Tetra­aqua(2,2'-bi­pyridine)­nickel(II) terephthalate

The reaction of nickel(II) nitrate with terephthalic acid and 2,2'-bi­pyridine in di­methyl­form­amide solution gives the title complex, [Ni(C₁₀H₈N₂)(H₂O)₄](C₈H₄O₄). The Ni^II ion is octahedrally coordinated to one 2,2'-bi­pyridine and four water mol­ecules and does not coordinate to the terephthalate anion. Hydro­gen bonds between the terephthalate anions and the [Ni(2,2'-bipy)(H₂O)₄]²⁺ cations produce a two-dimensional hydrogen-bonding architecture with double sheets.

S1. Comment

In recent years, significant research effort has been focused on coordination polymers, due to their potential applications in catalysis, ion exchange and gas adsorption (Eddaoudi et al., 2002; Moulton & Zaworotko, 2001) and popular bridging ligands in this field are terephthalic acid (H₂ta), 4,4'-bipyridine and their derivatives (Eddaoudi et al., 2001). Numerous complexes with the ta²⁻ ligand have been extensively studied, while new complexes are continuously being synthesized. Although the ta²⁻ ligand has many coordination modes, reports of complexes with terephthalate used as a synthon to generate supramolecular networks are still relatively rare (Allen et al., 1999; Burrows et al.,1996, 1997). We report here an example of ta²⁻ as a hydrogen-bonding linker in the presence of N-donor ligands. The title compound, (I), consists of an [Ni(H₂O)₄(2,2'-bipy)]²⁺ cation and a terephthalate anion. The geometry around the Ni^II ion is best described as distorted octahedral, and it associates with four water O atoms and two N atoms from one 2,2'-bipyridine ligand (Fig. 1). It should be pointed out that ta²⁻ is a free ligand and does not coordinate to the Ni atom, although IR indicates that the ta²⁻ ligand has a bridging coordination mode (Rogan et al., 2000).

The cations and anions of (I) form a two-dimensional hydrogen-bonding network (Fig. 2). Each cation, simplified as [Ni(H₂O)₄]²⁺, is linked to six terephthalate anions through hydrogen bonds (Fig. 3a), in which four of the six terephthate anions are from one sheet of the two-dimensional network and the remaining two are from another sheet. Each terephthate anion is in turn linked to six [Ni(H₂O)₄]²⁺ cations through hydrogen bonds (Fig. 3 b), four of which are from one sheet of the two-dimensional network and the remaining two are from another sheet. Each terephthalate carboxylate group is linked to three [Ni(H₂O)₄]²⁺ cations. There are two hydrogen bonds between terephthalate atom O2 and two [Ni(H₂O)₄]²⁺ cations from the same sheet. The second carboxylate O atom, O1, forms hydrogen bonds with two [Ni(H₂O)₄]²⁺ cations from different sheets. Therefore, each terephthalate anion forms eight hydrogen bonds with [Ni(H₂O)₄]²⁺ cations, which results in a two-dimensional hydrogen-bonding network with double sheets.

S2. Experimental

A solution (10 ml) of dimethylformamide containing Ni(NO₃)₂·6H₂O (0.5 mmol) and H₂ta (0.5 mmol, 0.083 g) was added slowly to a solution (10 ml) of dimethylformamide containing 2,2'-bipyridine (0.5 mmol). The starting mixture was stirred for a few minutes and left to stand at room temperature for about one month. Green block-shaped crystals of (I) were obtained. Analysis calculated for C₁₈H₂₀N₂NiO₈: C 47.93, H 4.47, N 6.21%; found: C 47.58, H 4.84, N 6.63%.

S3. Refinement

H atoms bonded to C atoms were treated as riding atoms, with a C—H distance of 0.93 Å.

Computing details

Data collection: SMART (Bruker, 1997); cell refinement: SMART; data reduction: SAINT (Bruker, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXP97 (Sheldrick, 1997); software used to prepare material for publication: SHELXTL (Bruker, 1997).

