A Structural study of the intermolecular interactions of tyramine with some π-acceptors: Quantification of biogenic amines based on charge-transfer complexation

Article abstract of DOI:10.1134/S1070363215010326

In this paper, we report the synthesis and characterization of four CT complexes of Ty with picric acid (PA), chloranilic acid (CLA), quinol (QL), and 1,3-dinitrobenzene (DNB), and present their thermal decomposition behavior. These complexes were structurally characterized to interpret the behavior of interactions using elemental analysis; IR and ¹H NMR spectroscopy. Finally, the thermal behavior of the obtained complexes and the kinetic thermodynamic parameters (E, A, ΔS, ΔH, and ΔG) were also investigated using Coats-Redfern and Horowitz-Metzger equations.

Full text of DOI:10.1134/S1070363215010326

ISSN 1070-3632, Russian Journal of General Chemistry, 2015, Vol. 85, No. 1, pp. 185–191. © Pleiades Publishing, Ltd., 2015.
A Structural Study of the Intermolecular Interactions
of Tyramine with Some π-Acceptors:
Quantification of Biogenic Amines Based
on Charge-Transfer Complexation1
Moamen S. Refata,b, Hosam A. Saada,c,
Abdel Majid A. Adama, and Hala H. Eldarotid
a Department of Chemistry, Faculty of Science, Taif University,
Al-Haweiah, P.O. Box 888, Taif, 21974 Saudi Arabia
e-mail: msrefat@yahoo.com
b Department of Chemistry, Faculty of Science, Port Said University, Port Said, Egypt
c Department of Chemistry, Faculty of Science, Zagazig University, Zagazig, Egypt
d Department of Chemistry, Faculty of Education, Alzaeim Alazhari University, Khartoum, Sudan
Received July 26, 2014
Abstract—In this paper, we report the synthesis and characterization of four CT complexes of Ty with picric
acid (PA), chloranilic acid (CLA), quinol (QL), and 1,3-dinitrobenzene (DNB), and present their thermal
decomposition behavior. These complexes were structurally characterized to interpret the behavior of
1
interactions using elemental analysis; IR and H NMR spectroscopy. Finally, the thermal behavior of the
obtained complexes and the kinetic thermodynamic parameters (E*, A, ΔS*, ΔH*, and ΔG*) were also
investigated using Coats–Redfern and Horowitz–Metzger equations.
Keywords: biogenic amines, tyramine, charge-transfer complex, thermal decomposition
DOI: 10.1134/S1070363215010326
INTRODUCTION
new method to measure Ty concentrations in foods
would be important. Many techniques have been
developed and improved for detection and quantifica-
tion of Ty in different food products, including
fluorometry, thin layer chromatography, capillary elec-
trophoresis, high-performance liquid chromatography
(HPLC) and electrochemical methods [7–10].
Tyramine (Ty, Scheme 1), is the most important
biogenic amine in fermented dairy products, in which
it produced through the microbial enzymatic decar-
boxylation of tyrosine [1]. In addition, it is also one of
the most biologically active of all biogenic amines [2].
It is found commonly in fermented foods, beverages,
meat, fish, seafood and dairy products [3]. Ty is an
indirectly acting sympathomimetic amine which re-
leases norepinephrine from a sympathetic nerve
ending. It is widely used as pharmacological tool to
understand and evaluate the role of the sympathetic
nervous system on human physiology and pathology
and its influence on the cardiovascular system [4]. The
ingestion of foods containing large amounts of Ty has
toxicological effects, causing symptoms such as migraine,
hypertension, brain haemorrhage, heart failure and
diarrhea [5, 6]. For this reason, the development of a
Charge-transfer (CT) complexation is of great
importance in chemical reactions, including addition,
substitution, condensation [11], biochemical and bio-
electrochemical energy-transfer processes [12], bio-
logical systems [13], and drug–receptor binding me-
chanisms. For example, drug action, enzyme catalysis,
ion transfers through lipophilic membranes [14], and
certain π-acceptors have been successfully utilized in
the pharmaceutical analysis of some drugs in pure
form or in pharmaceutical preparations [15–17]. Fur-
thermore, CT complexation is also of great importance
in many applications and fields, such as non-linear
optical materials, electrically conductive materials,
1 The text was submitted by the authors in English.
185

186
MOAMEN S. REFAT et al.
