Photochromic properties of the molecule Azure A chloride in polyvinyl alcohol matrix

Article abstract of DOI:10.1016/j.molstruc.2015.08.007

In the present work, isomerization, photophysical properties and heat conductivity of the substance Azure A chloride (AZAC): 3-amino-7-(dimethlamino)phenothiazin-5-ium chloride under the action of UV radiation in the presence of polyvinyl alcohol (PVA) matrix was studied using the Hartree-Fock (HF) and Density Functional Theory (DFT) methods. The electronic absorption spectra of AZAC in dimethylformamide (DMF) solution and in aqueous medium before and after UV radiation were calculated. The nature of absorption bands of AZAC and its tautomeric prototropic form with the transfer of the electron (AZAC₁) in the visible and near UV spectral regions was interpreted. The solvent effect on the absorption spectrum of the AZAC has established. The comparison of measured FTIR, UV-Visible data allowed assignments of major special features of title molecules. The frontier molecular orbital HOMO-LUMO have been also presented that shows the charge transfer interactions taking place within these molecules. The excitation energies for both molecules AZAC and AZAC₁ have also been calculated. The experimental as well as theoretical investigations of azure molecule have a close agreement and it gives other important clues about the properties of the system. Anisotropy of thermal conductivity in PVA-films containing AZAC and AZAC₁ were also measured.

Full text of DOI:10.1016/j.molstruc.2015.08.007

Accepted Manuscript
Photochromic properties of the molecule Azure A chloride in polyvinyl alcohol matrix
Siyamak Shahab, Liudmila Filippovich, Rakesh Kumar, Mahdieh Darroudi, Mostafa
Yousefzadeh Borzehandani, Maryam Gomar, Fatemeh Haji Hajikolaee
PII:
S0022-2860(15)30195-2
10.1016/j.molstruc.2015.08.007
MOLSTR 21739
DOI:
Reference:
To appear in: Journal of Molecular Structure
Received Date: 19 May 2015
Revised Date: 2 August 2015
Accepted Date: 3 August 2015
Please cite this article as: S. Shahab, L. Filippovich, R. Kumar, M. Darroudi, M.Y. Borzehandani, M.
Gomar, F.H. Hajikolaee, Photochromic properties of the molecule Azure A chloride in polyvinyl alcohol
matrix, Journal of Molecular Structure (2015), doi: 10.1016/j.molstruc.2015.08.007.
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Graphical Abstract
This work relates to a polyfunctional polymer PVA films containing photosensitive
photochromic organic dye. It also provide the possibility of combining them to create a heat-
polymer film of sun screen materials from a variable (adaptive) light transmittance in the
visible region of the spectrum depending on the intensity of solar radiation for use in
construction, automotive and aviation industries for glazing large skylights. Study of the
anisotropy of thermal conductivity allows you to select the substance which can more easily
conduct heat flux and in the meantime not warm when you use the sun.

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Dear Sir,
Please find herewith the enclosed manuscript:
Article title
Photochromic properties of the molecule Azure A chloride in polyvinyl alcohol matrix
The name of journal
Journal of Molecular Structure
The author’s affiliations with full postal address
Siyamak Shahab
Institute of Physical Organic Chemistry
National Academy of Sciences of Belarus,13 Surganov Str., Minsk 220072
E-mail: siyamak.shahab@yahoo.com
Liudmila Filippovich
Institute of Physical Organic Chemistry
National Academy of Sciences of Belarus,13 Surganov Str., Minsk 220072
E-mail: luda1977@list.ru
Rakesh Kumar
Department of Applied Sciences
CTIEMT, CT Group of Institutions, Jalandhar-144020 (Punjab) India.
E-mail: rakesh_nitj@yahoo.co.in
Mob. No. +91-9888 982369
Mahdieh Darroudi
Department of Organic Chemistry
Faculty of Chemistry, University of Mazandaran, Babolsar, Iran 47416.
E-mail: mahdie_darroudi@yahoo.com
Mostafa Yousefzadeh Borzehandani
Department of Organic Chemistry, Faculty of Chemistry, University of Mazandaran, 47416
Babolsar, Iran
E-mail: jan_1989@ymail.com
Maryam Gomar
Department of Chemistry, University of Yasouj, 75914-353, Yasouj, Iran
Fatemeh Haji Hajikolaee
Tajan High Education Institute, 47617-96486, Ghaemshahr, Mazandaran, Iran
E-mail: Fatima7_56@yahoo.com
4

