The ribbon structure of nickel(II) acetate–4,4′-bipyridine

One acetate chelates to an Ni atom and the other bridges two Ni atoms in the title compound, catena-poly[[di-μ-acetato-1κO:2κO′-bis­[(acetato-κ²O,O′)nickel(II)]]-di-μ-4,4′-bipyridine-1κN:1′κN′;2κN:2′κN′], [Ni₂(C₂H₃O₂)₄(C₁₀H₈N₂)₂]_n. The Ni atoms in the centrosymmetric [Ni₂(C₂H₃O₂)₄] arrangement are bridged by the C₁₀H₈N₂ ligands to afford a ribbon structure. The Ni atom, both acetates and the heterocyclic ligand all lie on special positions of m site symmetry.

Key indicators

• Single-crystal X-ray study
• T = 295 K
• Mean [sigma](C-C) = 0.009 Å
• R factor = 0.074
• wR factor = 0.148
• Data-to-parameter ratio = 12.0

checkCIF/PLATON results

No syntax errors found



Alert level B
ABSTM02_ALERT_3_B  The ratio of expected to reported Tmax/Tmin(RR') is < 0.75
            Tmin and Tmax reported:      0.440     0.921
            Tmin(prime) and Tmax expected:      0.855     0.920
            RR(prime) =      0.514
            Please check that your absorption correction is appropriate.
PLAT061_ALERT_3_B Tmax/Tmin Range Test RR' too Large .............       0.51

Alert level C
PLAT220_ALERT_2_C Large Non-Solvent    C     Ueq(max)/Ueq(min) ...       2.79 Ratio
PLAT242_ALERT_2_C Check Low       Ueq as Compared to Neighbors for         C7
PLAT341_ALERT_3_C Low Bond Precision on C-C bonds (x 1000) Ang ...          9
PLAT764_ALERT_4_C Overcomplete CIF Bond List Detected (Rep/Expd) .       1.15 Ratio

   0 ALERT level A = In general: serious problem
   2 ALERT level B = Potentially serious problem
   4 ALERT level C = Check and explain
   0 ALERT level G = General alerts; check

   0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   2 ALERT type 2 Indicator that the structure model may be wrong or deficient
   3 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion

---

S1. Comment

The 4,4'-bipyridine heterocycle has been used in the formation of a large number of metal complexes; in these, the ligand typically functions as a rigid spacer in the resulting linear, layer and network motifs. With nickel(II) carboxylates in particular, the crystallographically authenticated adducts include the 2-methyl-but-2-enedioate (Liao et al., 2001), benzoate (Biradha et al., 1999), phthalate (Yang et al., 2003), benzene-1,2,4,5-tetracarboxylate (Wu et al., 2002), pyridine-2,6-dicarboxylate (Wang et al., 2002) and pyridine-1,3,5-tricarboxylate (Prior et al., 2003). The list now includes the title acetate homologue, (I).

The title adduct of nickel(II) acetate with 4,4'-bipyridine is a centrosymmetric compound in which two acetates function in the bridging mode to two acetate-chelated Ni atoms across a centre of inversion. The planar four-membered Ni—O≐C≐O ring lies on a mirror plane so that the two C—O distances are equivalent. The buckled eight-membered Ni—O≐C≐ O—Ni—O≐C≐O— ring lies on another special position of m site symmetry. The O atoms surrounding the Ni atom comprise a rhombus, and the presence of the N atoms above and below it leads to a distorted octahedral environment for the metal atom (Fig. 1). The mode of coordination of the pair of N-heterocycles gives rise to the formation of a ribbon structure that propagates along the a axis (Fig. 2).

Only few metal acetates of this spacer heterocycle have been reported to date, these being the cobalt(II) derivative, a diaqua compound that crystallizes with both methanol and water (Zhang et al., 1999), and a copper(II) monohydrate that crystallizes in two forms (Castiñeriras et al., 2002; Conerney et al., 2003).

