Novel coordination compounds: Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) cations with acesulfame/N,N-diethylnicotinamide ligands

Article abstract of DOI:10.1080/00958972.2019.1705970

Five coordination complexes with Mn²⁺ (1), Co²⁺ (2), Ni²⁺ (3), Cu²⁺ (4), and Zn²⁺ (5) containing acesulfame (ace) and N,N-diethylnicotinamide (dena) ligands were synthesized and structural binding pro

Full text of DOI:10.1080/00958972.2019.1705970

Journal of Coordination Chemistry
ISSN: 0095-8972 (Print) 1029-0389 (Online) Journal homepage: https://www.tandfonline.com/loi/gcoo20
Novel coordination compounds: Mn(II),
Co(II), Ni(II), Cu(II), and Zn(II) cations with
acesulfame/N,N-diethylnicotinamide ligands
Tuğrul Yildirim, Dursun Ali Köse, Gülçin Alp Avci, Onur Şahin & Fatih Akkurt
To cite this article: Tuğrul Yildirim, Dursun Ali Köse, Gülçin Alp Avci, Onur Şahin & Fatih
Akkurt (2020): Novel coordination compounds: Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) cations
with acesulfame/N,N-diethylnicotinamide ligands, Journal of Coordination Chemistry, DOI:
10.1080/00958972.2019.1705970
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JOURNAL OF COORDINATION CHEMISTRY
https://doi.org/10.1080/00958972.2019.1705970
Novel coordination compounds: Mn(II), Co(II),
Ni(II), Cu(II), and Zn(II) cations with
acesulfame/N,N-diethylnicotinamide ligands
a
a
b
c
ꢀ
€
€
Tugrul Yildirim , Dursun Ali Kose , Gulc¸in Alp Avci , Onur S¸ahin and
Fatih Akkurtd
b
aDepartment of Chemistry, Hitit University, C¸orum, Turkey; Department of Molecular Biology and
c
Genetics, Hitit University, Corum, Turkey; Scientific and Technological Research Application Centre,
d
Sinop University, Sinop, Turkey; Department of Chemical Engineering, Gazi University,
Ankara, Turkey
ABSTRACT
ARTICLE HISTORY
Five coordination complexes with Mn2þ (1), Co2þ (2), Ni2þ (3),
Cu2þ (4), and Zn2þ (5) containing acesulfame (ace) and N,N-dieth-
ylnicotinamide (dena) ligands were synthesized and structural
binding properties investigated. Four compounds (1, 2, 4, and 5)
were examined with single crystal X-ray diffraction methods. The
structures containing Mn(II), Co(II), and Zn(II) were iso-structural.
Six-coordination of metal cations were completed with two moles
dena and four aqua ligands. The dena ligands were coordinated
via pyridine nitrogen as neutral-monodentate. Charge stabilities of
the complexes are complemented by two moles monoanionic ace
ligands, located outside of the coordination unit. In the Cu(II)
complex, the coordination is completed by acidic nitrogen and
carbonyl oxygen atoms of two ace ligands and pyridine nitrogen
of two moles dena ligands. The coordination to Cu(II) for ace
ligands was monoanionic-bidentate. All metal cations in the struc-
ture are distorted octahedral. Thermal decomposition of com-
plexes begins with removal of the aqua molecules from the
structures and is completed by combustion of organic ligands.
The final decomposition products of all structures have been
identified as corresponding metal oxides. Some biological applica-
tions (anti-fungal/anti-bacterial) were studied using 1–5.
Received 12 October 2019
Accepted 21 November 2019
KEYWORDS
Acesulfame; N,N-
diethylnicotinamide; coord-
ination compounds; anti-
microbial studies; structural
properties; thermal
investigation
€
CONTACT Dursun Ali Kose
dalikose@hitit.edu.tr
Supplemental data for this article is available online at https://doi.org/10.1080/00958972.2019.1705970.
ß 2020 Informa UK Limited, trading as Taylor & Francis Group

2
T. YILDIRIM ET AL.
1. Introduction
Acesulfame (C4H5SO4N) (Figure 1(a)), discovered by Karl Klaus in 1967, is an oxathiazi-
none dioxide derivative [1]. Acesulfame has been an artificial sweetener used world-
wide since 1983. It is also used as a food additive [2]. Since it cannot be digested by
metabolism, it is used as a sweetener by diabetics [3]. The potassium salt form is
widely used due to its high chemical and thermal stability; it is easy to purify due to
its low solubility in water.
In the acesulfame structure, the ring contains nitrogen and oxygen, imine, sul-
fonyl, and methyl groups. The methyl group is substituted on the alpha carbon,
and there are double bonds between the alpha and beta carbons. It is systematic-
ally referred to as 6-methyl-1,2,3-oxothiazin-4(3H)-one-2,2-dioxide [4]. It possesses
tautomeric properties due to the hydrogen exchange between the imine nitrogen
and the carbonyl oxygen. Tautomeric structures as lactim and lactam are involved
in many biological systems [5]. Also, needle-prism shaped crystals show the poly-
morphism feature [6].
Acesulfame is an important ligand in coordination chemistry. Thanks to the dif-
ferent functional groups (-CO, -NH, -SO2), acesulfame has different potential donors
and is a multifunctional ligand that can be attached to various metal ions via imine
nitrogen, carbonyl oxygen, sulfonyl oxygen, or ring oxygen. The metal complexes of
the acesulfamate ligand were first reported in 2005. The first synthesized complexes
are Mn2þ, Co2þ, Ni2þ, Cu2þ, and Cd2þ structures with the general structure
[M(ace)2(H2O)n] [7]. Due to the numerous electron donors present in the structure
of the acesulfame ligand, coordination compounds having different binding proper-
ties have been synthesized (the complementary ion with ionization of the acidic
imine nitrogen [8–10]; monodentate coordination over carbonyl oxygen [10–12];
monoanionic-monodentate coordination over imine nitrogen [11, 13, 14];