ACCEPTED MANUSCRIPT
Photochromic properties of the molecule Azure A chloride in polyvinyl alcohol matrix
Siyamak Shahaba, Liudmila Filippovicha, Rakesh Kumarb, c, Mahdieh Darroudid, Mostafa Yousefzadeh
Borzehandanie, Maryam Gomarf, Fatemeh Haji Hajikolaeeg
aInstitute of Physical Organic Chemistry, National Academy of Sciences of Belarus,13 Surganova Str, Minsk 220072
bDepartment of Applied Sciences, CTIT,CT Group of Institutions, Jalandhar-144020 ( Punjab) India.
cDepartment of Chemistry, Dr B R Ambedkar National Institute of Technology, Jalandhar-144011 (Punjab) India.
d
Department of Organic Chemistry, University of Mazandaran, 47416 Babolsar, Iran
eDepartment of Chemistry, Islamic Azad University-Rasht Branch, P.O. Box 41335-3516, Rasht, Iran
fDepartment of Chemistry, University of Yasouj, 75914-353, Yasouj, Iran
gTajan High Education Institute, 47617-96486, Ghaemshahr, Mazandaran, Iran
ABSTRACT
In the present work, isomerization, photophysical properties and heat conductivity of the
substance Azure A chloride (AZAC): 3-amino-7-(dimethlamino)phenothiazin-5-ium chloride
under the action of UV radiation in the presence of polyvinyl alcohol (PVA) matrix was studied
using the Hartree-Fock (HF) and Density Functional Theory (DFT) methods. The electronic
absorption spectra of AZAC in dimethylformamide (DMF) solution and in aqueous medium
before and after UV radiation were calculated. The nature of absorption bands of AZAC and its
tautomeric prototropic form with the transfer of the electron (AZAC1) in the visible and near UV
spectral regions was interpreted. The solvent effect on the absorption spectrum of the AZAC has
established. The comparison of measured FTIR, UV-Visible data allowed assignments of major
special features of title molecules. The frontier molecular orbital HOMO-LUMO have been also
presented that shows the charge transfer interactions taking place within these molecules. The
excitation energies for both molecules AZAC and AZAC1 have also been calculated. The
experimental as well as theoretical investigations of azure molecule have a close agreement and
it gives other important clues about the properties of the system. Anisotropy of thermal
conductivity in PVA-films containing AZAC and AZAC1 were also measured.
Keywords: DFT studies, UV and IR spectra, UV radiation, anisotropy,Thermal conductivity
Corresponding authors: rakesh_nitj@yahoo.co.in (R. Kumar); Mob. No. 9888982369
siyamak.shahab@yahoo.com (S. Shahab)
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1. Introduction
AZAC is a phenothiazine dye available as green to brown powder. It is formed by the oxidation
of methylene blue and is strongly metachromatic. It is utilized as a part of making azure eosin
stains for blood smear staining. Azure dyes are used as redox mediators for electrochemical
biosensing [1].
Azure A chloride is generally used as solvents and colored reagents in numerous experimental
and scientific investigations [2]. Estimation of the molecular orbital geometry demonstrate that
the visible absorption maxima of such type of molecules correspond to the electron transition
from highest occupied molecular orbital (HOMO) to the lowest unoccupied molecular orbital
(LUMO). The structure and the vibrational spectroscopic investigation of the thiazines are
critical for the understanding of their physicochemical and pharmaceutical properties.
Vibrational spectroscopic studies of thiazine dye and its derivatives have been reported in the
literature [3]. The solvent effect is closely related to the nature and degree of dye-solvent
interactions. The impact of solvent on the aggregate formation of a wide variety of ionic dyes has
also been reported by many researchers [4]. The present investigations expect to understand the
structural and bonding features and molecular information such as π conjugations, electron
delocalization and resonance interaction using UV-Vis calculations. In the prior study, FT-
Raman, IR as well as UV-VIS spectra of the phenothiazine dye AZAC have been recorded and
examined [1]. The authors have also reported the ability of the TD - DFT method to predict the
absorption spectra of a series of oxazine dyes and the effect of solvent on the accuracy of these
predictions [5]. Taking into the account of this study, it’s clear that in the series of oxazine dyes
an accurate prediction of the excitation energy requires the inclusion of solvent. A
spectrophotometric method for ascertaining the presence of anionic detergent in milk using azure
A dye is described in literature [6]. In the previous research vibrational assignments for the
observed Raman bands, based on the computed potential energy distribution (PED) and isotopic
shifts were made [7]. First time, azure B has been used as achromogenic reagent for the
spectrophotometric determination of product. The proposed method, which is simple and rapid,
offers the advantages of sensitivity and wide range of determinations without the need for
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extraction or heating and it does not involve any stringent reaction conditions [8]. Excited
electronic states of molecular systems can be calculated by TD DFT and TD HF methods [9-15].
Density functional theory is conceptually and computationally very similar to HF theory, but it
provides vastly improved results and has outcome turned into an exceptionally prevalent
technique. The aim of the current work is to study photophysical properties (photochromism,
isomerization) and anisotropy of thermal conductivity in colored stretched PVA-films by ab
initio (HF, DFT), UV/Vis- and IR-Spectroscopies and Indicator methods for determination of
Thermal Conductivity of polymer films.
2. Experimental
2.1 Reagent and Physical measurements
All chemical were used of analytical reagent grade. Used PVA «Mowiol 28-99» manufactured
by the Hoёchst Com. (Germany). Experimental UV-Vis spectrum of the compound was
recorded on UV-Visible Spectrophotometer Cary 300 (Varian, USA). Experimental IR spectrum
of films was recorded in the frequency region 400-4000 cm-1 on a spectrophotometer of Protégé
460 (Nicolet, US).
Photostability of films was studied using unfiltered radiation of high-pressure Hg-lamp DRSH-
