Synthesis and crystal structure of diaquadibenzoatobis(nicotinamide)nickel(II)

Article abstract of DOI:10.1134/S0036023606060088

A coordination compound of nickel(II) benzoate with nicotinamide [Ni(C ₆H₅COO)₂(L)₂(H₂O) ₂] (I) (L is nicotinic acid amide) is synthesized and studied by IR spectroscopy. Its crystal structure is solved by X-ray crystallography. The crystals of compound I are monoclinic: a = 7.152 ?, b = 18.266 ?, c = 10.341 ?, β = 109.24°, V = 1275.4 ?³, Z = 2, space group P2₁/c. Structural units of a crystal of I are centrosymmetric octahedral complex molecules. The coordination environment of the Ni atom contains two O atoms (Ni-O(1) 2.066(2) ?) and two N atoms (Ni-N(1) 2.091(2) ?) of the monodentate-coordinated benzoate anions and nicotinamide molecules, respectively, as well as two O atoms of the H ₂O molecules (Ni-O(1w) 2.110(2) ?). Pleiades Publishing, Inc., 2006.

Full text of DOI:10.1134/S0036023606060088

ISSN 0036-0236, Russian Journal of Inorganic Chemistry, 2006, Vol. 51, No. 6, pp. 895–900. © Pleiades Publishing, Inc., 2006.
Original Russian Text © T.V. Koksharova, G.G. Sadikov, A.S. Antsyshkina, I.S. Gritsenko, V.S. Sergienko, O.A. Egorova, 2006, published in Zhurnal Neorganicheskoi Khimii,
2006, Vol. 51, No. 6, pp. 966–971.
COORDINATION
COMPOUNDS
Synthesis and Crystal Structure
of Diaquadibenzoatobis(nicotinamide)nickel(II)
a
b
b
a
T. V. Koksharova , G. G. Sadikov , A. S. Antsyshkina , I. S. Gritsenko ,
b
c
V. S. Sergienko , and O. A. Egorova
Mechnikov University, ul. Petra Velikogo 2, Odessa, 270100 Ukraine
Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences,
Leninskii pr. 31, Moscow, 119991 Russia
a
b
c
Peoples Friendship University, ul. Miklukho-Maklaya 6, Moscow, 117198 Russia
Received May 23, 2005
Abstract—A coordination compound of nickel(II) benzoate with nicotinamide [Ni(C6H5COO)2(L)2(H2O)2]
(I) (L is nicotinic acid amide) is synthesized and studied by IR spectroscopy. Its crystal structure is solved by
X-ray crystallography. The crystals of compound I are monoclinic: a = 7.152 Å, b = 18.266 Å, c = 10. 341 Å,
β = 109.24°, V = 1275.4 Å3, Z = 2, space group P21/c. Structural units of a crystal of I are centrosymmetric
octahedral complex molecules. The coordination environment of the Ni atom contains two O atoms (Ni–O(1)
2.066(2) Å) and two N atoms (Ni–N(1) 2.091(2) Å) of the monodentate-coordinated benzoate anions and nic-
otinamide molecules, respectively, as well as two O atoms of the H2O molecules (Ni–O(1w) 2.110(2) Å).
DOI: 10.1134/S0036023606060088
Acido ligands, in particular halides and pseudoha- For this purpose, ethanol (10 ml) was added to the
lides, are known [1] to exert different effects on the unpurified product (0.1 g), and the mixture was brought
coordination mode of nicotinamide (L) in metal com- to a boil. Almost all the precipitate was dissolved to
plexes. In turn, it cannot be excluded that nicotinamide give a greenish solution opalescent on cooling. The
affects the coordination mode of complex acido ligands nondissolved portion was separated from the solution,
[2]. Structural studies of the nickel(II) nicotinamide which was cooled to room temperature, by filtration
complexes even with simple acido ligands are few. through a dense paper filter. Blue crystals of com-
More often authors have used indirect methods to deter- pound I suitable for X-ray diffraction analysis gradu-
mine the structures of nicotinamide complexes; these ally precipitated from the filtrate on standing.
methods include electron microscopy [3] and spectral
[1, 2, 4] and thermal methods [4, 5]. Studies on the
nickel(II) carboxylate nicotinamide complexes have to
date concerned only formate and acetate anions [1].