Scheme 1. Tyramine and acceptors
H
H
N
OH
O
OH
NO2
Cl
O2N
HO
Cl
NO2
OH
NO2
OH
Ty
NO2
PA
O
OH
QL
CLA
DNB
second-order non-linear optical activity, micro-emul-
sions, surface chemistry, photocatalysts, dendri-mers,
solar energy storage, organic semiconductors, and the
investigation of redox processes [18–23].
in pure–grade methanol. The resulting solutions were
stirred for approximately 30 min and allowed to
evaporate slowly at room temperature. The separated
solid complexes were filtered, washed well with
methanol and dried over anhydrous calcium chloride
for 24 h in desiccator. All the complexes are insoluble
in cold and hot water, but easily soluble in DMF and
DMSO.
The aim of this work was to provide basic data that
can be used for the detection and quantification of Ty
based on charge-transfer (CT) complexation.
EXPERIMENTAL
RESULTS AND DISCUSSION
Materials and methods. All of the chemicals used
throughout this study were of high reagent grade.
Tyramine (Ty), picric acid (PA), chloranilic acid
(CLA), quinol (QL), and 1,3-dinitrobenzene (DNB)
acceptors (Scheme 1) were purchased from Sigma-
Aldrich and were used without further purification.
The elemental analyses for carbon, hydrogen and
nitrogen contents were performed with the Micro
analyzer Perkin-Elmer CHN 2400 (USA) at Cairo
University, Egypt. Infrared spectra were measured in
KBr discs within the range of 4000–400 cm–1 on a
Shimadzu FT-IR spectrophotometer with 30 scans at
Elemental analyses (C, H, and N) of the Ty CT
complexes were performed, and the obtained analytical
data are as follows: [(Ty)(PA)]. Calculated, %: C
45.91, H 3.85, N 15.30. C14H14N4O8. Found, %: C
45.95; H 3.81; N 15.27. Mw 366.28. [(Ty)(CLA)].
Calculated, %:
C
48.58;
H
3.79;
N
4.05.
C14H13Cl2NO5. Found, %: C 48.55; H 3.82; N 4.00. Mw
346.16. [(Ty)(QL)]. Calculated, %: C 68.00; H 6.93; N
5.66. C14H17NO3. Found, %: C 68.05; H 7.00; N 5.63.
Mw 247.29. [(Ty)(DNB)]. Calculated, %: C 55.08; H
4.95; N 13.76. C14H15N3O5. Found, %: C 55.12; H
4.90; N 13.79. Mw 305.29.
1
2 cm–1 resolution at Taif University, Saudi Arabia. H
NMR spectra were collected by the Analytical Center
at King Abdul Aziz University, Saudi Arabia, on a
Bruker DRX-250 spectrometer operating at 250.13 MHz
with a dual 5 mm probe head. The measurements were
performed at ambient temperature using DMSO-d6 as a
solvent and TMS as an internal reference. The
thermogravimetric analysis (TG) was carried under a
static air atmosphere to a temperature of 800°C at a
heating rate of 10°C/min using a Shimadzu TGA–50H
thermal analyzer in the Central Lab at the Ain Shams
University, Egypt.
The elemental analyses data for the prepared CT
complexes are in agreement with the molar ratio
obtained from the spectrophotometric titrations. The
stoichiometry of all the Ty CT complexes was found to
have a 1 : 1 ratio. Based on the obtained data, the
prepared Ty CT complexes were formulated as
[(Ty)(PA)], [(Ty)(CLA)], [(Ty)(QL)], and [(Ty)(DNB)].
The formation of 1 : 1 complexes was strongly
supported by IR, 1H NMR, and thermal analyses data.
