
engineering and other sciences13–16. For example, Ali et al. (2017)17 characterized in his work the
morphological and optical properties of chalcone thin films, with possible application for optoelectronics
devices. The characterization process involved crystallographic analyses, a theoretical approach and other
experimental data. Also, Maidur et al. (2018)18 and Patil et al. (2016)19 studied third-order nonlinear
properties of two novel chalcone derivatives. Analogously, Chaudhry et al. (2017)20 showed through
computational study the potential nonlinear optical application of a novel chalcone. Many times,
chalcones can be associated with other molecules like polymers and composite materials. Shetty,
Raghavendra, and Dharmaprakash (2016)21 doped a chalcone with films of poly(methylmethacrylate)
representing a good candidate for an optical power limiting application.
Considering the wide use of chalcones, computational analysis is an important tool used for
describing and obtaining the molecular geometry in different media, such as solution or gas phase. Thus,
theoretical calculations can be applied to estimate the physical chemistry properties, such as nonlinear
optical (NLO) properties in different solvents. Indeed, this approach has been used in many studies. For
instance, Shkir et al., (2018) 22 describes the theoretical second and third nonlinear optical properties of a
novel D-π-A type chalcone derivative. Similarly, AlFaify et al. (2018) used computational methodologies
to describe electronic, spectroscopic and nonlinear optical properties of l-threoninium picrate (LTHP)
molecule 23.
In this sense, this paper aims to present the structural elucidation of a novel dimethoxy amino
chalcone (DAC), as well its theoretical nonlinear properties. The molecular structure of the proposed
chalcone was confirmed using Single Crystal X-ray Diffraction and spectroscopic analyses. Hirshfeld
surfaces were used for an improved understanding of the supramolecular arrangement and intermolecular
interaction. In addition, the electrical properties of DAC crystal were calculated by using the
supermolecule method (SM) to simulate the crystalline environment polarization on a DAC isolated
molecule.

Experimental and computational procedures
Synthesis and Crystallization
An ethanolic solution of sodium hydroxide 30% (w/v) (10 mL) was added in a flask along
with 2-aminoacetophenone (2 mmol). The reaction system was stirred until complete dissolution of the
acetophenone, then 3,4- dimethylmethoxybenzaldehyde (2mmol) was added to the mixture and the
reaction accompanied by CCD (Scheme 1). At the end of the reaction, a small amount of hydrochloric
acid 10% (v/v) was added to neutralize the system. The product was filtered and recrystallized by slow
evaporation from ethanol as solvent.
O
O
O
CH3
H
NaOH/EtOH
+
T.A
NH2
MeO
NH2
OMe
OMe
OMe
Scheme 1: Synthesis of DAC
Crystallographic characterization
A well-shaped single crystal of DAC was selected from the glass vial after crystallization for the
single crystal X-ray diffraction (SCXRD) experiment (Table 1). The crystal structure was elucidated
based on Mo Kα intensity data acquired on a Bruker-AXS Kappa Duo diffractometer. These intensity
data, measured on a APEX II CCD detector, were processed using SAINT24 and SADABS24 before
25
inputting them into the SHELXS-2014
program to solve structure with direct methods of phase
retrieval. The initially solved model was refined using full-matrix least-squares on F² with SHELXL-
201425.

Non-hydrogen atoms were refined respectively with free anisotropic and fixed isotropic [Uiso(H) =
2
3
1.2 Ueq (Csp or N) or 1.5Ueq (Csp )] displacement parameters. Hydrogen positions were defined
according to stereochemical assumptions and oscillated as the position of each bonded non-hydrogen
atom. A summary of crystal data and refinement statistics of DAC is displayed in Table 1. Interpretation
of the structure and graphical drawings were dealt with by MERCURY26 and ORTEP-327.

Table 1: Crystal data and Refinement Parameters of DAC
Structural formula
Formula weight
C17H17NO3
283,32 u.a
Monoclinic, C2/c
a = 31.262
b =4.289
c =25.694
α =90
Crystal system, space group, Z
Unit cell dimensions (Å)
Unit cell dimensions (º)
β=121.75
γ=90
Volume (ų)
Calculated density (g/cm³)
Absorption coefficient (mm-1)
Absorption correc. Tmin/Tmax
F(000)
2929.567
1.285
0.088
multi-scan Tmin/Tmax=0,542
1200
Z
8
θ range for data collection (deg)
index ranges
0.932-25.217
-36 to 36
-4 to 5
-30 to 21
6787
data collected
unique reflections
symmetry factor (Rint)
completeness to θ°max (%)
parameters refined
Goodness-of-fit on F²
Final R indices [I>2σ(I)]
R1 (all)
2584
0.0565
98.0
191
1.120
3.657
0.0844 (0.1165)
0.2656 (0.3176)
0.235/ -0.267
1589863
wR2 (all)
largest diff. peak hole (e/Å3)
CCDC deposit no.
Hirshfeld Surface Analysis
The Hirshfeld surface (HS) arose from an attempt to define the space occupied by a molecule in a
crystal in order to partition the crystal electron density into molecular fragments28,29. For this, a weight
function for each atom in a molecule is defined as
ꢃꢈꢄ ꢆ
ꢇꢃ
ꢅ
ꢄ ꢆ
ꢂꢃ ꢅ =
∑
ꢃꢈꢄ ꢆ
ꢉ∈ꢊꢋꢌꢍꢎꢏꢌꢍ ꢇꢉ
ꢅ
ꢃꢈꢄ ꢆ
where ꢇꢉ ꢅ are spherically averaged electron densities of the various atoms. Then, the electron
density of an atomic fragment can be defined as