JOURNAL OF COORDINATION CHEMISTRY
3
(a)
(b)
Figure 1. Molecular formulas of acesulfame (a) and N,N-diethylnicotinamide (b).
monoanionic-bidentate coordination over carbonyl oxygen and imine nitrogen [15,
16]; monodentate coordination over one sulfonyl oxygen [17]; bidentate coordin-
ation over two sulfonyl oxygens [18, 19]; a tridentate bridge connecting to one
metal via imine nitrogen, to two other metals via carbonyl oxygen [20–23]). In add-
ition, structural characteristics of alkaline earth metal cations of acesulfame/nicotina-
mide mixed liganded coordination compounds were investigated [24]. The structural
properties of the acesulfame ligand, which show similarities to saccharin in terms of
structural properties, will also reveal similar binding properties. Many metal com-
plexes of saccharin are present in literature [25].
N,N-Diethylnicotinamide (C10H14N2O) (Figure 1(b)) is colorless, odorless, and crystal-
line material that is currently used as a respiratory stimulant, has good solubility in
water and is insoluble in oils and ethers [6]. From this information, mixed ligand coor-
diantion compounds of Mn(II) (1), Co(II) (2), Ni(II) (3), Cu(II) (4), and Zn(II) (5) with ace-
sulfame/N,N-diethtylnicotinamide molecules were obtained. The structural properties
of the synthesized complexes were elucidated by elemental analysis, infrared spectros-
copy, single crystal X-ray diffraction (SC-XRD) analysis, solid-Ultra Violet visible spec-
troscopy (S-UV-vis), Thermo Gravimetric Analysis/Differential Thermal Analysis (TGA/
DTA), magnetic susceptibility, and melting point. Finally, some biological applications
of the complexes have been studied.
2. Experimental
2.1. Materials and methods
The perchlorate salts, Mn(ClO4)2ꢀH2O), (Co(ClO4)2ꢀ6H2O, Ni(ClO4)2ꢀ6H2O, Cu(ClO4)2ꢀ6H2O,
Zn(ClO4)2ꢀ6H2O, acesulfame-K, N,N-diethylnicotinamide used in the synthesis of com-
plexes were provided by Sigma-Aldrich company.
2.2. Synthesis
In the synthesis of the complexes, solution obtained by dissolving 0.01 mole of metal
-
cation perchlorate (ClO4 ) salts in 30 ml of water was mixed with the solution obtained
by dissolving 0.02 moles of acesulfame-K in 20 ml of water and precipitated with
potassium perchlorate (KClO4).
A little cold ethyl alcohol was added to the solution for complete precipitation.
After settling had taken place, filtration was carried out, and the solution was
stored. 0.02 mol of N,N-diethylnicotinamide was dissolved in 50 ml of water and

4
T. YILDIRIM ET AL.
Figure 2. Synthesis reaction of metal complexes.
added to the stored solution. It was then allowed to crystallize under ambient con-
ditions (Figure 2).
2.3. Biological applications
The antimicrobial activities of the synthesized materials dissolved in DMSO were exam-
ined by the disk diffusion method. Before the study, microorganisms from stocks were
activated in food broth twice for 16–18 h using a 37 ꢁC incubation medium. The
optical densities of all activated microorganisms were adjusted to approximately
600 nm (OD600 ꢂ 600) in the spectrophotometer. During the study, 100 lL of the cul-
ture suspension was inoculated onto Mueller Hinton Agar (MHA) and placed in the
petri dish with sterile discs prepared beforehand. Paper discs (6 mm in diameter) con-
taining 10 ml of synthesized substance to be tested (at a concentration of 5 mg/ml in
DMSO 10%) were placed at the edge of Petri plates containing MHA. Incubation of
the plates was done at 37 ꢁC for 24 h. Reading of the results was done by measuring
the diameters of the inhibition zones generated by the tested substances. 10% DMSO
was used as a negative control.
An inhibition zone was not seen in 10% DMSO used as control. The antimicrobial
effects against microorganisms of synthesized substance concentrated with DMSO
10% were calculated. All inhibition zones are reported as mm SD [26].

JOURNAL OF COORDINATION CHEMISTRY
5
Table 1. Elemental analysis results of metal-acesulfame/N,N-diethylnicotinamide mixed lig-
and compounds.
Content (%)
Exp. (Teo.)
M.W.
(g/mol) Yield
Decomp. leff.
Complexes
C
H
N
S
Color
temp. (ꢁC) (BM)
[Mn(C10H14N2O)2(H2O)4](C4H4NO4S)2 807.75
C28H44CoN6O14S2
[Co(C10H14N2O)2(H2O)4](C4H4NO4S)2 811.74
C28H44CoN6O14S2
[Ni(C10H14N2O)2(H2O)4](C4H4NO4S)2 811.50
C28H44CoN6O14S2
88
86
83
89
87
41.88 5.72 10.43 7.91 Pale-white
(41.63) (5.49) (10.40) (7.94)
41.09 5.91 10.32 7.97 Dark-pink
(41.43) (5.46) (10.35) (7.90)
41.21 5.97 10.33 7.97 Green
(41.44) (5.47) (10.36) (7.90)
44.48 5.52 10.98 8.38 Blue
(44.12) (5.02) (11.02) (8.41)
118
127
132
165
102
5.30
3.9
2.70
1.76
dia.
[Cu(C10H14N2O)2(C4H4NO4S)2]ꢀH2O
762.31
C28H38CuN6O11S2
[Zn(C10H14N2O)2(H2O)4](C4H4NO4S)2 818.19
C28H44CoN6O14S2
40.89 5.85 10.26 7.92 White
(41.10) (5.42) (10.27) (7.84)
Table 2. Some selected infrared bands of synthesized coordination compounds.
Groups
MnII
CoII
NiII
CuII
ZnII
ꢀ(OH)H2O
3600–3100
2984
3208
1650
1613
1493
1398
1293/1180
93
3600–3050
2986
3210
1650
1614
1492
1398
1293/1180
113
3600–3100
2985
3212
1650
1612
1493
1398
1294/1180
114
3550–3150
2983
3210
1657
1622
1459
1390
1294/1184
110
3550–3150
2979
3210
1656
1614
1461
1393
1292/1180
112
ꢀ(¼C–H)ring
ꢀ(C ¼ C)ring
ꢀ(C ¼ O)carbonyl
ꢀ(C–N)amide
ꢀ(C ¼ C)ring
ꢀ(C-N-C)amide
ꢀas(SO2)/ꢀs(SO2)
ꢀas-s
ꢀ(Ring)
1085–806
1346/941
973–713
649
1085–808
1345/940
970–710
649
1083–804
1347/941
971–710
647
1040–775
1347/946
900–668
649
1040–801
1366/942
977–713
649
ꢀs(CNS)/ꢀas(CNS)ace
ꢀ(C-N)amide
ꢀ(M-N)dena
ꢀ(M-N)ace
559
561
561
554
559
ꢀ(M-O)ace
–
–
–
481
–
ꢀ(M-O)aqua
517
518
517
517
516
3. Results and discussion
3.1. Elemental analysis
The elemental analysis data of compounds are given in Table 1. Also, the melting
points of the complexes, magnetic susceptibility data, colors, and yield calculations
are provided.
3.2. Infrared studies
In 1–5, infrared bands indicating coordination of the anionic ligand (as a counter ion)
to the metal were observed (Supplementary material Figure S1 and Table 2).
According to this, when they were coordinated to the metal cations, a shift was
detected at the absorption peaks corresponding to the functional groups. In the metal
complexes there was no peak attributable to N-H stretching due to the absence of
any N-H groups other than the acidic-N-H group of the ionized acesulfame ligand.
Except for the CuII complex, the structures were found to contain two N,N-

