Crystal structure and Hirshfeld surface analysis of tetra-aqua-bis-(isonicotinamide-κN 1)nickel(II) fumarate.

The reaction of NiCl2 with fumaric acid and isonicotinamide in a basic solution produces the title complex, [Ni(C6H6N2O)2(H2O)4](C4H2O4). The nickel(II) ion of the complex cation and the fumarate anion are each located on an inversion centre. The NiII ion is coordinated octa-hedrally by four water O atoms and two N atoms of isonicotinamide mol-ecules. The fumarate anion is linked to neighbouring complex cations via Owater-H⋯Ofumarate hydrogen bonds. In the crystal, the complex cations are further linked by O-H⋯O, N-H⋯O and C-H⋯O hydrogen bonds, forming a three-dimensional supra-molecular architecture. Hirshfeld surface analysis and two-dimensional fingerprint plots were used to analyse the inter-molecular inter-actions present in the crystal and indicate that the most important contributions for the crystal packing are from H⋯O/O⋯H (41.8%), H⋯H (35.3%) and H⋯C/C⋯H (10.2%) inter-actions.

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 the biological processes involved in the formation of vitamins and drug components. An important element for biological systems is nickel and nickel complexes have biological activities including anti­epileptic, anti­microbial, anti­bacterial and anti­cancer activities (Bombicz et al., 2001 ▸). Di­carb­oxy­lic acid ligands have been utilized primarily in the synthesis of a range of metal complexes. Di­carb­oxy­lic acids such as fumaric acid and amides have been particularly useful in creating many supra­molecular structures (Pavlishchuk et al., 2011 ▸; Ostrowska et al., 2016 ▸), in particular isonicotinamide with a variety of carb­oxy­lic acids (Vishweshwar et al., 2003 ▸; Aakeröy et al., 2002 ▸).

We have prepared a new NiII complex, tetra­aqua­bis(isonicotinamide-κN 1)nickel(II) fumarate, and determined its structure by single crystal X-ray diffraction. In addition, Hirshfeld surface analysis and fingerprint plots were used to understand the inter­molecular inter­actions in the crystal structure.

Structural commentary

The mol­ecular structure of the title complex is illustrated in Fig. 1 ▸. The nickel(II) ion is octa­hedrally coordinated to four water O atoms and two Npyridine atoms of isonicotinamide mol­ecules. The values of the Ni—Owater and Ni—Npyridine bond lengths and the bond angles involving atom Ni1 (Table 1 ▸) are close to those reported for similar nickel(II) complexes (Krämer et al., 2002 ▸; Bora & Das, 2011 ▸; Moroz et al., 2012 ▸).

Figure 1

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

Table 1

Selected geometric parameters (Å, °)

Ni1—O3	2.0537 (16)	Ni1—N1	2.1075 (18)
Ni1—O2	2.0812 (15)
O3—Ni1—O2	92.00 (7)	O3—Ni1—N1	86.97 (7)
O3—Ni1—O2i	88.00 (7)	O2—Ni1—N1	92.05 (6)
O3i—Ni1—N1	93.03 (7)	O2i—Ni1—N1	87.95 (7)

Symmetry code: (i) .

Supra­molecular features

In the crystal, each O atom of the fumarate dianion is linked to a water H atom via O—H⋯O hydrogen bonds, forming chains along the c-axis direction (Table 2 ▸, Fig. 2 ▸).

Table 2

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O3—H3B⋯O4	0.80 (3)	1.89 (3)	2.678 (2)	169 (3)
O2—H2A⋯O5	0.78 (3)	2.01 (3)	2.791 (3)	175 (3)
C6—H6⋯O1iii	0.93	2.31	3.230 (3)	172
N2—H2D⋯O1iii	0.93 (5)	2.31 (5)	3.230 (3)	172 (4)
C5—H5⋯O4iv	0.93	2.38	3.282 (3)	165
O2—H2B⋯O4iv	0.73 (3)	2.02 (3)	2.739 (2)	172 (3)
O3—H3A⋯O1v	0.73 (3)	2.07 (3)	2.798 (3)	175 (3)

Symmetry codes: (iii) ; (iv) ; (v) .

Figure 2

A view of the crystal packing of the title compound. Dashed lines indicate hydrogen bonds.

The fumarate anions and complex cations are linked by O—H⋯O hydrogen bonds; the complex cations also inter­act with each other through O—H⋯O, N—H⋯O and C—H⋯O hydrogen bonds, forming a three-dimensional supra­molecular architecture.

