Synthesis, crystal structure and Hirshfeld surface analysis of a 1D coordination polymer catena-poly[[di­aqua­bis­(nicotinamide-κN1)nickel(II)]-μ-fumarato-κ2O1:O4]

Kansiz, S.; Dege, N.; Kalibabchuk, V.A.

doi:10.1107/S2056989018011489

research communications

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 74| Part 9| September 2018| Pages 1263-1266

https://doi.org/10.1107/S2056989018011489

Open

access

Synthesis, crystal structure and Hirshfeld surface analysis of a 1D coordination polymer catena-poly[[diaquabis(nicotinamide-κN¹)nickel(II)]-μ-fumarato-κ²O¹:O⁴]

Sevgi Kansiz,^a Necmi Dege ^a and Valentina A. Kalibabchuk ^b ^*

^aOndokuz Mayıs University, Faculty of Arts and Sciences, Department of Physics, 55139, Kurupelit, Samsun, Turkey, and ^bDepartment of General Chemistry, O. O. Bohomolets National Medical University, Shevchenko Blvd. 13, 01601 Kiev, Ukraine
^*Correspondence e-mail: kalibabchuk@ukr.net

Edited by D.-J. Xu, Zhejiang University (Yuquan Campus), China (Received 19 July 2018; accepted 13 August 2018; online 16 August 2018)

The reaction of NiCl₂ with fumaric acid and nicotinamide in basic solution produces the title polymeric complex, [Ni(C₄H₂O₄)(C₆H₆N₂O)₂(H₂O)₂]_n. The Ni^II cation, located on an inversion centre, is coordinated by two O atoms of the fumarate dianions, two N atoms from nicotinamide ligands and two water molecules in a distorted octahedral fashion. In the crystal, the fumarate dianions bridge the Ni^II cations, forming polymeric chains propagating along the [101] direction; the polymeric chains are further linked by O—H⋯O, N—H⋯O and C—H⋯O hydrogen bonds, forming a three-dimensional supramolecular architecture. Hirshfeld surface analyses and two-dimensional fingerprint plots were used to analyse the intermolecular interactions present in the crystal, indicating that the most important contributions for the crystal packing are from H⋯O/O⋯H (35.9%), H⋯H (31.7%) and C⋯C (10.4%) interactions.

Keywords: crystal structure; fumaric acid; nicotinamide; nickel(II); Hirshfeld surfaces.

CCDC reference: 1563283

1. Chemical context

Metal complexes of biologically important ligands are sometimes more effective than the free ligands. Many transition and heavy metal cations play an important role in biological processes in the formation of many vitamins and drug components. An important element for biological systems is nickel. Nickel complexes have biological applications such as antiepileptic, antimicrobial, antibacterial and anticancer activities (Bombicz et al., 2001 ). The metal-ion geometries of coordination compounds can be easily identified. Dicarboxylic acid ligands are utilized in the synthesis of a range of metal complexes and fumaric acid and amide have been particularly useful in creating many supramolecular structures (Pavlishchuk et al., 2011 ; Ostrowska et al., 2016 ), in particular between nicotinamide and a variety of carboxylic acid molecules. We have prepared a new Ni^II complex, catena-poly[[diaquabis(nicotinamide-κN¹)nickel(II)]-μ-fumarato-κ²O¹:O⁴], whose structure has been determined by single crystal X-ray diffraction analysis. In addition, to understand the intermolecular interactions in the crystal structure, Hirshfeld surface analysis was performed.

2. Structural commentary

The molecular structure of the asymmetric unit of the title compound is illustrated in Fig. 1. This linear one-dimensional coordination polymer consists of a nickel centre coordinated in an octahedral fashion by two oxygen atoms of fumaric acid dianions, two nicotinamide nitrogen atoms and two aqua ligands.