Figures

	Fig. 1. View of the title compound, showing the atom-labelling scheme and displacement ellipsoids at the 50% probability level.
	Fig. 2. Stereoview of the two-dimensional hydrogen-bonding network in (I).
	Fig. 3. The hydrogen bonds formed (a) by the cations [symmetry codes: (A) 1 + x, y, −1 + z; (B) x, 1.5 − y, −0.5 + z; (C) 1 + x, y, z; (D) 1 + x, 1.5 − y, −0.5 + z; (E) x, y, −1 + z] and (b) by the anion [symmetry codes: (A) x, 1.5 − y, 0.5 + z; (B) −1 + x, y, z; (C) −1 + x, y, 1 + z; (D) x, y, 1 + z; (E) 1 + x, 1.5 − y, 0.5 + z]. The 2,2-bipyridine ligand has been omitted for clarity.

(I)

Crystal data

[Ni(C10H8N2)(H2O)4](C8H4O4)	F(000) = 936
Mr = 451.07	Dx = 1.555 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from all data reflections
a = 7.5503 (2) Å	θ = same as data collection–same as data collection°
b = 23.5347 (9) Å	µ = 1.06 mm^−1
c = 11.1050 (4) Å	T = 293 K
β = 102.427 (2)°	Block, green
V = 1927.06 (11) Å^3	0.40 × 0.20 × 0.20 mm
Z = 4

Data collection

Bruker SMART CCD area-detector diffractometer	5600 independent reflections
Radiation source: fine-focus sealed tube	3567 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.045
ϕ and ω scans	θmax = 30.0°, θmin = 2.1°
Absorption correction: empirical (using intensity measurements) multi-scan	h = −10→10
Tmin = 0.611, Tmax = 0.810	k = −33→13
15571 measured reflections	l = −15→15

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)] = 0.048	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.126	H atoms treated by a mixture of independent and constrained refinement
S = 0.95	w = 1/[σ^2(Fo^2) + (0.068P)^2] where P = (Fo^2 + 2Fc^2)/3
5600 reflections	(Δ/σ)max = 0.001
294 parameters	Δρmax = 1.62 e Å^−3
8 restraints	Δρmin = −0.72 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.