Database survey

A search of the Cambridge Structural Database (CSD, version 5.39, update of May 2018; Groom et al., 2016 ▸) revealed the structures of four similar tetra­aqua­bis­(isonicotinamide-κN 1)nickel(II) complexes with different counter-anions viz. bis­(4-formyl­benzoate) dihydrate (HUCLAT; Hökelek et al., 2009 ▸), bis­(3-hy­droxy­benzoate) tetra­hydrate (GANZAY; Zaman et al., 2012 ▸), bis­(thio­phene-2,5-di­carboxyl­ate) dihydrate (NETQIO; Liu et al., 2012 ▸) and naphthalene-1,5-di­sulfonate tetra­hydrate (TESDEC; Lian, 2012 ▸). In all four complexes, the cation possesses inversion symmetry with the nickel ion being located on a centre of symmetry. The Ni—Owater bond lengths vary from 2.044 to 2.086 Å, while the Ni—Npyridine bond lengths vary from 2.075 to 2.098 Å. In the title complex, the cation also possesses inversion symmetry and the Ni—Owater bond lengths [2.0812 (15) and 2.0537 (16) Å] and the Ni—Npyridine bond length [2.1075 (18) Å] fall within these limits.

Hirshfeld surface analysis

Crystal Explorer17.5 (Turner et al., 2017 ▸) was used to investigate the Hirshfeld surfaces and to analyse the inter­actions in the crystal. The Hirshfeld surfaces mapped over d norm, d i and d e are shown in Fig. 3 ▸. Red spots indicate the contacts involved in strong hydrogen bonds and inter­atomic contacts (Gümüş et al., 2018 ▸; Sen et al., 2018 ▸; Kansız & Dege, 2018 ▸); those in Fig. 3 ▸ correspond to the near-type H⋯O contacts resulting from C—H⋯O, O—H⋯O and N—H⋯O hydrogen bonds. The Hirshfeld surfaces were obtained using a standard surface (high) resolution with the three-dimensional d surfaces mapped over a fixed colour scale of −0.701 (red) to 1.286 (blue) a.u. The red spots in Fig. 4 ▸ correspond to the near-type H⋯O contacts resulting from O—H⋯O and N—H⋯O hydrogen bonds. Fig. 5 ▸ shows the two-dimensional fingerprint plot of the sum of the contacts contributing to the Hirshfeld surface represented in normal mode. In Fig. 6 ▸ a. the two symmetrical points at the top, bottom left and right with d e + d i = 1.7 Å indicate the presence of H⋯O/O⋯H (41.8%) contacts. Fig. 6 ▸ b shows the two-dimensional fingerprint plot of the (d i, d e) points associated with hydrogen atoms and 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 (35.3%). Fig. 6 ▸ c shows the contacts between the carbon atoms inside the surface and the hydrogen atoms outside the surface of Hirshfeld and vice versa (H⋯C/C⋯H) and has two symmetrical wings on the left and right sides (10.2%). C⋯C (4.2%), C⋯O/O⋯C (2.9%) and H⋯N/N⋯H (2.7%) contacts also contribute to the Hirshfeld surface.

Figure 3

The Hirshfeld surface of the title compound mapped over d norm, d i and d e.

Figure 4

The Hirshfeld surface mapped over d to visualize the intra­molecular and inter­molecular inter­actions in the title compound.

Figure 5

A fingerprint plot of the title compound.

Figure 6

(a) H⋯O/O⋯H, (b) H⋯H, (c) H⋯C/C⋯H, (d) C⋯C, (e) C⋯O/O⋯C and (f) H⋯N/N⋯H contacts in the title complex, showing their percentage contributions to the Hirshfeld surface.

Synthesis and crystallization

A solution of NaOH (52 mmol, 2.07 g) was added to an aqueous solution of fumaric acid (26 mmol, 3 g) under stirring. A solution of NiCl2·6H2O (25 mmol, 6.14 g) in methanol was then added. The mixture was heated at 353 K for 30 min. and then the blue mixture was filtered and left to dry at room temperature. The reaction mixture (0.88 mmol, 0.20 g) was dissolved in methanol and added to a ethanol solution of isonicotinamide (1.76 mmol, 0.21 g). The mixture was heated at 353 K for 60 min. under stirring and the resulting suspension was filtered and left to crystallize for three weeks at room temperature. The title compound was obtained as a blue solid and contained crystals suitable for X-ray diffraction analysis.