1000. The intensity of light falling perpendicular to the surface of the sample was 0.009 W/cm2.
At an exposure temperature of sample was 20-22 °C. The absorption spectra of the films were
measured before and after radiation. Heat conductivity of films was measured on the complex
equipment LC – 201 using indicator method of determining the heat conductivity of polymer
materials.
2.2 Preparation
PVA films were prepared from 10% PVA solutions, containing the AZAC, gelling and
plasticizing agents [16]. The films were cast on the polished glasses and dried in the closed box
at temperature 20-22 °C. Uniaxial orientation was done in the 4% boric acid (H3BO3) solution at
42-45 °C. The washed film was dried for 30 min at temperature 60-63 °C. The value of
stretching degree (Rs) was determined as the ratio between the length of the films after and
before uniaxial stretching. The thickness of the resulting films was between 50 to 55 µm.
3. Computational details
The theoretical molecular structures of AZAC and AZAC1 in the ground state were optimized by
HF/6-31G*, HF/6-311G* and DFT/B3LYP/6-311G* levels of theory in DMF and aqueous
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medium. Theoretical absorption spectra of the molecules optimized in solvents (DMF and water)
were calculated using TDHF/6-31G*, TDHF/6-311G* and TDB3LYP/6-311G* methods. To
account solvent effect Polarized Continuum Model (PCM) was used. The theoretical IR
spectrum of optimized molecules was calculated using the DFT/B3LYP/6-311G* method. The
scaling factor for the level of the theory is 0.98. The input files of both molecules were prepared
by Gauss View and also used for the visualization of the structure and simulated vibrational and
UV spectrum [ 17]. All the calculations are carried out using Gaussian 09 package [18].
4. Results and discussion
4.1 Geometric structure of AZAC and AZAC1
The geometry of the molecules AZAC and AZAC1 has been optimized DFT/B3LYP/6-311G*
levels of theory ( Figure 1). The calculated structural parameters bond lengths and bond angles
of the molecules are presented in Table S1& S2.
(a)
(b)
Fig. 1 Optimized molecular structures of (a) AZAC and (b) AZAC1
4.2. Electronic spectrum
Experimental and theoretical calculations demonstrate that AZAC molecule is very sensitive to
the presence of solvents due to a total charge of its molecule, and it reacts with a solvent and
change the absorption spectrum of AZAC. Calculated absorption spectra of AZAC in water,
DMF and experimental spectra of AZAC in water are presented (Fig. 2). In the transition from
water to DMF, absorption peak in the UV region does not undergo a large change, while in the
visible region hypsochromic shift with absorption band occur at 128nm. The experimental
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spectrum has a strong absorption band in the range 598-633 nm which is characterized by
maxima at 633 nm (Fig. 2c). DFT calculations of AZAC show maximum absorption at 630 nm (f
= 1.9). This absorption bond is belonged to the transition into the excited singlet state S1 and
describes by a wave function corresponding to a superposition of three configurations for one-
electron excitations (73→77, 76→77 and 77→76) (Table 1).
(a)
(b)
(c)
Fig. 2. Absorption spectrum Calculated (a ) - in water, (b) – in DMF) and (c ) Experimental UV-
Vis spectrum of AZAC in water at concentration 3.0·10–5 M/l
Excitation of an electron from molecular orbitals 76 to 77 are the main contributor for the
formation of the electronic spectrum at 630 nm (Fig. 3). It is clear from the MO (76) in which
electron cloud is localized in the centre of molecule and also around the S atom where the high
density of the electron cloud is observed. In MO 77, electron cloud is localized around the S
atom and also on the entire length of the molecule.
The experimental UV spectrum shows absorption threshold at about 614 nm whereas calculated
absorption band occur at 619 nm (f = 1.1). This absorption bond is belonged to the transition
into the excited singlet state S2 and describe by a wave function corresponding to a superposition
of two configurations for one-electron excitations (73→77 and 75→77) (Table. 1 & Fig. 3).
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73 MO ACCEPTED MANUSCRIPT
75 MO
76 MO
77 MO
Fig. 3 Molecular orbitals involved in formation of absorption spectrum of AZAC at λ = 630 and 619 nm.
Theoretical calculations don’t show absorption band at 598 nm but it appears in the experimental
spectrum that may be associated with a relative error of spectrophotometer. In the UV region of
spectrum DFT calculations show a peak of absorption at 285 nm whereas experimental spectrum
has an absorption band at 287 nm. This absorption band is belonged to the transition into the
excited singlet state S9 and describes by a wave function corresponding to a superposition of four
configurations for one-electron excitations (71→77, 76→78, 76→79 and 76→80) ( Table. 1).
In the transition from AZAC to AZAC1 under UV radiation appears photochromism. In our
case the photochromic effect must be due to a reversible electron transfer inside the molecule.
Calculated spectrum of AZAC1 in water is presented in Figure. 4. The calculated spectrum
shows absorption at 639 nm (f = 1.6). This absorption bond is belonged to the transition into the
excited singlet state S1 and describes by a wave function corresponding to a superposition of
three configurations for one-electron excitations (73→77, 75→77 and 76→77) (Table. 2).
Excitation of an electron from molecular orbitals MOs 73 - 77 are the main contributor to the
formation of the electronic spectrum at 639 nm. It can be seen that in 73 MO electron cloud is
localized to the benzene rings and around the S atom of the molecule AZAC1. Around the S
atom high density of the electron cloud is observed. In 77 MO electron cloud is localized to the S
atom and central part of the molecule.
In visible region has the one peak at 503 nm. This absorption bond is belongs to the transition
into the excited singlet state S4 that described by a wave function corresponding to a
superposition of four configurations for one-electron excitations (72→77, 73→77, 76→77 and
77→76) ( Fig.5).
10