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

	x	y	z	Uiso*/Ueq
Ni1	0.71544 (4)	0.862855 (13)	0.77665 (3)	0.02045 (10)
O1W	0.6789 (3)	0.80687 (9)	0.63470 (18)	0.0312 (4)
O2W	0.9928 (3)	0.85901 (10)	0.78807 (18)	0.0351 (5)
O3W	0.7289 (3)	0.79944 (9)	0.90265 (19)	0.0363 (5)
O4W	0.4351 (3)	0.86702 (9)	0.76326 (17)	0.0326 (4)
O1	0.5513 (2)	0.80045 (8)	1.08351 (16)	0.0320 (4)
O2	0.2999 (3)	0.83491 (10)	0.96353 (16)	0.0391 (5)
O3	0.1284 (3)	0.83785 (10)	1.58399 (16)	0.0384 (5)
O4	−0.1263 (3)	0.80519 (9)	1.46444 (17)	0.0351 (5)
N1	0.7146 (3)	0.93410 (9)	0.66487 (19)	0.0281 (5)
N2	0.7437 (3)	0.92773 (9)	0.90622 (19)	0.0264 (5)
C1	0.7091 (4)	0.93400 (13)	0.5437 (3)	0.0406 (7)
H1	0.6901	0.8998	0.5009	0.080*
C2	0.7308 (5)	0.98348 (16)	0.4795 (3)	0.0539 (9)
H2	0.7246	0.9821	0.3951	0.080*
C3	0.7610 (6)	1.03392 (15)	0.5409 (3)	0.0569 (10)
H3	0.7774	1.0672	0.4995	0.080*
C4	0.7668 (5)	1.03435 (13)	0.6671 (3)	0.0480 (8)
H4	0.7864	1.0681	0.7114	0.080*
C5	0.7431 (4)	0.98376 (12)	0.7260 (2)	0.0310 (6)
C6	0.7487 (4)	0.98055 (11)	0.8611 (2)	0.0302 (6)
C7	0.7591 (5)	1.02833 (13)	0.9363 (3)	0.0470 (8)
H7	0.7639	1.0645	0.9036	0.080*
C8	0.7622 (6)	1.02105 (15)	1.0610 (3)	0.0568 (10)
H8	0.7659	1.0523	1.1127	0.080*
C9	0.7598 (5)	0.96710 (16)	1.1063 (3)	0.0527 (9)
H9	0.7651	0.9612	1.1898	0.080*
C10	0.7494 (4)	0.92127 (13)	1.0269 (2)	0.0370 (7)
H10	0.7462	0.8848	1.0584	0.080*
C11	0.2962 (3)	0.81502 (11)	1.1723 (2)	0.0230 (5)
C12	0.1081 (3)	0.81469 (12)	1.1544 (2)	0.0292 (6)
H12	0.0373	0.8148	1.0747	0.080*
C13	0.0250 (3)	0.81427 (12)	1.2544 (2)	0.0287 (6)
H13	−0.1007	0.8126	1.2413	0.080*
C14	0.1295 (3)	0.81638 (10)	1.3744 (2)	0.0218 (5)
C15	0.3173 (3)	0.81679 (12)	1.3928 (2)	0.0278 (6)
H15	0.3876	0.8184	1.4726	0.080*
C16	0.4011 (3)	0.81489 (12)	1.2933 (2)	0.0290 (6)
H16	0.5270	0.8135	1.3067	0.080*
C17	0.3878 (3)	0.81636 (11)	1.0647 (2)	0.0238 (5)
C18	0.0381 (3)	0.81971 (11)	1.4831 (2)	0.0247 (5)
H1WA	0.651 (5)	0.7725 (9)	0.640 (3)	0.061 (12)*
H1WB	0.755 (4)	0.8087 (16)	0.587 (3)	0.064 (12)*
H2WA	1.029 (5)	0.8474 (15)	0.723 (2)	0.058 (11)*
H2WB	1.060 (4)	0.8476 (15)	0.849 (2)	0.054 (11)*
H3WA	0.666 (4)	0.7980 (14)	0.962 (2)	0.044 (9)*
H3WB	0.763 (6)	0.7655 (9)	0.906 (4)	0.082 (15)*
H4WA	0.363 (5)	0.8552 (16)	0.698 (3)	0.073 (13)*