ꢄ ꢆ
ꢇꢃ ꢅ = ꢂꢃ ꢅ ꢇ
ꢄ ꢆ ꢊꢋꢌꢄ ꢆ
ꢅ
ꢊꢋꢌꢄ ꢆ
ꢅ indicates the molecular electron density.
where ꢇ
It is a powerful graphical tool for molecular interaction analysis, evaluating the electronic
distribution in the environment external to the molecule30. The dnorm surface evaluates the distances
between atomic nucleus internal atoms and the HS (di) and the distance from the surface to the nearest
atom in the molecule (de), normalizing them as a function of van der Waals radius.
Instead of plotting de and di on the Hirshfeld surface, contact distances are normalized in Crystal
Explorer using the van der Waals radius of the appropriate internal and external atom of the surface31:
ꢐꢑꢋꢒꢊ = ꢓꢐꢉ − ꢅꢔꢕꢖꢗꢘꢅꢔꢕꢖ + ꢐꢍ − ꢅ
ꢔꢕꢖ
ꢄ
ꢔꢕꢖꢆ⁄
ꢅ
ꢍ
ꢍ
ꢉ
ꢉ
The blue color indicates low intensity, and red color indicates high intensity of contacts. In
addition, hydrophobic interactions are represented by shape index surface as large red and blue regions of
concave and convex curvature. This surface is a measure of ‘‘which’’ shape, defined in terms of principal
curvatures k1 and k2:
2
ꢠꢡ + ꢠꢢ
ꢠꢡ − ꢠꢢ
ꢙ = ꢛꢅꢜꢝꢛꢞ ꢟ
ꢚ
ꢣ
Shape index has the useful property that two shapes that differ by only a change of sign represent
complementary pairs and, because of this, maps of shape index on the Hirshfeld surface can be used to
identify complementary hollows (red) and bumps (blue) where two molecular surfaces touch one
another28.

Fig. 1: An outline of the bulk is displayed.
Powder Diffraction
The XRPD patterns of DAC were recorded using a XPERT PANalytical diffractometer with
filtered Kα1 radiation of a Cu tube, operating at 40 kV and 45 mA, equipped with X’Celerator detector.
To perform more accurate XRPD measurements 7 and 12 keV photons were used at XRD1 beam line of
Brazilian Synchroton, at 100K and room temperature. All measurements were carried out in transmission
mode holding the gently grind sample in 0.7 mm glass capillary. Procedures for the structural
determination were performed by DASH³²³²(32)(31) (30) using the XRPD
data and the molecular structure information obtained by NMR. To accomplish Rietveld analyses from
CIF corresponding to single crystal data analysis Diffrac.suite TOPAS version 4.2 was used considering
the Fundamental Parameters Approach (FPA).
Infrared and Raman spectroscopies
The infrared absorption spectra of DAC were obtained in KBr, ca. 1% solution, on FTIR/IR
Affinity-1 Shimadzu spectrophotometer. Moreover, to correct the systematic overestimation of the
vibrational frequencies, which is characteristic of the DFT methods33, a scale factor of 0.958 was applied

34
in the theoretical values . This provides more reliable values to compare to the experimental data from
2.6 NMR spectroscopy.
Raman spectra of different regions of a DAC crystal sample surface were collected with 20x
objective lens at room temperature using a PeakSeeker 785 (RAM – PRO – 785) Raman system with a
diode laser of 785 nm and 50 mW at the source. The backscattered Raman radiation was dispersed with a
grating and focused on a Peltier-cooled charge-coupled device CCD detector allowing us to obtaining a
spectral resolution of 6 cm-1. All spectra were recorded at room temperature in the spectral window of
(from 200 – to 2000) cm-1 with same acquisition time (10 s).
NMR spectroscopy
All NMR experiments were run on a BRUKER, DRX400 MHz equipment at 9.4 T, in a BBO 5
mm probe, at 298 K, and TMS (tetramethylsilane) for internal reference. For 1H, 13C NMR, DEPT135
and HSQC, CDCl3 was used as solvent. The splitting of proton and carbon resonances was reported as s=
singlet, d= doublet. 1H NMR δ (ppm): δ 3.93 (s ; 3H ; 4-OMe) ; δ 3.95 (s ; 3H ; 5-OMe) ; δ 6.29 (broad
single ; 2H ; -NH2 ) ; δ 6,70 (m ; 2H) ; δ 6.89 (d ; 1H ; 8.36 Hz) ; δ 7.15 (d ; 1H ; 1.59 Hz) ; δ 7,22 (dd ;
1H ; 1.86 e 8.18 Hz) ; δ 7.28 (m ; 1H) ; δ 7.47 (d ; 1H ; 15.50 Hz ; Cα) ; δ 7.69 (d ; 1H ; 15.50 Hz); δ 7.86
(m; 1H). 13C NMR δ (ppm): 191.7; 151.1; 150.8; 149.2; 143.1; 134.1; 130.9; 128.2; 122.7; 121.0; 119.3;
117.2; 115.8; 111.1; 110.0; 55.9.
To study the electrical properties of the DAC crystal we used the supermolecule method (SM) to
simulate the crystalline environment polarization on a DAC isolated molecule. This approach works with
a bulk consisting of a set of 11x11x11 unit cells, where each unit cell has 8 asymmetric units and each
asymmetric unit has 38 atoms, creating a bulk with 404624 atoms; as can be seen in an outline in Figure
1, the isolated DAC is in the middle of the bulk with a blue outline. The atoms that surround the isolated
molecule were considered as point charges.

Computational Methodology
To study the electrical properties of the DAC crystal we used the supermolecule method (SM) to
simulate the crystalline environment polarization on a DAC isolated molecule. This approach works with
a bulk consisting of a set of 11x11x11 unit cells, where each unit cell has 8 asymmetric units and each
asymmetric unit has 38 atoms, creating a bulk with 404624 atoms; as can be seen in an outline in Figure
1, the isolated DAC is in the middle of the bulk with a blue outline. The atoms that surround the isolated
molecule were considered as point charges.
The SM approach was used in Ref.35 to represent the dipole moment and the first
hyperpolarizability with results close to the experimental ones. In Ref.36, the authors calculated the
macroscopic properties of the linear ꢤꢄꢥꢆand second order nonlinear ꢤꢄꢦꢆcrystal susceptibilities for urea
and thiurea, using the SM approach, and their theoretical results were close to the experimental ones. In
Ref.37 the authors also simulated the properties of ꢤꢄꢥꢆ and ꢤꢄꢦꢆof the molecule 3-methyl-4-nitropyridine-
1-oxide with results again close to the experimental ones.
The iterative process of SM is carried out in several steps: First we determined the electric charge
of the isolated molecule, by adjusting the molecular electrostatic potential through a CHELPG fit,
considering the electric charge distributions in vacuum through the MP2 method, using ꢧ − ꢨꢥꢥ + ꢩꢄꢪꢆ
basis set 35,38. The partial atomic charges of the single isolated molecule of an asymmetric unit are
calculated by ꢫꢬꢭꢮꢯꢩ. Then we replace each corresponding atom in the unit cells generated by the
previously obtained partial atomic charge, and the static electric properties and the new partial atomic
charges of the asymmetric unit are calculated. The iterative process continues with the substitution of the
partial atomic charges in each calculation step, until the convergence of the electric dipole moment is
reached; see Figure 2.

