Bis(3-amino­pyrazine-2-carboxyl­ato-κ² N ¹,O)di­aqua­nickel(II) dihydrate

Abstract

In the title compound, [Ni(C₅H₄N₃O₂)₂(H₂O)₂]·2H₂O, the Ni^II ion lies on an inversion center and is coordinated in an slightly distorted octa­hedral environment by two N,O-chelating 3-amino­pyrazine-2-carboxyl­ate (APZC) ligands in the equatorial plane and two trans-axial aqua ligands. In the crystal, O—H⋯O, N—H⋯O and O—H⋯N hydrogen bonds involving the solvent water mol­ecules, aqua and APZC ligands form layers parallel to (010). These layers are linked further via O—H⋯O, N—H⋯O and C—H⋯O hydrogen bonds involving the axial aqua ligands, amino groups and the carboxyl­ate groups of the APZC ligands, forming a three-dimensional network.

Related literature  

For background to hybrid compounds, see: Bouchene et al. (2013 ▶); Bouacida et al. (2007 ▶, 2009 ▶). For the structure of the non-hydrated analogue, see: Ptasiewicz-Bak & Leciejewicz (1999 ▶). For 3-amino­pyrazine-2-carboxyl­ate–metal (M) complexes, see: Bouchene et al. (2013 ▶) [M = Co(II)]; Leciejewicz et al. (1997 ▶) [M = Ca(II)]; Leciejewicz et al. (1998 ▶) [M = Sr(II)]; Ptasiewicz-Bak & Leciejewicz (1997 ▶) [M = Mg(II)]; Tayebee et al. (2008 ▶) [M = Na(I)]; Ptasiewicz-Bak & Leciejewicz (1999 ▶). For proprieties and applications of pyrazine-2-carb­oxy­lic acid, see: Zhang & Mitchison (2003 ▶); Manju & Chaudhary, (2010 ▶); Chanda & Sangeetika (2004 ▶).

Experimental  

Crystal data  

• [Ni(C₅H₄N₃O₂)₂(H₂O)₂]·2H₂O

• M _r = 406.98

• Monoclinic,

• a = 9.7939 (15) Å

• b = 5.1123 (9) Å

• c = 16.776 (3) Å

• β = 115.838 (11)°

• V = 756.0 (2) ų

• Z = 2

• Mo Kα radiation

• μ = 1.34 mm⁻¹

• T = 150 K

• 0.18 × 0.16 × 0.15 mm

Data collection  

• Bruker APEXII CCD diffractometer

• 6200 measured reflections

• 1326 independent reflections

• 1121 reflections with I > 2σ(I)

• R _int = 0.051

Refinement  

• R[F ² > 2σ(F ²)] = 0.028

• wR(F ²) = 0.073

• S = 1.04

• 1326 reflections

• 127 parameters

• H atoms treated by a mixture of independent and constrained refinement

• Δρ_max = 0.36 e Å⁻³

• Δρ_min = −0.59 e Å⁻³

Data collection: APEX2 (Bruker, 2011 ▶); cell refinement: SAINT (Bruker, 2011 ▶); data reduction: SAINT; program(s) used to solve structure: SIR2002 (Burla et al., 2005 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012 ▶) and DIAMOND (Brandenburg & Berndt, 2001 ▶); software used to prepare material for publication: WinGX (Farrugia, 2012 ▶).

Supplementary Material

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1W—H1A⋯O2W i	0.83 (3)	1.97 (3)	2.789 (3)	169 (3)
O1W—H1B⋯O1ii	0.75 (3)	1.94 (3)	2.690 (3)	176 (4)
N3—H1N⋯O2W iii	0.86	2.27	3.117 (3)	168
O2W—H2A⋯O2W iv	0.77 (3)	2.12 (3)	2.867 (3)	164 (4)
O2W—H2B⋯N2v	0.78 (3)	2.03 (3)	2.792 (3)	168 (3)
N3—H2N⋯O2	0.86	2.10	2.733 (3)	130
N3—H2N⋯O2vi	0.86	2.20	2.871 (3)	135
C5—H5⋯O1W vii	0.93	2.54	3.377 (4)	150

Symmetry codes: (i) ; (ii) ; (iii) ; (iv) ; (v) ; (vi) ; (vii) .

supplementary crystallographic information

Comment

The pyrazine-2-carboxylic acid bridging ligand, owing to its ability to act in acidic environments (Zhang & Mitchison, 2003), has been extensively studied for biological applications, such as anti-tubercular (Manju et al., 2010), antipyretic, antitumor, and anticancer (Chanda et al., 2004). An additional amino substitution on 3-amino-2-pyrazine carboxylic acid could be expected to enhance crystal packing through extensive hydrogen bonding. APZC has a large variety of coordination geometries in metal complexes (Leciejewicz et al., 1997, 1998; Ptasiewicz-Bak & Leciejewicz, 1997; Tayebee et al., 2008).