H4WB	0.394 (4)	0.8535 (13)	0.823 (2)	0.040 (9)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Ni1	0.02102 (16)	0.02244 (16)	0.01970 (15)	−0.00099 (14)	0.00841 (11)	−0.00107 (13)
O1W	0.0370 (11)	0.0310 (11)	0.0311 (10)	−0.0119 (9)	0.0195 (9)	−0.0105 (8)
O2W	0.0212 (9)	0.0616 (14)	0.0239 (9)	0.0041 (9)	0.0078 (8)	−0.0004 (10)
O3W	0.0470 (12)	0.0334 (11)	0.0370 (11)	0.0126 (10)	0.0276 (10)	0.0114 (9)
O4W	0.0228 (9)	0.0520 (13)	0.0242 (9)	−0.0029 (9)	0.0075 (8)	−0.0014 (9)
O1	0.0306 (10)	0.0393 (11)	0.0311 (10)	0.0115 (9)	0.0175 (8)	0.0082 (8)
O2	0.0324 (10)	0.0652 (14)	0.0216 (9)	0.0095 (10)	0.0102 (8)	0.0078 (9)
O3	0.0355 (11)	0.0605 (14)	0.0217 (9)	−0.0127 (10)	0.0116 (8)	−0.0086 (9)
O4	0.0318 (10)	0.0463 (12)	0.0327 (10)	−0.0157 (9)	0.0192 (8)	−0.0122 (9)
N1	0.0312 (11)	0.0265 (11)	0.0282 (11)	0.0007 (9)	0.0099 (9)	0.0025 (9)
N2	0.0275 (11)	0.0290 (11)	0.0245 (10)	−0.0026 (9)	0.0095 (9)	−0.0039 (9)
C1	0.0556 (19)	0.0391 (17)	0.0302 (14)	0.0034 (15)	0.0158 (14)	0.0060 (13)
C2	0.078 (3)	0.051 (2)	0.0381 (17)	0.0023 (19)	0.0253 (18)	0.0129 (15)
C3	0.076 (3)	0.0415 (19)	0.056 (2)	−0.0048 (18)	0.0224 (19)	0.0191 (17)
C4	0.064 (2)	0.0289 (16)	0.0519 (19)	−0.0057 (15)	0.0141 (17)	0.0055 (14)
C5	0.0329 (14)	0.0260 (13)	0.0348 (14)	−0.0011 (11)	0.0087 (12)	0.0022 (11)
C6	0.0295 (13)	0.0263 (14)	0.0359 (14)	−0.0007 (11)	0.0093 (11)	−0.0034 (11)
C7	0.059 (2)	0.0293 (15)	0.0537 (19)	−0.0018 (15)	0.0144 (17)	−0.0115 (14)
C8	0.076 (3)	0.043 (2)	0.053 (2)	−0.0017 (18)	0.0176 (19)	−0.0247 (17)
C9	0.072 (2)	0.057 (2)	0.0319 (16)	−0.0058 (19)	0.0172 (16)	−0.0149 (15)
C10	0.0443 (17)	0.0428 (17)	0.0252 (13)	−0.0038 (14)	0.0106 (12)	−0.0048 (12)
C11	0.0242 (12)	0.0268 (13)	0.0203 (11)	0.0026 (10)	0.0095 (10)	0.0015 (10)
C12	0.0256 (13)	0.0450 (17)	0.0175 (11)	−0.0030 (12)	0.0056 (10)	−0.0025 (11)
C13	0.0208 (12)	0.0413 (16)	0.0260 (12)	−0.0046 (11)	0.0094 (10)	−0.0030 (11)
C14	0.0238 (12)	0.0235 (12)	0.0212 (11)	−0.0026 (10)	0.0116 (9)	−0.0005 (9)
C15	0.0244 (12)	0.0387 (15)	0.0203 (11)	0.0022 (11)	0.0047 (10)	0.0019 (10)
C16	0.0223 (12)	0.0428 (16)	0.0233 (12)	0.0053 (11)	0.0079 (10)	0.0037 (11)
C17	0.0285 (13)	0.0252 (13)	0.0211 (11)	0.0024 (10)	0.0126 (10)	−0.0001 (10)
C18	0.0283 (13)	0.0257 (13)	0.0234 (12)	−0.0034 (10)	0.0128 (10)	−0.0007 (10)