Fig.2. Evolution of values of the dipole moment of the DAC with the respective iteration numbers. Step 0
indicates the isolated molecule, and the other steps indicate the DAC crystal.
ꢄ
ꢆ
The components and the average values of electronic dipole moment ꢰꢱ, ꢰ , molecular linear
〈 〉
polarizability ꢄꢲꢱꢳ, ꢲ ꢆ and anisotropy of linear polarizability ꢄ∆ꢲꢆwere calculated using the MP2 theory,
and Density Functional Theory (DFT) at level ꢫꢴꢵ − ꢶꢨꢮꢷꢯ was employed for the calculation of the
〈 〉
components and the average values of the second hyperpolarizability ꢄꢸꢱꢳꢹꢺ, ꢸ ꢆ. The set basis ꢧ − ꢨꢥꢥ +
ꢩꢄꢪꢆwas used in both calculation methods.
The electrical parameters of the DAC crystal were calculated using the following expressions for
the total dipole moment,
ꢡ
ꢻ = ꢓꢻꢼꢢ + ꢻꢽꢢ + ꢻꢾꢢꢗꢢ,
(1)
average linear polarizability,
ꢿꢼꢼ + ꢿꢽꢽ + ꢿꢾꢾ
(2)
(3)
〈 〉
ꢿ =
,
3
anisotropy of linear polarizability,
ꢡ
ꢘ
ꢢ
∆ꢿ = 2ꣀꢡ ꣁꢓꢿꢼꢼ − ꢿꢽꢽꢗꢢ + ꢓꢿꢽꢽ − ꢿꢾꢾꢗ + ꢿꢾꢾ − ꢿꢼꢼ + 6ꢄꢿꢼꢾꢢ + ꢿꢼꢽꢢ+ꢿꢽꢾꢢꣂ ꢢ ,,
ꢘ
ꢢ
ꢄ
ꢆꢢ
first total hyperpolarizability,

ꢡ
ꢢ
ꢢ
(4)
(5)
꣄ꢄ
ꢆꢢ
ꢄ
ꢆꢢ
ꢄ
ꢆ ꣈
ꣃꢈꢋꢈꢃꢌ
=
ꣃꣅꣅꣅ + ꣃꣅ꣆꣆ + ꣃꣅ꣇꣇ + ꣃ꣆꣆꣆ + ꣃ꣆꣇꣇ + ꣃ꣆ꣅꣅ
+
ꣃ꣇꣇꣇ + ꣃ꣇ꣅꣅ + ꣃ꣇꣆꣆
,
and average second hyperpolarizability,
1
〈 〉
꣉ =
꣊
ꢓ꣉ꢉꢉ꣋꣋ + ꣉ꢉ꣋ꢉ꣋ + ꣉ꢉ꣋꣋ꢉꢗ.
15 ꢉ,꣋꣌ꢼ,ꢽ,ꢾ
Here the medium optical dispersion was not taken into account; therefore, the mean value (or
absolute value) of the static second hyperpolarizability can be simplified by using the Kleinmann39
approximation and calculated through the expression,
1
(6)
〈 〉
꣉ = ꣍꣉ꢼꢼꢼꢼ + ꣉ꢽꢽꢽꢽ + ꣉ꢾꢾꢾꢾ + 2ꢓ꣉ꢼꢼꢽꢽ + ꣉ꢼꢼꢾꢾ + ꣉ꢽꢽꢾꢾꢗ꣎.
5
〈 〉
The relation between the average linear polarizability ꢿ and the crystal linear refractive index (n)
is given by the Clausius- Mossotti equation 40, which is,
ꢞꢢ − 1
ꢞꢢ + 2
4ꢚ꣏
3
(7)
〈 〉
ꢿ ,
=
where N is the number of molecules per unit cell volume. The third-order electric susceptibility
(꣐ꢄ꣑ꢆ) is related with the average second hyperpolarizability by the expression 40,
ꢄ ꢆ
꣑
꣓
(8)
〈 〉
= ꣒ ꣏ γ ,
꣐
where f is the Lorentz local field correction factor given by,
ꢢ
ꢄ
ꢆ
ꢞ + 2
(9)
꣒ =
.
3
All the numerical results for the tensors’ polarizability and hyperpolarizabilities were obtained
from the Gaussian 0941 output file and converted by electronic units (esu).
For the theoretical calculations, the molecular geometries of DAC were carried out from the
crystallographic information file (CIF). Then this geometry was fully optimized using the density
functional theory (DFT) implemented in the Gaussian 09 package41, with the Handy and co-workers long-

range corrected version of B3LYP using the Coulomb-attenuating method, CAM-B3LYP42 as functional
and, as basis set, we used the 6-311+G(d) of Pople and co-workers43.
Results and discussion
Solid state characterization
The DAC compound, bearing two methoxy groups at 3’,4’-positions of ring B and an amine group
at 2-position of ring A, crystallized with one crystallographically independent molecule (Z′ = 1) in a
monoclinic space group C2/c (Z′ = 8) (see Table 1 for a summary of crystal data). Its conformation does
not differ much from those of the two polymorphs of the 3’,4’,5’-trimethoxy-2-amino analog 44,45. Its
molecule is almost completely planar, except for slight rotations on the three single bonds of the open-
chain (C1–C7, C7–C8 and C9–C10), as Figure 3 shows.
Fig 3. 30% probability ellipsoid plot of DAC. Non-hydrogen atoms are arbitrarily labelled, and hydrogen
atoms are shown as spheres of arbitrary radii. Colored area denotes the ꢙꢡꢡ(6) ring.
This conformational feature can be viewed in the slight twist of 13.0(2)° between the two least-
squares planes calculated through ring A (see Figure 3 for labeling scheme of chalcone rings) and through
the propanone non-hydrogen atoms. The coplanarity between the central mean plane calculated through
O1, C7, C8 and C9 and ring B is still higher (the bent angle between their least-square planes is