6
T. YILDIRIM ET AL.
diethylnicotinamide ligands and four water ligands in the complex; they are similar
(iso-structure). The CuII complex two N,N-diethylnicotinamide and two anionic acesul-
fame ligands in the coordination sphere. Accordingly, the M–N stretches of N,N-dieth-
ylnicotinamide in metal complexes of MnII, CoII, NiII, CuII, and ZnII were observed at
650 cmꢃ1, 649 cmꢃ1, 647 cmꢃ1, 650 cmꢃ1, and 649 cmꢃ1, respectively. These peaks indi-
cate coordination of the N,N-diethylnicotinamide from the pyridine nitrogen (¼N-) to
the metal cation. In the structures of MnII, CoII, NiII, and ZnII complexes, stretching
vibrations are generated around the 554–561 cmꢃ1 region of the acidic –N-H protons
in the structure of the acesulfame ligand, which acts as a balancing ion. However, ace-
sulfame is involved in the coordination sphere, binding monoanionic-bidentate (via
acidic nitrogen and a ketonic oxygen) in the CuII structure, which differs from the
monoanionic-monodentate bond type in other structures. A second M–O bonding
vibration (481 cmꢃ1) resulting from this complex supports this suggestion [27]. Except
for Cu(II) metal complex structure, M–O bonding vibrations of the water ligands in the
coordination cage are present at 516–519 cmꢃ1. Also, the characteristic peak of the
water -OH group, which supports the existence of aqua ligands, is observed at
3050–3600 cmꢃ1. However, due to the fact that the difference between the asymmet-
ric and symmetrical stretch of the SO2 groups does not change, SO2 groups do not
participate in coordination.
3.3. Thermal analysis
Thermal analysis curves obtained under nitrogen of the complexes are shown in
Supplementary material Figure S2. Decomposition curves of MnII, CoII, NiII, and ZnII
gave similar results, starting with removal of the aqua ligands. The degradation of
aqua ligands occurs at 90–180 ꢁC in 2 and 4 and 60–150 ꢁC in 1 and 5. The instability
of the structures increases due to the full and half-full electronic conformation of
Zn(II) and Mn(II). In the next step of decomposition, the acesulfame ligands, which are
stabilizing ions, are burned to form SO2 gas in one or two steps. Subsequent decom-
position steps are preceded by disruption of the N,N-diethylnicotinamide neutral lig-
and, followed by release of acesulfame residues. As the molecular structure of the
Cu(II) complex is different from other complexes, the thermal degradation steps are
also different. The thermal decomposition begins with the removal of two moles of
hydrate water outside the coordination unit at 49 ꢁC. After two SO2 are removed, the
N,N-diethylnicotinamide ligand is removed as a block in the dehydrated complex.
Finally, the remains of acesulfame are burned, and the degradation of the structure
was complete. In all metal complexes, the powder of the corresponding metal oxides
as final decomposition product was checked by powder XRD analysis. Some carbon-
ized carbon remains in the reaction vessel due to the thermal degradation being car-
ried out in nitrogen. The final colors are expected to be white; especially if the oxides
of Mn and Zn are dark black, this can be attributed to carbonized carbon remaining
[28, 29]. It is also supported by the fact that the amount of experimental residue is
slightly higher than the theoretical residue amounts. All decomposition steps and
decompositions products of complexes are shown in Table 3.