Table 1. The calculated electroniAc sCpeCctrEuPmTofEADZAMCANUSCRIPT
λ (nm)
630
Decomposition of the wave functions at once excited configuration
Oscillator strength (f)
1.9
73 -> 77
76 -> 77
76 <- 77
73 -> 77
75 -> 77
74 -> 77
73 -> 77
75 -> 77
76 -> 77
72 -> 77
70 -> 77
69 -> 77
71 -> 77
76 -> 78
69 -> 77
71 -> 77
76 -> 78
76 -> 79
76 -> 80
73 -> 78
75 -> 78
76 -> 79
0.10575
0.69771
-0.10612
-0.19542
0.67331
0.70478
0.66425
0.20527
-0.10188
0.70464
0.70509
0.10075
0.63725
0.24658
0.69440
-0.20063
0.62181
-0.10255
0.19473
-0.21804
0.20610
0.60755
619
1.1
465
458
0.0
0.0
448
369
326
0.0
0.0
0.0
320
285
0.0
1.1
271
0.0
In the UV region of spectrum DFT calculations show a peak of absorption at 290 nm. This
absorption bond is belongs to the transition into the excited singlet state S9 and described by a
wave function corresponding to a superposition of four configurations for one-electron
excitations (71→77, 76→78 and 76→80) (Table. 2).
Fig. 4. Calculated UV-Vis spectrum of AZAC1 in water
By comparing the absorption spectra of AZAC to AZAC1 in water was found the following
facts:
(1) Excited state 1 (S1): Bathochromic shift at 9 nm (630→639 nm) with increasing in the
oscillator strength at 0.2. (2) Excited state 2 (S2): The peak of absorption at 619 nm disappears in
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72 MO
73MO
75 MO
76 MO
77 MO
Fig. 5 Molecular orbitals involved in formation of absorption spectrum of the AZAC1 at λ = 639 and 503 nm.
electronic spectrum of AZAC1. There is a new absorption peak at 557 nm, but the transition is
forbidden by symmetry. (3) Excited state 4 (S4): Bathochromic shift at 45 nm with increasing in
Table 2. Selected molecular orbital transitions, excitation energies and oscillator strengths of AZAC1
λ (nm)
639
Decomposition of the wave functions at once excited configuration
Oscillator strength (f)
1.6
73 -> 77
0.61183, 75 -> 77
-0.30611, 76 -> 77
-0.16522
557
556
503
73 -> 77
0.29184, 74 -> 77
-0.10102, 75 -> 77
0.63357
0.0
0.0
0.8
73 -> 77
0.10869, 74 -> 77
0.16512, 76 -> 77
-0.10288
0.68203, 76 -> 77
70 -> 77 0.70524
0.59251, 76 -> 78
0.69552
72 -> 77
0.15180, 73 -> 77
0.66687, 76 <- 77
468
372
326
321
290
72 -> 77
-0.14904
0.0
0.0
0.0
0.0
0.9
69 -> 77
69 -> 77
71 -> 77
0.29473, 71 -> 77
0.63601, 71 -> 77
0.19083, 76 -> 78
-0.20457
0.12155
0.19087
-0.26175, 76 -> 78
0.62836, 76 -> 80
276
73 -> 78
-0.49077, 75 -> 78
0.49588
0.0
the oscillator strength at 0.8. (4) Excited state 9 (S9): Bathochromic shift at 5 nm with
decreasing in the oscillator strength at 0.2. The results of calculations of electronic spectra of
AZAC and AZAC1 in water and DMF with different methods and basis sets are given in Table 3.
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Table 3. Comparison of ab initio methods (TDHF and TDDFT) and various basis sets for calculation of absorption
peaks of AZAC and AZAC1 in water and DMF
Method
AZAC in aqueous
medium
AZAC in DMF
AZAC1 in aqueous
medium
AZAC1 in DMF
TDHF/6-31G*
561, 505, 488, 465,
403, 356, 348, 366,
307, 284
523, 505, 478, 466,
440, 377, 354, 316,
309, 290
573, 561, 523, 501,
486, 450, 434, 403,
355, 291
560, 551, 507, 475,
458, 460, 423, 401,
376, 301
TDHF/6-311G*
545, 412, 338, 313,
296, 260, 254, 231,
209, 192
510, 504, 483, 451,
444, 403, 382, 380,
356, 286
576, 555, 501, 488,
471, 390, 366, 352,
301, 288
506, 500, 471, 434,
404, 401, 390, 367,
307, 254
TDB3LYP/6-311G*
630, 619, 465, 458,
448, 369, 326, 320,
285, 271
502, 485, 461, 442,
428, 383, 352, 341,
309, 252
639, 557, 556, 503,
468, 372, 326, 322,
290, 276
580, 564, 555, 506,
496, 432, 376, 370,
333, 312
By comparing the calculated and experimental data we have found that B3LYP/6-311G* method
is better than the other methods that predicts changes in the absorption spectrum of AZAC.
4.3. UV radiation of PVA-films
In order to study photochromic properties of AZAC, their PVA film was prepared. The
absorption spectrum of the sample was recorded after one hour UV radiation. The absorption
spectrum of the sample was recorded again after 24 and 72 hours. During the time, the sample
was placed in a dark (vacuum). It is seen that initial PVA film containing AZAC (curve 1)
transfers to AZAC1 (curve 2) after one hour radiation (Fig. 6). The peak of absorption does not
change (λ = 640 nm). Over time (curves 3,4) the optical density of the sample begins to grow
(for curve 2: D = 0.10, for curve 3: D = 0.36). This indicates that the reduction reaction is
reversible to AZAC. After 6 days AZAC fully recovered and we have the curve 1 again.
Fig. 6 Experimental UV spectrum of film containing AZAC (1) – Initial film before radiation, (2) – after one hour
radiation, (3) – after 24 hours, (4) – after 72 hours.
In order to confirm the accuracy of our findings, IR spectroscopy was used. The observed and
calculated spectra of both AZAC & AZAC1 are found to be in good agreement with each other.
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Simulated results show that the theoretical spectrum reproduces the experimental one with their
main characteristics (Table. 4, Fig S3& S4).
Comparison of the IR spectra of AZAC and AZAC1 has shown some important characteristics:
1. 1708.88 сm-1 (stretching vibrations of NH2) and 2910.73 сm-1 (stretching vibrations of R-
N+≡C) indicates the presence of AZAC.
+
2. 1376.74 сm-1 (stretching vibrations of –NH2 ), 1708.29 сm-1 (stretching vibrations of –
+
+
NH2 salt), 2940.89 сm-1 (stretching vibrations of –NH2 ). Based on the IR spectra of
both compounds it is concluded that there is a transformation of AZAC to AZAC1
during UV irradiation of the samples.
Table 4. Experimental and calculated vibrational frequencies and their assignment of AZAC and AZAC1 by using
B3LYP/6-311G* method
AZAC
νcalc (cm-1)
445.76
AZAC1
νcalc (cm-1)
435.45
νexp (cm-1)
Assignment
vibrations of
methylene rocking
bending vibrations of
=C-H aromatic
bending vibrations of
=C-H (out-of-plane)
bending vibrations of
