μ-Aqua-κ2O:O-di-μ-4-methyl­benzoato-κ4O:O′-bis­[(4-methyl­benzoato-κO)(1,10-phenanthroline-κ2N,N′)nickel(II)]

Song, W.-D.; Yan, J.-B.; Hao, X.-M.

doi:10.1107/S1600536808017285

μ-Aqua-κ²O:O-di-μ-4-methylbenzoato-κ⁴O:O′-bis[(4-methylbenzoato-κO)(1,10-phenanthroline-κ²N,N′)nickel(II)]

In the title dinuclear complex, [Ni₂(C₈H₇O₂)₄(C₁₂H₈N₂)₂(H₂O)], each Ni^II atom is six-coordinated by three carboxylate O atoms from three 4-methylbenzoate ligands, two N atoms from two 1,10-phenanthroline ligands, and one μ₂-bridging aqua ligand. The dimeric complex is located on a crystallographic twofold axis and each Ni atom displays a distorted octahedral coordination geometry. The crystal structure is stabilized via intramolecular hydrogen bonding of the bridging water molecule and the uncoordinated carboxylate O atoms, and by C—H

O and π–π stacking interactions [centroid–centroid distances between neighbouring phenanthroline ring systems and between the benzene ring of a 4-methylbenzoate unit and a phenanthroline ring system are 3.662 (2) and 3.611 (3) Å, respectively].

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Supporting information

	Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536808017285/zl2119sup1.cif Contains datablocks I, global
	Structure factor file (CIF format) https://doi.org/10.1107/S1600536808017285/zl2119Isup2.hkl Contains datablock I

CCDC reference: 696428

checkCIF report

Key indicators

Single-crystal X-ray study
T = 296 K
Mean (C-C) = 0.005 Å
R factor = 0.044
wR factor = 0.118
Data-to-parameter ratio = 15.7

checkCIF/PLATON results

No syntax errors found



Alert level C
ABSTM02_ALERT_3_C  The ratio of expected to reported Tmax/Tmin(RR') is < 0.90
            Tmin and Tmax reported:      0.612     0.801
            Tmin(prime) and Tmax expected:      0.736     0.801
            RR(prime) =      0.832
            Please check that your absorption correction is appropriate.
PLAT220_ALERT_2_C Large Non-Solvent    C     Ueq(max)/Ueq(min) ...       2.75 Ratio
PLAT061_ALERT_4_C Tmax/Tmin Range Test RR' too Large .............       0.83
PLAT180_ALERT_4_C Check Cell Rounding: # of Values Ending with 0 =          3
PLAT194_ALERT_1_C Missing _cell_measurement_reflns_used datum ....          ?
PLAT731_ALERT_1_C Bond    Calc     0.83(3), Rep   0.830(10) ......       3.00 su-Ra
              O1W  -H1W     1.555   1.555
PLAT735_ALERT_1_C D-H     Calc     0.83(3), Rep   0.830(10) ......       3.00 su-Ra
              O1W  -H1W     1.555   1.555
PLAT736_ALERT_1_C H...A   Calc     1.75(3), Rep   1.746(12) ......       2.50 su-Ra
              H1W  -O2      1.555   2.555

Alert level G
PLAT860_ALERT_3_G Note: Number of Least-Squares Restraints .......          1

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

   4 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   1 ALERT type 2 Indicator that the structure model may be wrong or deficient
   2 ALERT type 3 Indicator that the structure quality may be low
   2 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

Comment top

In the structural investigation of 4-methylbenzoate complexes, it has been found that 4-methylbenzoic acid can function as a multidentate ligand [Song et al. (2007); Li et al. (2003); Li et al. (2004); Geetha et al. (1999)], with versatile binding and coordination modes. In this paper, we report the crystal structure of the title compound, (I), a new Ni complex obtained by the reaction of 4-methylbenzoic acid, 1,10-phenanthroline and nickel chloride in alkaline aqueous solution.