In continuation of our search to enrich the variety of such kinds of hybrid compounds and to investigate the influence of hydrogen bonds on the structural features (Bouacida et al., 2007, 2009), we report here the synthesis and crystal structure of the title compound, (I), as a extention of our earlier work on N,O chelated ligands (Bouchene et al.2013) which can be involved in covalent interactions in metal coordination chemistry.

The asymmetric unit of (I) consists of one-half of the molecule, with the other half generated by a crystallographic inversion center. The molecular structure is shown in Fig. 1. The Ni^II ion is coordinated by two 3-amino-2-pyrazine carboxylate ligands via N,O-chelating groups in the equatorial plane and two aqua O atoms in the axial sites forming a slightly distorted octahedral coordination environment. The Ni—N, Ni—O and Ni—O_aqua distances are consistent with the reported data for the anhydrous Ni(II)(APZC)₂(H₂O)₂ complex (Ptasiewicz-Bak & Leciejewicz, 1999). In the crystal, the solvent water molecules and complex molecules are involved in intermolecular O—H···O, O—H···N and N—H···O hydrogen bonds forming two-dimensional layers parallel to (010) (Fig.2). Further O—H···O hydrogen bonds (Fig.3) involving the aqua ligands, N—H···.O hydrogen bonds the carboxylate groups of the APZC ligands form a three-dimensional network.

Experimental

Nickel dichloride hexahydrate (0.2 mmol) and 3-aminopyrazine-2-carboxylic acid (0.02 mmol) were dissolved in acidified water with concentrated hydrogen chloride acid (37%). Light green crystals, suitable for X-ray diffraction study, were obtained from evaporation of obtained solution for three days.

Refinement

The H atoms bonded to C and N were located in differnce Fourier maps but subsequently introduced in calculated positions and treated as riding on their parent atoms (C or N) with C—H = 0.93 Å and N—H = 0.86 Å with U_iso(H) = 1.2U_eq(C or N). Atoms H1W and H2W were located in a difference Fourier map and refined isotropically wirh U_iso(H) = 1.5U_eq(O).

Figures

Fig. 1.

The molecular structure of the title compound. Displacement ellipsoids are drawn at the 50% probability level. H atoms are represented as small spheres of arbitrary radii. Symmetry code: (i)-x+1, -y+1, -z+2.

Fig. 2.

Partial packing plot viewed along the b axis showing the hydrogen bonds (dashed lines) forming layers.

Fig. 3.

Partial packing of (I) showing only the O—H···O hydrogen bonds which connect the layers in Fig. 2 into a three-dimensional network.

Crystal data

[Ni(C5H4N3O2)2(H2O)2]·2H2O	F(000) = 420
Mr = 406.98	Dx = 1.788 Mg m−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 9.7939 (15) Å	Cell parameters from 2285 reflections
b = 5.1123 (9) Å	θ = 2.7–25°
c = 16.776 (3) Å	µ = 1.34 mm−1
β = 115.838 (11)°	T = 150 K
V = 756.0 (2) Å3	Cube, white
Z = 2	0.18 × 0.16 × 0.15 mm

Data collection

Bruker APEXII CCD diffractometer	1121 reflections with I > 2σ(I)
Radiation source: sealed tube	Rint = 0.051
Graphite monochromator	θmax = 25.1°, θmin = 2.7°
φ and ω scans	h = −11→11
6200 measured reflections	k = −6→6
1326 independent reflections	l = −19→19

Refinement

Refinement on F2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.028	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.073	H atoms treated by a mixture of independent and constrained refinement
S = 1.04	w = 1/[σ2(Fo2) + (0.0363P)2 + 0.4886P] where P = (Fo2 + 2Fc2)/3
1326 reflections	(Δ/σ)max < 0.001
127 parameters	Δρmax = 0.36 e Å−3
0 restraints	Δρmin = −0.59 e Å−3