Interpretation of the IR spectra. The IR absorp-
tion spectra of the Ty solid CT complexes which
registered in the frequency range 4000–400 cm–1 using
KBr disc are are provided in Table 1. The spectrum of
free Ty donor displays a series of significan bands as:
Synthesis. The solid Ty complexes with PA, CLA,
QL or DNB acceptors were prepared by mixing
equimolar amounts of the Ty donor with each acceptor
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 85 No. 1 2015

A STRUCTURAL STUDY OF THE INTERMOLECULAR INTERACTIONS OF TYRAMINE
187
Table 1. IR spectral data (ν, cm–1) and tentative assignments for Ty donor, acceptors, and their complexes
Acceptor
Complexes
Ty
donor
Assignmentsa
PA
CLA
QL
DNB
PA
CLA
QL
DNB
3339
3283
3056
3374
3235
3262
–
–
3110
3424
3272
3076
3282
3236
3018
3192
–
–
3632 ν(O–H)
–
ν(N–H)
3031
3105 ν(C–H), arom.
2998
2916
2928
2861
–
–
2857
2836
–
2908
2987
2933
2944
2874 νs(C–H) + νas(C–H)
–
–
–
–
–
2723
2628
2524
2460
2669
2601
2492
2733
2626
2436
2740 Hydrogen bond
2490
2437
–
1663
1629
–
–
–
1665
1633
–
–
ν(C=O), CLA, complex
–
1596
1616
-
–
–
–
–
1608
–
1612
–
1612
1595
1608 νas(NO2); PA, DNB, complex
δ(N–H)
1518
1484
1567
–
–
–
1569
1544
1541
1515
1536 Ring breathing bands
1541
1492
1442
1416
–
1518
1477
1538
1490
1432
1498
1370
1468
1350 ν(C=C)
δ(C–H) deformation
1267
1174
1114
1071
1357
1303
1276
1226
1180
1108
1078
1021
1368
1263
1207
1168
1244
1222
1210
1164
1097
1364
1150
1069
1364
1336
1268
1197
1161
1083
1274
1226
1355
1220
1089
1041
1273 ν(C–C) + ν(C–O) + νas(C–N)
1222
1068
968
944
823
755
888
832
805
699
981
838
751
827
759
914
837
727
909
824
711
982
834
754
945
831
762
909
836
714
δ(C–H) in-plane bending
ν(C–Cl); CLA, complex
550
528
626
–
543
–
690
569
–
–
–
663
592
554
693
575
–
614
553
–
653
–
508
δ(C–N) out-of-plane bending
skeletal vibration
δ(ONO); PA, DNB, complex
CNC deformation
505
520
a (ν) stretching; (νs) symmetrical stretching; (νas) asymmetrical stretching; (δ) bending.
3339, 3283, and 1596 cm–1, which may assign to
ν(OH), ν(NH), and δ(NH). In the IR spectra of the CT
complexes, these significant bands are shifted and
decreased in intensity. This result could be attributed
to the expected changes in symmetry and electronic
structure changes upon the formation of the CT
complexes. The outlined changes in (N–H) in the Ty
donor upon complexation clearly confirm the
involvement of the NH2 group in hydrogen bonding
with acceptors. This bonding is confirmed by the
appearance of a weak absorption bands that appears
between 2400 and 2800 cm–1, representing the H-
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 85 No. 1 2015

188
MOAMEN S. REFAT et al.
bonded NH2 group. These group of bands were ob-
served at 2723, 2628, 2524, and 2460 cm–1 for PA
complex (Scheme 1), at 2669, 2601, and 2492 cm–1 for
CLA complex (Scheme 2), at 2733, 2626, and
2436 cm–1 for QL complex and 2740, 2490, and 2437 cm–1
for DNB complex. These bands are due to hydrogen
bonding in the complex which clearly indicates that the
complexation occurs through the formation of
intermolecular H-bond between the NH2 group in the
Ty donor and acceptors [24–32]. Furthermore, in CLA
complex, the carbonyl stretching vibration bands;
ν(C=O) appeared at 1665 and 1633 cm–1, slightly
shifted with respect to those of CLA (1663 and
1629 cm–1); this is probably due to intermolecular H-
bond with Ty. The electron density around protons
depends on the degree of electro negativity for atoms
attached with protons; therefore, the two withdrawing
nitro groups attached to DNB acceptor decrease the
electron density around the proton flanked between the
nitro groups, and increase the acidic character of this
proton which facilitates to make intermolecular
hydrogen bond with the lone pair of electron on the
nitrogen atom of the Ty donor [33, 34].