Figure 1
The molecular structure of the asymmetric unit of the title compound, showing the atom labelling. Displacement ellipsoids are drawn at the 20% probability level. [Symmetry codes: (i) −x + 1, −y + 2, −z + 2; (ii) −x, −y + 1, −z + 2.]

The Ni1—O2, Ni1—O3 and Ni1—N1 bond lengths are 2.0484 (12), 2.0792 (13) and 2.1187 (14) Å, respectively. The C—O bond lengths in the deprotonated carboxylic groups differ noticeably [C7—O1 = 1.248 (2) Å and C7—O2 = 1.266 (2) Å], which is typical for monodentately coordinated carboxylates (Gumienna-Kontecka et al., 2007 ; Pavlishchuk et al., 2010 ; Penkova et al., 2010 ). In the same way, the C6—O4 bond in the amide group [1.236 (2) Å] shows partial double-bond character. The values of the Ni—O_water and Ni—N_pyridine bond lengths and the bond angles involving the Ni1 atom (see supporting information) are close to those reported for similar nickel(II) complexes (Krämer et al., 2002 ; Bora & Das, 2011 ; Moroz et al., 2012 ). The conformation of the title compound is best defined by the torsion angles C4—C5—N1—Ni1, O1—C7—O2—Ni1 and C8—C7—O2—Ni1 of 172.22 (13)°, −26.7 (2)° and 151.80 (11)°, respectively.

3. Supramolecular features

In the crystal, the polymeric chains are linked by O—H⋯O, N—H⋯O and C—H⋯O hydrogen bonds (Table 1), forming a three-dimensional supramolecular architecture (Fig. 2). The shortest non-hydrogen-bonding intermolecular distances of the title compound are 2.870 (2) Å [for O3⋯O4(−x + 1, −y + 1, −z + 2)] and 2.855 (2) Å [for O3⋯O1(x + 1, y, z)]. The strongest hydrogen-bonded intermolecular distance is 2.06 Å [H3A⋯O4(−x + 1, −y + 1, −z + 2)].

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O3—H3A⋯O4ⁱⁱ	0.85	2.06	2.8699 (19)	159
O3—H3B⋯O1ⁱⁱⁱ	0.85	2.17	2.8550 (19)	138
O3—H3B⋯O1ⁱ	0.85	2.30	2.9916 (18)	138
N2—H2A⋯O4^iv	0.86	2.16	2.980 (2)	158
N2—H2B⋯O1^v	0.86	2.10	2.929 (2)	161
C3—H3⋯O1^v	0.93	2.40	3.296 (2)	162
Symmetry codes: (i) -x+1, -y+2, -z+2; (ii) -x+1, -y+1, -z+2; (iii) x+1, y, z; (iv) -x, -y, -z+1; (v) -x, -y+1, -z+1.

Figure 2
A partial view of the crystal packing of the title compound. Dashed lines indicate the hydrogen bonds (see Table 1

4. Hirshfeld surface analysis

The Hirshfield surface analysis was performed using the CrystalExplorer program (Turner et al., 2017 ). The Hirshfeld surfaces and their associated two-dimensional fingerprint plots were used to quantify the various intermolecular interactions in the synthesized complex. The Hirshfeld surfaces mapped over d_norm, d_i and d_e are shown in Fig. 3. The red spots indicate the intermolecular contacts associated with strong hydrogen bonds and interatomic contacts (Gümüş et al., 2018 ; Kansız & Dege, 2018 ; Sen et al., 2018 ). For the title compound, these correspond to the near-type H⋯O contacts resulting from O—H⋯O and N—H⋯O hydrogen bonds (Figs. 3 and 4). The Hirshfeld surfaces were generated using a standard (high) surface resolution with the three-dimensional d_norm surface mapped over a fixed colour scale of −1.219 (red) to 1.466 (blue) a.u.

Figure 3
The Hirshfeld surface of the title compound mapped over d_norm, d_i and d_e.

Figure 4
Hirshfeld surfaces mapped over d_norm to visualize the intermolecular interactions of the title compound.

