Synthesis and characterization of newly synthesized thiosemicarbazone ligands with IR, NMR and mass spectral techniques

Article abstract of DOI:10.13005/ojc/35Specialissue106

Among various organic chelating agents thiosemicarbazones occupy an important role due to their efficiency towards many metal ions through thionate sulphur atom and hydrazino nitrogen atom. Thiosemicarbazones can be obtained by condensing thiosemicarbazid

Full text of DOI:10.13005/ojc/35Specialissue106

ISSN: 0970-020 X
CODEN: OJCHEG
Vol. 35(Special Issue 1),
43-47 (2019)
ORIENTAL JOURNAL OF CHEMISTRY
An International Open Access, Peer Reviewed Research Journal
www.orientjchem.org
Synthesis and Characterization of Newly Synthesized
Thiosemicarbazone Ligands with IR, NMR and Mass
Spectral Techniques
N. RAMA JYOTHI* and N. A. MOHAMEd FAROOk
Department of Chemistry, Khadir Mohideen College, Adirampattinam, Tamilnadu-614701, India.
*Corresponding author E-mail: ramadasaradhi@gmail.com
http://dx.doi.org/10.13005/ojc/35Specialissue106
(Received: November 01, 2018; Accepted: March 18, 2019)
AbSTRACT
Among various organic chelating agents thiosemicarbazones occupy an important role
due to their efficiency towards many metal ions through thionate sulphur atom and hydrazino
nitrogen atom. Thiosemicarbazones can be obtained by condensing thiosemicarbazide with
various carbonyl compounds. In recent years, the usage of thiosemicarbazone ligands has been
reported by so many authors in the fields of analytical and biological. The present study reported
about of two newly synthesized thiosemicarbazone ligands, namely 2,3,4-trihydroxybenzaldehyde-
4-phenylthiosemicarbazone (THBPTSC) and 2,3,4-trihydroxybenzaldehyde-4-methylthiosemi
carbazone (THBMTSC).These two new ligands are characterized with various spectral techniques,
such as FT-IR, NMR and mass spectral techniques. The elemental composition was checked with
elemental analysis report. Molar conductivity measurements of the ligands also reported.
keywords: Thiosemicarbazones, 2,3,4-trihydroxybenzaldehyde-4-phenylthiosemicarbazone,
2,3,4-trihydroxybenzaldehyde-4-methylthiosemicarbazone, FT-IR, NMR, Mass spectra.
INTROdUCTION
such as antimicrobial, antimalarial, antiviral, anti-
tumor and anti-HIV activities.
Organic chelating agents play a vital role
in both analytical and biological fields. Among the
variousorganicchelatingagents,thiosemicarbazones
are very important groups because of their wide
applications.Thiosemicarbazones are having a great
biological activities due to their ability to coordinate to
the metal centers in enzymes. A number of studies
reveals the biological and pharmacological activities
of thiosemicarbazones and their metal complexes,
In recent years so many authors
reported biological and analytical applications of
thiosemicarbazones and/or their metal complexes.
Salsi et al.,1 reported anti-trypanosoma activity
of thiosemicarbazones derived from fluorinated
benzoylthioureas.Sens et al.,2 reported the synthesis
of new thiosemicarbazones which were acted as
inhibitors of Mycobacterium tuberculosis protein
This is an
Open Access article licensed under a Creative Commons license: Attribution 4.0 International (CC- BY).
Published by Oriental Scientific Publishing Company © 2018

