Thermal, spectral and biological properties of Zn(II) complex compounds with phenazone

Article abstract of DOI:10.1007/s10973-006-8114-0

The thermal decomposition of the complexes Zn(form)₂ 2phen (I), Zn(ac)₂ 2phen (II), Zn(prop)₂ 2phen (III), Zn(but) ₂ 2phen (IV), where phen=phenazone, form=formiate, ac=acetate, prop=propionate, but=butyrate has

Full text of DOI:10.1007/s10973-006-8114-0

Journal of Thermal Analysis and Calorimetry, Vol. 88 (2007) 1, 219–223
THERMAL, SPECTRAL AND BIOLOGICAL PROPERTIES OF Zn(II)
COMPLEX COMPOUNDS WITH PHENAZONE
Erika Szunyogová1, Katarína Györyová2*, Daniela Hudecová3, Lenka Piknová2, J. Chomi¹2,
Zuzanna Vargová2 and V. Zele×ák2
1Department of Biophysics, Institute of Experimental Physics, Slovak Academy of Science, Watsonova 47
043 53 Koëice, Slovak Republic
2Department of Inorganic Chemistry, P. J. žafarik University, Moyzesova 11, 041 54 Koëice, Slovak Republic
3Department of Biochemistry and Microbiology, Slovak University of Technology, Radlinského 9
812 37 Bratislava, Slovak Republic
The thermal decomposition of the complexes Zn(form)2⋅2phen (I), Zn(ac)2⋅2phen (II), Zn(prop)2⋅2phen (III), Zn(but)2⋅2phen (IV),
where phen=phenazone, form=formiate, ac=acetate, prop=propionate, but=butyrate has been studied in air by TG/DTG and DTA
methods. The possible mechanism of the thermal decomposition was proposed. The final product of thermal decomposition was
ZnO. IR data show unidentate coordination of carboxylate group to Zn(II) ion. The complexes were tested against various strains of
microorganisms and their efficiency decrease in the sequence yeasts>bacteria>filamentous fungi.
Keywords: biological properties, IR spectra, phenazone, thermal properties, zinc(II) complexes
Introduction
Experimental
Carboxylatometal(II) complexes with N-donor lig-
ands have been interesting from chemical and biolog-
ical aspects for last decades. It is of interest to study
interactions between metal ions and heterocyclic ni-
trogen compounds that are present in living systems
and are used as medicaments. It is also known that
heterocyclic compounds play significant role in bio-
logical systems that are a part of some vitamins and
drugs [1].
The following chemicals of A. R. grade were used in
the synthesis of the prepared complexes:
HCOOH 98% (Lachema), CH3COOH 98%
(Lachema), CH3CH2COOH 99% (Lachema),
CH3CH2CH2COOH 98% (Lachema), ZnCO3
(Lachema), phenazone (Aldrich). Zinc carboxylates
were prepared from zinc carbonate and appropriate
carboxylic acid in molar ratio 1:2.
The interaction of Zn(II) atom that has a key role
in many biological processes is a subject of consider-
able interest. Zinc forms more than 300 metalloen-
zymes and its complexes have antimicrobial effect
against bacteria, fungi and viruses [2, 3]. Zinc(II)
complexes are interesting from chemical viewpoint
and biological activity.
In recent years we have studied synthesis, spec-
tral, thermal, structural, chromatographic and biologi-
cal properties of several zinc(II) aliphatic [4–6] and
aromatic carboxylates and their halogenoderivatives
[7–9]. This paper describes the preparation of the
zinc(II) complexes with phenazone and the study of
their thermal, spectral and biological properties.
Syntheses
Zn(form)2⋅2phen (I)
A water solution of 0.31 g zinc(II) formiate
(0.002 mol) was added to a water solution of 0.753 g
phenazone (0.004 mol) in molar ratio 1:2. The reac-
tion mixture was stirred together during 30 min.
The prepared complex was filtered off and reduced in
volume in waterbath at 70°C. In a few days the white
powder precipitated. Anal. calcd. for compound (I):
C 54.16; H 4.93; N 10.54; Zn 12.29%. Found:
C 54.30; H 4.90; N 10.40; Zn 10.90%.
Zn(ac)2⋅2phen (II)
The reaction mixture of a water solution containing
0.36 g (0.002 mol) zinc(II) acetate (0.002 mol) and
0.753 g phenazone (0.004 mol) was under continual
*
Author for correspondence: katarina.gyoryova@upjs.sk
1388–6150/$20.00
Akadémiai Kiadó, Budapest, Hungary
Springer, Dordrecht, The Netherlands
© 2007 Akadémiai Kiadó, Budapest