Fig. 5 shows the two-dimensional fingerprint of the sum of the contacts contributing to the Hirshfeld surface represented in normal mode. The graph shown in Fig. 6a represents the O⋯H/H⋯O contacts (35.9%) between the oxygen atoms inside the surface and the hydrogen atoms outside the surface, d_e + d_i = 1.9 Å, and two symmetrical points at the top, bottom left and right. These are characteristic of O—H⋯O and N—H⋯O hydrogen bonds. Fig. 6b (H⋯H) shows the two-dimensional fingerprint of the (d_i, d_e) points associated with hydrogen atoms. It is characterized by an end point that points to the origin and corresponds to d_i = d_e = 1.08 Å, which indicates the presence of the H⋯H contacts in this study (31.7%). The graph shown in Fig. 6d (C⋯H/H⋯C) shows the contact between the carbon atoms inside the surface and the hydrogen atoms outside the Hirshfeld surface and vice versa (9.5%). In addition, C⋯C (10.4%), N⋯H/H⋯N (3.6%) and Ni⋯O/O⋯Ni (3.4%) contacts contribue to the Hirshfeld surface.

Figure 5
A fingerprint plot of the title compound.

Figure 6
Two-dimensional fingerprint plots with a d_norm view of the O⋯H/H⋯O (35.9%), H⋯H (31.7%), C⋯C (10.4%) and C⋯H/H⋯C (9.5%) contacts in the title compound.

5. Synthesis and crystallization

A solution of NaOH (52 mmol, 2.07 g) was added to an aqueous solution of H₂Fum (26 mmol, 3 g) with stirring. A solution of NiCl₂·6H₂O (26 mmol, 6.14 g) in ethanol was added. The mixture was heated at 353 K for an hour and then the pink mixture was filtered and left to dry at room temperature. The reaction mixture (0.88 mmol, 0.20 g) was dissolved in ethanol and added to a methanol solution of nicotinamide (1.76 mmol, 0.21 g). The mixture was heated at 353 K for 30 min with stirring and the resulting suspension was filtered. On slow evaporation of the filtrate, over a period of three weeks, blue block-shaped crystals of the title complex were obtained.

6. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2. The C-bound H atoms were positioned geometrically and refined using a riding model: C—H = 0.93 Å with U_iso(H) = 1.2U_eq(C).

Table 2
Experimental details

Crystal data
Chemical formula	[Ni(C₄H₂O₄)(C₆H₆N₂O)₂(H₂O)₂]
M_r	453.05
Crystal system, space group	Triclinic, P $[\overline{1}]$
Temperature (K)	296
a, b, c (Å)	7.3660 (5), 7.5521 (5), 8.9344 (6)
α, β, γ (°)	109.672 (2), 102.556 (2), 98.887 (2)
V (Å³)	442.57 (5)
Z	1
Radiation type	Mo Kα
μ (mm⁻¹)	1.15
Crystal size (mm)	0.21 × 0.17 × 0.14

Data collection
Diffractometer	Stoe IPDS 2
Absorption correction	Analytical (X-RED32; Stoe & Cie, 2002 )
T_min, T_max	0.622, 0.746
No. of measured, independent and observed [I > 2σ(I)] reflections	20590, 2203, 2075
R_int	0.029
(sin θ/λ)_max (Å⁻¹)	0.669

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.029, 0.076, 1.09
No. of reflections	2203
No. of parameters	134
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.33, −0.51
Computer programs: X-AREA (Stoe & Cie, 2002), SHELXT2014 (Sheldrick, 2015a ), SHELXL2016 (Sheldrick, 2015b ), ORTEP-3 for Windows and WinGX (Farrugia, 2012 ) and PLATON (Spek, 2009 ).