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JYOTHI et al., Orient. J. Chem., Vol. 35(Special Issue 1), 43-47 (2019)
tyrosine phosphate A.Deng et al.,3 reported the anti-
ExpERIMENTAL
cancer property of copper complexes of 2-pyridine
thiosemicarbazone ligands.A few studies4-7 reported
about the analytical and biological properties
of thiosemicarbazones. Antimicrobial activity of
thiosemicarbazones and their metal complexes
were studied by Ibrahim et al.,8,9 andTemraz et al.,10.
Kalinowski et al.,11 was reported the importance of
thiosemicarbazones in cancer treatment. Matesanz
and Souza12 reviewed about the antitumor activity
of thiosemicarbazone ligands.
Chemicals
The chemicals used in this study was all are
pure analytical grade. A Fisher-scientific stirrer was
used for the stirring of the reactants which contains
a hot plate.
Synthesis scheme for 2,3,4-trihydroxybenzal
dehyde-4-phenylthiosemicarbazone (THbpTSC)
Methanolic solutions of 1.54 g of 2,3,4-
trihydroxybenzaldehyde (M.Wt. 303.35 g) in
100 mL and 1.67 g of 4-phenylthiosemicarbazide
(M.Wt.105.16 g) in 100 mL were refluxed nearly 4 h
in a round bottom flask.The resultant product (yield,
79%) was separated by filtration and then it was
dried.The final product was recrystallized once again
from methanol.The synthesis scheme ofTHBPTSC
is presented below (Scheme 1).
This paper describes synthesis and
characterization of two new ligands namely, 2,3,4-
trihydroxybenzaldehyde-4-phenylthiosemicarbazone
(THBPTSC) and 2,3,4-trihydroxybenzalde-hyde-4-
methylthiosemicarbazone (THBMTSC). These newly
synthesized chelating agents were characterized with
elemental analysis, molar conductivity measurement,
FT-IR, NMR, and mass spectra.
OH
HO
S
-H2O
HO
OH
S
H2N
O
N
N
HO
N
H
H
N
N
OH
H
H
4-phenylthiosemicarbazide
2,3,4-trihydroxybenzaldehyde
Scheme 1. Synthesis scheme of 2,3,4-trihydroxybenzaldehyde-4-phenylthiosemicarbazone
2,3,4-trihydroxybenzaldehyde-4-phenylthiosemicarbazone
Synthesis of 2,3,4-trihydroxybenzaldehyde-4-
methylthiosemicarbazone (THbMTSC)
4-methyl-3-thiosemicarbazide (M.Wt. 105.16 g) in
methanol for nearly 4 h 30 min in a round bottom flask.
The resultant product (yield, 84%) was separated
by filtration and then dried. The final product was
recrystallized once again with methanol.
Synthesis of THBMTSC is presented
in Scheme 2. THBMTSC was synthesized by
the refluxing of 1.54 g of 2,3,4-trihydroxybenzldehyde
(M.Wt. 303.35 g) in methanol and 1.05 g of
OH
S
HO
HO
-H2O
HO
OH
H2N
S
O
N
N
H
H
N
N
N
OH
H
H
4-methylthiosemicarbazide
2,3,4-trihydroxybenzaldehyde
2,3,4-trihydroxybenzaldehyde-4-methylthiosemicarbazone
Scheme 2. Synthesis of 2,3,4-trihydroxybenzaldehyde-4-methylthiosemicarbazone
Characterization of thiosemicarbazones with
Elemental Analysis, FT-IR, NMR, and Mass spectra
Elemental analysis (C,H,N and S) of
were recorded on a JMS 700 mass spectrometer
(JEOL, Tokyo, Japan).
THBPTSC and THBMTSC were performed on
Thermo Scientific elemental analyzer (Thermo Eager
300 Flash EA1112, USA).Molar conductivity studies
were performed with portable molar conductivity
meter (MT-115, Manti Lab Solutions, India). FT-IR
spectra were recorded on a Nicolet FT-IR 560 Magna
spectrometer. High Resolution FAB mass spectra
RESULTS ANd dISCUSSION
The synthesized thiosemicarbazone
ligands,THBPTSC andTHBMTSC are characterized
with elemental analysis, molar conductivity
measurements and with various spectral techniques,
such FTIR, NMR and mass spectra.

