Bis(4-amino-pyridinium) hexa-aqua-nickel(II) bis-(sulfate).

In the title compound, (C5H7N2)2[Ni(H2O)6](SO4)2, the Ni(II) cation is located on an inversion centre and is coordinated by six aqua ligands in a slightly distorted octa-hedral coordination environment. The [Ni(H2O)6](2+) ions are connected through an extensive network of O-H⋯O hydrogen bonds to sulfate anions, leading to the formation of layers parallel to (001). The 4-amino-pyridinium cations are located between these layers and are connected to the anionic framework by N-H⋯O hydrogen bonds. Weak π-π inter-actions between the pyridine rings, with a centroid-centroid distance of 3.754 (9) Å, provide additional stability to the crystal packing.

Related literature

For applications of metal sulfate complexes, see: Rekik et al. (2008 ▶). For clinical background to 4-amino­pyridine, see: Judge & Bever (2006 ▶); Schwid et al. (1997 ▶); Strupp et al. (2004 ▶). For related compounds, see: Anderson et al. (2005 ▶); Hajlaoui et al. (2011 ▶); Quah et al. (2010 ▶); Rotondo et al. (2009 ▶).

Experimental

Crystal data

(C5H7N2)2[Ni(H2O)6](SO4)2

M = 549.18

Triclinic,

a = 6.212 (2) Å

b = 7.015 (3) Å

c = 12.422 (2) Å

α = 100.61 (3)°

β = 99.26 (2)°

γ = 99.57 (2)°

V = 514.3 (3) Å3

Z = 1

Ag Kα radiation

λ = 0.56085 Å

μ = 0.64 mm−1

T = 293 K

0.30 × 0.20 × 0.20 mm

Data collection

Enraf–Nonius TurboCAD-4 diffractometer

5919 measured reflections

5022 independent reflections

3986 reflections with I > 2σ(I)

R int = 0.014

2 standard reflections every 120 min intensity decay: 5%

Refinement

R[F 2 > 2σ(F 2)] = 0.038

wR(F 2) = 0.097

S = 1.11

5022 reflections

174 parameters

6 restraints

H atoms treated by a mixture of independent and constrained refinement

Δρmax = 0.75 e Å−3

Δρmin = −1.06 e Å−3

Data collection: CAD-4 EXPRESS (Enraf–Nonius, 1994 ▶); cell refinement: CAD-4 EXPRESS; data reduction: XCAD4 (Harms & Wocadlo, 1995 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012 ▶); software used to prepare material for publication: WinGX (Farrugia, 2012 ▶).

Crystal structure: contains datablock(s) I, cad4. DOI: 10.1107/S1600536813032558/wm2787sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536813032558/wm2787Isup2.hkl

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

(C5H7N2)2[Ni(H2O)6](SO4)2	Z = 1
Mr = 549.18	F(000) = 286
Triclinic, P1	Dx = 1.773 Mg m−3
Hall symbol: -P 1	Ag Kα radiation, λ = 0.56085 Å
a = 6.212 (2) Å	Cell parameters from 25 reflections
b = 7.015 (3) Å	θ = 9–11°
c = 12.422 (2) Å	µ = 0.64 mm−1
α = 100.61 (3)°	T = 293 K
β = 99.26 (2)°	Block, blue
γ = 99.57 (2)°	0.30 × 0.20 × 0.20 mm
V = 514.3 (3) Å3

Enraf–Nonius TurboCAD-4 diffractometer	Rint = 0.014
Radiation source: fine-focus sealed tube	θmax = 28.0°, θmin = 2.4°
Graphite monochromator	h = −10→10
ω scans	k = −11→11
5919 measured reflections	l = −2→20
5022 independent reflections	2 standard reflections every 120 min
3986 reflections with I > 2σ(I)	intensity decay: 5%

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)] = 0.038	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.097	H atoms treated by a mixture of independent and constrained refinement
S = 1.11	w = 1/[σ2(Fo2) + (0.0459P)2 + 0.2397P] where P = (Fo2 + 2Fc2)/3
5022 reflections	(Δ/σ)max = 0.001
174 parameters	Δρmax = 0.75 e Å−3
6 restraints	Δρmin = −1.06 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. 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 > 2sigma(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.