RCH=CR’R”
bending vibrations of
=C-H aromatic
νexp (cm-1)
Assignment
bending vibrations of
=C-H aromatic
bending vibrations of
=C-H (out-of-plane)
bending vibrations of
=C-H aromatic
421.54
422.61
480.02
663.66
852.34
917.98
1093.48
1142.86
1237.35
488.01
673.56
841.11
898.08
1080.46
1222.57
1205.43
479.85
663.23
852.25
917.93
1093.70
1142.75
1237.73
489.06
669.78
870.01
905.34
1075.21
1131.68
1245.80
bending vibrations of
=C-H aromatic
S-C=CH
S-C=CH
stretching vibrations
of C-N
stretching vibrations
of C-N
stretching vibrations
of C-N
Nme2
bending vibrations of
methylene
stretching vibrations
+
of C-N –Nme2
stretching vibrations
of C=C of the
aromatic ring
stretching vibrations
of C=C of the
aromatic ring
stretching vibrations
of
1331.27
1377.46
1370.09
1385.61
1331.67
1376.74
1312.59
1365.12
bending vibrations of
methylene
+
-NH2
1425.00
1603.22
1449.31
1600.36
bending vibrations of
methylene
stretching vibrations
of C=C of the
1425.67
1662.98
1433.77
1654.04
stretching vibrations
of C=C of the alkene
stretching vibrations
of C=N
aromatic ring
1662.87
1626.62
stretching vibrations
of C=C of the
1708.29
1721.72
stretching vibrations
of NH2+ salt
aromatic ring
1708.88
2910.73
2941.28
3382.89
1689.66
2896.84
2965.86
3360.12
stretching vibrations
of NH2
2335.94
2911.06
2940.89
3382.72
2356.15
2932.74
2967.18
3387.09
stretching vibrations
of C-H aliphatic
stretching vibrations
of C-H aromatic
stretching vibrations
of R-N+≡C
stretching vibrations
of C-H aromatic
-NH2 aromatic
stretching vibrations
+
of -NH2 aromatic
-NH2 aromatic
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4.4. Anisotropy of thermal conductivity of PVA-films.
During chemical photochromism many properties of the system like refractive index, solubility,
viscosity and thermal conductivity changes. In the present work, we have studied thermal
conductivity of the PVA-AZAC and PVA-AZAC1 systems. In the earlier research reports,
special paints were used to sharply change the initial color at a critical temperature (Tcr). The
isothermal surface moves at a certain speed in the proportion to a local gradient of the
temperature field. Thermo-physical characteristics of the material can be judged by the speed of
isotherm movement and the form of flowing surface.
Thermal indicators of small sizes at small Tcr were used to avoid thermal destruction of polymer
material. Firstly, thermal indicator is putting on a film by a thin layer and at regular intervals by
a draw plate. Then, after some drying period its colored surface contacts to (30 sec.) a heat metal
needles (it is heated up approximately to 55 ºC). Thermo-physical properties of the films were
determined by heat conductivity of samples in parallel (λ||) and perpendicular (λ ) directions of
stretching axis. In case of anisotropic materials an ellipse is drawn. During this work, it was
established that the oriented PVA-films is the phenomenon of anisotropy of thermal conductivity
(λ|| / λ ). Thermal conductivity in a (λ||) direction is higher than as compared to their
perpendicular orientations (λ ).
It has been noticed that during thermal expansion and thermal conductivity, geometric
parameters of molecule and intermolecular forces play a significant role. In unstretched PVA-
films anisotropy of thermal conductivity is not observed appreciably (λ|| = 0,875; λ = 0,869
W/m.°C) whereas in stretched PVA-films it is noticed very clearly (Table. 5). When we inject
the dye in PVA-film there is change in its thermal conductivity (Table. 6). It has been found that
along an axis of orientation, it increases, whereas in perpendicular direction it reduces. Results of
thermal conductivity measurements of PVA-films containing AZAC and AZAC1 depending on
stretching degree ( Table. 6).
Table 5. Dependence of thermal conductivity on stretching degree in pure PVA-films
λ, W/ m.ºC
Rs
λ||
λ
λ|| / λ
1.15
1.38
1.60
1.75
1.86
1.5
2
2.5
3
0.876
0.878
0.880
0.881
0.882
0.764
0.636
0.549
0.503
0.475
4
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Table 6. Thermal conductivity of PVA-films containing AZAC and AZAC1 at concentration 0.2 wt.%
λ, W/ m.ºC
λ
Dye
Rs
λ||
λ|| / λ
3.40
3.55
3.91
4.52
4.29
4.93
5.78
7.68
2
3
4
5
2
3
4
5
0.865
0.851
0.844
0.840
0.866
0.853
0.849
0.837
0.254
0.240
0.216
0.186
0.202
0.173
0.147
0.109
AZAC
AZAC1
The obtained data suggest that in the PVA-AZAC1 system, anisotropy of thermal conductivity is
stronger than in the PVA - AZAC system. In some photochromic compounds we have found that
the isomers which are less stable (have a larger energy system) have a greater anisotropy of
thermal conductivity as compared with the more stable isomers. Theoretical calculation of the
full energies of AZAC and AZAC1 by DFT/B3LYP/6-311G* levels of theory lead to the
following values: HFAZAC = -1564.5995599 and HFAZAC1 = -1564.5897449.
5. Conclusions
In the present paper, geometric parameters, electronic and IR spectra of the molecules Azure A
chloride (AZAC) 3-amino-7-(dimethlamino)phenothiazin-5-ium chloride and its tautomeric
prototropic form with the transfer of the electron (AZAC1) by DFT and HF methods using 6-
31G*, 6-311G* basis sets were calculated. UV-Vis absorption spectra were analyzed via
experimental and theoretical calculation (TD HF, TD DFT) methods. Photochromic properties of
the AZAC appear as a result of UV radiation was also established. In stretched PVA-films
containing AZAC are phenomena of anisotropy of thermal conductivity. The full energies of
AZAC and AZAC1 by DFT/B3LYP/6-311G* were also calculated. This study suggests that
isomers which are less stable have a greater anisotropy of thermal conductivity as compared to
those which is more stable.
Acknowledgement
One of the author Dr. Rakesh Kumar is higly thankful to Dr. B R Ambedkar National Institute of
Technology, Jalandhar for providing the research infrastructure to carry out the theoretical work
present in the manuscript.
16