produced signals: 2.45 s (3H, tyramine NH2 and OH),
2.69 t (2H, CH2–Ph), 2.94 t (2H, NH2CH2), 5.04 s (1H,
chloranilic acid OH), 6.69 t (2H, phenol C3,5H), 7.01 t
(2H, phenol C2,6H), 7.96 s (1H, hydrogen bonded OH
of chloranilic acid). When Ty donor complexed with
CLA acceptor, the signals of OH and NH2 protons
appeared at δ = 2.45. The high upfield shift of this
characteristic signal confirms the formation of CT
complex between Ty and CLA. It has been found that,
the phenolic proton signal, which is observed at
approximately ~9.15 ppm in the spectrum of the free
CLA acceptor [36] , decreased in intensity with a high
up-field shift for the nonhydrogen-bonded one (δ
~5.04) in the spectrum of this complex. Instead, the
peak appeared at 7.96 ppm, is attributed to the
hydrogen bonded OH of CLA. This situation
confirmed the formation of the CT complex between
one of the phenolic protons of CLA to the –NH2 group
of Ty.
Thermal analyses results. Thermal analysis (TG)
was carried out in order to confirm the composition
and structures of the formed CT complexes. The
possible thermal degradation data for these complexes
are provided in Table 2. Fairly close values of the
calculated and experimental percentage of the moieties
expelled from these complexes strongly support the
stoichiometry and the structures proposed for the
complexes. The TG thermogram of the PA complex
indicated that it was thermally decomposes in two
degradation steps. The first decomposition step in the
temperature range of 200–350°C has a weight loss of
approximately 62.52% and is attributed to the loss of
the acceptor moiety (PA). The second decomposition
step occurred within the 350–690°C temperature range
and was assigned to the removal of the donor moiety
(Ty). The thermal degradation of the CLA complex
occurs in two degradation stages within the 210–700°C
temperature range. The first stage of decomposition
corresponds to the loss of the acceptor moiety with a
weight loss of 60.25%. The second stage of decom-
position corresponds to the loss of the donor moiety
with a weight loss of 39.66%, which is very close to
the calculated value (39.63%). The thermal degrada-
tion of the QL complex occurs in two degradation
stages within the 50–800°C temperature range. The
first stage of decomposition corresponds to the loss of
the donor moiety with a weight loss of 55.50% very
close to the expected theoretical value of 55.47%. The
second stage of decomposition corresponds to the loss
of the acceptor moiety with a weight loss of 44.00%,
Interpretation of the 1H NMR spectra. The
nuclear magnetic resonance spectra present the per-
suasive confirmation of the complexation pathway.