However, the most divergent coordination behavior is
possible just for carboxylate ligands. Carboxylate ions
can act as monodentate chelating-bridging ligands and
outer-sphere anions.
IR absorption spectra were recorded on a Specord
75 IR spectrophotometer (4000–400 cm–1). Samples
were KBr pellets (and as Nujol mulls for nicotinamide).
Thermal stability of complex I was studied on a
Paulik-Paulik-Erdey derivatograph in air in the temper-
ature interval from 20 to 500°C at a heating rate of
10 K/min.
X-ray diffraction analysis. The crystals of com-
pound I (C26H26N4O8Ni) are monoclinic: a = 7.152(1) Å,
b = 18.266(2) Å, c = 10.341(2) Å, β = 109.24(2)°, V =
In this work, we synthesized the product of interac-
tion of nickel(II) benzoate with nicotinamide and
solved its crystal structure.
1275.4(3) Å3, FW = 581.2, F(000) = 604, ρcalc
=
1.513 g/cm3, µMo = 1.61 mm–1, Z = 2, space group
P21/c.
EXPERIMENTAL
Synthesis of [Ni(C6H5COO)2(L)2(H2O)2] (I). Nic-
The experimental data set (2246 independent non-
otinamide (0.61 g, 0.005 mol) was dissolved in ethanol zero reflections) were obtained from a prismatic sample
(5 ml). Dry Ni(C6H5COO)2 · 2H2O (0.84 g, 0.0025 mol) 0.06 × 0.10 × 0.16 mm on an Enraf-Nonius CAD4 dif-
fractometer (λCuKα radiation, graphite monochroma-
was added by portions with stirring. The mixture was
heated and then magnetically stirred for 15 min. A pre- tor, θ/2θ scan mode, 2θmax = 70°). The structure was
cipitate was isolated, washed with a small amount of
ethanol, and dried in a desiccator above CaCl2 to a con-
solved by the heavy-atom method. All atoms were
located from Fourier different syntheses. Non-hydro-
stant weight. The obtained product was recrystallized. gen atoms were refined by the full-matrix least-squares
895

896
KOKSHAROVA et al.
Table 1. Fractional coordinates of atoms and thermal displacements Ueq/Uiso for compound I
Atom
x
y
z
Ueq/Uiso, Å2
Ni(1)
N(1)
0
0
0
0.0320(2)
0.0348(4)
0.0550(6)
0.0536(5)
0.0406(4)
0.0677(7)
0.0402(6)
0.0478(7)
0.0453(6)
0.0363(5)
0.0353(5)
0.0406(6)
0.0377(5)
0.0423(6)
0.0505(7)
0.0557(8)
0.0552(7)
0.0481(6)
0.0384(5)
0.0427(5)
0.10(1)
0.0124(3)
–0.3011(4)
–0.4263(3)
0.0984(2)
–0.1910(3)
0.1567(4)
0.1637(4)
0.0185(4)
–0.1325(3)
–0.1291(4)
–0.2980(4)
0.0905(4)
0.2802(4)
0.3617(4)
0.2544(5)
0.0667(5)
–0.0150(4)
–0.0082(4)
0.2991(3)
0.284(6)
0.0484(1)
0.0721(2)
0.0012(1)
0.0957(1)
0.1479(1)
0.0954(1)
0.1290(2)
0.1145(2)
0.0659(1)
0.0345(1)
0.0444(2)
0.1915(1)
0.1776(2)
0.2214(2)
0.2797(2)
0.2944(2)
0.2503(2)
0.1419(1)
–0.0333(1)
–0.080(3)
–0.009(2)
0.103(3)
0.1858(2)
0.5307(3)
0.3464(2)
–0.0626(2)
–0.1745(3)
0.2517(3)
0.3715(3)
0.4286(3)
0.3621(2)
0.2414(3)
0.4133(3)
–0.2191(3)
–0.2219(3)
–0.2975(3)
–0.3722(3)
–0.3698(3)
–0.2942(3)
–0.1457(3)
0.0738(2)
0.112(5)
N(2)
O(1)
O(2)
O(3)
C(1)
C(2)
C(3)
C(4)
C(5)
C(6)
C(7)
C(8)
C(9)
C(10)
C(11)
C(12)
C(13)
O(1w)
H(1w1)
H(2w1)
H(1N2)
H(2N2)
H(2)
0.364(7)
0.136(4)
0.07(1)
–0.209(7)
–0.390(5)
0.251(4)
0.574(4)
0.09(1)
0.055(2)
0.574(4)
0.07(1)
0.107(1)
0.210(3)
0.036(7)
0.07(1)
H(3)
0.258(5)
0.163(2)
0.417(4)
H(4)
0.024(4)
0.138(2)
0.513(3)
0.052(9)
0.050(9)
0.07(1)
H(5)
–0.233(5)
0.345(5)
–0.000(2)
0.142(2)
0.193(3)
H(8)
–0.175(4)
–0.299(3)
–0.429(4)
–0.427(3)
–0.283(3)
H(9)
0.483(5)
0.211(2)
0.058(9)
0.08(1)
H(10)
H(11)
H(12)
0.315(5)
0.308(2)
–0.017(5)
–0.142(5)
0.336(2)
0.063(9)
0.058(9)
0.259(2)
method in the anisotropic approximation. Hydrogen 4σ(F0); R1 = 0.0545, wR2 = 0.1246 for all reflections;
atoms were refined in the isotropic approximation. An
extinction correction was applied during refinement
(extinction coefficient is 0.0039(7)).