JOURNAL OF COORDINATION CHEMISTRY
7

8
T. YILDIRIM ET AL.
Table 4. The crystal data of the metal cation complexes.
Chemical formula
C28H44MnN6O14S2 (1) C28H44CoN6O14S2 (2)
C28H40CuN6O12S2 (4)
C28H44ZnN6O14S2 (5)
MW
807.75
Monoclinic
P21/c
811.74
Monoclinic
P21/c
780.32
Triclinic
P1
818.81
Monoclinic
P21/c
Crystal system
Space group
Temperature (K)
a, b, c (Å)
296
296
296
296
16.0714(11),
7.8371(5),
16.3644(12)
90.00
112.031(2)
90.00
15.943(2),
7.7475(10),
16.3037(19)
90.00
110.719(4)
90.00
7.9257(10),
8.3989(11),
13.6183(17)
100.797
96.782(5)
93.958
16.0081(12),
7.7531(5),
16.3152(14)
90.00
111.942(3)
90.00
a (ꢁ)
b (ꢁ)
c (ꢁ)
V (Å3)
Z
1910.6(2)
2
1883.5(4)
2
880.4(2)
1
1878.2(2)
2
Light source
Mo Ka/0.71073
0.52
Mo Ka/0.71073
0.64
Mo Ka/0.71073
0.81
Mo Ka/0.71073
0.84
m (mmꢃ1
)
Crystal size (mm)
Dc (g/cm3)
h range (ꢁ)
Color
0.25 ꢄ 0.21 ꢄ 0.18
0.16 ꢄ 0.14 ꢄ 0.10
0.19 ꢄ 0.13 ꢄ 0.07
0.18 ꢄ 0.14 ꢄ 0.11
1.404
1.431
1.472
1.447
3.0–28.3
Colorless
0.535, 0.746
0.030
0.666
0.049, 0.114, 1.09
3.0–28.3
Pink
0.594, 0.746
0.044
0.617
0.114, 0.309, 1.16
3.2–28.3
Purple
0.502, 0.746
0.055
0.617
0.130, 0.353, 1.12
3.0–28.3
Colorless
0.326, 0.746
0.038
0.667
0.046, 0.114, 1.11
Tmin, Tmax
Rint
(sin h/k)max (Åꢃ1
R[F2 > 2r(F2)],
Wr(F2), S
)
Measured reflections
Independent
reflections
Parameter number
Absolute
12348
4513
39177
3672
23174
3421
12853
4363
245
0.46(4)
240
0.46(4)
231
0.46(4)
246
0.46(4)
structure
parameter
Dqmax, Dqmin
0.34, ꢃ0.52
2.25, ꢃ1.23
0.42, ꢃ0.62
0.44, ꢃ0.46
(e Åꢃ3
)
3.4. X-ray diffraction analysis
Data were collected at 296 K with a D8-QUEST diffractometer with Mo-Ka laser by
selecting appropriate crystals of 1, 2, 4, and 5 suitable for SC-XRD studies. SHELXS-97
[30] software was used for solution of the crystal structures. For the refining of the col-
lected data, full-matrix least squares was used on F2 by using SHELXL-2013 [31] soft-
ware. Other than hydrogen, all atoms were refined with anisotropic parameters.
Hydrogens bound to carbon were placed from different maps and then treated as rid-
ing with 0.93–0.97 Å C-H distances. Hydrogens of water molecules were freely refined
by being placed on a different map. Methods used in characterization; Bruker APEX2
[32] for data collection, MERCURY program for molecular graphs [33] and WinGX [34]
software for preparing material for publication. The data obtained and the details of
the crystal structures are given in Table 4.
3.5. Description of structures
The structure solutions generated by the collected data reveal that 1, 2, and 5 are
very similar. Compound 4 was crystallized in the P-1 space group, while the space
group of 1, 2, and 5 was P21/c. The structural data of the crystals are summarized in
Table 4. Bond lengths of the coordination compounds are listed in Table 5 together