	x	y	z	Uiso*/Ueq
Ni1	0.0000	0.0000	0.0000	0.01654 (6)
O1	0.15341 (17)	−0.21342 (15)	−0.07350 (9)	0.02370 (18)
O2	0.28416 (17)	0.11424 (15)	0.12233 (10)	0.0257 (2)
O3	0.10291 (17)	0.16756 (15)	−0.10704 (9)	0.02297 (18)
C1	0.9486 (2)	−0.2906 (2)	0.45752 (12)	0.0243 (2)
N2	0.9660 (3)	−0.1384 (2)	0.68016 (12)	0.0418 (4)
H1	0.9714	−0.0903	0.7496	0.050*
C3	0.7706 (3)	−0.2354 (3)	0.61472 (15)	0.0395 (4)
H3	0.6434	−0.2507	0.6454	0.047*
C5	1.1512 (3)	−0.1901 (2)	0.53005 (15)	0.0316 (3)
H5	1.2830	−0.1752	0.5032	0.038*
C4	1.1524 (3)	−0.1156 (3)	0.63905 (16)	0.0389 (4)
H4	1.2856	−0.0473	0.6861	0.047*
N1	0.9396 (3)	−0.3609 (3)	0.35006 (12)	0.0338 (3)
C2	0.7559 (3)	−0.3115 (3)	0.50454 (13)	0.0305 (3)
H2	0.6191	−0.3773	0.4601	0.037*
H103	0.056 (4)	0.261 (3)	−0.1106 (18)	0.030 (5)*
H203	0.236 (3)	0.205 (3)	−0.1029 (16)	0.023 (4)*
H7	1.061 (5)	−0.333 (4)	0.327 (2)	0.062 (8)*
H6	0.827 (5)	−0.410 (4)	0.307 (2)	0.048 (7)*
S1	0.62063 (5)	0.35433 (4)	0.81367 (3)	0.02033 (7)
O5	0.85539 (16)	0.44487 (16)	0.86606 (11)	0.0306 (2)
O7	0.53371 (17)	0.21768 (17)	0.88249 (10)	0.0295 (2)
O4	0.48753 (19)	0.50858 (17)	0.81131 (13)	0.0354 (3)
O6	0.6085 (2)	0.2407 (2)	0.70136 (11)	0.0420 (3)
H1O1	0.257 (3)	−0.228 (3)	−0.0278 (18)	0.047 (7)*
H2O1	0.065 (4)	−0.327 (3)	−0.098 (2)	0.059 (8)*
H1O2	0.363 (4)	0.225 (2)	0.129 (2)	0.047 (7)*
H2O2	0.367 (3)	0.034 (3)	0.1328 (19)	0.032 (5)*

	U11	U22	U33	U12	U13	U23
Ni1	0.01578 (10)	0.01730 (10)	0.01684 (10)	0.00301 (7)	0.00362 (7)	0.00442 (7)
O1	0.0239 (4)	0.0213 (4)	0.0263 (5)	0.0059 (3)	0.0053 (4)	0.0045 (4)
O2	0.0219 (4)	0.0216 (4)	0.0301 (5)	0.0031 (3)	−0.0012 (4)	0.0038 (4)
O3	0.0195 (4)	0.0242 (4)	0.0287 (5)	0.0051 (3)	0.0078 (4)	0.0113 (4)
C1	0.0253 (6)	0.0268 (6)	0.0222 (6)	0.0068 (5)	0.0044 (5)	0.0081 (5)
N2	0.0545 (10)	0.0452 (8)	0.0222 (6)	0.0137 (7)	0.0035 (6)	−0.0014 (6)
C3	0.0401 (9)	0.0538 (10)	0.0278 (7)	0.0136 (8)	0.0131 (7)	0.0080 (7)
C5	0.0255 (6)	0.0327 (7)	0.0340 (7)	0.0020 (5)	0.0014 (6)	0.0079 (6)
C4	0.0395 (8)	0.0317 (8)	0.0358 (8)	0.0025 (6)	−0.0064 (7)	−0.0006 (6)
N1	0.0303 (6)	0.0498 (8)	0.0217 (6)	0.0093 (6)	0.0061 (5)	0.0071 (6)
C2	0.0256 (6)	0.0398 (8)	0.0253 (6)	0.0043 (6)	0.0061 (5)	0.0064 (6)
S1	0.01526 (12)	0.02018 (13)	0.02486 (15)	0.00201 (10)	0.00201 (10)	0.00623 (11)
O5	0.0164 (4)	0.0257 (5)	0.0454 (7)	−0.0001 (3)	−0.0019 (4)	0.0076 (5)
O7	0.0222 (4)	0.0331 (5)	0.0390 (6)	0.0067 (4)	0.0098 (4)	0.0184 (5)
O4	0.0231 (5)	0.0246 (5)	0.0571 (8)	0.0068 (4)	−0.0024 (5)	0.0124 (5)
O6	0.0400 (7)	0.0518 (8)	0.0275 (6)	0.0023 (6)	0.0070 (5)	−0.0019 (5)