Special details

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

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
C1	0.2428 (3)	0.2367 (5)	0.99519 (16)	0.0089 (5)
C2	0.2750 (3)	0.4494 (4)	1.06347 (15)	0.0079 (5)
C3	0.1864 (3)	0.4915 (5)	1.11094 (15)	0.0090 (5)
C4	0.3430 (3)	0.8353 (5)	1.18295 (16)	0.0098 (5)
H4	0.3692	0.9711	1.2239	0.012*
C5	0.4304 (3)	0.7942 (5)	1.13805 (15)	0.0097 (5)
H5	0.5141	0.8999	1.1492	0.012*
N1	0.3937 (2)	0.6010 (4)	1.07831 (13)	0.0074 (4)
N2	0.2227 (2)	0.6890 (4)	1.17019 (13)	0.0102 (4)
N3	0.0696 (2)	0.3396 (4)	1.10092 (14)	0.0125 (5)
H1N	0.0202	0.3689	1.1316	0.015*
H2N	0.0436	0.2122	1.0637	0.015*
O1	0.33555 (17)	0.2240 (3)	0.96010 (11)	0.0090 (4)
O2	0.13487 (18)	0.0885 (3)	0.97784 (12)	0.0137 (4)
O1W	0.6426 (2)	0.2542 (4)	1.10017 (12)	0.0102 (4)
H1A	0.726 (3)	0.312 (6)	1.1356 (19)	0.015*
H1B	0.652 (3)	0.124 (6)	1.083 (2)	0.015*
O2W	0.0735 (2)	0.6137 (4)	0.76616 (12)	0.0133 (4)
H2A	0.046 (4)	0.472 (6)	0.754 (2)	0.02*
H2B	0.104 (3)	0.663 (6)	0.733 (2)	0.02*
Ni1	0.5	0.5	1	0.00664 (16)

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
C1	0.0073 (11)	0.0071 (12)	0.0116 (12)	0.0010 (9)	0.0036 (10)	0.0014 (10)
C2	0.0067 (12)	0.0078 (12)	0.0087 (11)	0.0002 (9)	0.0029 (10)	0.0009 (9)
C3	0.0078 (11)	0.0088 (12)	0.0098 (11)	0.0029 (10)	0.0031 (9)	0.0029 (11)
C4	0.0114 (12)	0.0077 (12)	0.0105 (12)	−0.0014 (9)	0.0050 (10)	−0.0024 (10)
C5	0.0068 (12)	0.0089 (12)	0.0137 (13)	−0.0011 (9)	0.0048 (10)	−0.0017 (10)
N1	0.0040 (10)	0.0067 (10)	0.0102 (10)	0.0004 (8)	0.0019 (8)	0.0009 (8)
N2	0.0097 (10)	0.0101 (11)	0.0123 (10)	−0.0008 (8)	0.0061 (9)	0.0001 (8)
N3	0.0094 (10)	0.0139 (11)	0.0195 (11)	−0.0052 (9)	0.0113 (9)	−0.0056 (9)
O1	0.0069 (8)	0.0093 (8)	0.0137 (9)	−0.0018 (7)	0.0073 (7)	−0.0032 (7)
O2	0.0092 (9)	0.0135 (9)	0.0213 (10)	−0.0055 (7)	0.0092 (8)	−0.0059 (8)
O1W	0.0077 (9)	0.0081 (9)	0.0147 (9)	−0.0015 (7)	0.0046 (8)	−0.0030 (8)
O2W	0.0148 (10)	0.0129 (9)	0.0169 (10)	−0.0035 (8)	0.0115 (8)	−0.0018 (8)
Ni1	0.0049 (2)	0.0062 (2)	0.0106 (2)	−0.00089 (17)	0.00506 (18)	−0.00108 (18)

Geometric parameters (Å, º)