9.89(18)°). The torsions around C1–C7 and C9–C10 also describe the coplanarity between both ring A or
B and the propanone moiety, respectively (Table 2).
Table 2: Selected torsion angles of DAC
Torsion
DAC
C6–C1–C7–C8
C6–C1–C7–O1
C2–C1–C7–O1
C2–C1–C7–C8
C9–C8–C7–O1
C9–C8–C7–C1
C8–C9–C10–C11
C8–C9–C10–C15
C11–C12–O2–C16
14.3(7)
-168.5(5)
11.3(8)
-165.9(5)
9.1(8)
-173.5(5)
-9.1(8)
166.6(5)
1.2(7)
C13–C12–O2–C16
C12–C13–O3–C17
C14–C13–O3–C17
-178.9(4)
179.3(4)
0.1(7)
These two planarity deviations arose from the steric hindrance between vicinal hydrogen atoms
bonded to C8 carbon and the carbons at the ortho-position of rings A and B44. As a consequence of these
planarity deviations, phenyl rings A and B are twisted by 19.18(16)°. Likewise, the torsion values on the
C7–C8 bond axis evidenced a subtle coplanarity deviation in the propanone moiety (Table 2), as
mentioned above. All torsions around this three-bond axis measure close to either 0° or 180°.
Contrary to the aforementioned trimethoxy analog, which is present with the methyl moiety of
methoxy in the para-position, and is outside the phenyl ring B plane, both methyl groups of DAC are
coplanar to phenyl ring B. Furthermore, an anti (also called s-cis) conformation around C7–C8 can be
described compound for 1, which is preferred over the syn one in chalcone class 46–49
.
Concerning the non-covalent contact pattern, an intramolecular hydrogen bond is formed between
1
the carbonyl and amine groups, assembling a S1 (6) ring. The other amine hydrogen, which is not
involved in this hydrogen bonded intramolecular motif, is engaged in bifurcated non-classical hydrogen
bonds with both methoxy oxygens of a glide-symmetry-related molecule, giving rise to a ꢫꢦꢥ(11) running

along [001]. Interactions involving the amine and methoxy groups are also found in one of the two
polymorphs of the 1-like compound present with one further methoxy moiety at 5-position of ring B.6 In
the other polymorph, amine groups are intermolecularly involved only in N-H…p contacts5. In addition,
two of these one-dimensional chains, growing in opposite directions parallel to the c axis, are cross-linked
through a weak non-classical hydrogen bond between the carbonyl oxygen and the para-position methyl
group of 21-screw axis symmetry related neighbors (Figure 4). This last contact, together with the chain
motif, gives rise to a second level ꣔ꢨꢦ(9) motif made up of four hydrogen bonded molecules, constituting
the main supramolecular entity of the crystal packing of DAC.
Fig 4. Crystal packing of DAC showing the chains running in the opposite direction along the [001] direction
(framed). Only hydrogens involved in the shown contacts are displayed. H…A and D-H…A
measurements are shown. Colored area denotes the ꣕꣑ꢢ(9) motif.

Hirshfeld surface (HS) analysis was used for an improved understanding of intermolecular
interactions and their role in the supramolecular arrangement of DAC. The first approach involves the
normalization of de and di contacts on a unique surface named dnorm, showed in Figure 5 with the
fingerprint plots for H-O contacts. By analyzing the red spots on the HS, it can be noted that the N1-
H1A⋯O3 interaction is slightly stronger than the N1-H1A⋯O2 interaction (red spots more intense),
which is confirmed by distances between donor and acceptor atoms (3.058 Å and 3.288 Å, respectively).
In addition, H bonds are characterized on the fingerprints plots of Figure 5 as two pointed peaks, where
the upper peak corresponds to donor regions and lower peak corresponds to acceptor region.
Fig 5. HS dnorm of DAC showing the intensity of selected H-Bond, followed by the fingerprint plots of H-O
contacts.
The crystal packing of DAC is also stabilized by both π⋯π and C-H⋯π interactions, as showed in
Figures 6(a) and 6(b). There is one interaction between dimethoxy rings (represented by Cg1, in red) and
one other between the amino rings (represented by Cg2, in blue), with Cg⋯Cg = 4.289 Å. This π⋯π
interaction is recognized as two triangular shapes like a bowtie over aromatic rings on HS (Figure 6(c))

and is highlighted blue with de ≈ di ≈ 1.8 Å in the fingerprint plot (Figure 6(e)). Also, there is an
interaction between atoms C15 and H15 and Cg2 [D-H···A = C-H⋯Cg2; d(D-H) = 0.930 Å; d(H. ..A)
=
3.532 Å; d(D...A) = 4.435 Å; ∡(D-H...A) = 164.57°], evidenced by a large red depression over the dimethoxy
ring (acceptor region) and a blue convex spot over H15 in the shape index HS (Figure 6(d)). Finally, these
interactions are represented by C-H contacts and look like “wings” in the fingerprint plots (Figure 6(f)).
Fig 6. π···π and C-H···π interactions involved in the crystal packing of DAC (a); Evidence of these
interactions in the shape index HS (b) and fingerprints plots for C···C and C···H contacts (c).
The solid-state characterization was expanded to DAC in powder form, and the structure
determined by single-crystal DRX showed to be stable in ambient conditions; however, it underwent a
structural phase transition at about 100 K (see Figure 7). The structural parameters refined by Rietveld
Method using synchrotron radiation are shown in Table 1.
From the low temperature measurements, one can see an unexpected phase transition, where the
low-temp phase seems to have larger lattice parameters (see most intense peaks shift to higher d values).

The Bragg peaks referring to C2/c structure become broad, suggesting the reduction of its crystalline size
domain.
Fig 7. Calculated (red lines) and experimental (black lines) XRPD patterns of DAC collected with different
excitation energies at room temperature and low temperature (100 K).
Spectroscopic characterization
The vibrational spectral analysis is discussed based on the characteristic vibrations of the main
absorbing groups of DAC. Detailed vibrational assignments of main IR and Raman modes (theoretical
and experimental) are shown in Table 3. For visual analysis, the observed and simulated FTIR and FT-
Raman spectra are overlapped, as presented in Figures 8(a) and 8(b). The observed discrepancies are
justified because the calculations were made for an isolated molecule in a vacuum, while the experiments
were performed using a solid sample.

