Tetra­aqua­bis(pyridine-3-sulfonato-κN)nickel(II)

In the mol­ecule of the title compound, [Ni(C₅H₄NO₃S)₂(H₂O)₄], the Ni^II cation is located on an inversion center and is coordinated by four water mol­ecules and two pyridine-3-sulfonate anions with an NiN₂O₄ distorted octa­hedral geometry. The face-to-face separation of 3.561 (5) Å between parallel pyridine rings indicates the existence of weak π–π stacking between the pyridine rings. The structure also contains inter­molecular O—H...O hydrogen bonding and weak C—H...O hydrogen bonding.

Key indicators

• Single-crystal X-ray study
• T = 295 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.024
• wR factor = 0.065
• Data-to-parameter ratio = 13.3

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S1. Comment

As π-π stacking between aromatic rings plays an important role in electron transfer process in some biological system (Deisenhofer & Michel, 1989), π-π stacking has attracted our much attention in past years (Su & Xu, 2004; Liu et al., 2004; Li et al., 2005). In order to investigate the influence of substituents on aromatic stacking, the title pyridine-sulfate complex has recently prepared and its crystal structure is reported here.

The molecular structure of the title compound is shown in Fig. 1. The Ni^II cation is located in an inversion center and coordinated by four water molecules and two pyridine-3-sulfonate anions with a NiN₂O₄ distorted octahedral geometry (Table 1), similar to the analogue of Zn^II (Walsh & Hathaway, 1980). Partially overlapped arrangement is observed between parallel pyridine rings (Fig. 2). The face-to-face separation of 3.561 (5) Å between parallel pyridine rings is shorter than the van der Waals thickness of an aromatic ring (3.70 Å; Cotton & Wilkinson, 1972), and indicates the existence of weak π–π stacking between the pyridine rings.

The intermolecular O—H···O hydrogen bonding and weak C—H···O hydrogen bonding (Table 2) help to stabilize the crystal structure.

Related literature

For general background, see: Deisenhofer & Michel (1989); Su & Xu (2004); Liu et al. (2004); Li et al. (2005). For a related structure, see: Walsh & Hathaway (1980). For related literature, see: Cotton & Wilkinson (1972).

S2. Experimental

Pyridine-3-sulfonic acid (0.159 g, 1 mmol), Na₂CO₃ (0.053 g, 0.5 mmol), NiCl₂.6H₂O (0.238 g, 1 mmol) were dissolved in a mixture solution of water (8 ml) and ethanol (2 ml). The solution was placed in a 15 ml Teflon-lined stainless steel autoclave under autogenous pressure at 398 K for 75 h and filtered after cooling to room temperature. The blue single crystals of the title compound were obtained from the filtrate after 3 months.

S3. Refinement

Water H atoms were located in a difference Fourier map and refined as riding in as-found relative positions with U_iso(H) = 1.5U_eq(O). Aromatic H atoms were placed in calculated positions with C—H = 0.93 Å and refined in riding mode with U_iso(H) = 1.2U_eq(C).

Computing details

Data collection: PROCESS-AUTO (Rigaku, 1998); cell refinement: PROCESS-AUTO (Rigaku, 1998); data reduction: CrystalStructure (Rigaku/MSC, 2002); program(s) used to solve structure: SIR92 (Altomare et al., 1993); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures

	Fig. 1. The molecular structure of the title compound with 40% probability displacement (arbitrary spheres for H atoms) [symmetry codes: (i)1 - x,1 - y,1 - z].
	Fig. 2. A diagram showing π-π stacking between pyridine rings [symmetry code: (ii) 1 - x,1 - y,-z].