S2. Experimental

Nickel acetate tetrahydrate (0.5 mmol) and 4,4'-bipyridine (0.5 mmol) were dissolved in N,N-dimethylformamide (8 ml). The mixture was placed in a 15 ml Teflon-lined Parr bomb which was then heated at 383 K for 48 h. Blue crystals of (I) were obtained from the cooled solution in about 50% yield.

S3. Refinement

The C-bound H atoms were generated geometrically, with C—H_pyridyl = 0.93 Å and U_iso(H) = 1.2U_eq(C), and C—H_methyl = 0.98 Å and U_iso(H) = 1.5U_eq(C)], and were included in the refinement in the riding-model approximation. The methyl groups were rotated to fit the electron density.

Computing details

Data collection: SMART (Bruker, 2002); cell refinement: SAINT (Bruker, 2002); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPII (Johnson, 1976); software used to prepare material for publication: SHELXL97.

Figures

	Fig. 1. A plot showing the numbering scheme of (I). Displacement ellipsoids are drawn at the 50% probability level and H atoms are shown as small spheres of arbitrary radii. Symmetry codes are as given in Table 1.
	Fig. 2. A plot showing the formation of the ribbon in the unit cell.

catena-poly[[di-µ-acetato-1κO:2κO'-bis[(acetato-κ²O,O')nickel(II)]]- di-µ-4,4'-bipyridine-1κN:1'κN';2κN:2'κN']

Crystal data

[Ni2(C2H3O2)4(C10H8N2)2]	F(000) = 688
Mr = 332.96	Dx = 1.574 Mg m^−3
Orthorhombic, Pnnm	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2 2n	Cell parameters from 416 reflections
a = 11.278 (2) Å	θ = 2.5–19.2°
b = 11.532 (2) Å	µ = 1.40 mm^−1
c = 10.802 (2) Å	T = 295 K
V = 1404.9 (4) Å^3	Block, blue
Z = 4	0.11 × 0.08 × 0.06 mm

Data collection

Bruker APEX CCD area-detector diffractometer	1307 independent reflections
Radiation source: fine-focus sealed tube	975 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.094
ϕ and ω scans	θmax = 25.0°, θmin = 2.5°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −8→13
Tmin = 0.440, Tmax = 0.921	k = −13→9
5686 measured reflections	l = −11→12

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)] = 0.074	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.148	H-atom parameters constrained
S = 1.18	w = 1/[σ^2(Fo^2) + (0.059P)^2 + 0.0628P] where P = (Fo^2 + 2Fc^2)/3
1307 reflections	(Δ/σ)max = 0.001
109 parameters	Δρmax = 0.74 e Å^−3
0 restraints	Δρmin = −0.69 e Å^−3

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

	x	y	z	Uiso*/Ueq	Occ. (<1)
Ni1	0.42858 (9)	0.33337 (9)	0.5000	0.0228 (4)
O1	0.4331 (3)	0.4287 (3)	0.6565 (4)	0.035 (1)
O2	0.4008 (4)	0.1756 (4)	0.6000 (4)	0.038 (1)
N1	0.6137 (6)	0.3129 (6)	0.5000	0.023 (2)
N2	1.2438 (6)	0.3547 (5)	0.5000	0.024 (2)
C1	0.6757 (5)	0.3149 (5)	0.6049 (6)	0.033 (2)
C2	0.7976 (5)	0.3201 (5)	0.6089 (5)	0.032 (2)
C3	0.8609 (7)	0.3278 (7)	0.5000	0.024 (2)
C4	0.9925 (7)	0.3411 (7)	0.5000	0.027 (2)
C5	1.0586 (5)	0.3462 (5)	0.6087 (5)	0.034 (2)
C6	1.1814 (5)	0.3531 (5)	0.6043 (6)	0.034 (2)
C7	0.5000	0.5000	0.7071 (8)	0.028 (2)
C8	0.5000	0.5000	0.8461 (9)	0.066 (3)
C9	0.3849 (7)	0.1241 (7)	0.5000	0.030 (2)
C10	0.3420 (8)	−0.0006 (8)	0.5000	0.060 (3)
H1	0.6345	0.3125	0.6794	0.040*
H2	0.8369	0.3185	0.6846	0.038*
H5	1.0202	0.3451	0.6849	0.040*
H6	1.2225	0.3568	0.6789	0.040*
H8a	0.4328	0.5430	0.8757	0.099*	0.50
H8b	0.5716	0.5354	0.8757	0.099*	0.50
H8c	0.4955	0.4216	0.8757	0.099*	0.50
H10a	0.3963	−0.0477	0.5464	0.090*	0.50
H10b	0.3377	−0.0284	0.4164	0.090*	0.50
H10c	0.2648	−0.0044	0.5373	0.090*	0.50