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JYOTHI et al., Orient. J. Chem., Vol. 35(Special Issue 1), 43-47 (2019)
Elemental Analysis FT-IR spectral analysis
Elemental analysis reports of both the
chelating agents, THBPTSC and THBMTSC are
presented in Fig. 1 and 2.The calculated elemental
analysis data of THBPTSC (C14H13N3SO3) is C:
55.38%; H: 4.32%; N: 13.84%; S: 10.55%; O:
15.32%.This calculated data is well coincide with the
practically obtained values as C: 54.58%; H: 4.31%;
N: 12.89%; and S: 11.56% to above mentioned
formula of THBPTSC. The theoretically calculated
composition forTCMTSC (C9H11N3SO3), (C:44.76%;
H: 4.58%; N: 17.40%; S: 13.26% and O: 19.89%)
is well in agreement with the practically found data
(C: 45.22%; H: 4.58%; N: 16.33% and S: 15.29%)to
the above proposed formula for THBMTSC.
FT-IR spectrum of THBPTSC is presented
in Fig. 3. The FT-IR data of THBPTSC is as follows:
C=N peak appears at 1609 cm-1, C=S peak appears
at 1255 cm-1 and -NH peak appears at 3400 cm-1.
This obtained data confirms the formation of
the newly synthesized ligand, THBPTSC. FT-IR
spectrum of THBMTSC is presented in Fig. 4. FT-IR
data of THBMTSC is as follows, C=N peak appears
at 1630 cm-1 C=S peak appears at 1248 cm-1 and
-NH peak appears at 3250 cm-1.This obtained data
confirms the formation of the newly synthesized
ligand, THBMTSC.
100
95
Molar conductivity measurements
90
Molar conductivity values of THBPTSC
and THBMTSC are 27.5 and 30.0 S cm2 mol-1,
respectively. This indicates both ligands are having
similar conductivity values.
85
8
C=N
1609 Cm
OH
-1
HO
OH
S
80
75
70
N
N
N
H
H
M.Wt. 303.35
C=S
1255 Cm
-1
4000
3500
3000
2500
2000
1500
1000
500
-1
W avelength (Cm )
Fig. 3. FT-IR Spectrum of THbpTSC
100
90
80
70
60
Fig. 1. Elemental analysis report of THbpTSC
9
C=N
1630 Cm
OH
-1
HO
OH
S
N
N
N
H
H
M.Wt. 241.28
C=S
1248 Cm
-1
4000
3500
3000
2500
2000
1500
1000
500
W ave length (Cm -1)
Fig. 4. FT-IR Spectrum of THbMTSC
proton NMR spectral characterization
Proton NMR spectrum data (DMSO/TMS)
1
of THBPTSC is obtained as: H NMR (300 MHz,
DMSO-d6): d=11.580 (s, 1H), 9.91 (s, 1H), 9.53
(s, 1H), 9.03 (broad, 1H), 8.45 (s, 2H), 8.34 (s, 1H),
7.57 (d, 1H), 7.33 (m, 2H), 7.16 (t, 1H), 6.35 (d, 1H).
Based on the obtained proton NMR data it is clear
Fig. 2. Elemental analysis report of THbMTSC

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JYOTHI et al., Orient. J. Chem., Vol. 35(Special Issue 1), 43-47 (2019)
that the formation of THBPTSC. The proton NMR
Mass spectral characterization of ligands
spectrum of THBPTSC is presented in Fig. 5. The
proton NMR spectrum (DMSO/TMS) of THBMTSC is
obtained as:d=11.22 (s, 1H;Ar-N-NH), 9.49 (broad, 1H;
Ar-OH), 8.98 (broad, 1H; Ar-OH), 8.42 (broad, 1H; Ar-
OH), 8.25 (m, 2H;CH3NH and Ar-CH), 7.14 (d, J=8.4
Hz, 1H; Ar), 6.34 (d, J= 8.4 Hz, 1H; Ar), 2.98 (d, 3H;
NCH3). Based on the obtained proton NMR data it is
clear that the formation ofTHBMTSC.The proton NMR
spectrum of THBPTSC is presented in Figure 6.
Based on molecular formula the molecular
weight of THBPTSC is calculated as 303. The
molecular weight obtained practically with mass
spectrum as 304. Based on molecular formula
the molecular weight of THBMTSC is calculated
as 241. The molecular weight obtained practically
with mass spectrum as 242. The mass spectra of
THBPTSC and THBMTSC are presented in Fig. 7,
8, respectively.
Fig. 7. Mass Spectrum of THbpTSC
Fig. 5. proton NMR Spectrum of THbpTSC
Fig. 6. proton NMR Spectrum of THbMTSC
Fig. 8. Mass Spectrum of THbMTSC
CONCLUSION
chelatingagentscanbeusedforthechelationwithCu(II)
metal ions.The biological activities of both the chelating
agents and their metal complexes will be evaluated in
our future studies.
Thisstudyconfirmstheformationof twonew
thiosemicarbazone chelating compounds namely,
2,3,4-trihydroxybenzaldehyde-4-phenylthiosemi
carbazone (THBPTSC) and 2,3,4-trihydroxy
benzaldehyde-4-methylthiosemicarbazone
(THBMTSC).The formation of these two new thiosemi
-carbazonechelatingcompoundswasconfirmedbythe
elementalanalysisstudiesandvariousspectralanalysis
techniques, as FT-IR, 1H NMR and mass.These organic
ACkNOwLEdgMENT
This research did not receive any specific
grantfromfundingagenciesinthepublic, commercial,
or not-for-profit sectors.
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