Tetraaquabis(pyridine-3-sulfonato-κN)nickel(II)

Crystal data

[Ni(C5H4NO3S)2(H2O)4]	F(000) = 460
Mr = 447.08	Dx = 1.782 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 5256 reflections
a = 7.5399 (8) Å	θ = 2.8–24.0°
b = 12.6939 (15) Å	µ = 1.47 mm^−1
c = 8.7810 (8) Å	T = 295 K
β = 97.419 (12)°	Prism, blue
V = 833.40 (15) Å^3	0.32 × 0.22 × 0.20 mm
Z = 2

Data collection

Rigaku R-AXIS RAPID IP diffractometer	1524 independent reflections
Radiation source: fine-focus sealed tube	1449 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.019
Detector resolution: 10.0 pixels mm^-1	θmax = 25.4°, θmin = 2.8°
ω scans	h = −9→9
Absorption correction: multi-scan (ABSCOR; Higashi, 1995)	k = −15→15
Tmin = 0.660, Tmax = 0.745	l = −9→10
8877 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.024	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.065	H-atom parameters constrained
S = 1.06	w = 1/[σ^2(Fo^2) + (0.0323P)^2 + 0.5265P] where P = (Fo^2 + 2Fc^2)/3
1524 reflections	(Δ/σ)max < 0.001
115 parameters	Δρmax = 0.29 e Å^−3
0 restraints	Δρmin = −0.37 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
Ni	0.5000	0.5000	0.5000	0.02883 (13)
S	0.45204 (7)	0.75905 (4)	−0.03581 (6)	0.03407 (15)
N1	0.5850 (2)	0.54221 (13)	0.28948 (18)	0.0307 (3)
O1	0.76142 (19)	0.48676 (11)	0.60868 (18)	0.0388 (3)
H1B	0.8326	0.5397	0.5900	0.058*
H1A	0.8182	0.4333	0.5998	0.058*
O2	0.50231 (19)	0.34035 (11)	0.45010 (17)	0.0411 (3)
H2A	0.5076	0.3156	0.3615	0.062*
H2B	0.4194	0.3021	0.4815	0.062*
O3	0.5370 (3)	0.76975 (16)	−0.1732 (2)	0.0687 (6)
O4	0.4828 (2)	0.85025 (12)	0.0624 (2)	0.0554 (5)
O5	0.2658 (2)	0.73019 (12)	−0.06337 (19)	0.0481 (4)
C1	0.7217 (3)	0.49242 (15)	0.2368 (3)	0.0370 (5)
H1	0.7768	0.4372	0.2943	0.044*
C2	0.7839 (3)	0.51907 (18)	0.1020 (3)	0.0452 (5)
H2	0.8783	0.4819	0.0693	0.054*
C3	0.7053 (3)	0.60162 (17)	0.0150 (3)	0.0405 (5)
H3	0.7461	0.6218	−0.0762	0.049*
C4	0.5641 (2)	0.65298 (14)	0.0684 (2)	0.0298 (4)
C5	0.5074 (3)	0.62143 (15)	0.2044 (2)	0.0320 (4)
H5	0.4116	0.6565	0.2384	0.038*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Ni	0.0309 (2)	0.0273 (2)	0.0284 (2)	0.00105 (13)	0.00426 (14)	0.00418 (13)
S	0.0419 (3)	0.0278 (3)	0.0317 (3)	0.0027 (2)	0.0018 (2)	0.00399 (19)
N1	0.0329 (8)	0.0290 (8)	0.0302 (8)	0.0016 (7)	0.0037 (6)	0.0034 (7)
O1	0.0336 (7)	0.0355 (8)	0.0467 (9)	0.0018 (6)	0.0031 (6)	0.0056 (6)
O2	0.0512 (9)	0.0328 (8)	0.0409 (8)	−0.0017 (6)	0.0122 (7)	−0.0002 (6)
O3	0.0861 (14)	0.0758 (13)	0.0491 (11)	0.0261 (11)	0.0269 (10)	0.0305 (9)
O4	0.0591 (10)	0.0297 (8)	0.0707 (11)	0.0048 (7)	−0.0174 (8)	−0.0095 (8)
O5	0.0441 (9)	0.0358 (8)	0.0600 (10)	0.0039 (7)	−0.0103 (7)	−0.0022 (7)
C1	0.0360 (11)	0.0328 (11)	0.0417 (12)	0.0064 (8)	0.0034 (9)	0.0061 (8)
C2	0.0417 (12)	0.0431 (12)	0.0542 (14)	0.0126 (10)	0.0188 (10)	0.0065 (10)
C3	0.0455 (12)	0.0393 (11)	0.0395 (12)	0.0036 (9)	0.0154 (9)	0.0055 (9)
C4	0.0337 (9)	0.0255 (9)	0.0295 (10)	−0.0002 (7)	0.0016 (8)	0.0005 (7)
C5	0.0333 (9)	0.0314 (10)	0.0313 (10)	0.0041 (8)	0.0047 (8)	0.0004 (8)