Fig 8. Overlapped experimental (red) and theoretical (black) IR and Raman spectra of DAC (a) from 0 to
4000 cm-1 and zoomed region (b) from 200 to 2000 cm-1.
Table 3. Vibrational assignments, scattering activities and scaled frequencies (cm-1) calculated, with CAM-
B3LYP/6-311+ G(d), to C17H17NO3. a) Scale factor:0.958; b) Scale factor:0.955. * indicates the most intense
experimental peaks.
Raman
scattering
activities
Scaled
Raman
freq.b
Unscaled IR
freq.
IR scattering
activities
Scaled IR
freq.a
Exp. IR
freq.
Exp. Raman
freq.
Rigid Rings A-B bending; Amine stretching out off plane
280.36
294.64
86.1
83.3
1.6
268.6
282.3
267.7
255.0
277.6
337.2
395.4
409.6*
The same as before + torsion of H around C(27) in CH3 of ring
B
1.1
281.4
491
508
In plane stretching ring A; bending O(5) and H around C(27)
574.35
35.6
10.6
550.2
548.5

525
556
428.9
490.9
508.3
527.3
560.0
600
615
Out off plane and out off phase H stretching in amine
In plane stretching ring B;
638.8
52.69
36.6
3.8
2
612.0
655.1
610.1
653.0
618.5
683.81
660
687*
719
734*
765
811*
820
844*
861
Out off plane stretching of H of ring A
768.99
840.9
52.4
3.5
736.7
734.4
768.3*
815.8
856.2
Out off plane stretching of H of ring B
36.29
1
805.6
803.1
925
980*
Out off plane stretching of H of the open ring
1038.02
1043.13
41.7
52.5
994.4
999.3
991.3
996.2
Almost planar Out off phase stretching of H of the open ring;
in plane stretching of ring A
In-plane deformation/breathing mode of ring A and out-off
phase of H in amine
120.2
219.6
978.0
1007
1023
1062.1
1082.62
1099.54
61.13
65.2
17.7
35.6
2.5
1017.5
1037.1
1053.4
1014.3
1033.9
1050.1
1004.9*
In-plane deformation mode of ring B
Another In-plane deformation/breathing mode of ring A and
out-off phase of H in amine
120.6
1044.0
1045
Out off phase vibrations of H(20) and H(8) causing a slight In-
plane deformation of ring B
1183.22
1194.86
1209.2
54.1
254.19
113
55
17
1133.5
1144.7
1158.4
1130.0
1141.1
1154.8
1080.1
1142.8
1156.4
1081
1145*
1153*
Out off phase In-plane vibrations of H in ring A
Breathing mode of ring B caused by in-phase and in-plane vib
of H of CH3´s
159.4
Similar Breathing mode of ring B caused by in-phase and in-
plane vib of H of CH3´s
In-phase vib of H in the open ring; slight breathing of ring A
caused by in-plane H vib and C(16)-C(10) stretching
Similar In-phase vib of H in the open ring; slight breathing of
rings A and B
Deformation of rings A and B; stretching o C(11)-O(1)
connecting CH3
In plane Deformation of rings B; huge displacement of H(8)
and alternate stretching of C-O connecting CH3´s
Similar In plane Deformation of rings B; huge displacement of
H(3 and H(15) in the open ring
In plane Deformation of rings A and B; huge out-off phase
displacement of H(20) and H(15)
In plane Deformation of rings A and B; huge out-off phase
displacement of H(22) and H(18)
In plane Deformation of rings A and B; huge displacement of
H(22)
In plane Deformation of rings A and B; huge displacement of
H(13) linked to the open ring
1237.49
1244.62
1288.11
1311.48
1316.05
1321.4
72.5
383.55
80.1
188.3
35
1185.5
1192.3
1234.0
1256.4
1260.8
1265.9
1295.1
1306.9
1327.0
1350.1
1181.8
1188.6
1230.1
1252.5
1256.8
1261.9
1291.1
1302.8
1322.9
1345.9
1210*
1196.1
21.64
51.22
291.7
17
1233
130.2
248.6
119.3
146.6
126.21
23
1236.1
1273.0
1261*
1275
1351.93
1364.19
1385.2
8.7
218
1325.0
1345.9
1307*
1325
1359
75.6
247.7
1409.32
43.7
1421
1438
1452
1466
1486
In plane Deformation of ring B; huge displacements of H(20)
and H´s linked to C(27) in CH3
1477.72
70.13
230.78
1415.7
1411.2
1362.1
In plane Deformation of ring A; huge displacements of H(32),
(38) and (22); C(10)-O(9) stretching
In plane Deformation of ring B; huge displacements of H(28),
(29) and (30) linked to C(27) in CH3
1502.96
1511.2
13.7
21.9
319.6
179.9
1439.8
1447.7
1435.3
1443.2
1420.9
1446.5*
1511*
1544
huge displacements of H´s linked to C(33) in CH3
huge displacements of H´s linked to C(27) in CH3
1526.84
1527.66
77.15
49.2
16.2
10.5
1462.7
1463.5
1458.1
1458.9
1466.2
1488.4
In plane Deformation of ring A; huge displacements of H(32),
(18) and (22);
In plane Deformation of ring B; huge displacements of H(8),
(2) and (20), C-O alternate stretching and in phase vib of H´s
in CH3´s
1541.23
1580.01
48.75
168.2
191.5
1476.5
1513.6
1471.9
1508.9
1512.0
1577*
1599
532.366
1546.1*
In plane Deformation of ring A; huge displacement of H(38),
and in phase vib of H´s in NH2
In plane Deformation of rings A and B; huge displacements of
H(25) and H(26) in NH2; C(10)-O(9) stretching
In plane Deformation of rings A and B; huge displacements of
H(25) and H(26) in NH2 (opposite to the previous mode);
1620.78
1652.29
1656.75
105.5
463.09
161.9
768.8
986
1552.7
1582.9
1587.2
1547.8
1577.9
1582.2
1576.2*
1592.3*
1617*
1644*
23.3