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Ni1	0.0112 (5)	0.0337 (7)	0.0236 (6)	−0.0011 (5)	0.000	0.000
O1	0.023 (2)	0.046 (3)	0.037 (3)	−0.009 (2)	−0.001 (2)	−0.015 (2)
O2	0.032 (3)	0.047 (3)	0.035 (3)	0.004 (2)	0.0041 (19)	0.006 (2)
N1	0.014 (3)	0.034 (4)	0.021 (4)	−0.002 (3)	0.000	0.000
N2	0.017 (4)	0.029 (4)	0.026 (4)	0.003 (3)	0.000	0.000
C1	0.020 (3)	0.051 (4)	0.028 (4)	0.002 (3)	0.007 (3)	0.005 (3)
C2	0.018 (3)	0.053 (4)	0.024 (3)	0.002 (3)	−0.005 (3)	0.008 (3)
C3	0.014 (4)	0.020 (4)	0.037 (5)	−0.004 (4)	0.000	0.000
C4	0.018 (4)	0.032 (5)	0.030 (5)	0.001 (4)	0.000	0.000
C5	0.018 (3)	0.057 (4)	0.026 (3)	0.001 (3)	0.001 (3)	−0.003 (3)
C6	0.014 (3)	0.055 (4)	0.032 (4)	−0.001 (3)	−0.002 (3)	0.000 (3)
C7	0.013 (5)	0.048 (6)	0.022 (5)	0.012 (4)	0.000	0.000
C8	0.10 (1)	0.076 (8)	0.025 (6)	−0.030 (7)	0.000	0.000
C9	0.014 (4)	0.028 (5)	0.047 (7)	0.007 (4)	0.000	0.000
C10	0.027 (6)	0.040 (7)	0.11 (1)	−0.004 (5)	0.000	0.000

Geometric parameters (Å, º)