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References
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Agabekov, J. of App. Spect. 81 (2014) 42-47.
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[16] L.N. Filippovich, N.G. Ariko, H.A. Almodarresiyeh, S.N. Shahab, P.M. Malashko, V.E.
Agabekov. J. Semiconductor Physics, Quantum Electronics and Optoelectronics. 16 (2013) 220-
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17

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Highlights
•
•
•
•
Optimization of Azure A chloride
UV-Vis and IR spectra were recorded and compared with calculated ones
Charge transfer occur within the molecules
Preparation of polarizing films

ACCEPTED MANUSCRIPT
Supplementry Data
Table S1. Optimized geometric parameters of AZAC with HF/6-31G*, HF/6-311G* and
B3LYP/6-311G* methods
Parameter
Bond length (Å)
C(18)-H(32)
Method
HF/6-311G*
1.0823
HF/6-31G*
1.0773
B3LYP/6-311G*
1.0901
C(18)-H(31)
1.0841
1.0823
1.0979
C(18)-H(30)
1.0840
1.0756
1.0979
C(17)-H(29)
1.0774
1.0820
1.0901
C(17)-H(28)
1.0837
1.0819
1.0974
C(17)-H(27)
1.0837
1.0756
1.0974
N(16)-C(18)
1.4561
1.4606
1.4574
N(16)-C(17)
1.4574
1.4621
1.4586
C(15)-H(26)
1.0703
0.9913
1.0833
C(14)-N(16)
1.3427
1.3531
1.3686
C(14)-C(15)
1.4116
1.4267
1.4150
C(13)-H(25)
1.0697
1.0497
1.0825
C(13)-C(14)
1.4299
1.3431
1.4286
C(12)-H(24)
1.0738
1.0711
1.0853
C(12)-C(13)
1.3548
1.4425
1.3730
C(11)-C(15)
1.3749
1.3750
1.3899
C(10)-C(12)
1.4167
1.4170
1.4191
C(10)-C(11)
1.4141
1.4264
1.4238
N(9)-C(10)
1.3370
1.3046
1.3584
S(8)-C(11)
1.7455
1.3646
1.7574
N(7)-H(23)
1.0060
1.0071
1.1002
N(7)-H(22)
0.9968
1.0109
1.0140
C(6)-H(21)
1.0733
1.0734
1.0852
C(5)-N(9)
1.2966
1.3078
1.3162
C(5)-C(6)
1.4422
1.4246
1.4471
C(4)-S(8)
1.7371
1.7456
1.7562
C(4)-C(5)
1.4463
1.4219
1.4602
C(3)-H(20)
1.0742
1.0741
1.0874
C(3)-C(4)
1.3607
1.3722
1.3700
C(2)-N(7)
1.3133
1.3142
1.3173
C(2)-C(3)
1.4193
1.4050
1.4332
C(1)-H(19)
1.0730
1.0736
1.0886
C(1)-C(6)
1.3402
1.3493
1.3539
C(1)-C(2)
1.4404
1.4274
1.4510
Bond angle (°)
H(32)-C(18)-H(31)
H(32)-C(18)-H(30)
H(32)-C(18)-N(16)
H(31)-C(18)-H(30)
H(31)-C(18)-N(16)
H(30)-C(18)-N(16)
H(29)-C(17)-H(28)
H(29)-C(17)-H(27)
H(29)-C(17)-N(16)
H(28)-C(17)-H(27)
H(28)-C(17)-N(16)
H(27)-C(17)-N(16)
C(18)-N(16)-C(17)
C(18)-N(16)-C(14)
C(17)-N(16)-C(14)
H(26)-C(15)-C(14)
H(26)-C(15)-C(11)
C(14)-C(15)-C(11)
N(16)-C(14)-C(15)
N(16)-C(14)-C(13)
C(15)-C(14)-C(13)
H(25)-C(13)-C(14)
H(25)-C(13)-C(12)
C(14)-C(13)-C(12)
HF/6-31G*
108.1750
108.1718
108.9874
108.8573
111.2765
111.2731
108.1333
108.1359
108.8392
108.9210
111.3511
111.3537
118.7912
120.4744
120.7343
120.2548
118.9241
120.8212
121.2245
120.9374
117.8380
120.2672
119.1478
120.5850
HF/6-311G*
109.2515
108.2794
111.0333
108.2520
111.0182
108.9226
109.3177
108.2263
111.1415
108.1976
111.1286
108.7356
118.2054
120.5498
120.2215
120.2566
118.8601
120.8605
121.5177
121.0014
117.8621
120.2200
119.1312
120.5748
B3LYP/6-311G*
108.0595
108.0621
109.1735
108.3789
111.5210
111.5247
108.0088
108.0108
109.0178
108.4429
111.6147
111.6167
119.3494
120.2560
120.3946
120.2533
118.8380
120.9087
121.1431
121.0045
117.8524
120.2187
119.1195
120.6618