GOOF was 1.049, 231 independent parameters. The
residual electron density was ρmax = 0.325, ∆ρmin
=
−0.556 e Å–3.
The final refinement parameters were R1 = 0.0396,
wR2 = 0.1125 for 1781 reflections for which F0 ≥
All calculations were performed according to the
SHELXL97 program package [6].
RUSSIAN JOURNAL OF INORGANIC CHEMISTRY Vol. 51 No. 6 2006

SYNTHESIS AND CRYSTAL STRUCTURE
Table 2. Bond lengths (d) and bond angles (ω) for compound I
897
Bond
d, Å
Bond
d, Å
Ni(1)–N(1)
2.091(2)
2.110(2)
1.342(3)
1.235(3)
1.246(4)
1.379(4)
1.381(3)
1.390(4)
1.500(4)
1.389(4)
1.378(4)
Ni(1)–O(2)
N(1)–C(1)
N(2)–C(6)
O(2)–C(13)
C(1)–C(2)
C(3)–C(4)
C(4)–C(6)
C(7)–C(12)
C(8)–C(9)
2.066(2)
1.342(3)
1.322(4)
1.266(3)
1.369(4)
1.391(4)
1.500(4)
1.393(4)
1.376(4)
1.378(5)
Ni(1)–O(1w)
N(1)–C(5)
O(1)–C(6)
O(3)–C(13)
C(2)–C(3)
C(4)–C(5)
C(7)–C(8)
C(7)–C(13)
C(9)–C(10)
C(11)–C(12)
C(10)–C(11)
Angle
ω, deg
Angle
ω, deg
N(1)Ni(1)O(2)
O(2)Ni(1)O(1w)
Ni(1)N(1)C(5)
Ni(1)O(2)C(13)
C(1)C(2)C(3)
C(3)C(4)C(5)
C(5)C(4)C(6)
N(2)C(6)O(1)
O(1)C(6)C(4)
C(8)C(7)C(13)
C(7)C(8)C(9)
C(9)C(10)C(11)
C(7)C(12)C(11)
O(2)C(13)C(7)
90.85(7)
87.01(7)
120.2(2)
125.9(2)
119.5(3)
118.0(2)
117.4(2)
121.6(3)
119.8(2)
121.7(2)
120.3(3)
120.1(3)
120.9(3)
117.9(2)
N(1)Ni(1)O(1w)
Ni(1)N(1)C(1)
C(1)N(1)C(5)
N(1)C(1)C(2)
C(2)C(3)C(4)
C(3)C(4)C(6)
N(1)C(5)C(4)
N(2)C(6)C(4)
C(8)C(7)C(12)
C(12)C(7)C(13)
C(8)C(9)C(10)
C(10)C(11)C(12)
O(2)C(13)O(3)
O(3)C(13)C(7)
93.39(8)
121.9(2)
117.8(2)
122.6(3)
118.8(3)
124.5(2)
123.2(2)
118.5(2)
118.9(2)
119.3(2)
120.1(3)
119.6(3)
124.8(3)
117.2(2)
The coordinates of atoms and the temperature O(1w)···O(3) 2.568(3) Å, angle O(1w)H(1w1)O(3)
parameters Ueq /Uiso for the structure of compound I are 162(4)°), this bond closing the six-membered H-het-
erocycle Ni(1)O(1w)H(1w1)O(3)C(13)O(2).
presented in Table 1. The interatomic distances and
bond angles are listed in Table 2.