The chemical shifts (δ) of the different types of protons
of the CT complexes are given below. The free Ty
donor produced signals: 2.53 t (2H, NH2CH2), 2.70 t
(2H, CH2–Ph), 4.14 b (3H, NH2 and OH), 6.68 t (2H,
1
phenol C3,5H), 6.9 t (2H, phenol C2,6H). The H NMR
spectrum of free Ty donor displays a characteristic
broad signal at 4.14 ppm, corresponding to the protons
of NH2 and OH groups. On complexation with PA and
CLA acceptors, these two signals appeared at new δ
values. The reaction of Ty donor with PA acceptor
yielded a new CT complex, which produced signals:
2.45 s (3H, tyramine NH2 and OH), 2.69 t (2H, CH2–Ph),
2.94 t (2H, NH2CH2), 6.68 t (2H, phenol C3,5H), 6.92 t
(2H, phenol C2,6H), 7.70 s (1H, hydrogen bonded OH
of picric acid), 8.59 s (2H, picric acid protons). The
signals attributed to NH2 and OH protons in this
complex appeared at 2.45 ppm. The peak at 11.94 ppm,
which is assigned to the OH proton of free picric acid
[35], was upfield shifted to 7.70 ppm in the spectrum
of this complex. Together, these data indicate that NH2
group in Ty and OH group in PA are involved in the
formation of the CT complex between Ty donor and
PA acceptor. The reaction of Ty donor with CLA
acceptor formed a new CT complex. This compound
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 85 No. 1 2015

A STRUCTURAL STUDY OF THE INTERMOLECULAR INTERACTIONS OF TYRAMINE
189
Table 2. Thermal decomposition data for the Ty–CT complexes
TG, weight loss, %
Complex
[(Ty)(PA)]
Stage
TG range, °C
Lost fragments
found
62.52
37.41
60.25
39.66
55.50
44.00
99.96
calculated
62.55
37.45
60.37
I
200–350
350–690
210–400
400–700
50–305
PA acceptor
Ty donor
II
I
[(Ty)(CLA)]
[(Ty)(QL)]
CLA acceptor
Ty donor
II
I
39.63
55.47
Ty donor
II
I
305–800
120–345
44.53
100.0
QL acceptor
Ty + DNB
[(Ty)(DNB)]
which is in good agreement with the calculated value
(44.53%). The TG thermogram of the DNB complex
indicated that it is thermally stable in the 25–120°C
temperature range. The thermal decomposition of this
complex proceeds via one degradation step. The
decomposition begins at ~120°C and completes at
~345°C, and the observed weight loss associated with
this step is (found 99.94, calculared 100.0%), which
can be attributed to the loss of the C14H15N3O5 moiety
(Ty + DNB).
Thermodynamic results. Nowadays, there has
been increasing interest in determining the rate-
dependent parameters of solid-state non-isothermal
decomposition reactions by analysis of the TG curves.
Several equations have been proposed to analyze a TG
curve and to obtain the kinetic thermodynamic
parameters. Two different methods were employed to
evaluate the kinetic thermodynamic parameters: the
Coats–Redfern method [37] and the Horowitz–
Metzger method [38]. The thermodynamic parameters
Scheme 2.
O2N
HO
HO
H
H
O
OH
O
NO2
H
H
N
H
H
N
O2N
H
H
N
QL
PA
DNB
CLA
OH
Ty
O
Cl
O2N
HO
H
HO
H
O
H
OH
N
H
N
H
H
Cl
O
O2N
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 85 No. 1 2015

190
MOAMEN S. REFAT et al.
Table 3. Kinetic parameters determined using the Coats–
Redfern (CR) and Horowitz–Metzger (HM) methods
increasing thermal stability of complexes. Therefore,
the E* value for the CLA complex is higher compared
to the other complexes, which indicates the higher
thermal stability of the CLA complex. By comparing
the E* values for the main decomposition stage of the
Ty complexes, we observed the following trend for the
different acceptors: CLA > DNB > QL > PA. These
differences may be due to the reactivity of the
complexes and the electronic configuration of the
acceptor when complexed with the Ty donor. The
entropy of activation (ΔS*) is found to be negative in
all cases, which indicates that the decomposition
reactions proceed spontaneously and the activation
complexes have more ordered structure than the
reactants. The ΔS* values of the Ty CT complexes
occur in a decreasing order as follows: QL complex >
DNB complex > PA complex > CLA complex. The
satisfactory values for the correlation coefficients from
the Arrhenius plots of the thermal decomposition steps
were observed to be r ~ 1 for all cases, which indicates
a good fit with the linear function and reasonable
agreement between the experimental data and the
kinetic parameters.
Methods
Complex
Parametera
CR
HM
QL complex
r
0.9954
0.9922
E, kJ/mol
A, s–1
2.55E+05 2.65E+05
6.04E+14 5.01E+15
ΔS, J mol–1 K–1 –3.04E+01 –4.98E+01
ΔH, kJ/mol
ΔG, J/mol
2.41E+05 2.62E+05
2.23E+05 2.20E+05
DNB complex r
E, kJ/mol
A, s–1
0.9940
0.9932
2.75E+05 2.82E+05
4.90E+15 3.85E+16
ΔS, J mol–1 K–1 –4.70E+01 –6.11E+01
ΔH, kJ/mol
ΔG, J/mol
r
2.64E+05 2.70E+05
2.30E+05 2.22E+05
PA complex
0.9990
0.9981
E, kJ/mol
A, s–1
1.62E+05 1.80E+05
2.64E+08 8.92E+09
Complexation pathway. Based on the above data
the proposed complexation mechanism of these CT
complexes between Ty donor with acceptors can be
illustrated by the Scheme 2.