SZUNYOGOVÁ et al.
stirring for 30 min. The mixture was filtered off and
Biochemistry and Microbiology, Faculty of Chemical
and Food Technology STU, Bratislava, Slovakia),
Botrytis cinerea CCM F-16, Trichoderma
viride CCM F-534 (both from the Czech Collection of
Microorganisms, Masaryk University, Brno, Czech
Republic) and Microsporum gypseum (from the Lab-
oratory of Medical Mycology, Postgraduate Medical
Institute, Bratislava, Slovakia) was observed by
macro-dilution technique on solidified broth medium
during static culturing [12]. Chromatographically
pure compounds were dissolved in dimethylsulfoxide
(DMSO); its final concentration never exceeded
1.0 vol% in either control or treated samples. Concen-
tration of tested Zn(II) compounds was in the range of
0.01–3.00 mmol dm–3 in all experiments.
reduced in volume in waterbath at 80°C. In several
days a white powder precipitated. Anal. calcd. for
compound (II): C 32.12; H 3.20; N 5.02; Zn 11.67%.
Found: C 32.08; H 3.19; N 5.12; Zn 11.56%.
Zn(prop)2⋅2phen (III)
A water solution of 0.753 g phenazone (0.004 mol)
was added to a water solution of 0.423 g zinc(II) pro-
pionate (0.002 mol). The reaction mixture was stirred
together for 30 min. Then it was filtered off and in
waterbath. In several days white powder precipitated.
Anal. calcd.: C 57.21; H 5.83; N 14.31; Zn 11.12%.
Found: C 55.35; H 5.46; N 14.40; Zn 10.87%.
The antimicrobial activity was characterized by
the IC50 values (concentration of a compound which
in comparison to the control inhibits the growth of mi-
croorganisms to 50%) and MIC values (minimal in-
hibitory concentration of a derivative which inhibits
microbial growth by 100%). The IC50 and MIC values
were read from toxicity curves. MIC experiments on
subculture dishes were used to assess the minimal
microbicidal concentration (MMC). Subcultures were
prepared separately in Petri dishes containing compe-
tent agar medium and incubated at 30°C for 48 h (bac-
teria, yeasts) and at 25°C for 96 h (filamentous fungi).
The MMC value was taken as the lowest concentra-
tion, which showed no visible growth of microbial
colonies in the subculture dishes.
Zn(but)2⋅2phen (IV)
The reaction mixture of a water solution containing
0.479 g zinc(II) butyrate (0.002 mol) and 0.753 g
phenazone (0.004 mol) was under continual stirring
for 30 min. The mixture was filtered off and reduced
in volume in waterbath at 70°C. In several days a
white powder precipitated. Anal. calcd. for com-
pound (IV): C 58.51; H 6.22; N 9.10; Zn 10.61%.
Found: C 58.29; H 6.40; N 9.25; Zn 9.72%.
Instrumentation
C, H, N analyses were performed using a Perkin
Elmer 2400 CHN analyser. Zinc content was deter-
mined complexometrically.
TG/DTG and DTA measurements were carried
out using a Perkin Elmer DSC7/TGA7 thermoana-
lyser in air atmosphere, heating rate 10°C min–1 and
sample mass 10 mg.
IR spectra were recorded on a SPECORD M-80
spectrophotometer in the range 4000–400 cm–1 using
KBr pellets.
Results and discussion
Thermal behaviour
Zn(form)2⋅2phen (I)
The TG/DTG and DTA curves of compound (I) are
given in Fig. 1. The TG curve indicates that it is ther-
mally stable up to 120°C. Above this temperature
2 mol of phenazone are released in an endothermic
effect with a minimum on the DTA curve at 280°C.
In the next step of thermal decomposition the com-
pound loses formaldehyde and carbone dioxide, ac-
companied by an endothermic effect at 330°C on the
DTA curve. The final product was ZnO. The following
mechanism of thermal decomposition was proposed:
Antimicrobial activity
The antibacterial activity of the prepared Zn(II) com-
pounds was evaluated by a micro-dilution [10]
method using G+ bacteria Staphylococcus
aureus CCM 3953, G– bacteria Escherichia
coli CCM 3988 (both from the Czech Collection of
Microorganisms, Masaryk University, Brno, Czech
Republic) and by macrodilution method in L-shape
tubes using the yeasts Candida parapsilosis (pur-
chased from the Laboratory of Medical Mycology,
Postgraduate Medical Institute, Bratislava, Slovakia)
under vigorous shaking [11]. The efficiency of pre-
pared derivatives on filamentous fungi Rhizopus
oryzae, Alternaria alternata, Fusarium nivale (from
the Collection of Microorganisms of Department of
Zn(HCOO)2⋅2phen → 2phen + CH2O + CO2 + ZnO
Zn(ac)2⋅2phen (II)
The TG curve of compound (II) indicates that the
complex is stable up to 160°C as given in Fig. 2. Then
two mol of phenazone are released in one step fol-
lowed by elimination of acetone and carbon dioxide
220
J. Therm. Anal. Cal., 88, 2007