As illustrated in Figure 1, each Ni^II atom, lies on a crystallographic two fold axis, and has a distorted octahedral geometry with the six coordinating atoms being three carboxyl O atoms from two µ₂-bridging 4-methylbenzoate ligands and one 4-methylbenzoate ligand, two N atoms from two 1,10-phenanthroline ligands, and one µ₂-bridging aqua ligand. Therefore, the O1W water molecule bridges both Ni atoms [Ni1···O1W···Ni2ⁱ 110.40 (11)°, symmetry code i = -x, y, -z+1/2] and with a Ni···Niⁱ distance of 3.449 (3) Å. This value is similar to that observed for a binuclear pivalate complexes with a bridging water molecule Ni₂L₄(µ-OH₂)(µ-OOCCMe₃)₂(OOCCMe₃)₂, (L₂=Py₂, (3,4-lutidine)₂, (N-nitroxyethylnicotinamide)₂, Dipy) [Eremenko et al. (1999)], for which ferromagnetic spin exchange was observed. The Ni···O1W distance is 2.100 (14) Å which is a little shorter than that in other similar complexes [Sung et al., 2000; Novak et al., 2005], suggesting their non-negligible interactions.

The interactions of the structural components are governed by O—H···O hydrogen bonds, C—H···O interactions (Table 1) and by two types of π-π stacking interactions between two closeby phenantroline rings and between a phenyl ring of a 4-methylbenzoate unit and a phenantroline unit. The centroid to centroid distances for the further π-π stacking interaction is 3.662 (2) Å [symmetry code = x, -y, z-1/2], that of the latter 3.611 (3) Å [symmetry code = 1/2-x, 1/2-y, 1-z], respectively, thus indicating weak π-π stacking interactions (Fig. 2).

Related literature top

For the coordination chemistry of 4-methyl benzoate complexes see: Song et al. (2007); Li et al. (2003, 2004); Geetha et al. (1999). For related complexes, see: Eremenko et al. (1999), Sung et al. (2000); Novak et al. (2005).

Experimental top

A mixture of nickel chloride (1 mmol), 4-methylbenzate (1 mmol), 1,10-phenanthroline (1 mmol), NaOH (1.5 mmol) and H₂O (12 ml) was placed in a 23 ml Teflon reactor, which was heated to 433 K for three days and then cooled to room temperature at a rate of 10 K h^-1. The crystals obtained were washed with water and dryed in air.

Computing details top

Data collection: APEX2 (Bruker, 2004); cell refinement: SAINT (Bruker, 2004); data reduction: SAINT (Bruker, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: XP in SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top

	Fig. 1. The structure of (I), showing the atomic numbering scheme. Non-H atoms are shown as 30% probability displacement ellipsoids. Symmetry code i = -x, y, -z+1/2.
	Fig. 2. A packing view of the title compound. The purple spheres represent ring centroids involved in π-π stacking interactions (blue dashed lines). The green dashed lines represent C—H···O and O—H···O hydrogen bonds.

µ-aqua-κ²O:O-di-µ-4-methylbenzoatoκ⁴O:O'-bis[(4-methylbenzoato- κO)(1,10-phenanthroline-κ²N,N')nickel(II)] top

Crystal data top

[Ni₂(C₈H₇O₂)₄(C₁₂H₈N₂)₂(H₂O)]	Z = 4
M_r = 1036.39	F(000) = 2152
Monoclinic, C2/c	D_x = 1.442 Mg m⁻³
Hall symbol: -C 2yc	Mo Kα radiation, λ = 0.71073 Å
a = 23.4180 (6) Å	θ = 1.3–28.0°
b = 15.4595 (4) Å	µ = 0.85 mm⁻¹
c = 15.6140 (3) Å	T = 296 K
β = 122.351 (1)°	Block, blue
V = 4775.4 (2) Å³	0.35 × 0.32 × 0.26 mm

Data collection top

Bruker APEXII area-detector diffractometer	5125 independent reflections
Radiation source: fine-focus sealed tube	3585 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.077
ϕ and ω scans	θ_max = 27.0°, θ_min = 1.7°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −29→29
T_min = 0.612, T_max = 0.801	k = −19→18
23989 measured reflections	l = −19→19