C(10)-O(9) stretching
In plane Deformation of ring B; huge displacements of H(3)
and H(20); as well as H(25) and H(26) in NH2; C(10)-O(9)
stretching
1675.45
121.6
4195.8
1605.1
1600.1
1601.1*
Almost the same as previous
1685.24
1696.04
1742.82
33.44
204.55
279.6
378.94
407.35
649.9
1614.5
1624.8
1669.6
1609.4
1619.7
1664.4
1615.1
1626.6
1644.2
Similar vibration of NH2, without C=O vib; but causing a huge
deformation of ring A
Hugh stretching of C(10)-O(9) and C(12)=C(14) in the open
ring , slight deformation of rings A and B
1645
2830
2839
2936
2960
2971
2987
3002
3038
3075
H breathing mode in CH3, mainly in that of C(27)
H breathing mode in CH3, mainly in that of C(33)
Out-off phase vib of H(29) and H(30) in CH3, that of C(27)
3037.96
3042.14
3100.52
49.7
61.54
34.58
82.33
184.31
35.4
2910.4
2914.4
2970.3
2901.3
2905.2
2961.0
Out-off phase vib of H(35) and H(36) in CH3, that of C(33)
3105.97
36.51
65.23
2975.5
2966.2
H´s stretching/breathing mode in NH2
Out-off phase vib of H´s in NH2
3580.13
3732.12
93.1
83.2
383
3429.8
3575.4
3419.0
3564.2
3330
3548
67.1
As Figure 8(a) shows, in the region of 3050 cm-1 to 3010 cm-1 bands of aromatic CH stretching
vibrations usually appear 50. These theoretical values calculated in this paper are in the region of 3063 cm-
1 to 3098 cm-1, while in experimental IR these vibrations are in the region of 3072 cm-1 to 3003 cm-1.
The carbonyl group stretching vibrations appear for flavonoid and chalcone derivatives in the
spectral region 1660 – 1580 cm-1 as a consequence of the conjugation effect that increases the single bond
character of carbonyl and vinyl groups51. These vibrational modes are observed in the experimental IR
spectrum in 1617 cm-1 and 1644 cm-1, respectively, and in 1576.2 cm-1 and 1592.3 cm-1 in the
experimental Raman spectrum. This value for a vinyl group is in good agreement with the expected value
of 1660 – 1600 cm-1 for this vibrational mode. Additionally, DFT calculations assign the C=O band at
1614 cm-1 and the C=C band at 1669 cm-1.
The O-CH3 stretching vibration appears in the wide region between 850 and 1100 cm-1 with an
intensity varying from weak to strong52. These bands are observed in 1045 cm-1 and 1024 cm-1 in
vibrational spectra of ABC; on the other hand, 1037 cm-1 and 1058 cm-1 are the theoretical values for this
vibration. The asymmetric stretching of the methoxy group attached to an aromatic ring appears in the
range 1310 to 1210 cm-1 52. DFT calculations and experimental IR give the range of 1260 cm-1 to 1234
cm-1 as asymmetric methoxy stretching vibrations.

For the amino group, N-H stretch vibrations occur between 3500 cm-1 and 3300 cm-1, primary
amines generate two bands, of which the higher frequency band in the pair is due to asymmetric vibration,
while the lower frequency band results from symmetric vibration50. In the present study, these stretching
modes are assigned at 3575 cm-1 and 3429 cm-1 in IR spectrum and at 3568 cm-1 and 3458 cm-1 for
theoretical spectra (Figure 8(a)). The blue shifting of NH2 symmetric stretching is due to the formation of
intramolecular N-H…O hydrogen bonding. The N-H scissoring mode, in primary amines, appears as a
medium to strong intensity band between 1640 cm-1 and 1560 cm-1 50, while rocking deformation is
expected in the 1090–1060 cm-1 region53 and, finally, the wagging mode is expected in the range 520-720
cm-1 54. Our theoretical values for these vibrational modes are 1605 cm-1, 1017 cm-1 and 612 cm-1,
respectively. These values are in good agreement with experimental IR and Raman, as can be seen in
Table 3 and Figure 8(b).
The C-N stretch absorption in aromatic amines occurs at 1350 to 1250 cm-1 as a medium to strong
intensity band. This absorption occurs at a higher frequency because the resonance enhances the double
50
bond character between the ring and the atom of nitrogen bound to it . This stretching mode appears in
IR at 1307-1359 cm-1 and in DFT at 1307-1350 cm-1.
For the methyl group, we analyzed the C−H stretching modes. In sp3 C−H stretch, there are two
important bands: 2962 cm-1 for asymmetric stretch, and 2872 cm-1 for symmetric stretching vibration
mode 50. The features at 2830 - 3075 cm-1 region in the IR spectrum can be assigned to these vibrational
modes, while our DFT calculations show these modes around 2975 cm-1 and 2910 cm-1, respectively.
Nonlinear Optical Properties
In this section our theoretical results for the electrical parameters of the DAC crystal are
presented. We can see from Table 4 that the value of the average electric dipole is 1.22D and the value of
the average linear polarizability is ꢨꢨ. ꢨꢨ × ꢥ꣖ꣀꢦ꣗꣘꣙꣚. The y-component of the dipole moment gives the
greatest contribution for the ꢰ-value, and the diagonal components of the linear polarizability tensor,

which are responsible for the calculation of the mean polarizability (equation (2)), are those with the
highest values, highlighting the component αzz, which contributes almost half of the 〈α〉-value. The off-
diagonal terms are considered in the anisotropy of linear polarizability calculated through equation
(3),which have the value ꢀꢁ. ꢂꢁ × ꢃꢄꢅꢀꢆꢇꢈꢉ. Also, in Table 4 the ꢊꢋꢌ − ꢍꢎꢏꢐꢑ/ꢒ − ꢎꢃꢃ + ꢓ(ꢔ)
results for the second hyperpolarizability (in ꢃꢄꢅꢎꢒ esu) for DAC crystal are presented. As can be noted,
the tensor component ꢕꢖꢖꢖꢖ is much larger than the other -components and participates with more than
〈 〉
65% of ꢕ -value.
Table 4. MP2/6 – 311 + G(d) results for the compounds and average values of the dipole moment (D) and linear
polarizability (in 10-24 esu) and CAM – B3LYP/6 – 311 + G(d) results for the second hyperpolarizability (in 10-36
esu) for DAC crystal.
ꢗꢙ
〈 〉
ꢗ
ꢗꢘ
ꢗꢚ
0.76
ꢛꢘꢘ
-0.92
ꢛꢘꢙ
-0.22
ꢛꢙꢙ
1.22
ꢛꢘꢚ
ꢛꢙꢚ
9.11
〈 〉
ꢛ
ꢛꢚꢚ
30.17
ꢜꢘꢘꢘꢘ
19.73
4.52
23.12
ꢜꢚꢚꢚꢚ
-5.12
ꢜꢘꢘꢙꢙ
6.69
46.70
ꢜꢘꢘꢚꢚ
28.87
33.33
ꢜꢙꢙꢙꢙ
16.95
ꢜꢙꢙꢚꢚ
19.93
〈 〉
ꢜ
281.28
85.79
The linear refractive index for the DAC crystal calculated from equation (7) is ꢝ = ꢃ. ꢆꢞꢆ, and
with this value the Lorentz local field factor is ꢟ = ꢃ. ꢆꢃꢄꢁ. From these results and the value of the
average second hyperpolarizability, which is ꢁꢠ. ꢂꢞ × ꢃꢄꢅꢎꢒ esu, the third-order electric susceptibility
ꢡꢢ(ꢎ)ꢣ, which is an important parameter for determining the nonlinear optical properties of the crystals
and can be measured experimentally by the Z-scan technique, was calculated through equation (8), and
we found: ꢢ(ꢎ) = ꢃꢎ. ꢎꢃ × ꢃꢄꢅꢀꢀꢤꢀꢥꢅꢀ.
The DAC molecule can be considered a donor-acceptor-donor (D-A-D) type, where the
ꢦꢧꢀ group and the two ꢨꢊꢧꢎ groups behave like electron donors and the chalcone bridge as an electron
acceptor group. As the OMe group is a stronger donor group than ꢦꢧꢀ, the charge transfer occurs from