Zn(II) COMPLEX COMPOUNDS WITH PHENAZONE
Fig. 1 TG/DTG and DTA curves of Zn(form)2⋅2phen (I)
Fig. 3 TG/DTG and DTA curves of Zn(prop)2⋅2phen (III)
gins with a minimum on the DTA curve at 220°C in
an endothermic effect. In next step, diethyl ketone
and carbon dioxide are released at 320°C as it is dis-
played on the DTA curve. The final product was ZnO.
The scheme of possible thermal decomposition is
here:
Zn(CH3CH2COO)2⋅2phen → 2phen + (C2H5)2CO +
+ CO2 + ZnO
Zn(but)2⋅2phen (IV)
The TG/DTG and DTA curves of compound (IV) are
depicted in Fig. 4. The thermal decomposition begins
with the release of 2 mol phenazone with an
endothermic peak at 220°C. Then it is followed by
pyrolysis of butyrate anion attributing to the ellimi-
nation of dipropylketone and carbon dioxide. It is dis-
played on the DTA curve as an endothermic effect
with a minimum at 340°C. ZnO was found as a final
product. The scheme of possible thermal decomposi-
tion is here:
Fig. 2 TG/DTG and DTA curves of Zn(ac)2⋅2phen (II)
in the next step. The final product was ZnO. The most
probable scheme of the thermal decomposition is
here:
Zn(CH3CH2CH2COO)2⋅2phen → 2phen +
+ (C3H7)2CO + CO2 + ZnO
Zn(CH3COO)2⋅2phen → 2phen + (CH3)2CO +
The study of thermal behaviour of the prepared
compounds suggest that the formation of intermedi-
ates is various and depends on the length of a
carboxylic chain. The presence of intermediates and
volatiles products were confirmed by IR spectra
+ CO2 + ZnO
Zn(prop)2⋅2phen (III)
(υ
=1715 cm–1, υ
=2980 cm–1; υ
=
The TG curve displays that compound (III) is ther-
mally stable up to 140°C as given in Fig. 3. Above
this temperature, the elimination of neutral ligand be-
CO (ketone)
(C–H) CH
as(CO 2 )
3
2350 cm–1, υ
) =1342 cm–1, δ =670 cm–1) and
s(CO 2
CO 2
methods of qualitative chemical analyses.
J. Therm. Anal. Cal., 88, 2007
221