The amide group is virtually coplanar to its pyridine
ring (the corresponding dihedral angle is 1.4°). The
pyridine ring is roughly perpendicular to the phenyl
ring of the benzoate anion.
RESULTS AND DISCUSSION
Crystals of compound I are built of centrosymmetric
octahedral molecular complexes (Fig. 1a). The Ni atom
is coordinated by two O atoms (Ni–O(1) 2.066(2) Å) of
The molecular complexes are packed in a crystal
due to weak secondary interactions and hydrogen
bonds. A strong contact between the complexes forms
the centrosymmetric binuclear fragment (Fig. 1b) due
to the PD-type π–π stacking interaction [7] between the
nicotinamide ligands of the neighboring complexes.
the benzoate anions, two
N atoms (Ni–N(1)
2.091(2) Å) of the monodentate nicotinamide mole-
cules, and two O atoms of the H2O molecules
(Ni−O(1w) 2.110(2) Å). The water molecule forms an The distance between the planes of the overlapping
intramolecular bond with the uncoordinated O(3) atom ligands in I (3.6 Å) falls in the range 3.3–3.8 Å, which
of the benzoate anion (O(1w)–H(1w1)···O(3) (–x, –y, is characteristic of aromatic systems. This contact is
−z) O(1w)–H(1w1) 0.96(5), H(1w1)···O(3) 1.64(5), strengthened, probably, due to the attractive T-type
RUSSIAN JOURNAL OF INORGANIC CHEMISTRY Vol. 51 No. 6 2006

898
KOKSHAROVA et al.
(a)
C(9)
C(8)
O(1w)
C(10)
O(3A)
O(2)
Ni(1)
C(13)
O(3)
C(11)
C(7)
C(12)
Ni(1)
C(1)
C(5)
C(2)
C(4)
O(1)
C(3)
C(6)
N(2)
(b)
Ni(1B)
O(3B)
O(1wC)
C(7B)
C(8C)
C(9B)
O(2B)
C(10C)
C(11C) C(12C)
C(5B)
H(3A)
O(1B)
Ni(1B)
C(3)
N(2)
C(2)
C(4B)
C(4)
C(1B)
C(6B)
N(2B)
C(6)
C(1)
C(2B)
C(3B)
N(1)
O(3)
O(1)
C(5)
C(12B)C(11B)
C(10B)
O(2)
C(13B)
C(7)
O(1wA)
C(7A)
C(8) C(9)
O(1wB)
C(8A)
C(9A)
C(10A)
Ni(1A)
O(3A)
C(2A)
C(11A)
C(12A)
C(5A)
C(4A)
O(1A)
C(6A)
N(2A)
C(1A)
C(2A)
C(3A)
Fig. 1. Panel (a): Structure of complex I. Panel (b): PD-type π−π-stacking contact in a supramolecular chain with additional weak
attractive T-type interaction (dotted line) and the hydrogen bond between nicotinamide and pyridine (dashed line).
interaction [8], because the H(3a) atom of nicotinamide NH2 group in nicotinamide forms a weak hydrogen
lies above the center of the benzoate phenyl ring at a
distance of 3.96 Å. The angle formed by the planes of
the C(1)–C(5) and C(7)–C(11) atoms of the contacting
complexes is 89.6°. In addition to the above-mentioned
bond with the terminal carboxyl O(3) atom of the
neighboring complex (N(2)–H(1N2)···O(3) (x, y, 1 + z):
N(2)–H(1N2)
0.87(5),
H(1N2)···O(3) 2.68(4),
N(2)···O(3) 3.202(4) Å, angle N(2)H(1N2)O(3)
weak secondary interactions, one of the H atoms of the 156(2)°).