right to left in the DAC molecule, as shown in Figure 9 (a). The value of the ꢢ(ꢎ)for the DAC is high
when compared with other chalcone derivatives studied by the Z-scan technique by D’Silva et al.,
(2012)55; namely, (2E)-1-(4-bromophenyl)-3-[4-methylsulfanyl) phenyl]prop-2-en-1-one (4Br4MSP),
(2E)-1-(3-bromophenyl)-3-[4(methylsulfanyl)
phenyl]prop-2-en-1-one
(3Br4MSP)
and
(2E)-
3[4(methylsulfanyl)phenyl]-1-(4-nitrophenyl)prop-2-en-1-one (4N4MSP).The values of the third-order
electric susceptibility (in units of ꢃꢄꢅꢀꢀꢤꢀꢥꢅꢀ) of the chalcone derivatives 4Br4MSP and 3Br4MSP are
2.27 and 1.98 respectively55, while the value for DAC is 13.31, which is therefore 5.86 and 6.72 times
higher than these values, respectively.
The important fact to emphasize about this increase in ꢢ(ꢎ)for DAC (Figure 9(a)) when compared
with the other chalcone derivatives, showed in Figures 9(b) and 9(c), is the stronger donor character of
the two ꢨꢊꢧꢎ in comparison with ꢩꢊꢧꢎ, both bonded at the benzene ring, as can be seen in Figure 9.
Also, the electron donor character of the bromine is weaker than the ꢦꢧꢀ group, and the value of
ꢢ(ꢎ)increase as stronger is the donor group (or acceptor group).
As can be seen from Figure 9(d), the compound 4N4MSP present the highest value of the third-
order susceptibility, ꢢ(ꢎ) = ꢀ. ꢎꢒ × ꢃꢄꢅꢀꢀꢤꢀꢥꢅꢀ55, when compared with the other two 4-methilsulfanyl
chalcone derivatives cited above. In this particular case, the molecule type is a acceptor-acceptor-donor
(A-A-D) and the increase in the ꢢ(ꢎ) is attributed to the fact that the charge transfer occurs between the
two end molecule groups, donor and acceptor55, and the longer the charge transfer axis the greater is the
nonlinearity 55,56
.

Fig. 9. Four Chalcone derivatives, DAC (a), 4Br4MSP (b), 3Br4MSP (c) and 4N4MSP (d); on the right are
shown the values of the real part of the third-order electric susceptibility (in units of 10-22m2V-2 and the
molecule types donor-acceptor-donor (D-A-D) or acceptor-acceptor-donor (A-A-D).
〈 ꢄ
Figures 10(a), 10(b) and 10(c) show, respectively, the average linear polarizability ꢲ −꣛, ꣛
ꢆ〉
〈 ꢄ
ꢆ〉
〈 ꢄ
ꢆ〉
and the average second hyperpolarizabilities, ꢸ −꣛; ꣛, ꣖, ꣖ and ꢸ −ꢦ꣛; ꣛, ꣛, ꣖ , as a function of
the applied electric field frequencies. The behavior of the curves in Figures 10(a) and 10(b) is similar,
presenting a monotonic increase in the parameters with the increase in the frequencies. However, for

〈 ꢄ
ꢆ〉
〈 ꢄ
ꢆ〉
ꢪ = ꢄ. ꢃꢄ ꢫ. ꢉ.. the values of ꢲ −꣛, ꣛ and ꢸ −꣛; ꣛, ꣖, ꣖ reaches 1.3 and 5.3 times the static
value respectively, showing that this second parameter presents a more abrupt increase.
Fig. 10. Dynamic evolution of the calculated values of the linear polarizability (in 10-24 esu) and second
hyperpolarizability (in 10-36 esu) for DAC (( a), (b) and (c)) and with respective values of frequencies.
To enrich our understanding of the NLO optical properties of the DAC isolated molecule we
consider the effects of the several solvent media on the electric parameters, both in the presence of static
ꢄ ꢆ
and dynamic external electric field. The average values of electronic dipole moment ꢰ , average
〈 〉
molecular linear polarizability ꢲ , first hyperpolarizability parallel to dipole moment ꣜||꣝ꢄ꣖; ꣖, ꣖ꢆ and
〈 〉
the average value of the second hyperpolarizability ꢸ , were calculated using Density Functional Theory
(DFT) at level ꢫꢴꢵ − ꢶꢨꢮꢷꢯ with set basis ꢧ − ꢨꢥꢥ + ꢩꢄꢪꢆ. With this purpose, we have considered
the solvent media to be: chloroform (ε = 4.71), dichloromethane (ε = 8.93), acetone (ε = 20.49), ethanol (ε
= 24.85), methanol (ε = 32.61), dimethyl sulfoxide (ε = 46.70) and water (ε = 78.36), where ε denotes the
static dielectric constant of each solvent medium; the gas-phase (ε = 1.00) results are also presented for
comparison.
〈 〉
ꢀ , average linear polarizability
Table 5 shows the DFT results for the average dipole moment
〈
〉
〈
〉
ꢲꢄ꣖; ꣖ꢆ , first hyperpolarizability ꣜||꣝ꢄ꣖; ꣖, ꣖ꢆ and second hyperpolarizability ( ꢸꢄ꣖; ꣖, ꣖, ꣖ꢆ ) in