Refinement

Crystal data, data collection and structure refinement details are summarized in Table 3 ▸. The water and NH2 hydrogen atoms were located from difference-Fourier maps and freely refined. The C-bound H atoms were positioned geometrically and refined using a riding model: C—H = 0.93–0.97 Å with U iso(H) = 1.2U eq(C).

Table 3

Experimental details

Crystal data
Chemical formula	[Ni(C6H6N2O)2(H2O)4](C4H2O4)
M r	489.08
Crystal system, space group	Monoclinic, P21/c
Temperature (K)	296
a, b, c (Å)	9.6140 (8), 9.9819 (9), 11.3874 (10)
β (°)	113.157 (7)
V (Å3)	1004.76 (16)
Z	2
Radiation type	Mo Kα
μ (mm−1)	1.03
Crystal size (mm)	0.58 × 0.50 × 0.39
Data collection
Diffractometer	STOE IPDS 2
Absorption correction	Integration (X-RED32; Stoe & Cie, 2002 ▸)
T min, T max	0.527, 0.593
No. of measured, independent and observed [I > 2σ(I)] reflections	5175, 2075, 1777
R int	0.045
(sin θ/λ)max (Å−1)	0.628
Refinement
R[F 2 > 2σ(F 2)], wR(F 2), S	0.041, 0.104, 1.05
No. of reflections	2075
No. of parameters	171
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å−3)	0.39, −0.83

Computer programs: X-AREA (Stoe & Cie, 2002 ▸), X-RED (Stoe & Cie, 2002 ▸), SHELXL2017 (Sheldrick, 2015 ▸), ORTEP-3 for Windows (Farrugia, 2012 ▸), WinGX (Farrugia, 2012 ▸) and PLATON (Spek, 2009 ▸).

Crystal structure: contains datablock(s) I. DOI: 10.1107/S2056989018013580/qm2126sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S2056989018013580/qm2126Isup2.hkl

CCDC reference: 1579677

Additional supporting information: crystallographic information; 3D view; checkCIF report

[Ni(C6H6N2O)2(H2O)4](C4H2O4)	F(000) = 508
Mr = 489.08	Dx = 1.617 Mg m−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 9.6140 (8) Å	Cell parameters from 8294 reflections
b = 9.9819 (9) Å	θ = 2.0–28.5°
c = 11.3874 (10) Å	µ = 1.03 mm−1
β = 113.157 (7)°	T = 296 K
V = 1004.76 (16) Å3	Prism, blue
Z = 2	0.58 × 0.50 × 0.39 mm

STOE IPDS 2 diffractometer	2075 independent reflections
Radiation source: sealed X-ray tube, 12 x 0.4 mm long-fine focus	1777 reflections with I > 2σ(I)
Detector resolution: 6.67 pixels mm-1	Rint = 0.045
rotation method scans	θmax = 26.5°, θmin = 2.8°
Absorption correction: integration (X-RED32; Stoe & Cie, 2002)	h = −12→10
Tmin = 0.527, Tmax = 0.593	k = −12→12
5175 measured reflections	l = −14→14

Refinement on F2	0 restraints
Least-squares matrix: full	Hydrogen site location: mixed
R[F2 > 2σ(F2)] = 0.041	H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.104	w = 1/[σ2(Fo2) + (0.073P)2 + 0.0362P] where P = (Fo2 + 2Fc2)/3
S = 1.05	(Δ/σ)max < 0.001
2075 reflections	Δρmax = 0.39 e Å−3
171 parameters	Δρmin = −0.82 e Å−3

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.

Refinement. Refined as a 2-component inversion twin.