Ni1—O1	2.017 (4)	C4—C5^i	1.392 (7)
Ni1—O1^i	2.017 (4)	C5—C6	1.388 (7)
Ni1—O2	2.139 (4)	C7—O1^iii	1.243 (5)
Ni1—O2^i	2.139 (4)	C7—C8	1.50 (1)
Ni1—N1	2.101 (6)	C9—O2^i	1.246 (6)
Ni1—N2^ii	2.099 (6)	C9—C10	1.52 (1)
O1—C7	1.243 (5)	C1—H1	0.93
O2—C9	1.246 (6)	C2—H2	0.93
N1—C1	1.332 (7)	C5—H5	0.93
N1—C1^i	1.332 (7)	C6—H6	0.93
N2—C6^i	1.328 (6)	C8—H8a	0.96
N2—C6	1.328 (6)	C8—H8b	0.96
C1—C2	1.376 (8)	C8—H8c	0.96
C2—C3	1.379 (7)	C10—H10a	0.96
C3—C2^i	1.379 (7)	C10—H10b	0.96
C3—C4	1.49 (1)	C10—H10c	0.96
C4—C5	1.392 (7)
O1—Ni1—O1^i	113.9 (2)	C5^i—C4—C3	122.5 (4)
O1—Ni1—O2	92.5 (2)	C6—C5—C4	120.5 (6)
O1—Ni1—O2^i	152.9 (2)	N2—C6—C5	123.9 (6)
O1—Ni1—N1	92.1 (2)	O1—C7—O1^iii	127.8 (8)
O1—Ni1—N2^ii	87.8 (2)	O1—C7—C8	116.1 (4)
O1^i—Ni1—O2	152.9 (2)	O1^iii—C7—C8	116.1 (4)
O1^i—Ni1—O2^i	92.5 (2)	O2—C9—O2^i	120.2 (8)
O1^i—Ni1—N1	92.1 (2)	O2—C9—C10	119.9 (4)
O1^i—Ni1—N2^ii	87.8 (2)	O2^i—C9—C10	119.9 (4)
O2—Ni1—O2^i	60.7 (2)	N1—C1—H1	118.3
O2—Ni1—N1	92.9 (2)	C2—C1—H1	118.3
O2—Ni1—N2^ii	87.4 (2)	C1—C2—H2	120.2
O2^i—Ni1—N1	92.9 (2)	C3—C2—H2	120.2
O2^i—Ni1—N2^ii	87.4 (2)	C6—C5—H5	119.7
N1—Ni1—N2^ii	179.7 (3)	C4—C5—H5	119.7
C7—O1—Ni1	138.1 (4)	N2—C6—H6	118.0
C9—O2—Ni1	89.4 (4)	C5—C6—H6	118.0
C1—N1—C1^i	116.6 (7)	C7—C8—H8a	109.5
C1—N1—Ni1	121.3 (3)	C7—C8—H8b	109.5
C1^i—N1—Ni1	121.3 (3)	H8a—C8—H8b	109.5
C6^i—N2—C6	116.0 (7)	C7—C8—H8c	109.5
C6^i—N2—Ni1^iv	121.6 (3)	H8a—C8—H8c	109.5
C6—N2—Ni1^iv	121.6 (3)	H8b—C8—H8c	109.5
N1—C1—C2	123.5 (6)	C9—C10—H10a	109.5
C1—C2—C3	119.5 (6)	C9—C10—H10b	109.5
C2^i—C3—C2	117.1 (7)	H10a—C10—H10b	109.5
C2^i—C3—C4	121.5 (4)	C9—C10—H10c	109.5
C2—C3—C4	121.5 (4)	H10a—C10—H10c	109.5
C5—C4—C5^i	115.0 (7)	H10b—C10—H10c	109.5
C5—C4—C3	122.5 (4)
O1^i—Ni1—O1—C7	−59.7 (6)	C1^i—N1—C1—C2	1 (1)
N2^ii—Ni1—O1—C7	−146.2 (5)	Ni1—N1—C1—C2	−169.5 (4)
N1—Ni1—O1—C7	33.5 (5)	N1—C1—C2—C3	2 (1)
O2^i—Ni1—O1—C7	133.9 (5)	C1—C2—C3—C2^i	−5 (1)
O2—Ni1—O1—C7	126.5 (5)	C1—C2—C3—C4	176.1 (6)
O1—Ni1—O2—C9	172.6 (4)	C2^i—C3—C4—C5	−178.4 (7)
O1^i—Ni1—O2—C9	5.0 (6)	C2—C3—C4—C5	0 (1)
N2^ii—Ni1—O2—C9	85.0 (4)	C2^i—C3—C4—C5^i	0 (1)
N1—Ni1—O2—C9	−95.2 (4)	C2—C3—C4—C5^i	178.4 (7)
O2^i—Ni1—O2—C9	−3.5 (5)	C5^i—C4—C5—C6	−2 (1)
O1—Ni1—N1—C1	27.9 (6)	C3—C4—C5—C6	176.9 (6)
O1^i—Ni1—N1—C1	141.9 (6)	C6^i—N2—C6—C5	2 (1)
O2^i—Ni1—N1—C1	−125.4 (6)	Ni1^iv—N2—C6—C5	−168.2 (5)
O2—Ni1—N1—C1	−64.7 (6)	C4—C5—C6—N2	0 (1)
O1—Ni1—N1—C1^i	−141.9 (6)	Ni1—O1—C7—O1^iii	31.6 (4)
O1^i—Ni1—N1—C1^i	−27.9 (6)	Ni1—O1—C7—C8	−148.4 (4)
O2^i—Ni1—N1—C1^i	64.7 (6)	Ni1—O2—C9—O2^i	6.1 (8)
O2—Ni1—N1—C1^i	125.4 (6)	Ni1—O2—C9—C10	−171.8 (7)

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