Supporting information

CCDC reference: 1563283

Crystal structure: contains datablocks I, global. DOI: https://doi.org/10.1107/S2056989018011489/xu5933sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2056989018011489/xu5933Isup2.hkl

checkCIF report

Computing details top

Data collection: X-AREA (Stoe & Cie, 2002); cell refinement: X-AREA (Stoe & Cie, 2002); data reduction: X-AREA (Stoe & Cie, 2002); program(s) used to solve structure: SHELXT2014 (Sheldrick, 2015a); program(s) used to refine structure: SHELXL2016 (Sheldrick, 2015b); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012); software used to prepare material for publication: WinGX (Farrugia, 2012) and PLATON (Spek, 2009).

catena-poly[[diaquabis(nicotinamide-κN¹)nickel(II)]-µ-fumarato-κ²O¹:O⁴] top

Crystal data top

[Ni(C₄H₂O₄)(C₆H₆N₂O)₂(H₂O)₂]	Z = 1
M_r = 453.05	F(000) = 234
Triclinic, P1	D_x = 1.700 Mg m⁻³
a = 7.3660 (5) Å	Mo Kα radiation, λ = 0.71073 Å
b = 7.5521 (5) Å	Cell parameters from 9881 reflections
c = 8.9344 (6) Å	θ = 3.0–28.3°
α = 109.672 (2)°	µ = 1.15 mm⁻¹
β = 102.556 (2)°	T = 296 K
γ = 98.887 (2)°	Block, blue
V = 442.57 (5) Å³	0.21 × 0.17 × 0.14 mm

Data collection top

Stoe IPDS 2 diffractometer	2075 reflections with I > 2σ(I)
φ and ω scans	R_int = 0.029
Absorption correction: analytical (X-RED32; Stoe & Cie, 2002)	θ_max = 28.4°, θ_min = 2.9°
T_min = 0.622, T_max = 0.746	h = −9→9
20590 measured reflections	k = −10→10
2203 independent reflections	l = −11→11

Refinement top

Refinement on F²	0 restraints
Least-squares matrix: full	Hydrogen site location: mixed
R[F² > 2σ(F²)] = 0.029	H-atom parameters constrained
wR(F²) = 0.076	w = 1/[σ²(F_o²) + (0.0376P)² + 0.3311P] where P = (F_o² + 2F_c²)/3
S = 1.09	(Δ/σ)_max < 0.001
2203 reflections	Δρ_max = 0.33 e Å⁻³
134 parameters	Δρ_min = −0.51 e Å⁻³