ΔS, J mol–1 K–1 –9.32E+01 –6.33E+01
ΔH, kJ/mol
ΔG, J/mol
1.62E+05 1.82E+05
2.30E+05 2.42E+05
CONCLUSIONS
CLA complex r
E, kJ/mol
A, s–1
0.9932
0.9941
This study has demonstrated the complexation
behavior of this bioactive amine with PA, CLA, QL
and DNB π-acceptors. The solid CT complexes were
isolated and structurally characterized using elemental
3.20E+05 3.38E+05
3.21E+18 8.30E+19
ΔS, J mol–1 K–1 –1.11E+02 –1.22E+02
1
analysis, IR, H NMR, and thermogravimetric (TG)
analysis. The kinetic parameters (E*, A, ΔS*, ΔH*, and
ΔG*) have been estimated. It was observed that the
reaction stoichiometry is 1 : 1, and the resulting CT
complexes were shown to have the general formula:
[(Ty)(acceptor)]. The interaction between the Ty and
the acceptors was taking place by the formation of
intermolecular hydrogen bond. The TG analysis
indicates that the formation of complexes was
thermally stable, exothermic, spontaneous. The data
obtained herein, can be used in further studies to
assessment of Ty quantitatively in food products.
ΔH, kJ/mol
3.15E+05 3.42E+05
ΔG, J/mol
a (r) correlation coefficient of the linear plot.
2.22E+05 2.41E+05
[i.e., the activation energy (E*), the frequency factor
(A), the enthalpy of activation (H*), the entropy of
activation (S*), and the Gibbs free energy of activation
(G*)] associated with the complexes were evaluated
graphically by employing the Coats–Redfern and
Horowitz–Metzger methods, and the evaluated data are
listed in Table 3. The kinetic data obtained from the
two methods are comparable and can be considered in
good agreement with each other. The activation energy
(E*) of the complexes is expected to increase with the
REFERENCES
1. Kuley, E. and Özogul, F., Food Chem., 2011, vol. 127,
p. 1163.
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 85 No. 1 2015

A STRUCTURAL STUDY OF THE INTERMOLECULAR INTERACTIONS OF TYRAMINE
191
2. Ladero, V., Fernández, M., Cuesta, I., and Alvarez, M.A.,
and Zengin, M., Sol. Energy, 2005, vol. 79, p. 96.
Food Microbiol., 2010, vol. 27, p. 933.
3. Hernández-Cázares, A.S., Aristoy, M.C., and Toldrá, F.,
21. Andrade, S.M., Costa, S.M.B., and Pansu, R., J. Colloid
Interface Sci., 2000, vol. 226, p. 260.
J. Food Eng., 2011, vol. 106, p. 166.
22. Jakubiak, R., Bao, Z., and Rothberg, L., Synth. Met.,
4. Quevedo, R., Nuñez-Dallos, N., Wurst, K., and Duarte-
2000, vol. 114, p. 61.
Ruiz, Á., J. Mol. Struct., 2012, vol. 1029, p. 175.
23. Eychmuller, A, and Rogach, A.L., Pure Appl. Chem.,
5. McCabe-Sellers, B.J., Staggs, C.G., and Bogle, M.L.,
2000, vol. 72, p. 179.
J. Food Compos. Anal., 2006, vol. 19, p. 58.
24. Adam, A.M.A., Russ. J. Gen. Chem., 2014, vol. 84,
6. Smith, R.R., Dimayuga, E.R., Keller, J.N., and
no. 6, p. 1225.
Maragos, W.F., Neurochem. Res., 2005, vol. 30, p. 527.