Ni1—O3i	2.0388 (11)	N2—C4	1.336 (3)
Ni1—O3	2.0388 (11)	N2—C3	1.342 (3)
Ni1—O1	2.0578 (12)	N2—H1	0.8600
Ni1—O1i	2.0578 (12)	C3—C2	1.357 (2)
Ni1—O2i	2.0701 (12)	C3—H3	0.9300
Ni1—O2	2.0701 (12)	C5—C4	1.357 (3)
O1—H1O1	0.818 (15)	C5—H5	0.9300
O1—H2O1	0.860 (15)	C4—H4	0.9300
O2—H1O2	0.828 (15)	N1—H7	0.85 (3)
O2—H2O2	0.839 (14)	N1—H6	0.79 (3)
O3—H103	0.77 (2)	C2—H2	0.9300
O3—H203	0.82 (2)	S1—O6	1.4574 (14)
C1—N1	1.324 (2)	S1—O4	1.4686 (12)
C1—C2	1.412 (2)	S1—O5	1.4793 (12)
C1—C5	1.413 (2)	S1—O7	1.4897 (12)
O3i—Ni1—O3	180.00 (5)	C2—C1—C5	117.08 (14)
O3i—Ni1—O1	92.26 (5)	C4—N2—C3	121.02 (15)
O3—Ni1—O1	87.74 (5)	C4—N2—H1	119.5
O3i—Ni1—O1i	87.74 (5)	C3—N2—H1	119.5
O3—Ni1—O1i	92.26 (5)	N2—C3—C2	121.01 (17)
O1—Ni1—O1i	180.00 (7)	N2—C3—H3	119.5
O3i—Ni1—O2i	93.96 (5)	C2—C3—H3	119.5
O3—Ni1—O2i	86.04 (5)	C4—C5—C1	119.69 (16)
O1—Ni1—O2i	89.83 (5)	C4—C5—H5	120.2
O1i—Ni1—O2i	90.17 (5)	C1—C5—H5	120.2
O3i—Ni1—O2	86.04 (5)	N2—C4—C5	121.31 (16)
O3—Ni1—O2	93.96 (5)	N2—C4—H4	119.3
O1—Ni1—O2	90.17 (5)	C5—C4—H4	119.3
O1i—Ni1—O2	89.83 (5)	C1—N1—H7	115.4 (19)
O2i—Ni1—O2	180.00 (7)	C1—N1—H6	123 (2)
Ni1—O1—H1O1	109.7 (18)	H7—N1—H6	121 (3)
Ni1—O1—H2O1	112.7 (19)	C3—C2—C1	119.88 (16)
H1O1—O1—H2O1	107.0 (19)	C3—C2—H2	120.1
Ni1—O2—H1O2	123.5 (17)	C1—C2—H2	120.1
Ni1—O2—H2O2	114.9 (14)	O6—S1—O4	111.02 (9)
H1O2—O2—H2O2	108.4 (18)	O6—S1—O5	109.76 (8)
Ni1—O3—H103	118.3 (16)	O4—S1—O5	110.07 (7)
Ni1—O3—H203	118.9 (13)	O6—S1—O7	108.89 (8)
H103—O3—H203	103.5 (18)	O4—S1—O7	109.07 (8)
N1—C1—C2	121.41 (14)	O5—S1—O7	107.96 (7)
N1—C1—C5	121.51 (14)

D—H···A	D—H	H···A	D···A	D—H···A
N2—H1···O2ii	0.86	2.43	3.102 (2)	136
N2—H1···O3iii	0.86	2.23	2.983 (2)	147
O1—H1O1···O7ii	0.82 (2)	2.03 (2)	2.8231 (16)	163 (2)
O1—H2O1···O5iv	0.86 (2)	1.82 (2)	2.6741 (16)	172 (2)
O2—H1O2···O4v	0.83 (2)	1.90 (2)	2.6952 (17)	161 (2)
O2—H2O2···O7ii	0.84 (2)	1.95 (2)	2.7480 (16)	159 (2)
N1—H6···O4ii	0.80 (3)	2.17 (3)	2.957 (2)	173 (3)
N1—H7···O5vi	0.86 (3)	2.55 (3)	3.153 (2)	129 (2)
N1—H7···O6vi	0.86 (3)	2.15 (3)	2.998 (2)	170 (2)
O3—H103···O5vii	0.77 (2)	1.96 (2)	2.7072 (15)	164 (2)
O3—H203···O7viii	0.815 (19)	1.876 (19)	2.6682 (15)	164 (2)

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N2—H1⋯O2i	0.86	2.43	3.102 (2)	136
N2—H1⋯O3ii	0.86	2.23	2.983 (2)	147
O1—H1O1⋯O7i	0.82 (2)	2.03 (2)	2.8231 (16)	163 (2)
O1—H2O1⋯O5iii	0.86 (2)	1.82 (2)	2.6741 (16)	172 (2)
O2—H1O2⋯O4iv	0.83 (2)	1.90 (2)	2.6952 (17)	161 (2)
O2—H2O2⋯O7i	0.84 (2)	1.95 (2)	2.7480 (16)	159 (2)
N1—H6⋯O4i	0.80 (3)	2.17 (3)	2.957 (2)	173 (3)
N1—H7⋯O5v	0.86 (3)	2.55 (3)	3.153 (2)	129 (2)
N1—H7⋯O6v	0.86 (3)	2.15 (3)	2.998 (2)	170 (2)
O3—H103⋯O5vi	0.77 (2)	1.96 (2)	2.7072 (15)	164 (2)
O3—H203⋯O7vii	0.815 (19)	1.876 (19)	2.6682 (15)	164 (2)

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