Geometric parameters (Å, º)

Ni1—O1W	2.0273 (19)	C3—C4	1.392 (5)
Ni1—O3W	2.033 (2)	C3—H3	0.9300
Ni1—O2W	2.0725 (19)	C4—C5	1.389 (4)
Ni1—N2	2.077 (2)	C4—H4	0.9300
Ni1—N1	2.085 (2)	C5—C6	1.494 (4)
Ni1—O4W	2.0918 (19)	C6—C7	1.392 (4)
O1W—H1WA	0.842 (18)	C7—C8	1.391 (5)
O1W—H1WB	0.863 (18)	C7—H7	0.9300
O2W—H2WA	0.870 (18)	C8—C9	1.367 (5)
O2W—H2WB	0.800 (18)	C8—H8	0.9300
O3W—H3WA	0.893 (18)	C9—C10	1.384 (4)
O3W—H3WB	0.837 (18)	C9—H9	0.9300
O4W—H4WA	0.853 (18)	C10—H10	0.9300
O4W—H4WB	0.853 (18)	C11—C12	1.392 (3)
O1—C17	1.263 (3)	C11—C16	1.406 (3)
O2—C17	1.254 (3)	C11—C17	1.504 (3)
O3—C18	1.254 (3)	C12—C13	1.387 (4)
O4—C18	1.261 (3)	C12—H12	0.9300
N1—C1	1.337 (3)	C13—C14	1.396 (3)
N1—C5	1.345 (3)	C13—H13	0.9300
N2—C10	1.341 (3)	C14—C15	1.389 (3)
N2—C6	1.343 (3)	C14—C18	1.516 (3)
C1—C2	1.393 (4)	C15—C16	1.387 (4)
C1—H1	0.9300	C15—H15	0.9300
C2—C3	1.363 (5)	C16—H16	0.9300
C2—H2	0.9300
O1W—Ni1—O3W	92.08 (9)	C3—C4—H4	120.4
O1W—Ni1—O2W	89.20 (8)	N1—C5—C4	122.0 (3)
O3W—Ni1—O2W	91.47 (9)	N1—C5—C6	115.5 (2)
O1W—Ni1—N2	173.13 (9)	C4—C5—C6	122.6 (3)
O3W—Ni1—N2	94.61 (9)	N2—C6—C7	121.8 (3)
O2W—Ni1—N2	92.17 (8)	N2—C6—C5	115.1 (2)
O1W—Ni1—N1	94.43 (9)	C7—C6—C5	123.1 (3)
O3W—Ni1—N1	173.25 (9)	C8—C7—C6	119.0 (3)
O2W—Ni1—N1	86.85 (9)	C8—C7—H7	120.5
N2—Ni1—N1	78.93 (9)	C6—C7—H7	120.5
O1W—Ni1—O4W	90.50 (8)	C9—C8—C7	118.8 (3)
O3W—Ni1—O4W	89.03 (8)	C9—C8—H8	120.6
O2W—Ni1—O4W	179.42 (8)	C7—C8—H8	120.6
N2—Ni1—O4W	88.07 (8)	C8—C9—C10	119.5 (3)
N1—Ni1—O4W	92.68 (8)	C8—C9—H9	120.2
Ni1—O1W—H1WA	124 (3)	C10—C9—H9	120.2
Ni1—O1W—H1WB	117 (3)	N2—C10—C9	122.2 (3)
H1WA—O1W—H1WB	108 (4)	N2—C10—H10	118.9
Ni1—O2W—H2WA	117 (2)	C9—C10—H10	118.9
Ni1—O2W—H2WB	121 (3)	C12—C11—C16	119.0 (2)
H2WA—O2W—H2WB	110 (3)	C12—C11—C17	121.1 (2)
Ni1—O3W—H3WA	125 (2)	C16—C11—C17	119.9 (2)
Ni1—O3W—H3WB	135 (3)	C13—C12—C11	120.6 (2)
H3WA—O3W—H3WB	98 (4)	C13—C12—H12	119.7
Ni1—O4W—H4WA	120 (3)	C11—C12—H12	119.7
Ni1—O4W—H4WB	118 (2)	C12—C13—C14	120.3 (2)
H4WA—O4W—H4WB	105 (4)	C12—C13—H13	119.9
C1—N1—C5	118.4 (2)	C14—C13—H13	119.9
C1—N1—Ni1	126.4 (2)	C15—C14—C13	119.3 (2)
C5—N1—Ni1	114.73 (17)	C15—C14—C18	120.5 (2)
C10—N2—C6	118.7 (2)	C13—C14—C18	120.2 (2)
C10—N2—Ni1	125.84 (19)	C16—C15—C14	120.6 (2)
C6—N2—Ni1	115.40 (17)	C16—C15—H15	119.7
N1—C1—C2	122.1 (3)	C14—C15—H15	119.7
N1—C1—H1	118.9	C15—C16—C11	120.1 (2)
C2—C1—H1	118.9	C15—C16—H16	119.9
C3—C2—C1	119.8 (3)	C11—C16—H16	119.9
C3—C2—H2	120.1	O2—C17—O1	124.1 (2)
C1—C2—H2	120.1	O2—C17—C11	118.3 (2)
C2—C3—C4	118.4 (3)	O1—C17—C11	117.5 (2)
C2—C3—H3	120.8	O3—C18—O4	124.5 (2)
C4—C3—H3	120.8	O3—C18—C14	118.4 (2)
C5—C4—C3	119.3 (3)	O4—C18—C14	117.1 (2)
C5—C4—H4	120.4

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1W—H1WA···O1^i	0.84 (2)	1.92 (2)	2.719 (3)	157 (3)
O1W—H1WB···O4^ii	0.86 (2)	1.78 (2)	2.634 (3)	167 (4)
O2W—H2WA···O3^ii	0.87 (2)	1.87 (2)	2.726 (3)	168 (4)
O2W—H2WB···O2^iii	0.80 (2)	2.00 (2)	2.748 (3)	156 (4)
O3W—H3WA···O1	0.89 (2)	1.75 (2)	2.644 (3)	175 (3)
O3W—H3WB···O4^iv	0.84 (2)	1.91 (2)	2.722 (3)	163 (4)
O4W—H4WA···O3^v	0.85 (2)	1.98 (2)	2.795 (3)	158 (4)
O4W—H4WB···O2	0.85 (2)	1.90 (2)	2.745 (3)	171 (3)

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