C1—O2	1.228 (3)	N1—Ni1	2.0657 (19)
C1—O1	1.281 (3)	N3—H1N	0.86
C1—C2	1.510 (3)	N3—H2N	0.86
C2—N1	1.327 (3)	O1—Ni1	2.0233 (16)
C2—C3	1.427 (3)	O1W—Ni1	2.0755 (18)
C3—N3	1.331 (3)	O1W—H1A	0.83 (3)
C3—N2	1.351 (3)	O1W—H1B	0.74 (3)
C4—N2	1.332 (3)	O2W—H2A	0.77 (3)
C4—C5	1.381 (3)	O2W—H2B	0.78 (3)
C4—H4	0.93	Ni1—O1i	2.0233 (16)
C5—N1	1.340 (3)	Ni1—N1i	2.066 (2)
C5—H5	0.93	Ni1—O1Wi	2.0755 (18)
O2—C1—O1	124.7 (2)	H1N—N3—H2N	120
O2—C1—C2	119.8 (2)	C1—O1—Ni1	115.72 (15)
O1—C1—C2	115.5 (2)	Ni1—O1W—H1A	118 (2)
N1—C2—C3	120.2 (2)	Ni1—O1W—H1B	113 (2)
N1—C2—C1	116.0 (2)	H1A—O1W—H1B	110 (3)
C3—C2—C1	123.7 (2)	H2A—O2W—H2B	108 (3)
N3—C3—N2	117.7 (2)	O1—Ni1—O1i	180
N3—C3—C2	122.7 (2)	O1—Ni1—N1	80.54 (7)
N2—C3—C2	119.6 (2)	O1i—Ni1—N1	99.46 (7)
N2—C4—C5	122.8 (2)	O1—Ni1—N1i	99.46 (7)
N2—C4—H4	118.6	O1i—Ni1—N1i	80.54 (7)
C5—C4—H4	118.6	N1—Ni1—N1i	180.0000 (10)
N1—C5—C4	119.5 (2)	O1—Ni1—O1Wi	89.81 (7)
N1—C5—H5	120.3	O1i—Ni1—O1Wi	90.19 (7)
C4—C5—H5	120.3	N1—Ni1—O1Wi	90.92 (7)
C2—N1—C5	119.9 (2)	N1i—Ni1—O1Wi	89.08 (7)
C2—N1—Ni1	112.20 (15)	O1—Ni1—O1W	90.19 (7)
C5—N1—Ni1	127.92 (16)	O1i—Ni1—O1W	89.81 (7)
C4—N2—C3	117.9 (2)	N1—Ni1—O1W	89.08 (7)
C3—N3—H1N	120	N1i—Ni1—O1W	90.92 (7)
C3—N3—H2N	120	O1Wi—Ni1—O1W	180.00 (9)
O2—C1—C2—N1	180.0 (2)	N3—C3—N2—C4	177.5 (2)
O1—C1—C2—N1	1.0 (3)	C2—C3—N2—C4	−1.1 (3)
O2—C1—C2—C3	0.2 (4)	O2—C1—O1—Ni1	178.74 (18)
O1—C1—C2—C3	−178.8 (2)	C2—C1—O1—Ni1	−2.3 (3)
N1—C2—C3—N3	−177.5 (2)	C1—O1—Ni1—N1	2.15 (16)
C1—C2—C3—N3	2.3 (4)	C1—O1—Ni1—N1i	−177.85 (16)
N1—C2—C3—N2	1.0 (3)	C1—O1—Ni1—O1Wi	−88.81 (16)
C1—C2—C3—N2	−179.2 (2)	C1—O1—Ni1—O1W	91.19 (16)
N2—C4—C5—N1	0.5 (4)	C2—N1—Ni1—O1	−1.50 (15)
C3—C2—N1—C5	0.0 (3)	C5—N1—Ni1—O1	179.2 (2)
C1—C2—N1—C5	−179.9 (2)	C2—N1—Ni1—O1i	178.50 (15)
C3—C2—N1—Ni1	−179.41 (17)	C5—N1—Ni1—O1i	−0.8 (2)
C1—C2—N1—Ni1	0.8 (2)	C2—N1—Ni1—O1Wi	88.16 (16)
C4—C5—N1—C2	−0.7 (3)	C5—N1—Ni1—O1Wi	−91.1 (2)
C4—C5—N1—Ni1	178.57 (17)	C2—N1—Ni1—O1W	−91.84 (16)
C5—C4—N2—C3	0.4 (3)	C5—N1—Ni1—O1W	88.9 (2)

Symmetry code: (i) −x+1, −y+1, −z+2.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1W—H1A···O2Wi	0.83 (3)	1.97 (3)	2.789 (3)	169 (3)
O1W—H1B···O1ii	0.75 (3)	1.94 (3)	2.690 (3)	176 (4)
N3—H1N···O2Wiii	0.86	2.27	3.117 (3)	168
O2W—H2A···O2Wiv	0.77 (3)	2.12 (3)	2.867 (3)	164 (4)
O2W—H2B···N2v	0.78 (3)	2.03 (3)	2.792 (3)	168 (3)
N3—H2N···O2	0.86	2.10	2.733 (3)	130
N3—H2N···O2vi	0.86	2.20	2.871 (3)	135
C5—H5···O1Wvii	0.93	2.54	3.377 (4)	150

Symmetry codes: (i) −x+1, −y+1, −z+2; (ii) −x+1, −y, −z+2; (iii) −x, −y+1, −z+2; (iv) −x, y−1/2, −z+3/2; (v) x, −y+3/2, z−1/2; (vi) −x, −y, −z+2; (vii) x, y+1, z.