7. Apetrei, I.M. and Apetrei, C, Sens. Actuators B, 2013,
25. Refat, M.S., Saad, H.A., and Adam, A.M.A., Russ. J.
Gen. Chem., 2014, vol. 84, no. 7, p. 1417.
vol. 178, p. 40.
26. Adam, A.M.A. and Refat, M.S., Russ. J. Gen. Chem.,
8. Banks, C.N. and Adams, M.E., Toxicon, 2012, vol. 59,
2014, vol. 84, no. 9, p. 1847.
p. 320.
27. Refat, M.S., and Adam, A.M.A., J. Mol. Liq., 2014,
9. Huang, J., Xing, X., Zhang, X., He, X., Lin, Q, Lian, W.,
vol. 196, p. 142.
and Zhu, H., Food Res. Int., 2011, vol. 44, p. 276.
28. Adam, A.M.A., Spectrochim. Acta A, 2014, vol. 127,
10. Raoof, J.B., Ojani, R., Baghayeri, M., and Amiri-Aref, M.,
p. 107.
Anal. Methods, 2012, vol. 4, p. 1579.
29. Adam, A.M.A., Spectrochim. Acta A, 2013, vol. 104,
11. Roy, T., Dutta, K., Nayek, M.K., Mukherjee, A.K.,
Banerjee, M., and Seal, B.K., J. Chem. Soc., Perkin
Trans., 1999, vol. 2, p. 2219.
p. 1.
30. Adam, A.M.A., Refat, M.S., and Saad, H.A., J. Mol.
Strut., 2013, vol. 1051, p. 144.
12. Roy, D.K., Saha, A., and Mukherjee, A.K., Spec-
trochim. Acta A, 2005, vol. 61, p. 2017.
31. Adam, A.M.A., Refat, M.S., and Saad, H.A., J. Mol.
Strut., 2013, vol. 1037, p. 376.
13. Slifkin, A.M., Charge-transfer Interaction of Biomole-
cules, Academic Press, New York, 1971.
32. Refat, M.S., Gobouri, A.A., Adam, A.M.A., and Saad, H.A.,
Phys. Chem. Liqs., 2014, vol. 52, no. 5, p. 680.
14. Dozal, A., Keyzer, H., Kim, H.K., and Wang, W.W.,
Int. J. Antimicrob. Agent, 2000, vol. 14, p. 261.
15. Korolkovas, A., Essentials of Medical Chemistry, 2 ed.,
33. Refat, M.S., El-Sayed, M.Y., Adam, A.M.A., Saad, H.A.,
and Eldaroti, H.H., Int. J. Electrochem. Sci., 2013,
vol. 8, p. 4234.
Wiley, New York, 1998.
34. Adam, A.M.A., Refat, M.S., Saad, H.A., and Eldaroti, H.H.,
16. Pandeeswaran, M., El-Mossalamy, E.H., and Elango, E.H.,
Eur. Chem. Bul., 2012, vol. 1, no. 7, p. 241.
Int. J. Chem. Kinet., 2009, vol. 41, p. 787.
35. Kross, R.D. and Fassel, V.A., J. Am. Chem. Soc., 1957,
17. Pandeeswaran, M. and Elango, K.P., Spectrochim. Acta
A, 2010, vol. 75, p. 1462.
vol. 79, p. 38.
36. AL-Attas, A.S., Habeeb, M.M., and AL-Raimi, D.S.,
18. Yakuphanoglu, F. and Arslan, M., Solid State Commun.,
J. Mol. Struct., 2009, vol. 928, p. 158.
2004, vol. 132, p. 229.
37. Coats, A.W. and Redfern, J.P., Nature (London), 1964,
19. Yakuphanoglu, F. and Arslan, M., Opt. Mater., 2004,
vol. 201, p. 68.
vol. 27, p. 29.
38. Horowitz, H.H. and Metzger, G., Anal. Chem., 1963,
20. Yakuphanoglu, F., Arslan, M., Kucukislamoglu, M.,
vol. 35, p. 1464.
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 85 No. 1 2015