JOURNAL OF COORDINATION CHEMISTRY
9
ꢁ
Table 5. Some important bond distances and angles for 1, 2, 4, and 5 (Å, ).
Complex 1
Mn1–O2i
Mn1–O2
2.1517(16)
2.1517(16)
2.1564(17)
2.1564(17)
2.3202(18)
2.3202(18)
180.0
90.68(7)
89.32(7)
89.32(7)
90.68(7)
O3–Mn1–O3i
O2i–Mn1–N1
O2–Mn1–N1
O3–Mn1–N1
O3i–Mn1–N1
O2i–Mn1–O3i
O2–Mn1–O3i
O2i–Mn1–N1i
O2–Mn1–N1i
O3–Mn1–N1i
O3i–Mn1–N1i
180.0
N1–Mn1–N1i
C1–N1–Mn1
C5–N1–Mn1
Mn1–O2–H2B
Mn1–O2–H2A
Mn1–O3–H3A
Mn1–O3–H3B
C2–C1–N1–Mn1
C4–C5–N1–Mn1
180.0
89.58(7)
90.42(7)
91.95(7)
88.05(7)
89.32(7)
90.68(7)
90.42(7)
89.58(7)
88.05(7)
91.95(7)
122.70(15)
119.82(15)
129(2)
120(2)
127(2)
Mn1–O3
Mn1–O3i
Mn1–N1
Mn1–N1i
O2i–Mn1–O2
O2i–Mn1–O3
O2–Mn1–O3
O2i–Mn1–O3i
O2–Mn1–O3i
Complex 2
N1–Co1
118(2)
178.5(2)
ꢃ178.50(18)
2.200(6)
2.076(5)
2.076(5)
2.081(6)
2.081(6)
2.200(6)
123.4(6)
120.0(5)
180.0
O3i–Co1–O2
O3–Co1–O2
O3i–Co1–O2i
O3–Co1–O2i
O2–Co1–O2i
O3i–Co1–N1
O3–Co1–N1
O2–Co1–N1
O2i–Co1–N1
90.9(3)
89.1(3)
89.1(3)
90.9(3)
180.0
89.4(2)
90.6(2)
87.2(3)
92.8(3)
O3i–Co1–N1i
O3–Co1–N1i
O2–Co1–N1i
O2i–Co1–N1i
N1–Co1–N1i
Co1–O2–H2A
Co1–O2–H2B
Co1–O3–H3A
Co1–O3–H3B
90.6(2)
89.4(2)
92.8(3)
87.2(3)
180.0
131(7)
123(7)
119(7)
119(2)
Co1–O3i
Co1–O3
Co1–O2
Co1–O2i
Co1–N1i
C1–N1–Co1
C5–N1–Co1
O3i–Co1–O3
Complex 4
N1–Cu1
2.014(9)
1.934(7)
1.934(7)
2.014(9)
123.3(8)
C5–N1–Cu1
C13–O2–Cu1
O2i–Cu1–O2
O2i–Cu1–N1
O2–Cu1–N1
118.7(7)
111.0(6)
180.0
90.3(3)
89.7(3)
O2i–Cu1–N1i
O2–Cu1–N1i
89.7(3)
90.3(3)
180.0
8.2(12)
ꢃ172.9(8)
O2–Cu1
Cu1–O2i
N1–Cu1–N1i
Cu1–N1i
N3–C13–O2–Cu1
C12–C13–O2–Cu1
C1–N1–Cu1
Complex 5
N1–Zn1
2.216(2)
2.0792(17)
2.0792(17)
2.0921(18)
2.0922(18)
2.216(2)
122.74(17)
119.93(17)
180.0
O3i–Zn1–O2i
O3–Zn1–O2i
O3i–Zn1–O2
O3–Zn1–O2
O2i–Zn1–O2
O3i–Zn1–N1i
O3–Zn1–N1i
O2i–Zn1–N1i
O2–Zn1–N1i
88.82(8)
91.18(8)
91.18(8)
88.82(8)
180.0
90.64(8)
89.36(8)
92.10(8)
87.90(8)
O3i–Zn1–N1
O3–Zn1–N1
O2i–Zn1–N1
O2–Zn1–N1
N1i–Zn1–N1
Zn1–O2–H2A
Zn1–O2–H2B
Zn1–O3–H3A
Zn1–O3–H3B
89.36(8)
90.64(8)
87.90(8)
92.10(8)
180.0
126(2)
117(2)
122(2)
124(2)
Zn1–O3i
Zn1–O3
Zn1–O2i
Zn1–O2
Zn1–N1i
C1–N1–Zn1
C5–N1–Zn1
O3i–Zn1–O3
with the bond angles and other related geometric data. The parameters of hydrogen
bonds are detailed in Table 6.
3.6. Complexes 1, 2, and 5
Atomic numbered molecular structures of 1, 2, and 5 are given in Figure 3. The asym-
metric units of 1, 2, and 5 contain one M(II) cation (M ¼ Mn(II) in 1, Co(II) in 2, and
Zn(II) in 5), one dena ligand, one uncoordinated ace anion and two aqua ligands. Each
M(II) ion inserted in the center of symmetry is coordinated with two nitrogens (N1
and N1i) from different dena ligands, and with four oxygens (O2, O3, O2i, and O3i)
from water ligands [(i) ꢃx þ 1, ꢃy þ 1, ꢃz þ 1]. The coordination geometry around the
metal cations (M ¼ Mn(II) in 1, Co(II) in 4 and Zn(II) in 5) was determined to be dis-
torted octahedral.
The Mn-O bond lengths of 1 are 2.1517(16) and 2.1564(17) Å, Co–O bond lengths
of 2 are 2.076(5) and 2.081(6) Å, and Zn-O bond lengths of 5 are 2.0792(17) and
2.0922(18) Å [35, 36]. The axial Mn-N bond length is 2.3202(18) Å, axial Co–N bond