	x	y	z	Uiso*/Ueq
Ni1	0.500000	0.500000	0.500000	0.02691 (15)
O2	0.39639 (19)	0.36038 (17)	0.35626 (16)	0.0352 (3)
O3	0.3976 (2)	0.65707 (16)	0.38085 (15)	0.0345 (3)
O4	0.45031 (18)	0.63766 (14)	0.16741 (14)	0.0399 (4)
O5	0.2761 (2)	0.47778 (18)	0.11437 (18)	0.0473 (4)
O1	1.0888 (2)	0.70001 (16)	0.31656 (18)	0.0506 (4)
N1	0.6822 (2)	0.52490 (16)	0.44312 (18)	0.0315 (4)
C7	0.3828 (2)	0.5393 (2)	0.10101 (19)	0.0328 (4)
C8	0.4341 (3)	0.4863 (2)	0.0015 (2)	0.0357 (5)
N2	1.0342 (3)	0.5042 (3)	0.2095 (3)	0.0605 (7)
C2	0.8968 (2)	0.5673 (2)	0.33931 (19)	0.0344 (4)
C3	0.8503 (3)	0.6699 (2)	0.3963 (2)	0.0402 (5)
H3	0.891089	0.755195	0.401464	0.048*
C4	0.7431 (3)	0.6452 (2)	0.4456 (2)	0.0392 (5)
H4	0.711583	0.715976	0.482316	0.047*
C6	0.8353 (3)	0.4416 (2)	0.3374 (2)	0.0423 (5)
H6	0.864249	0.369442	0.300562	0.051*
C1	1.0136 (3)	0.5951 (2)	0.2856 (2)	0.0402 (5)
C5	0.7303 (3)	0.4249 (2)	0.3910 (2)	0.0401 (5)
H5	0.691168	0.339653	0.390746	0.048*
H3B	0.402 (3)	0.655 (3)	0.312 (3)	0.048 (8)*
H3A	0.318 (3)	0.670 (3)	0.369 (2)	0.038 (7)*
H2B	0.434 (4)	0.297 (3)	0.354 (3)	0.051 (9)*
H2A	0.364 (4)	0.389 (3)	0.287 (3)	0.056 (9)*
H2C	1.030 (6)	0.554 (6)	0.139 (5)	0.133 (17)*
H2D	0.989 (5)	0.420 (5)	0.199 (4)	0.104 (14)*
H8	0.367 (3)	0.424 (3)	−0.058 (3)	0.053 (7)*

	U11	U22	U33	U12	U13	U23
Ni1	0.0289 (2)	0.0249 (2)	0.0340 (2)	0.00018 (13)	0.01994 (16)	−0.00068 (12)
O2	0.0414 (9)	0.0306 (8)	0.0386 (8)	0.0005 (7)	0.0210 (7)	−0.0031 (6)
O3	0.0366 (9)	0.0352 (8)	0.0389 (8)	0.0044 (7)	0.0226 (7)	0.0032 (6)
O4	0.0537 (10)	0.0327 (8)	0.0455 (8)	−0.0069 (7)	0.0328 (7)	−0.0049 (6)
O5	0.0479 (10)	0.0543 (10)	0.0529 (10)	−0.0138 (8)	0.0341 (8)	−0.0076 (7)
O1	0.0464 (10)	0.0421 (9)	0.0781 (12)	−0.0012 (7)	0.0405 (9)	0.0097 (8)
N1	0.0330 (9)	0.0291 (8)	0.0412 (9)	−0.0003 (7)	0.0241 (8)	0.0002 (7)
C7	0.0389 (11)	0.0291 (9)	0.0366 (9)	0.0038 (9)	0.0216 (9)	0.0031 (8)
C8	0.0425 (13)	0.0329 (11)	0.0393 (11)	−0.0024 (9)	0.0244 (10)	−0.0040 (8)
N2	0.0581 (16)	0.0683 (18)	0.0789 (18)	−0.0089 (12)	0.0526 (15)	−0.0146 (12)
C2	0.0274 (10)	0.0407 (12)	0.0397 (9)	0.0013 (9)	0.0182 (8)	0.0042 (9)
C3	0.0419 (12)	0.0314 (10)	0.0578 (12)	−0.0019 (9)	0.0309 (11)	0.0025 (9)
C4	0.0429 (12)	0.0305 (10)	0.0544 (12)	−0.0005 (9)	0.0302 (10)	−0.0024 (9)
C6	0.0422 (13)	0.0372 (12)	0.0592 (13)	−0.0031 (10)	0.0325 (11)	−0.0112 (10)
C1	0.0333 (11)	0.0469 (13)	0.0485 (11)	0.0040 (9)	0.0245 (10)	0.0086 (10)
C5	0.0424 (12)	0.0313 (11)	0.0584 (12)	−0.0042 (9)	0.0325 (11)	−0.0069 (9)