Special details top

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
Ni1	0.500000	1.000000	1.000000	0.01693 (10)
O2	0.33073 (17)	0.81811 (18)	1.06897 (15)	0.0230 (3)
O1	0.03134 (19)	0.80242 (19)	0.93228 (17)	0.0288 (3)
O3	0.69940 (18)	0.84277 (19)	1.04390 (16)	0.0265 (3)
H3A	0.714414	0.842222	1.140797	0.040*
H3B	0.805970	0.895352	1.036435	0.040*
O4	0.1845 (2)	0.2218 (2)	0.65461 (17)	0.0365 (3)
N1	0.4051 (2)	0.7960 (2)	0.75121 (17)	0.0208 (3)
N2	0.0821 (3)	0.1382 (2)	0.3790 (2)	0.0344 (4)
H2A	0.030092	0.020641	0.362653	0.041*
H2B	0.075841	0.173000	0.296112	0.041*
C8	0.0907 (2)	0.5495 (2)	1.0232 (2)	0.0201 (3)
H8	0.185109	0.498535	1.069060	0.024*
C7	0.1527 (2)	0.7390 (2)	1.00643 (19)	0.0179 (3)
C4	0.2550 (2)	0.4705 (2)	0.5543 (2)	0.0201 (3)
C5	0.3392 (2)	0.6063 (2)	0.7149 (2)	0.0205 (3)
H5	0.350571	0.563601	0.801926	0.025*
C3	0.2450 (3)	0.5333 (3)	0.4242 (2)	0.0280 (4)
H3	0.190437	0.446164	0.314732	0.034*
C6	0.1722 (3)	0.2659 (2)	0.5321 (2)	0.0228 (3)
C1	0.3942 (3)	0.8543 (3)	0.6243 (2)	0.0258 (4)
H1	0.440043	0.985427	0.647565	0.031*
C2	0.3180 (3)	0.7284 (3)	0.4605 (2)	0.0317 (4)
H2	0.315654	0.773682	0.375558	0.038*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Ni1	0.01813 (15)	0.01127 (14)	0.01788 (16)	−0.00304 (10)	0.00371 (11)	0.00516 (11)
O2	0.0213 (6)	0.0206 (6)	0.0234 (6)	−0.0051 (5)	0.0041 (5)	0.0100 (5)
O1	0.0261 (6)	0.0247 (6)	0.0374 (7)	0.0034 (5)	0.0054 (5)	0.0176 (6)
O3	0.0237 (6)	0.0306 (7)	0.0305 (7)	0.0067 (5)	0.0098 (5)	0.0168 (6)
O4	0.0547 (9)	0.0216 (6)	0.0254 (7)	−0.0050 (6)	0.0003 (6)	0.0128 (5)
N1	0.0232 (7)	0.0164 (6)	0.0187 (6)	−0.0006 (5)	0.0042 (5)	0.0053 (5)
N2	0.0527 (11)	0.0158 (7)	0.0227 (8)	−0.0083 (7)	0.0013 (7)	0.0061 (6)
C8	0.0212 (8)	0.0164 (7)	0.0216 (8)	−0.0002 (6)	0.0054 (6)	0.0087 (6)
C7	0.0207 (7)	0.0133 (7)	0.0174 (7)	−0.0012 (6)	0.0067 (6)	0.0046 (6)
C4	0.0210 (8)	0.0157 (7)	0.0212 (8)	0.0005 (6)	0.0050 (6)	0.0065 (6)
C5	0.0242 (8)	0.0168 (7)	0.0190 (7)	0.0013 (6)	0.0053 (6)	0.0071 (6)
C3	0.0363 (10)	0.0205 (8)	0.0187 (8)	−0.0043 (7)	0.0021 (7)	0.0057 (7)
C6	0.0269 (8)	0.0157 (7)	0.0226 (8)	0.0013 (6)	0.0037 (6)	0.0073 (6)
C1	0.0309 (9)	0.0168 (8)	0.0252 (9)	−0.0037 (7)	0.0050 (7)	0.0086 (7)
C2	0.0454 (11)	0.0240 (9)	0.0218 (9)	−0.0038 (8)	0.0045 (8)	0.0125 (7)

Geometric parameters (Å, º) top

Ni1—O2ⁱ	2.0484 (12)	N2—H2A	0.8600
Ni1—O2	2.0484 (12)	N2—H2B	0.8600
Ni1—O3	2.0792 (13)	C8—C8ⁱⁱ	1.326 (3)
Ni1—O3ⁱ	2.0792 (13)	C8—C7	1.500 (2)
Ni1—N1	2.1187 (14)	C8—H8	0.9300
Ni1—N1ⁱ	2.1187 (14)	C4—C5	1.386 (2)
O2—C7	1.266 (2)	C4—C3	1.388 (2)
O1—C7	1.248 (2)	C4—C6	1.500 (2)
O3—H3A	0.8501	C5—H5	0.9300
O3—H3B	0.8501	C3—C2	1.387 (3)
O4—C6	1.236 (2)	C3—H3	0.9300
N1—C1	1.340 (2)	C1—C2	1.379 (3)
N1—C5	1.341 (2)	C1—H1	0.9300
N2—C6	1.327 (2)	C2—H2	0.9300