10
T. YILDIRIM ET AL.
ꢁ
Table 6. Hydrogen-bond parameters for 1, 2, 4 and 5 (Å, ).
D-Hꢀ ꢀ ꢀA
Complex 1
D-H
Hꢀ ꢀ ꢀA
Dꢀ ꢀ ꢀA
D-Hꢀ ꢀ ꢀA
C5—H5ꢀ ꢀ ꢀO2i
C9—H9Bꢀ ꢀ ꢀO4
C14—H14Aꢀ ꢀ ꢀO5ii
O2—H2Bꢀ ꢀ ꢀO7iii
O2—H2Aꢀ ꢀ ꢀO7
O3—H3Aꢀ ꢀ ꢀO1iv
O3—H3Bꢀ ꢀ ꢀN3i
Complex 2
0.93
0.97
0.96
0.84(2)
0.82(2)
0.82(2)
0.84(2)
2.57
2.44
2.55
1.87(2)
1.87(2)
1.89(2)
2.04(2)
3.172(3)
3.184(4)
3.446(4)
2.703(2)
2.684(2)
2.691(3)
2.852(3)
123
134
156
172(3)
173(3)
163(3)
164(3)
C1—H1ꢀ ꢀ ꢀO3i
C5—H5ꢀ ꢀ ꢀO3
0.93
0.93
0.97
2.60
2.52
2.46
3.128(11)
3.086(10)
3.162(13)
3.404(14)
2.865(9)
2.714(10)
2.673(8)
2.699(8)
117
120
129
C7—H7Bꢀ ꢀ ꢀO5i
C14—H14Aꢀ ꢀ ꢀO4ii
O2—H2Aꢀ ꢀ ꢀN3i
O2—H2Bꢀ ꢀ ꢀO1iii
O3—H3Aꢀ ꢀ ꢀO7
O3—H3Bꢀ ꢀ ꢀO7iv
Complex 4
0.96
2.46
168
0.84(2)
0.83(2)
0.83(2)
0.84(2)
2.10(5)
1.91(4)
1.85(3)
1.91(2)
153(9)
163(13)
168(10)
157(6)
C1—H1ꢀ ꢀ ꢀO6ii
C5—H5ꢀ ꢀ ꢀO2i
C12—H12ꢀ ꢀ ꢀO2iii
O6—H6Aꢀ ꢀ ꢀO1
O6—H6Bꢀ ꢀ ꢀO1iv
Complex 5
0.93
0.93
0.93
0.84(2)
0.83(2)
2.32
2.39
2.45
2.1(2)
2.3(2)
3.05(2)
2.908(13)
3.378(14)
2.67(2)
135
115
178
123(22)
129(25)
2.89(2)
C5—H5ꢀ ꢀ ꢀO3i
C9—H9Bꢀ ꢀ ꢀO5
C14—H14Cꢀ ꢀ ꢀO4ii
O2—H2Aꢀ ꢀ ꢀO1iii
O2—H2Bꢀ ꢀ ꢀN3i
O3—H3Aꢀ ꢀ ꢀO7
O3—H3Bꢀ ꢀ ꢀO7iv
0.93
0.97
0.96
0.82(2)
0.83(2)
0.82(2)
0.81(2)
2.47
2.40
2.50
1.92(2)
2.04(2)
1.87(2)
1.92(2)
3.048(3)
3.161(4)
3.400(4)
2.719(3)
2.864(3)
2.680(3)
2.712(3)
121
135
156
166(3)
169(3)
169(3)
166(3)
Symmetry codes: (i) ꢃx þ 1, ꢃy þ 2, ꢃz þ 1; (ii) ꢃx, ꢃy þ 1, ꢃz þ 1; (iii) ꢃx þ 2, ꢃy þ 2, ꢃz þ 1 for 1; (i) ꢃx þ 1,
ꢃy þ 1, ꢃz þ 1; (ii) x, y ꢃ 1, z; (iii) x, ꢃy þ 1/2, z ꢃ 1/2; (iv) ꢃx þ 1, ꢃy, ꢃz þ 1 for 2; (i) ꢃx þ 1, ꢃy þ 1, ꢃz þ 1; (ii)
x, y þ 1, z; (iii) ꢃx þ 1, y þ 1/2, ꢃz þ 1/2; (iv) ꢃx þ 1, ꢃy þ 2, ꢃz þ 1 for 3; (i) ꢃx þ 1, ꢃy þ 1, ꢃz þ 1; (ii) x, y þ 1,
z; (iii) ꢃx þ 1, ꢃy þ 2, ꢃz þ 1; (iv) ꢃx þ 1, y þ 1/2, ꢃz þ 3/2 for 4.
length is 2.200(6) Å and axial Zn-N bond length is 2.216(2) Å [35–38]. The structures of
1, 2, and 5 form layers with hydrogen bonds and O-Hꢀ ꢀ ꢀO, O-Hꢀ ꢀ ꢀN and C-Hꢀꢀ(R)
(Table 6). In 1, 2 and 5, the combination of O-Hꢀ ꢀ ꢀO and O-Hꢀ ꢀ ꢀN hydrogen bonds
2
2
produce edge-fused R2 (8) and R4 (8) rings which run parallel to the [010] direction
(Supplementary material Figure S3). All of these intermolecular interactions give 3 D
framework results.
3.7. Complex 4
The molecular structure of 4, with atom numbering scheme, is shown in Figure 4. The
asymmetric unit of 4 contains one Cu(II), one N,N-diethylnicotinamide ligand, one ace-
sulfame ligand, and one non-coordinated water. Cu(II) is located on a center of sym-
metry and coordinated by two nitrogens of two different N,N-diethylnicotinamide
ligands and two oxygens from acesulfame ligands. The coordination geometry around
Cu(II) can be described as distorted square planar geometry. The Cu-O bond length is
1.934(7) Å, while Cu-N bond length is 2.014(9) Å [39–43], respectively. Molecules of 4
are linked by C-Hꢀ ꢀ ꢀO and O-Hꢀ ꢀ ꢀO hydrogen bonds (Table 6). The water O6 in the
molecule at (x, y, z) acts as a hydrogen-bond donor, to O1 in the molecule at (x, y, z)

JOURNAL OF COORDINATION CHEMISTRY
11
Figure 3. The molecular structures of 1, 2, and 5 (M ¼ Mn(II) in 1, Co(II) in 2, and Zn(II) in 5)
showing the atom-numbered scheme [(i) ꢃx þ 1, ꢃy þ 1, ꢃz þ 1].
2
and O1 in the molecule at (ꢃx þ 2, ꢃy þ 2, ꢃz þ 1), forming centrosymmetric R4 (8)
2
rings (Supplementary material Figure S4) and R2 (8) rings (Supplementary material
Figure S5).
3.8. Solid state UV-visible analysis
For determination of electronic transitions, metal-acesulfame/N,N-diethylnicotinamide
complexes were investigated in solid-state visible spectra at 900–200 nm (Figure 5 and
Table 7). The d–d transitions of 2 are visible at 737 nm (T2g!Eg), 659 nm (T1g!T2g)
and 494 nm (T1g!T1g). The three spin-allowed d-d transitions of 3 correspond to the
839 nm (A2g!T1g), 635 nm (A2g!T1g) and 489 nm (A2g!T2g). These transitions indicate
that the d orbitals of the NiII metal cation are in octahedral geometry. The multiple
absorption bands of 4 form overlapping peaks, giving a broad band from 833–475 nm
(peak point 657) (T2g!Eg). This shows that the Cu2þ cation supports “pseudo-
octahedral” coordination geometry with Jahn-Teller distortion. Zn2þ is diamagnetic
and does not show any d-d electronic transition.

12
T. YILDIRIM ET AL.
Figure 4. Molecular structure of 4 showing the numbered atoms [(i) ꢃx þ 1, ꢃy þ 1, ꢃz þ 1].
Complex 1 containing Mn(II) has the highest magnetic moment. Thus, in the Mn(II)
complex, the d-d transitions will be very weak and the color is pale white.
The high intensity transition bands at low wavelength are not d-d transitions, but
can be attributed to metal!ligand charge transfer transitions with high energies. For
2 such transition is 255 nm, for 3 249 nm and for 4 246 nm (M!L). For Mn(II) (1) and
Zn(II) (5) complexes, the peaks at 241 nm and 253 nm can be interpreted as
ligand!metal (L!M) charge transfer [44].
3.9. Biological applications
Antimicrobial activity studies were performed in-vitro against gram-positive
(Enterococcus faecalis ATCC 29212 and Staphylococcus aureus ATCC 6538), gram-nega-
tive bacteria (Pseudomonas aeroginosa ATCC 27853 and Escherichia coli ATCC 25922),
and fungus (Candida albicans ATCC 10231) using disk diffusion method for 1–5. The
results are summarized in Table 8. Biological studies based on investigation of anti-
microbial properties of molecules against various bacterial and fungal species were
performed. According to the results obtained, 5 against gram-positive bacteria
Staphylococcus aureus ATCC 6538 and gram-negative bacteria Pseudomonas aeroginosa
ATCC 27853 were determined to be effective. Complex 4 showed activity against
gram-negative bacteria Staphylococcus aureus ATCC 6538. The other complexes did not