ACCEPTED MANUSCRIPT
H(24)-C(12)-C(13)
H(24)-C(12)-C(10)
C(13)-C(12)-C(10)
C(15)-C(11)-C(10)
C(15)-C(11)-S(8)
C(10)-C(11)-S(8)
C(12)-C(10)-C(11)
C(12)-C(10)-N(9)
C(11)-C(10)-N(9)
C(10)-N(9)-C(5)
C(11)-S(8)-C(4)
H(23)-N(7)-H(22)
H(23)-N(7)-C(2)
H(22)-N(7)-C(2)
H(21)-C(6)-C(5)
H(21)-C(6)-C(1)
C(5)-C(6)-C(1)
N(9)-C(5)-C(6)
N(9)-C(5)-C(4)
C(6)-C(5)-C(4)
S(8)-C(4)-C(5)
120.3938
117.4656
122.1406
121.4621
117.8024
120.7355
117.1531
117.6982
125.1487
125.2813
103.2681
117.4223
121.6244
120.9532
116.7081
121.1836
122.1083
117.4711
125.2983
117.2305
120.2680
118.7761
120.9558
120.8793
118.8125
120.3082
120.8625
119.4546
119.6829
121.7617
118.5241
119.7142
120.6356
117.0056
122.2693
121.4601
117.7533
120.7706
117.0104
117.5127
125.8071
124.8467
103.2361
117.8690
120.1284
120.6904
116.0022
121.5698
122.4457
117.7011
125.0948
117.5876
120.2957
118.7609
120.9988
120.6941
118.7733
120.4840
121.9336
119.1148
119.3406
121.3362
118.0031
118.9253
120.8833
116.8225
122.2941
121.4600
117.7238
120.8162
116.8229
117.1886
125.9885
123.8098
103.2281
119.8412
120.2741
119.8847
115.9616
121.4699
122.5684
117.2437
125.9317
116.8246
120.2257
118.7392
121.0351
120.6641
118.6681
120.6678
122.4497
118.4326
119.1177
123.2816
116.9321
119.7863
S(8)-C(4)-C(3)
C(5)-C(4)-C(3)
H(20)-C(3)-C(4)
H(20)-C(3)-C(2)
C(4)-C(3)-C(2)
N(7)-C(2)-C(3)
N(7)-C(2)-C(1)
C(3)-C(2)-C(1)
H(19)-C(1)-C(6)
H(19)-C(1)-C(2)
C(6)-C(1)-C(2)