Refinement top

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)] = 0.043	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.117	H atoms treated by a mixture of independent and constrained refinement
S = 1.08	w = 1/[σ²(F_o²) + (0.0505P)² + 0.0814P] where P = (F_o² + 2F_c²)/3
5125 reflections	(Δ/σ)_max = 0.001
326 parameters	Δρ_max = 0.40 e Å⁻³
1 restraint	Δρ_min = −0.49 e Å⁻³

Crystal data top

[Ni₂(C₈H₇O₂)₄(C₁₂H₈N₂)₂(H₂O)]	V = 4775.4 (2) Å³
M_r = 1036.39	Z = 4
Monoclinic, C2/c	Mo Kα radiation
a = 23.4180 (6) Å	µ = 0.85 mm⁻¹
b = 15.4595 (4) Å	T = 296 K
c = 15.6140 (3) Å	0.35 × 0.32 × 0.26 mm
β = 122.351 (1)°

Data collection top

Bruker APEXII area-detector diffractometer	5125 independent reflections
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	3585 reflections with I > 2σ(I)
T_min = 0.612, T_max = 0.801	R_int = 0.077
23989 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.043	1 restraint
wR(F²) = 0.117	H atoms treated by a mixture of independent and constrained refinement
S = 1.08	Δρ_max = 0.40 e Å⁻³
5125 reflections	Δρ_min = −0.49 e Å⁻³
326 parameters