O2ⁱ—Ni1—O2	180.0	C8ⁱⁱ—C8—C7	124.0 (2)
O2ⁱ—Ni1—O3	96.22 (5)	C8ⁱⁱ—C8—H8	118.0
O2—Ni1—O3	83.78 (5)	C7—C8—H8	118.0
O2ⁱ—Ni1—O3ⁱ	83.78 (5)	O1—C7—O2	126.09 (15)
O2—Ni1—O3ⁱ	96.22 (5)	O1—C7—C8	119.43 (14)
O3—Ni1—O3ⁱ	180.0	O2—C7—C8	114.47 (14)
O2ⁱ—Ni1—N1	89.41 (5)	C5—C4—C3	118.21 (15)
O2—Ni1—N1	90.59 (5)	C5—C4—C6	117.84 (15)
O3—Ni1—N1	86.92 (5)	C3—C4—C6	123.89 (15)
O3ⁱ—Ni1—N1	93.08 (5)	N1—C5—C4	123.40 (15)
O2ⁱ—Ni1—N1ⁱ	90.59 (5)	N1—C5—H5	118.3
O2—Ni1—N1ⁱ	89.41 (5)	C4—C5—H5	118.3
O3—Ni1—N1ⁱ	93.08 (5)	C2—C3—C4	118.71 (16)
O3ⁱ—Ni1—N1ⁱ	86.92 (5)	C2—C3—H3	120.6
N1—Ni1—N1ⁱ	180.00 (8)	C4—C3—H3	120.6
C7—O2—Ni1	128.31 (11)	O4—C6—N2	122.05 (16)
Ni1—O3—H3A	109.5	O4—C6—C4	120.06 (16)
Ni1—O3—H3B	109.3	N2—C6—C4	117.87 (15)
H3A—O3—H3B	109.5	N1—C1—C2	122.83 (16)
C1—N1—C5	117.63 (15)	N1—C1—H1	118.6
C1—N1—Ni1	120.90 (11)	C2—C1—H1	118.6
C5—N1—Ni1	121.25 (11)	C1—C2—C3	119.17 (17)
C6—N2—H2A	120.0	C1—C2—H2	120.4
C6—N2—H2B	120.0	C3—C2—H2	120.4
H2A—N2—H2B	120.0

Ni1—O2—C7—O1	−26.7 (2)	C6—C4—C3—C2	176.66 (18)
Ni1—O2—C7—C8	151.80 (11)	C5—C4—C6—O4	−1.8 (3)
C8ⁱⁱ—C8—C7—O1	−6.3 (3)	C3—C4—C6—O4	−178.95 (19)
C8ⁱⁱ—C8—C7—O2	175.1 (2)	C5—C4—C6—N2	176.32 (17)
C1—N1—C5—C4	−2.4 (3)	C3—C4—C6—N2	−0.8 (3)
Ni1—N1—C5—C4	172.22 (13)	C5—N1—C1—C2	0.3 (3)
C3—C4—C5—N1	2.5 (3)	Ni1—N1—C1—C2	−174.31 (16)
C6—C4—C5—N1	−174.83 (15)	N1—C1—C2—C3	1.5 (3)
C5—C4—C3—C2	−0.5 (3)	C4—C3—C2—C1	−1.4 (3)

Symmetry codes: (i) −x+1, −y+2, −z+2; (ii) −x, −y+1, −z+2.

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O3—H3A···O4ⁱⁱⁱ	0.85	2.06	2.8699 (19)	159
O3—H3B···O1^iv	0.85	2.17	2.8550 (19)	138
O3—H3B···O1ⁱ	0.85	2.30	2.9916 (18)	138
N2—H2A···O4^v	0.86	2.16	2.980 (2)	158
N2—H2B···O1^vi	0.86	2.10	2.929 (2)	161
C3—H3···O1^vi	0.93	2.40	3.296 (2)	162

Symmetry codes: (i) −x+1, −y+2, −z+2; (iii) −x+1, −y+1, −z+2; (iv) x+1, y, z; (v) −x, −y, −z+1; (vi) −x, −y+1, −z+1.