JOURNAL OF COORDINATION CHEMISTRY
13
Figure 5. UV-Vis NIR spectra of 1–5.
Table 7. The UV-Vis transition bands of metal-acesulfam/N,N-diethylnicotinamide complexes.
Comp.
Trans.
C28H44MnN6O14S2
C
28H44CoN6O14S2
C
28H44NiN6O14S2
C
28H38CuN6O11S2
C
28H44ZnN6O14S2
(1)
(2)
(3)
(4)
(5)
d-d
–
737.00 (T2g!Eg)
839.00(A2g!T1g)
833.00-475.00
–
657.00(T2g!Eg)
d-d
d-d
–
–
–
659.00(T1g!T2g)(F)
635.00(A2g!T1g)(F)
–
–
–
–
–
494.00(T1g!T1g)(P)
489.00(A2g!T2g)(P)
M!L
255
249
246
–
L!M
241
–
–
253
Table 8. Biological activity zones of inhibition (ZOI; mm) of the molecules.
Species
dena
PT
DMSO
1
2
3
4
5
E. coli
12.0 0.0
11.0 1.0
6.5 0.5
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
2.5 0.5
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
3.0 1.0
2.0 1.0
C. albicans
E. faecalis
P. aeruginosa
S. aureus
2.5 1.5
ND: not determined inhibition zone.

14
T. YILDIRIM ET AL.
Figure 6. Study of substances on gram-positive bacteria: (a) Enterococcus faecalis ATCC 29212; (b)
Staphylococcus aureus ATCC 6538.
Figure 7. Study of substances on gram-negative bacteria: (a) Pseudomonas aeroginosa ATCC 27853;
(b) Escherichia coli ATCC 25922.
Figure 8. Study of substances on fungi.

JOURNAL OF COORDINATION CHEMISTRY
15
have antibacterial or antifungal properties. Figures 6 and 7 show the effect of gram-
positive bacteria cultures and gram-negative bacteria cultures; the effect of complexes
placed on fungal cultures is shown in Figure 8.
4. Conclusion
Coordination compounds of MnII, CoII, NiII, CuII, and ZnII containing acesulfame and/or
N,N-diethylnicotinamide ligands were synthesized. The obtained compounds have
ace–dena ligands in 1:2:2 ratio. The single crystal structure analysis of all molecules
except [Ni(dena)2(H2O)4](ace)2 (3) were solved. Molecular structure of the Ni(II) complex
is proposed by using the results of the spectroscopic and thermal analysis. MnII, CoII,
and ZnII are isostructural with octahedral geometries completed with four water
ligands and the pyridine nitrogens of two N,N-diethylnicotinamide ligands; these
ligands exhibit neutral-monodentate bonding. Two moles of mono-anionic acesulfame
ligands, outside the coordination sphere, act as charge balancers for the complexes.
The acesulfamate anions are involved in the molecular structure interacting with lat-
tice components through hydrogen bond interactions. In the Cu(II) metal complex,
two moles of acesulfame ligands coordinate to the metal as monoanionic bidentate
(acidic –N–H and ketonic ¼ O) entering the coordination cage. The metal cation com-
pletes its octahedral coordination with two ligands of dena (pyridine ring ¼ N–atoms).
Disclosure statement
No potential conflict of interest was reported by the authors.
Acknowledgments
The authors acknowledge Hitit University Unit of Scientific Research Projects (FEF19004.15.009)
and Scientific and Technological Research Application and Research Center, Sinop University,
Turkey, for the use of the Bruker D8 QUEST diffractometer.
References
[1] K. Clauss, H. Jensen. Angew. Chem. Int. Ed. Engl., 2, 869 (1973).
[2] V.D. Duffy, G.H. Anderson. J. Am. Diet. Assoc., 98, 580 (1998).
[3] O. Yurdakul, D.A. Kose. Hittite J. Sci. Eng., 1, 51 (2015).
[4] A. Mukherjee, J. Chakrabarti. Food Chem. Toxicol., 35, 1177 (1997).
[5] A.D. Popova, E.A. Velcheva, B.A. Stamboliyska. J. Mol. Struct., 1019, 23 (2012).
[6] S.P. Velaga, V.R. Vangala, S. Basavoju, D. Bostrom. Chem. Commun., 46, 3562 (2010).
[7] N. C¸etin. Synthesis, Spectroscopic, Thermal and Chromotropic Properties of Some
Acesulfame-Transition Metal Complexes. Master Thesis, Ondokuz Mayıs University Science
Institution (2005).
_
_
ꢀ
€
€
[8] H. Ic¸budak, Z. Heren, A. Uyanık, M. Odabas¸oglu. J. Therm. Anal. Calorim., 82, 303 (2005).
[9] H. Ic¸budak, A. Uyanık, A. Bulut, C. Arıcı. D. Ulku. Zeitsch Kristallog., 222, 432 (2007).
_
€ €
€
€
[10] O. S¸ahin, H. Ic¸budak, O. Buyukgungor. Chin. J. Struct. Chem., 29, 1047 (2010).
_
€ €
€
€
[11] H. Ic¸budak, E. Adıyaman, N. C¸etin, A. Bulut, O. Buyukgungor. Trans. Met. Chem., 31, 666
(2006).
_
[12] E. Adıyaman, N. Dege, H. Ic¸budak. Acta Cryst., C63, 13 (2007).