Geometric parameters (Å, º)

Ni—O1^i	2.0828 (14)	O1—H1B	0.8886
Ni—O1	2.0828 (14)	O1—H1A	0.8115
Ni—O2^i	2.0739 (14)	O2—H2A	0.8450
Ni—O2	2.0739 (14)	O2—H2B	0.8642
Ni—N1^i	2.1026 (16)	C1—C2	1.370 (3)
Ni—N1	2.1026 (16)	C1—H1	0.9300
S—O5	1.4412 (16)	C2—C3	1.384 (3)
S—O3	1.4438 (18)	C2—H2	0.9300
S—O4	1.4445 (16)	C3—C4	1.381 (3)
S—C4	1.7788 (19)	C3—H3	0.9300
N1—C1	1.341 (3)	C4—C5	1.379 (3)
N1—C5	1.341 (2)	C5—H5	0.9300
O2^i—Ni—O2	180.0	C5—N1—Ni	121.36 (13)
O2^i—Ni—O1^i	89.12 (6)	Ni—O1—H1B	114.4
O2—Ni—O1^i	90.88 (6)	Ni—O1—H1A	120.2
O2^i—Ni—O1	90.88 (6)	H1B—O1—H1A	106.0
O2—Ni—O1	89.12 (6)	Ni—O2—H2A	124.1
O1^i—Ni—O1	180.0	Ni—O2—H2B	117.1
O2^i—Ni—N1^i	92.95 (6)	H2A—O2—H2B	101.9
O2—Ni—N1^i	87.05 (6)	N1—C1—C2	123.07 (19)
O1^i—Ni—N1^i	92.61 (6)	N1—C1—H1	118.5
O1—Ni—N1^i	87.39 (6)	C2—C1—H1	118.5
O2^i—Ni—N1	87.05 (6)	C1—C2—C3	119.6 (2)
O2—Ni—N1	92.95 (6)	C1—C2—H2	120.2
O1^i—Ni—N1	87.39 (6)	C3—C2—H2	120.2
O1—Ni—N1	92.61 (6)	C4—C3—C2	117.6 (2)
N1^i—Ni—N1	180.0	C4—C3—H3	121.2
O5—S—O3	114.30 (12)	C2—C3—H3	121.2
O5—S—O4	112.45 (10)	C5—C4—C3	119.71 (18)
O3—S—O4	111.67 (12)	C5—C4—S	119.06 (14)
O5—S—C4	106.36 (9)	C3—C4—S	121.23 (15)
O3—S—C4	105.58 (10)	N1—C5—C4	122.60 (18)
O4—S—C4	105.69 (9)	N1—C5—H5	118.7
C1—N1—C5	117.40 (17)	C4—C5—H5	118.7
C1—N1—Ni	121.22 (13)

Symmetry code: (i) −x+1, −y+1, −z+1.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1A···O3^ii	0.81	2.39	3.162 (3)	158
O1—H1A···O4^ii	0.81	2.44	3.119 (2)	142
O1—H1B···O4^iii	0.89	1.83	2.722 (2)	177
O2—H2A···O3^iv	0.84	1.97	2.787 (2)	163
O2—H2B···O5^v	0.86	1.89	2.748 (2)	174
C1—H1···O4^ii	0.93	2.34	3.212 (3)	155

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