Acknowledgements

The authors acknowledge the Faculty of Arts and Sciences, Ondokuz Mayıs University, Turkey, for the use of the Stoe IPDS 2 diffractometer (purchased under grant F.279 of the University Research Fund).

References

Bombicz, P., Forizs, E., Madarász, J., Deák, A. & Kálmán, A. (2001). Inorg. Chim. Acta, 315, 229–235. Google Scholar
Bora, S. J. & Das, B. K. (2011). J. Mol. Struct. 999, 83–88. Web of Science CrossRef Google Scholar
Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849–854. Web of Science CrossRef CAS IUCr Journals Google Scholar
Gumienna-Kontecka, E., Golenya, I. A., Dudarenko, N. M., Dobosz, A., Haukka, M., Fritsky, I. O. & Świątek-Kozłowska, J. (2007). New J. Chem. 31, 1798–1805. Web of Science CSD CrossRef CAS Google Scholar
Gümüş, M. K., Kansız, S., Aydemir, E., Gorobets, N. Y. & Dege, N. (2018). J. Mol. Struct. 1168, 280–290. Google Scholar
Kansız, S. & Dege, N. (2018). J. Mol. Struct. 1173, 42–51. Google Scholar
Krämer, R., Fritsky, I. O., Pritzkow, H. & Kovbasyuk, L. (2002). J. Chem. Soc. Dalton Trans. pp. 1307–1314. Google Scholar
Moroz, Y. S., Demeshko, S., Haukka, M., Mokhir, A., Mitra, U., Stocker, M., Müller, P., Meyer, F. & Fritsky, I. O. (2012). Inorg. Chem. 51, 7445–7447. Web of Science CSD CrossRef CAS PubMed Google Scholar
Ostrowska, M., Fritsky, I. O., Gumienna-Kontecka, E. & Pavlishchuk, A. V. (2016). Coord. Chem. Rev. 327–328, 304–332. Web of Science CrossRef CAS Google Scholar
Pavlishchuk, A. V., Kolotilov, S. V., Zeller, M., Shvets, O. V., Fritsky, I. O., Lofland, S. E., Addison, A. W. & Hunter, A. D. (2011). Eur. J. Inorg. Chem. pp. 4826–4836. Web of Science CSD CrossRef Google Scholar
Pavlishchuk, A. V., Kolotilov, S. V., Zeller, M., Thompson, L. K., Fritsky, I. O., Addison, A. W. & Hunter, A. D. (2010). Eur. J. Inorg. Chem. pp. 4851–4858. Web of Science CSD CrossRef Google Scholar
Penkova, L., Demeshko, S., Pavlenko, V. A., Dechert, S., Meyer, F. & Fritsky, I. O. (2010). Inorg. Chim. Acta, 363, 3036–3040. Web of Science CSD CrossRef CAS Google Scholar
Sen, P., Kansiz, S., Dege, N., Iskenderov, T. S. & Yildiz, S. Z. (2018). Acta Cryst. E74, 994–997. Web of Science CrossRef IUCr Journals Google Scholar
Sheldrick, G. M. (2015a). Acta Cryst. A71, 3–8. Web of Science CrossRef IUCr Journals Google Scholar
Sheldrick, G. M. (2015b). Acta Cryst. C71, 3–8. Web of Science CrossRef IUCr Journals Google Scholar
Spek, A. L. (2009). Acta Cryst. D65, 148–155. Web of Science CrossRef CAS IUCr Journals Google Scholar
Stoe & Cie (2002). X-AREA and X-RED32. Stoe & Cie GmbH, Darmstadt, Germany. Google Scholar
Turner, M. J., MacKinnon, J. J., Wolff, S. K., Grimwood, D. J., Spackman, P. R., Jayatilaka, D. & Spackman, M. A. (2017). CrystalExplorer 17.5. University of Western Avustralia, Perth. Google Scholar

This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.