Special details top

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
Ni1	0.045434 (16)	0.85690 (2)	0.38073 (2)	0.03319 (13)
C1	0.09421 (15)	1.00994 (18)	0.5312 (2)	0.0456 (7)
H1	0.0520	1.0348	0.4882	0.055*
C2	0.14290 (18)	1.0573 (2)	0.6149 (2)	0.0573 (8)
H2	0.1330	1.1122	0.6277	0.069*
C3	0.20514 (18)	1.0217 (2)	0.6776 (2)	0.0588 (9)
H3	0.2383	1.0529	0.7330	0.071*
C4	0.21914 (15)	0.9386 (2)	0.6588 (2)	0.0505 (8)
C5	0.28260 (17)	0.8954 (3)	0.7205 (3)	0.0660 (10)
H5	0.3179	0.9244	0.7757	0.079*
C6	0.29252 (16)	0.8141 (3)	0.7008 (2)	0.0653 (10)
H6	0.3343	0.7879	0.7430	0.078*
C7	0.23985 (14)	0.7668 (2)	0.6159 (2)	0.0491 (8)
C8	0.24653 (16)	0.6815 (2)	0.5925 (3)	0.0573 (9)
H8	0.2869	0.6518	0.6331	0.069*
C9	0.19382 (17)	0.6424 (2)	0.5102 (3)	0.0569 (8)
H9	0.1973	0.5850	0.4955	0.068*
C10	0.13391 (15)	0.68918 (19)	0.4475 (2)	0.0480 (7)
H10	0.0986	0.6623	0.3902	0.058*
C11	0.17777 (13)	0.80871 (18)	0.55122 (19)	0.0408 (7)
C12	0.16736 (14)	0.89602 (19)	0.5737 (2)	0.0413 (6)
C13	−0.03124 (13)	0.72317 (18)	0.4141 (2)	0.0382 (6)
C14	−0.04880 (13)	0.68008 (18)	0.4834 (2)	0.0400 (6)
C15	−0.05758 (15)	0.59133 (19)	0.4793 (2)	0.0492 (7)
H15	−0.0538	0.5590	0.4324	0.059*
C16	−0.07204 (18)	0.5503 (2)	0.5444 (3)	0.0593 (9)
H16	−0.0767	0.4904	0.5415	0.071*
C17	−0.07961 (17)	0.5960 (2)	0.6133 (3)	0.0608 (9)
C18	−0.07257 (18)	0.6851 (2)	0.6154 (3)	0.0650 (9)
H18	−0.0786	0.7177	0.6601	0.078*
C19	−0.05673 (16)	0.7264 (2)	0.5519 (2)	0.0526 (8)
H19	−0.0514	0.7862	0.5555	0.063*
C20	−0.0955 (2)	0.5511 (3)	0.6843 (3)	0.0894 (13)
H20A	−0.0833	0.5882	0.7409	0.134*
H20B	−0.0703	0.4982	0.7082	0.134*
H20C	−0.1430	0.5385	0.6489	0.134*
C21	0.07639 (13)	0.96624 (16)	0.2598 (2)	0.0345 (6)
C22	0.11522 (13)	1.04903 (17)	0.2811 (2)	0.0372 (6)
C23	0.17742 (15)	1.0578 (2)	0.3710 (2)	0.0522 (8)
H23	0.1939	1.0137	0.4189	0.063*
C24	0.21486 (18)	1.1324 (2)	0.3892 (3)	0.0652 (10)
H24	0.2571	1.1369	0.4488	0.078*
C25	0.19139 (19)	1.1998 (2)	0.3216 (3)	0.0600 (9)
C26	0.12895 (18)	1.19063 (19)	0.2329 (3)	0.0562 (8)
H26	0.1119	1.2356	0.1861	0.067*
C27	0.09145 (15)	1.11616 (18)	0.2125 (2)	0.0446 (7)
H27	0.0498	1.1112	0.1520	0.054*
C28	0.2333 (2)	1.2813 (2)	0.3433 (3)	0.0947 (15)
H28A	0.2293	1.3171	0.3901	0.142*
H28B	0.2172	1.3124	0.2812	0.142*
H28C	0.2798	1.2658	0.3722	0.142*
N1	0.10564 (11)	0.93089 (14)	0.51042 (16)	0.0379 (5)
N2	0.12593 (11)	0.77022 (14)	0.46695 (16)	0.0385 (5)
O1	−0.00788 (10)	0.79909 (12)	0.43632 (15)	0.0443 (5)
O2	−0.04096 (10)	0.68100 (13)	0.33837 (15)	0.0501 (5)
O3	0.10179 (9)	0.90933 (11)	0.32838 (13)	0.0407 (4)
O4	0.02143 (9)	0.95844 (11)	0.17574 (13)	0.0382 (4)
O1W	0.0000	0.77938 (16)	0.2500	0.0367 (6)