ACCEPTED MANUSCRIPT
Table S2. Optimized geometric parameters of AZAC1 by HF/6-31G*, HF/6-311G* and
B3LYP/6-311G* methods
Parameter
Bond length (Å)
N(18)-H(32)
Method
HF/6-311G*
1.0125
HF/6-31G*
1.0029
B3LYP/6-311G*
1.0106
N(18)-H(31)
1.1134
1.0108
1.0103
C(17)-N(18)
1.3389
1.3561
1.3446
C(16)-H(30)
1.0843
1.0991
1.0854
C(16)-C(17)
1.4321
1.4328
1.4331
C(15)-H(29)
1.0797
1.0833
1.0849
C(15)-C(16)
1.3656
1.3696
1.3641
C(14)-H(28)
1.0874
1.0822
1.0861
C(14)-C(17)
1.4233
1.4203
1.4147
C(13)-C(14)
1.3867
1.3870
1.3829
C(12)-C(15)
1.4366
1.4359
1.4320
C(12)-C(13)
1.4483
1.4461
1.4413
N(11)-C(12)
1.3352
1.3367
1.3378
S(10)-C(13)
1.7627
1.7614
1.7502
C(9)-H(27)
1.0912
1.0901
1.0886
C(9)-H(26)
1.0912
1.0922
1.0939
C(9)-H(25)
1.0932
1.0989
1.0956
C(8)-H(24)
1.0845
1.0860
1.0885
C(8)-H(22)
1.0992
1.0911
1.0945
N(7)-C(9)
1.4683
1.4702
1.4668
N(7)-C(8)
1.4694
1.4680
1.4652
C(6)-H(21)
1.0820
1.0833
1.0850
C(5)-H(20)
1.0798
1.0849
1.0816
C(5)-C(6)
1.3538
1.3599
1.3630
C(4)-N(7)
1.3490
1.3526
1.3500
C(4)-C(5)
1.4466
1.4423
1.4404
C(3)-H(19)
1.0888
1.0851
1.0824
C(3)-C(4)
1.4341
1.4300
1.4231
C(2)-S(10)
1.7618
1.7606
1.7516
C(2)-C(3)
1.3856
1.3834
1.3811
C(1)-N(11)
1.3362
1.3344
1.3339
C(1)-C(6)
1.4340
1.4312
1.4320
C(1)-C(2)
1.4389
1.4417
1.4418
Bond angle (°)
H(32)-N(18)-H(31)
H(32)-N(18)-C(17)
H(31)-N(18)-C(17)
N(18)-C(17)-C(16)
N(18)-C(17)-C(14)
C(16)-C(17)-C(14)
H(30)-C(16)-C(17)
H(30)-C(16)-C(15)
C(17)-C(16)-C(15)
H(29)-C(15)-C(16)
H(29)-C(15)-C(12)
C(16)-C(15)-C(12)
H(28)-C(14)-C(17)
H(28)-C(14)-C(13)
C(17)-C(14)-C(13)
C(14)-C(13)-C(12)
C(14)-C(13)-S(10)
C(12)-C(13)-S(10)
C(15)-C(12)-C(13)
C(15)-C(12)-N(11)
C(13)-C(12)-N(11)
C(12)-N(11)-C(1)
C(13)-S(10)-C(2)
H(27)-C(9)-H(26)
H(27)-C(9)-H(25)
H(27)-C(9)-N(7)
H(26)-C(9)-H(25)
HF/6-31G*
117.1117
121.4890
121.7740
120.2205
120.7199
119.6001
119.3618
120.7729
120.1289
121.1300
116.9012
121.9220
119.1820
120.8933
120.6793
121.1107
118.2294
120.8561
117.2797
117.1229
125.6709
123.9866
103.7699
108.1602
108.5123
108.7109
109.4001
HF/6-311G*
117.1102
121.3971
121.6609
120.0001
120.7203
119.5670
119.1202
120.7701
120.1264
121.1241
116.9002
121.8831
119.2332
120.6440
120.6678
121.1223
118.2226
120.8320
117.3349
117.1005
125.3101
123.8556
103.5611
108.1791
108.5094
108.7110
109.3966
B3LYP/6-311G*
117.1052
121.5498
121.3448
119.9678
120.7177
119.3145
119.1114
120.7652
120.1234
121.1229
116.8960
121.9811
119.1326
120.5500
120.3174
121.1174
118.1566
120.7259
117.1462
117.0883
125.7655
123.7249
103.2355
108.1708
108.5101
108.7050
109.3995

ACCEPTED MANUSCRIPT
H(26)-C(9)-N(7)
H(25)-C(9)-N(7)
H(24)-C(8)-H(23)
H(24)-C(8)-H(22)
H(24)-C(8)-N(7)
H(23)-C(8)-H(22)
H(23)-C(8)-N(7)
H(22)-C(8)-N(7)
C(9)-N(7)-C(8)
C(9)-N(7)-C(4)
C(8)-N(7)-C(4)
H(21)-C(6)-C(5)
H(21)-C(6)-C(1)
H(20)-C(5)-C(6)
H(20)-C(5)-C(4)
C(6)-C(5)-C(4)
N(7)-C(4)-C(5)
N(7)-C(4)-C(3)
C(5)-C(4)-C(3)
H(19)-C(3)-C(4)
H(19)-C(3)-C(2)
C(4)-C(3)-C(2)
S(10)-C(2)-C(3)
S(10)-C(2)-C(1)
C(3)-C(2)-C(1)
N(11)-C(1)-C(6)
N(11)-C(1)-C(2)
C(6)-C(1)-C(2)
110.9598
111.0115
109.0021
108.4424
108.9056
109.2196
110.9126
110.9015
118.4202
120.8673
120.5076
120.8353
116.5541
119.2193
120.1103
120.8670
120.8633
121.1940
118.1121
120.1196
119.1631
120.7739
118.0795
120.5294
121.4136
117.3048
126.0190
116.6663
110.9568
111.1100
108.5322
108.2998
108.9100
109.2311
110.9101
110.8976
118.4188
120.8660
120.5031
120.8407
116.7430
119.2284
120.0586
120. 7374
120.8602
121.1894
118.0045
120.1010
119.1504
120.8834
118.0882
120.5237
121.4021
117.2997
126.0215
116.6741
110.9572
111.0176
108.5388
108.3015
108.9071
109.2234
110.9085
110.8915
118.4154
120.8631
120.5099
120.8396
116.8877
119.2253
120.0305
120.7433
120.8534
121.1770
117.9696
120.0029
119.0548
120.9421
118.0685
120.5311
121.4004
117.3125
126.0164
116.6707

ACCEPTED MANUSCRIPT
Fig. S3 Experimental IR spectrum of AZAC and AZAC1

ACCEPTED MANUSCRIPT
Fig. S4 Calculated IR spectrum of AZAC and AZAC1