Ni1—O3i	2.0536 (15)	C7—C8	1.499 (3)
Ni1—O3	2.0537 (16)	C8—C8ii	1.309 (5)
Ni1—O2	2.0812 (15)	C8—H8	0.95 (3)
Ni1—O2i	2.0812 (15)	N2—C1	1.322 (4)
Ni1—N1	2.1075 (18)	N2—H2C	0.93 (6)
Ni1—N1i	2.1075 (18)	N2—H2D	0.93 (5)
O2—H2B	0.73 (3)	C2—C3	1.378 (3)
O2—H2A	0.78 (3)	C2—C6	1.384 (3)
O3—H3B	0.80 (3)	C2—C1	1.501 (3)
O3—H3A	0.73 (3)	C3—C4	1.376 (3)
O4—C7	1.253 (3)	C3—H3	0.9300
O5—C7	1.255 (3)	C4—H4	0.9300
O1—C1	1.242 (3)	C6—C5	1.379 (3)
N1—C4	1.332 (3)	C6—H6	0.9300
N1—C5	1.334 (3)	C5—H5	0.9300
O3i—Ni1—O3	180.0	O5—C7—C8	116.5 (2)
O3i—Ni1—O2	88.00 (7)	C8ii—C8—C7	123.7 (3)
O3—Ni1—O2	92.00 (7)	C8ii—C8—H8	120.6 (17)
O3i—Ni1—O2i	92.00 (7)	C7—C8—H8	115.6 (16)
O3—Ni1—O2i	88.00 (7)	C1—N2—H2C	104 (4)
O2—Ni1—O2i	180.0	C1—N2—H2D	121 (3)
O3i—Ni1—N1	93.03 (7)	H2C—N2—H2D	121 (4)
O3—Ni1—N1	86.97 (7)	C3—C2—C6	117.72 (19)
O2—Ni1—N1	92.05 (6)	C3—C2—C1	119.23 (19)
O2i—Ni1—N1	87.95 (7)	C6—C2—C1	123.0 (2)
O3i—Ni1—N1i	86.97 (7)	C4—C3—C2	119.6 (2)
O3—Ni1—N1i	93.03 (7)	C4—C3—H3	120.2
O2—Ni1—N1i	87.95 (7)	C2—C3—H3	120.2
O2i—Ni1—N1i	92.05 (6)	N1—C4—C3	123.1 (2)
N1—Ni1—N1i	180.0	N1—C4—H4	118.4
Ni1—O2—H2B	121 (2)	C3—C4—H4	118.4
Ni1—O2—H2A	115 (2)	C5—C6—C2	119.0 (2)
H2B—O2—H2A	107 (3)	C5—C6—H6	120.5
Ni1—O3—H3B	116 (2)	C2—C6—H6	120.5
Ni1—O3—H3A	117 (2)	O1—C1—N2	122.9 (2)
H3B—O3—H3A	106 (3)	O1—C1—C2	119.0 (2)
C4—N1—C5	117.25 (18)	N2—C1—C2	118.0 (2)
C4—N1—Ni1	120.76 (14)	N1—C5—C6	123.3 (2)
C5—N1—Ni1	121.62 (14)	N1—C5—H5	118.4
O4—C7—O5	124.33 (18)	C6—C5—H5	118.4
O4—C7—C8	119.12 (18)
O4—C7—C8—C8ii	17.1 (4)	C1—C2—C6—C5	178.9 (2)
O5—C7—C8—C8ii	−160.8 (3)	C3—C2—C1—O1	15.0 (3)
C6—C2—C3—C4	−1.7 (3)	C6—C2—C1—O1	−163.2 (2)
C1—C2—C3—C4	179.9 (2)	C3—C2—C1—N2	−166.6 (3)
C5—N1—C4—C3	0.6 (4)	C6—C2—C1—N2	15.1 (4)
Ni1—N1—C4—C3	−172.50 (19)	C4—N1—C5—C6	−1.9 (4)
C2—C3—C4—N1	1.2 (4)	Ni1—N1—C5—C6	171.21 (19)
C3—C2—C6—C5	0.6 (3)	C2—C6—C5—N1	1.3 (4)

D—H···A	D—H	H···A	D···A	D—H···A
O3—H3B···O4	0.80 (3)	1.89 (3)	2.678 (2)	169 (3)
O2—H2A···O5	0.78 (3)	2.01 (3)	2.791 (3)	175 (3)
C6—H6···O1iii	0.93	2.31	3.230 (3)	172
N2—H2D···O1iii	0.93 (5)	2.31 (5)	3.230 (3)	172 (4)
C5—H5···O4iv	0.93	2.38	3.282 (3)	165
O2—H2B···O4iv	0.73 (3)	2.02 (3)	2.739 (2)	172 (3)
O3—H3A···O1v	0.73 (3)	2.07 (3)	2.798 (3)	175 (3)