RUSSIAN JOURNAL OF INORGANIC CHEMISTRY Vol. 51 No. 6 2006

SYNTHESIS AND CRYSTAL STRUCTURE
899
N(1)
N(2)
O(3)
O(1)
Fig. 2. Structure of a layer fragment in complex I. Hydrogen bonds (dashed line) are marked only for the central chain of the frag-
ment.
The sequence of the above-described contact units (Fig. 2) resembles that observed in the structure of
copper(II) valerate [9]. However, in crystals of com-
pound II, the chains were formed of binuclear com-
plexes of the “chinese lantern” type.
forms chain ensembles that are linked into layers through
the N(2)−H(2N2)···O(1) hydrogen bonds (–x – 1, –y,
1 − z): N(2)–H(2N2) 0.94(4), H(2N2)···O(1) 2.05(4),
N(2)···O(1) 2.973(4) Å, angle N(2)H(2N2)O(1)
The role of the water molecule in the structure of
168(3)°). The pattern of chain linkage into layers compound I is not confined to the inner sphere; it acts,
Table 3. Wavenumbers (frequencies, cm–1) of maxima of the absorption bands in the IR spectra of nicotinamide (L) and the
[Ni(C6H5COO)2L2(H2O)2] complex (I)
Assignment
L (KBr pellets)
–
L (Nujol mulls)
–
I
ν(OH)
ν(NH)
ν(CH) (L)
3472
3376, 3300, 3170
3350, 3145
3397, 3193
3068, 2905
3090, 3035, 2970, 2960,
2910, 2890, 2820
–
ν(C=O)
∆(NH2)
νas(COO–)
1687
1665
1610
1693, 1670
1627
–
–
–
–
1602 (vs)
1590 (sh)
1398 (vs)
1202
ν
ring(L)
νs(COO–)
1580
1585, 1560
–
1290, 1250, 1205
1160, 1134
1030, 1005
890, 835, 760
–
∆(CCH), δ(CCC)
∆(NH2), δ(CCH)
1295, 1195
1145, 1120
1020, 965
1170, 1135
1070, 1053
νring(L)
ν(CC), δ(CCC)
∆(OCO)
880, 820, 765
855, 840, 795, 755
–
726
∆(CCN)ring(L)
∆(CNC)ring(L)
∆(CCN), δ(CCC)
702
710
698
635, 610
635, 615
595, 500
677, 652
518
550
RUSSIAN JOURNAL OF INORGANIC CHEMISTRY Vol. 51 No. 6 2006

900
KOKSHAROVA et al.
the νas(CéO–) and νs(CéO–) absorption frequencies.
For the starting nickel(II) benzoate, νas(CéO–) and
νs(CéO–) appear in the IR spectrum at 1596 and
most likely, as a proton donor in the intermolecular
bond with neighboring complexes in the layer (O(1w)–
H(2w1)···O(1) (1 + x, y, z): O(1w)–H(2w1) 0.79(4),
H(2w1)···O(1) 2.21(4), O(1w)···O(1) 2.924(3) Å, angle
O(1w)H(2w1)O(1) 151(4)°.
1498 cm–1, respectively, and ∆ν(COO–) is at 98 cm–1.
For complex I, these values are 1602, 1398, and
204 cm–1, respectively. Thus, ∆∆ν(COO–) is 106 cm–1,
indicating a substantial change in the symmetry of the
benzoate ion due to complexation of nickel(II) ben-
zoate with nicotinamide. This is caused by a change in
the denticity of the benzoate anion. The latter is biden-
tate in the initial nickel(II) benzoate, but it is monoden-
tate in heteroligand complex I, where the inner sphere
contains nicotinamide and water along with the ben-
zoate ligand. The ν(éH) band of the water molecules in
the IR spectrum of compound I lies in the region char-
acteristic of the stretching vibrations of the O–H bonds
in aqua complexes [11]; this band appears at slightly
lower frequencies than in similar nickel(II) com-
plexes, where formate and acetate are the caboxylate
anions [1].