SZUNYOGOVÁ et al.
It is proposed that the different thermal stability
is caused by the presence of various carboxylate an-
ion and N-donor ligand.
IR spectra
The absorption bands of carbonyle group occurred in
the range 1700–1680 cm–1. Calculated form IR spec-
tra the magnitude of ΔCOO was determined, where
ΔCOO=ν
–νs(COO – ) . It is used as a criterion how
–
carboxyalsa(CtOeOgr) oups are coordinated to metal ions [13].
Calculations gave values of ΔCOO in the range
340–200 cm–1. The values of ΔCOO, the three bands in
the range 920–740 cm–1 and a strong absorption band
around 540 cm–1 confirm unidentate mode of
carboxylate to Zn2+ ion for compounds I–IV.
The other characteristic absorption bands of the pre-
pared complexes are reported in Table 1. The position
of all found bands is in a good accordance with litera-
ture data [14].
Fig. 4 TG/DTG and DTA curves of Zn(but)2⋅2phen (IV)
Table 1 Characteristic absorption bands in the IR spectra of the prepared complexes [ν(cm–1)]
Assignment/compound
(I)
(II)
(III)
(IV)
ν(C=O)
1680
1640
1700
1600
1700
1640
1690
1650
νas(COO–
)
νs(COO –
1400
1400
1300
1400
)
ΔCOO
240
200
340
250
ν(C– H)
3050
3080
3090
3070
ph
δ(C– H)
1400–1000
750–600
1550
1400–1000
750–580
1560
1380–1000
800–550
1560
1390–1000
800–580
1570
ph
γ(C– H)
ph
ν(C=C)
ph
ν(C– C)
1520
1510
1510
1500
ph
ν(C– C)
1600–1550
1590–1515
1600–1510
1600–1570
pyr
ph – phenyl, pyr – pyrazole
Table 2 Antimicrobial activity of Zn(II) complexes characterized by numerical values of IC50 and MIC (mmol dm–3)
Bacteria
S. aureus
IC50 MIC
Yeasts
Filamentous fungi
B. cinerea F. nivale
IC50 MIC
E. coli
C. parapsilosis
R. oryzae
A. alternata
Complex
IC50
MIC
IC50
MIC
IC50
MIC
IC50
MIC
IC50
MIC
(I)
1.39
1.39
1.23
1.34
>3
2s
2c
2c
2c
>3
1.89
2.35
1.42
2.82
>3
3s
>3
3s
0.01
0.01
0.01
0.01
1.79
3s
2s
1.86
2.82
1.80
1.95
>3
>3
>3
3s
1.94
2.40
1.53
0.86
>3
>3
>3
3s
2.66
>3
>3
>3
>3
>3
>3
>3
>3
>3
>3
>3
>3
>3
>3
>3
>3
(II)
(III)
(IV)
(V)
>3
2s
2.1
1.53
>3
>3
>3
>3
>3
2s
>3
>3
(I) – Zn(form)2⋅2phen, (II) – Zn(ac)2⋅2phen, (III) – Zn(prop)2⋅2phen, (IV) – Zn(but)2⋅2phen, (V) – phenazone, s – microbistatical
effect, c – microbicidal effect
222
J. Therm. Anal. Cal., 88, 2007

Zn(II) COMPLEX COMPOUNDS WITH PHENAZONE
Ackowledgements
Biological properties
Results of the quantitative determination of anti-
microbial activity, characterized by IC50 and MIC val-
ues, are presented in Table 2. The compounds tested
differ in their bioactivities against bacteria, yeasts and
filamentous fungi; the bioactivities decrease in the se-
quence yeasts>bacteria>filamentous fungi.
This work was supported by the Slovak Ministry of Education
VEGA project No. 1/2474/05. This financial support is grate-
fully acknowledged.
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DOI: 10.1007/s10973-006-8114-0
J. Therm. Anal. Cal., 88, 2007
223