solvent media. As can be noted, the absolute values of all electric parameters increases with the increase
in the solvent dielectric constant value.
Table 5. CAM-B3LYP/6-311+G(d) results for the dynamic linear polarizability (in 10-24 esu), first static
hyperpolarizability (in 10-30 esu) and second static hyperpolarizability (in 10-36 esu) for DAC in several solvent
media.
ꣃ||꣞ꢄ0; 0,0ꢆ
〈 〉
ꢀ
〈
〉
〈
꣉ꢄ0; 0,0,0ꢆ
〉
Medium
ꢿꢄ0; 0ꢆ
Gas-Phase
Chloroform
Dichloromethane
Acetone
1.32
1.64
1.68
36.70
45.33
47.33
48.84
49.02
49.27
49.52
49.75
-14.93
-28.92
-32.32
-34.77
-35.12
-35.52
-35.91
-36.28
92.72
206.36
239.46
265.09
268.93
273.31
277.67
281.80
1.74
1.75
Ethanol
Methanol
1.76
1.77
1.78
Dimethylsulfoxide
Water
ꢄ
ꢆ
In Table 6 for ꣟ = ꢥ꣖ꢧ꣗. ꢥ꣠꣡ we present our results for ꢲ −꣛; ꣛ , ꣜∥꣝ꢄ−꣛;
ω
, ꣖ꢆ which
ꢄ
ꢆ
corresponds to the Pockels effect, and ꣜∥꣝ −ꢦ꣛; ꣛, ꣛ related with the second harmonic generation
ꢄ
ꢆ
ꢄ
ꢆ
(SHG). Also shown in Table 6 are the second hyperpolarizabilities, ꢸ −꣛; ꣛, ꣖, ꣖ and ꢸ −ꢦ꣛; ꣛, ꣛, ꣖ ,
which correspond to the dc-Kerr effect and dc-SHG. As can be seen, the variation of the absolute values
of the electric parameters does not show a well-defined increase with the increase in of the dielectric
constant value of the solvent medium, as observed previously in Table 4.
Table 6. CAM-B3LYP/6-311+G(d) dynamic results for the linear polarizability (in 10-24 esu), first static
hyperpolarizability (in 10-30 esu) and second hyperpolarizability (in 10-36 esu) for DAC in several solvent media
for λ= 1064.1 nm
ꢄ
ꢆ
ꢄ
ꢆ
ꢆ ꣃ ꣞ −꣢; ꣢, 0 ꣃ∥꣞ −2꣢; ꣢, ꣢
꣉ −꣢; ꣢, 0,0 ꣉ −2꣢; ꣢, ꣢, 0
ꢄ
ꢄ
ꢆ
ꢄ
ꢆ
Medium
ꢿ −꣢; ꣢
∥
Gas-Phase
37.84
43.04
-17.70
-30.70
-32.19
-32.54
-26.26
-45.68
-46.55
-45.55
114.96
225.27
241.89
248.21
197.83
391.25
406.40
401.39
Chloroform
Dichloromethane 42.93
Acetone
42.38

Ethanol
42.41
42.11
-32.73
-32.48
-33.76
-32.87
-45.74
-44.88
-47.60
-45.25
250.30
248.72
260.46
253.14
403.90
396.12
424.19
401.17
Methanol
Dimethylsulfoxide 42.92
Water 42.16
(
)
(
)
However, we can note that the greatest values of ꢬ∥ꢖ −ꢀꢪ; ꢪ, ꢪ ; ꢬ∥ꢖ −ꢪ; ꢪ, ꢄ ;
(
)
(
)
ꢕ −ꢀꢪ; ꢪ, ꢪ, ꢄ and ꢕ −ꢪ; ꢪ, ꢄ, ꢄ occur for DMSO (DiMethylSulfoxide), which is the polar solvent
(
)
with the largest dipole moment value, while the greatest value of ꢭ −ꢪ; ꢪ occurs for Chloroform,
which is a weak polar solvent. This effect can be explained by the increasing of the oxygen O1 charge,
which acts as an electrons receptor of the benzene ring A, decreasing the electron density and the resonant
stability, making it difficult to the electrophilic attack. The charge of the benzene ring A is 0.140e in gas-
phase, 0.134e in chloroform and 0.151e in DMSO. The total charge of the benzene ring A-O1 is -0.45e in
gas-phase, -0.49e in chloroform and -0.485e in DMSO. More details about transfer charge in gas-phase,
chroloform and DMSO can be seen in Table 7.
Table 7: CAM-B3LYP/6-311+G(d) results for the CHELPG atomic charges of DAC in solvent medium
Charge (e)
Atom Gas-phase Chloroform DMSO
O3
O2
O1
-0.387067 -0.421206 -0.431907
-0.394828 -0.423871 -0.448542
-0.592522 -0.627972 -0.636515
C13
C17
0.258014 0.270976
0.23231 0.240527
0.26955
0.22809
H17A -0.005142 0.005023 0.012514
H17B 0.032645 0.03524 0.03913
H17C -0.013467 -0.00575 0.003417
C12
-0.16225 -0.169856 -0.175064
H12
0.135582 0.149218 0.157707
C11 -0.295695 -0.302663 -0.301702
H11
C10
C9
H9
C8
0.151407 0.164439 0.167172
0.173544 0.148692 0.153707
-0.008861 0.009886 0.003064
0.104644 0.096941 0.096451
-0.374604 -0.406958 -0.396414
H8
C7
C6
0.128571
0.650884 0.674342 0.655201
-0.262821 -0.277926 -0.259031
0.15106
0.151918

C1
H1
C2
H2
C3
-0.06129 -0.060135 -0.081129
0.087021 0.092755 0.105589
-0.206889 -0.215003 -0.20794
0.108526 0.118908 0.121684
-0.002218 -0.011454 -0.014603
H3
C14
C16
0.09193
0.30386
0.102691 0.107382
0.30011 0.318667
0.228802 0.221717 0.233387
H16A -0.009541 0.005093 0.006546
H16B 0.033249 0.038797 0.037413
H16C -0.008008 0.003884 0.006855
C15 -0.364944 -0.352587 -0.380379
H15
C4
0.197643 0.204054
-0.3368 -0.330392 -0.338112
0.22154
H4
C5
N1
0.139255 0.150348 0.159483
0.583325 0.564597 0.557956
-1.017371 -1.014227 -1.017664
H1A 0.410895 0.423257 0.429805
H1B 0.452213 0.447446 0.444774