H1W	0.0180 (14)	0.7449 (15)	0.231 (2)	0.055*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Ni1	0.0289 (2)	0.0333 (2)	0.03124 (19)	−0.00013 (14)	0.01199 (15)	0.00146 (14)
C1	0.0499 (18)	0.0420 (17)	0.0396 (15)	−0.0063 (13)	0.0203 (15)	−0.0012 (13)
C2	0.073 (2)	0.0460 (19)	0.0487 (18)	−0.0183 (16)	0.0300 (19)	−0.0083 (15)
C3	0.061 (2)	0.064 (2)	0.0419 (17)	−0.0304 (17)	0.0205 (17)	−0.0091 (15)
C4	0.0402 (17)	0.064 (2)	0.0356 (15)	−0.0185 (15)	0.0125 (14)	0.0014 (14)
C5	0.0388 (19)	0.091 (3)	0.0448 (19)	−0.0174 (18)	0.0070 (16)	0.0044 (18)
C6	0.0310 (17)	0.101 (3)	0.0457 (19)	0.0010 (18)	0.0081 (15)	0.0197 (19)
C7	0.0334 (16)	0.067 (2)	0.0442 (17)	0.0057 (14)	0.0190 (14)	0.0181 (15)
C8	0.0416 (19)	0.073 (2)	0.058 (2)	0.0215 (16)	0.0272 (17)	0.0271 (18)
C9	0.054 (2)	0.053 (2)	0.064 (2)	0.0190 (16)	0.0329 (19)	0.0184 (16)
C10	0.0445 (18)	0.0455 (18)	0.0514 (18)	0.0048 (14)	0.0239 (15)	0.0067 (14)
C11	0.0308 (15)	0.0531 (18)	0.0350 (15)	0.0006 (12)	0.0152 (13)	0.0114 (12)
C12	0.0330 (16)	0.0520 (17)	0.0339 (14)	−0.0060 (13)	0.0146 (13)	0.0058 (12)
C13	0.0265 (14)	0.0417 (16)	0.0413 (15)	0.0033 (11)	0.0148 (13)	0.0053 (12)
C14	0.0306 (15)	0.0458 (17)	0.0402 (15)	−0.0008 (12)	0.0166 (13)	0.0048 (12)
C15	0.0525 (19)	0.0475 (19)	0.0493 (18)	−0.0021 (14)	0.0282 (16)	0.0022 (14)
C16	0.073 (2)	0.0474 (19)	0.064 (2)	−0.0109 (16)	0.041 (2)	0.0020 (16)
C17	0.066 (2)	0.065 (2)	0.055 (2)	−0.0126 (17)	0.0349 (19)	0.0052 (16)
C18	0.078 (3)	0.073 (2)	0.062 (2)	−0.0128 (19)	0.049 (2)	−0.0112 (18)
C19	0.058 (2)	0.0500 (18)	0.0551 (19)	−0.0080 (15)	0.0339 (17)	−0.0040 (15)
C20	0.113 (4)	0.099 (3)	0.085 (3)	−0.023 (3)	0.072 (3)	0.006 (2)
C21	0.0323 (15)	0.0353 (15)	0.0360 (14)	−0.0004 (11)	0.0183 (13)	−0.0004 (11)
C22	0.0370 (15)	0.0387 (15)	0.0371 (14)	−0.0039 (12)	0.0206 (13)	−0.0061 (12)
C23	0.0476 (19)	0.0549 (19)	0.0452 (17)	−0.0100 (15)	0.0189 (15)	−0.0063 (14)
C24	0.057 (2)	0.076 (3)	0.054 (2)	−0.0284 (18)	0.0244 (18)	−0.0272 (18)
C25	0.080 (3)	0.051 (2)	0.070 (2)	−0.0269 (17)	0.053 (2)	−0.0229 (17)
C26	0.079 (2)	0.0380 (17)	0.064 (2)	−0.0070 (16)	0.047 (2)	−0.0035 (15)
C27	0.0492 (18)	0.0381 (15)	0.0465 (16)	−0.0061 (13)	0.0256 (15)	−0.0052 (13)
C28	0.128 (4)	0.072 (3)	0.118 (3)	−0.058 (3)	0.088 (3)	−0.047 (2)
N1	0.0359 (13)	0.0400 (13)	0.0321 (11)	−0.0037 (10)	0.0144 (10)	0.0031 (10)
N2	0.0322 (13)	0.0413 (13)	0.0379 (12)	0.0017 (10)	0.0160 (11)	0.0087 (10)
O1	0.0481 (12)	0.0377 (11)	0.0510 (11)	−0.0047 (9)	0.0292 (10)	−0.0003 (9)
O2	0.0545 (13)	0.0541 (13)	0.0440 (11)	−0.0156 (10)	0.0280 (11)	−0.0065 (10)
O3	0.0312 (10)	0.0435 (11)	0.0417 (11)	0.0000 (8)	0.0156 (9)	0.0100 (9)
O4	0.0334 (10)	0.0377 (10)	0.0333 (10)	−0.0050 (8)	0.0110 (9)	−0.0003 (8)
O1W	0.0379 (16)	0.0344 (15)	0.0364 (14)	0.000	0.0190 (13)	0.000