Published data [1, 2, 10] were taken into account
when assigning frequencies of the fundamental absorp-
tion bands in the IR spectra of nicotinamide and com-
plex I (Table 3). Nicotinamide molecules in the solid
state are associated due to hydrogen bonds, which
noticeably affects the frequencies of several bands in
the IR spectrum. This more strongly affects the spectra
of crystalline amides, while no substantial influence is
observed for the IR spectra of crystalline metal com-
plexes with amides when L is not coordinated through
the nitrogen atom of the amino group. This is indicated
by a comparative analysis of X-ray diffraction and
spectral data for many complexes [2]. Therefore, the IR
spectra of the initial nickel(II) benzoate and complex I
were recorded as KBr pellets, whereas the spectra of
nicotinamide were obtained as both KBr pellets and
Nujol mulls. The spectra recorded in Nujol are poorly
informative for nickel(II) benzoate and complex I,
because the Nujol absorption bands are partially over-
lapped with the absorption bands of the carboxyl group.
The TG curve for compound I exhibits two features:
the endotherm at 93–170°C (maximum at 140°C,
weight loss 17.9%) and the exotherm at 300–400°C
(maximum at 350°C, weight loss 45.0%). The total
weight loss on heating to 500°C is 82.2%. The absence
of a separate endotherm due to the loss of the H2O mol-
ecules (the water content in complex I is 6.2 wt %)
agrees with their inner-sphere character, which was
found by X-ray diffraction.
According to X-ray crystal data, nicotinamide in
complex I is coordinated to the nickel atom through the
nitrogen heteroatom of the pyridine ring. This agrees
with the fact that the IR absorption bands νring at both
~1600 and ~1000 cm–1 shift to the high-frequency
region as compared to the spectrum of free nicotin-
amide. The noncoordination of the amide group is con-
firmed by the following reasoning. Firstly, the ν(NH)
frequencies in the IR spectrum of complex I are higher
than those in the spectrum of free nicotinamide both in
the solid state and in Nujol, which indicates the absence
of a bond between the nickel atom and the amino nitro-
gen atom of ligand L in complex I. Second, the ν(C=é)
frequency (amide band I) for complex I is also
increased, which is caused by the absence of a bond
between the oxygen atom of the amide group and the
nickel atom.
REFERENCES
1. A. Yu. Tsivadze, G. V. Tsintsadze, Yu. Ya. Kharitonov,
and L. V. Gverdtsiteli, Zh. Neorg. Khim. 23 (2), 447
(1978).
2. G. V. Tsintsadze, M. V. Shavtvaladze, and A. Yu. Tsi-
vadze, Koord. Khim. 16 (12), 1666 (1990).
3. Zhou Bao-xue, Zhoun Ding, and Cai Wei-min, J. Harbin
Inst. Technol. 35 (2), 176 (2003).
4. S. Çakir, E. Biçer, H. Içbudak, et al., Pol. J. Chem. 75 (3),
371 (2001).
5. E. Jóna, A. Sirota, P. Simon, and M. Kubranová, Ther-
mochim. Acta 258, 161 (1995).
In the spectrum of complex I, the νring and δ(NH2)
frequencies of coordinated nicotinamide appear as rel-
atively low-intensity bands at ~1600 cm–1. The same
region contains the very intense band νas(CéO–), which
6. G. M. Sheldrick, SHELXL97. Program for Refinement of
Crystal Structures (Univ. of Göttingen, Göttingen,
1997).
7. C. Janiak, J. Chem. Soc., Dalton Trans., 3885 (2000).
8. K. Müller-Dethlefs and P. Hobza, Chem. Rev. 100, 143
is intrinsic to carboxylates [1]. Therefore, the νring band
(2000).
degenerates to a shoulder at νas(CéO–), and the ν(NH2)
band in the IR spectrum of complex I becomes indis-
cernible. The νs(CéO–) band at ~1400 cm–1 is the stron-
gest band in the IR spectrum of complex I. The viola-
tion of bond equivalence due to the formation of hetero-
ligand coordination compounds from simple
carboxylates should increase the difference between
9. A. S. Antsyshkina, T. V. Koksharova, G. G. Sadikov,
et al., Zh. Neorg. Khim. 51 (6), 972 (2006) [Russ. J.
Inorg. Chem. 51 (6), 901 (2006)].
10. A. A. Shabilalov, N. N. Borisova, and M. A. Azizov,
Koord. Khim. 13 (9), 1227 (1987).
11. Yu. N. Kukushkin, The Chemistry of Coordination Com-
pounds (Vysshaya shkola, Moscow, 1985) [in Russian].
RUSSIAN JOURNAL OF INORGANIC CHEMISTRY Vol. 51 No. 6 2006