16
T. YILDIRIM ET AL.
~
[13] M. Cavicchioli, A.C. Massabni, T.A. Heinrich, C.M. Costa-Neto, E.P. Abrao, B.A.L. Fonseca,
E.E. Castellano, P.P. Corbi, W.R. Lustri, C.Q.F. Leite. J. Inorg. Biochem., 104, 533 (2010).
[14] B.F. Wicker, R. Seaman, N.W. Hoffman, J.H. Davis, R.E. Sykora. Acta Cryst., E67, 286 (2011).
_
[15] N. Dege, H. Ic¸budak. E. Adıyaman. Acta Cryst., C62, 401 (2006).
_
[16] A. Bulut, H. Ic¸budak, G. Sezer, C. Kazak. Acta Cryst., C61, 228 (2005).
[17] P. Serdar. Synthesis, Spectroscopic, Thermal and Chromotropic Properties of Aromatic
and Aliphatic N-Base Ligand Complexes of Copper Acesulfame. Master Thesis, Ondokuz
Mayıs University Science Institution (2012).
ꢁ
ꢁ
[18] O.E. Piro, G.A. Echeverrıa, E.E. Castellano, B.S. Parajon-Costa, E.J. Baran. Z. Naturforsch.,
B70, 491 (2015).
ꢁ
ꢁ
[19] E.J. Baran, B.S. Parajon-Costa, G.A. Echeverrıa, O.E. Piro. Maced. J. Chem. Chem. Eng., 34,
95 (2015).
_
[20] Z.S. S¸ahin, F. Sevindi, H. Ic¸budak, S¸. Is¸ık. Acta Crystallogr. C Cryst. Struct. Commun., C66,
m314 (2010).
_
€
€ €
€
€
[21] G. Demirtas¸, N. Dege, H. Ic¸budak, O. Yurdakul, O. Buyukgungor. J. Inorg. Organomet.
Polym. Mater., 22, 671 (2012).
_
[22] H. Ic¸budak, G. Demirtas¸, G. Dege. Maced. J. Chem. Chem. Eng., 34, 105 (2015).
ꢁ
ꢁ
[23] G.A. Echeverrıa, O.E. Piro, B.S. Parajon-Costa, E.J. Baran. Z. Naturforsch., B72, 739 (2017).
[24] T. Yıldırım. Some of the Transition Metal Cations –Which Ones Include Acesulfame -
Nicotinamide/N,N’-Diethylnicotinamide- Complex Ligand Coordınatıon Compounds’
Synthesis, Structural Characterization and Various Biological Activations’ Examination.
Master Thesis, Hitit University Science Institution (2017).
[25] E.J. Baran, V.T. Yilmaz. Coord. Chem. Rev., 250, 1980 (2006).
[26] O. Erel. Clin. Biochem., 37, 112 (2004).
_
€
€
€
€
[27] D.A. Kose, G. Gokc¸e, S. Gokc¸e, I. Uzun. J. Therm. Anal. Calorim., 95, 247 (2009).
€ €
ꢀ
€
€
[28] D.A. Kose, H. Necefoglu, O. S¸ahin, O. Buyukgungor. J. Therm. Anal. Calorim., 110, 1233 (2012).
€
[29] D.A. Kose, H. Necefoglu, H. Icbudak. J. Coord. Chem., 61, 3508 (2008).
[30] G.M. Sheldrick. Acta Crystallogr. A Found. Crystallogr., A64, 112 (2008).
[31] G.M. Sheldrick. Acta Crystallogr. C Struct. Chem., C71, 3 (2015).
[32] Clare F. Macrae, Ian J. Bruno, James A. Chisholm, Paul R. Edgington, Patrick McCabe, Elna
Pidcock, Lucia Rodriguez-Monge, Robin Taylor, Jacco van de Streek and Peter A. Wood and
Cambridge Crystallographic Data Centre. APEX2, Bruker AXS Inc., Madison, Wisconsin, USA
(2013).
[33] C.F. Macrae, I.J. Bruno, J.A. Chisholm, P.R. Edgington, P. McCabe, E. Pidcock, L. Rodriguez-
Monge, R. Taylor, J. van de Streek, P.A. Wood. J. Appl. Crystallogr., 41, 466 (2008).
[34] L.J. Farrugia. J. Appl. Crystallogr., 45, 849 (2012).
[35] D.A. Kose, O. Sahin, O. Buyukgungor. Eur. Chem. Bull., 1, 196 (2012).
[36] T. Hokelek, E.G. Saglam, B. Tercan, O. Aybirdi, H. Necefoglu. Acta Crystallogr. E Struct. Rep.
Online, E67, m28 (2011).
[37] T. Hokelek, H. Dal, B. Tercan, F.E. Ozbek, H. Necefoglu. Acta Crystallogr. E Struct. Rep.
Online, E65, m481 (2009).
[38] T. Hokelek, H. Dal, B. Tercan, F.E. Ozbek, H. Necefoglu. Acta Crystallogr. E Struct. Rep.
Online, E65, m533 (2009).
[39] Z. Vaskova, J. Moncol, M. Korabik, J. Medvecka, J. Svorec, Z. Padelkova, M. Valko, D.
Valigura. Polyhedron, 30, 86 (2011).
[40] J. Moncol, M. Palicova, P. Segl’a, M. Koman, M. Melnik, M. Valko, T. Glowiak. Polyhedron,
21, 365 (2002).
[41] M. Korabik, Z. Repicka, L. Martiska, J. Moncol, J. Svorec, Z. Padelkova, T. Lis, M. Mazur, D.
Valigura. Z. Anorg. Allg. Chem., 637, 224 (2011).
[42] Z. Repicka, J. Moncol, M. Puchonova, V. Jorik, D. Miklos, T. Lis, Z. Padelkova, M. Mazur, D.
Valigura. Struct. Chem., 21, 1093 (2010).
ꢁ
[43] M. Puchonova, M. Mazur, Z. Ruzickova, D. Valigurad, J. Monco. J. Mol. Struct., 1181, 373 (2019).
€
€
€ €
€
€
[44] D.A. Kose, B. Ozturk, O. S¸ahin, O. Buyukgungor. J. Therm. Anal. Calorim., 115, 1515(2014).