Geometric parameters (Å, º) top

Ni1—O4ⁱ	2.0533 (17)	C14—C15	1.384 (4)
Ni1—O3	2.0546 (17)	C15—C16	1.386 (4)
Ni1—O1	2.0665 (18)	C15—H15	0.9300
Ni1—N1	2.084 (2)	C16—C17	1.375 (4)
Ni1—O1W	2.1001 (14)	C16—H16	0.9300
Ni1—N2	2.108 (2)	C17—C18	1.386 (5)
C1—N1	1.328 (3)	C17—C20	1.513 (4)
C1—C2	1.396 (4)	C18—C19	1.387 (4)
C1—H1	0.9300	C18—H18	0.9300
C2—C3	1.363 (5)	C19—H19	0.9300
C2—H2	0.9300	C20—H20A	0.9600
C3—C4	1.395 (4)	C20—H20B	0.9600
C3—H3	0.9300	C20—H20C	0.9600
C4—C12	1.395 (4)	C21—O4	1.259 (3)
C4—C5	1.433 (5)	C21—O3	1.262 (3)
C5—C6	1.343 (5)	C21—C22	1.501 (3)
C5—H5	0.9300	C22—C27	1.377 (4)
C6—C7	1.437 (4)	C22—C23	1.386 (4)
C6—H6	0.9300	C23—C24	1.382 (4)
C7—C8	1.399 (4)	C23—H23	0.9300
C7—C11	1.408 (4)	C24—C25	1.371 (5)
C8—C9	1.357 (5)	C24—H24	0.9300
C8—H8	0.9300	C25—C26	1.382 (5)
C9—C10	1.408 (4)	C25—C28	1.520 (4)
C9—H9	0.9300	C26—C27	1.378 (4)
C10—N2	1.326 (3)	C26—H26	0.9300
C10—H10	0.9300	C27—H27	0.9300
C11—N2	1.360 (3)	C28—H28A	0.9600
C11—C12	1.448 (4)	C28—H28B	0.9600
C12—N1	1.352 (3)	C28—H28C	0.9600
C13—O2	1.260 (3)	O4—Ni1ⁱ	2.0533 (17)
C13—O1	1.263 (3)	O1W—Ni1ⁱ	2.1001 (14)
C13—C14	1.504 (4)	O1W—H1W	0.830 (10)
C14—C19	1.379 (4)

O4ⁱ—Ni1—O3	91.85 (7)	C16—C15—H15	119.7
O4ⁱ—Ni1—O1	91.01 (7)	C17—C16—C15	121.6 (3)
O3—Ni1—O1	177.14 (7)	C17—C16—H16	119.2
O4ⁱ—Ni1—N1	87.80 (8)	C15—C16—H16	119.2
O3—Ni1—N1	85.72 (8)	C16—C17—C18	117.7 (3)
O1—Ni1—N1	94.35 (8)	C16—C17—C20	121.5 (3)
O4ⁱ—Ni1—O1W	98.37 (7)	C18—C17—C20	120.8 (3)
O3—Ni1—O1W	86.43 (6)	C17—C18—C19	121.0 (3)
O1—Ni1—O1W	93.19 (6)	C17—C18—H18	119.5
N1—Ni1—O1W	170.16 (6)	C19—C18—H18	119.5
O4ⁱ—Ni1—N2	167.39 (8)	C14—C19—C18	120.9 (3)
O3—Ni1—N2	87.68 (8)	C14—C19—H19	119.6
O1—Ni1—N2	89.52 (8)	C18—C19—H19	119.6
N1—Ni1—N2	79.60 (9)	C17—C20—H20A	109.5
O1W—Ni1—N2	94.17 (8)	C17—C20—H20B	109.5
N1—C1—C2	122.7 (3)	H20A—C20—H20B	109.5
N1—C1—H1	118.6	C17—C20—H20C	109.5
C2—C1—H1	118.6	H20A—C20—H20C	109.5
C3—C2—C1	119.0 (3)	H20B—C20—H20C	109.5
C3—C2—H2	120.5	O4—C21—O3	124.9 (2)
C1—C2—H2	120.5	O4—C21—C22	118.2 (2)
C2—C3—C4	120.1 (3)	O3—C21—C22	116.8 (2)
C2—C3—H3	120.0	C27—C22—C23	118.8 (3)
C4—C3—H3	120.0	C27—C22—C21	121.7 (2)
C3—C4—C12	116.9 (3)	C23—C22—C21	119.5 (3)
C3—C4—C5	124.4 (3)	C24—C23—C22	119.8 (3)
C12—C4—C5	118.7 (3)	C24—C23—H23	120.1
C6—C5—C4	121.8 (3)	C22—C23—H23	120.1
C6—C5—H5	119.1	C25—C24—C23	121.8 (3)
C4—C5—H5	119.1	C25—C24—H24	119.1
C5—C6—C7	121.3 (3)	C23—C24—H24	119.1
C5—C6—H6	119.4	C24—C25—C26	117.8 (3)
C7—C6—H6	119.4	C24—C25—C28	120.9 (4)
C8—C7—C11	117.6 (3)	C26—C25—C28	121.3 (4)
C8—C7—C6	124.0 (3)	C27—C26—C25	121.3 (3)
C11—C7—C6	118.4 (3)	C27—C26—H26	119.4
C9—C8—C7	119.7 (3)	C25—C26—H26	119.4
C9—C8—H8	120.2	C22—C27—C26	120.5 (3)
C7—C8—H8	120.2	C22—C27—H27	119.7
C8—C9—C10	119.5 (3)	C26—C27—H27	119.7
C8—C9—H9	120.2	C25—C28—H28A	109.5
C10—C9—H9	120.2	C25—C28—H28B	109.5
N2—C10—C9	122.4 (3)	H28A—C28—H28B	109.5
N2—C10—H10	118.8	C25—C28—H28C	109.5
C9—C10—H10	118.8	H28A—C28—H28C	109.5
N2—C11—C7	122.5 (3)	H28B—C28—H28C	109.5
N2—C11—C12	117.6 (2)	C1—N1—C12	117.7 (2)
C7—C11—C12	119.9 (3)	C1—N1—Ni1	128.51 (19)
N1—C12—C4	123.5 (3)	C12—N1—Ni1	113.21 (18)
N1—C12—C11	116.6 (2)	C10—N2—C11	118.2 (2)
C4—C12—C11	119.9 (3)	C10—N2—Ni1	129.91 (19)
O2—C13—O1	124.9 (2)	C11—N2—Ni1	111.72 (18)
O2—C13—C14	117.7 (2)	C13—O1—Ni1	123.86 (17)
O1—C13—C14	117.4 (2)	C21—O3—Ni1	120.08 (16)
C19—C14—C15	118.2 (3)	C21—O4—Ni1ⁱ	129.80 (16)
C19—C14—C13	122.0 (3)	Ni1—O1W—Ni1ⁱ	110.41 (11)
C15—C14—C13	119.8 (3)	Ni1—O1W—H1W	129 (2)
C14—C15—C16	120.5 (3)	Ni1ⁱ—O1W—H1W	96 (2)
C14—C15—H15	119.7

Symmetry code: (i) −x, y, −z+1/2.

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C1—H1···O4ⁱ	0.93	2.49	3.007 (3)	115
C6—H6···O2ⁱⁱ	0.93	2.52	3.296 (4)	142
C8—H8···O3ⁱⁱⁱ	0.93	2.52	3.379 (4)	153
O1W—H1W···O2ⁱ	0.83 (1)	1.75 (1)	2.560 (2)	166 (3)

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

Experimental details

Crystal data
Chemical formula	[Ni₂(C₈H₇O₂)₄(C₁₂H₈N₂)₂(H₂O)]
M_r	1036.39
Crystal system, space group	Monoclinic, C2/c
Temperature (K)	296
a, b, c (Å)	23.4180 (6), 15.4595 (4), 15.6140 (3)
β (°)	122.351 (1)
V (Å³)	4775.4 (2)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.85
Crystal size (mm)	0.35 × 0.32 × 0.26

Data collection
Diffractometer	Bruker APEXII area-detector diffractometer
Absorption correction	Multi-scan (SADABS; Sheldrick, 1996)
T_min, T_max	0.612, 0.801
No. of measured, independent and observed [I > 2σ(I)] reflections	23989, 5125, 3585
R_int	0.077
(sin θ/λ)_max (Å⁻¹)	0.639

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.043, 0.117, 1.08
No. of reflections	5125
No. of parameters	326
No. of restraints	1
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.40, −0.49

Computer programs: APEX2 (Bruker, 2004), SAINT (Bruker, 2004), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), XP in SHELXTL (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).