Bis(2,2′-bipyridine-κ²N,N′)(croconato-κ²O,O′)nickel(II)

The title compound, [Ni(C₅O₅)(C₁₀H₈N₂)₂], lies across a crystallographic twofold axis, around which two 2,2′-bipyridine (2,2′-bipy) ligands are arranged in a propeller manner. The local geometry of the NiN₄O₂ coordination core basically adopts an octa­hedral geometry. The mol­ecular twofold axis is along the direction of the mol­ecular dipole moment, and the complex is packed with its dipole moment alternately along the +b and −b directions. The crystal structure is stabilized by inter­molecular C—H...O hydrogen bonds.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.004 Å
• R factor = 0.044
• wR factor = 0.102
• Data-to-parameter ratio = 15.4

checkCIF/PLATON results

No syntax errors found



Alert level C
            Value of measurement temperature given =   293.000
            Value of melting point given =     0.000
SHFSU01_ALERT_2_C  Test not performed. _refine_ls_shift/su_max and
            _refine_ls_shift/esd_max not present.
            Absolute value of the parameter shift to su ratio given   0.001
PLAT153_ALERT_1_C The su's on the Cell Axes   are Equal (x 100000)        500 Ang.

Alert level G
PLAT199_ALERT_1_G Check the Reported _cell_measurement_temperature        293 K
PLAT200_ALERT_1_G Check the Reported _diffrn_ambient_temperature .        293 K

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

   3 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
   0 ALERT type 3 Indicator that the structure quality may be low
   0 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

The croconate C₅O₅^2- anion has attracted increasing attention in recent years because this polydentate ligand gave rise to a variety of interesting complexes (Chen et al., 2008; Coronado et al., 2007; Chen et al., 2005; Wang et al., 2002;). Typically, the C₅O₅^2- anion serves as a terminal bidentate chelate ligand or a bridging ligand utilizing more than two O atoms for coordination. We previously reported a mixing-coordinated complex [Ni(C₅O₅)(phen)₂] with 1,10-phenanthroline (phen) as the first ligand and the C₅O₅^2- anion as the second ligand (Chen et al., 2007). The similar chelating behavior of 2,2'-bipy and 1,10-phen prompted us to replace phen ligand by 2,2'-bipy. In this report, the structure of this mixing-coordinated complex is reported.

The title compound crystalizes to the same space group as [Ni(C₅O₅)(phen)₂]. Both crystals have very similar cell parameters and show many common features. The chiral molecule lies across twofold axis which is along the direction of the molecular dipole moment. Around the molecular axis, two 2,2'-bipy ligands are arranged in a propeller manner. The Ni²⁺ is coordinated by four N atoms of the two 2,2'-bipy ligands and two O atoms of a croconate ligand to furnish a slightly distored octahedral NiN₄O₂ coordination core. The dihedral angle between the croconate plane and a 2,2'-bipy plane is 88.7 (1)°, and that between the two 2,2'-bipy planes is 81.9 (1)° in [Ni(C₅O₅) (2,2'-bipy)₂]. These are close to the corresponding dihedral angles (86.9 (1)° and 86.6 (1)°) in [Ni(C₅O₅)(phen)₂]. The C—O bond lengths involving coordinated O atoms are longer than those of other C—O bonds. In both crystals, molecules packed alternately along +b and-b directions.

However, we can not fail to notice some differences between the two crystals. The Ni—O band length of [Ni(C₅O₅)(2,2'-bipy)₂] {2.102 (2) Å} is longer than that {2.098 (3) Å} of [Ni(C₅O₅)(phen)₂]. Meanwhile, the Ni—N band lengths of [Ni(C₅O₅)(2,2'-bipy)₂] {2.059 (2), 2.066 (2) Å} is considerably shorter than those {2.071 (3), 2.088 (3) Å} of [Ni(C₅O₅)(phen)₂]. It seems that 2,2'-bipyridine is a stronger ligand to Ni²⁺ in comparison with 1,10-phenanthroline. The crystal structure is stabilized by intermolecular C—H···O hydrogen bonds (Table 1).

Related literature

For the synthesis, see: Chen et al. (2008). For related structures, see: Chen et al. (2005, 2007). For other related literature, see: Coronado et al. (2007); Wang et al. (2002).

S2. Experimental

[K₂(C₅O₅)] (0.050 g, 0.23 mmol) and NiCl₂.6H₂O (0.060 g, 0.25 mmol) were dissolved in mixed solvent of water (15 ml) and dimethylformamide (10 ml). Then 2,2'-bipy (0.080 g, 0.51 mmol) was added. The mixture was heated to 340–350 K under continuous stirring for 20 min and then filtered. The green-yellow prisms crystals were obtained by slow evaporation at 313 K.

S3. Refinement

All H atoms were positioned geometrically and allowed to ride on their attached atom. The C—H bond lengths for aromatic groups were set to 0.93 Å.

Computing details

Data collection: APEX2 (Bruker, 2005); cell refinement: APEX2 (Bruker, 2005); data reduction: APEX2 (Bruker, 2005); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures

Fig. 1. The molecular structure of [Ni(C5O5) (2,2'-bipy)2]. Displacement ellipsoids are drawn at the 30% probability level and H atoms have been omitted. [symmetry code: (i) -x + 1, y, -z + 3/2.]

Bis(2,2'-bipyridine-κ²N,N')(croconato-κ²O,O')nickel(II)

Crystal data

[Ni(C5O5)(C10H8N2)2]	F(000) = 1048
Mr = 511.13	Dx = 1.577 Mg m^−3
Orthorhombic, Pbcn	Mo Kα radiation, λ = 0.71069 Å
Hall symbol: -P_2n 2ab	Cell parameters from 2518 reflections
a = 12.725 (5) Å	θ = 2.5–23.4°
b = 10.752 (5) Å	µ = 0.95 mm^−1
c = 15.733 (5) Å	T = 293 K
V = 2152.6 (15) Å^3	Prism, green-yellow
Z = 4	0.20 × 0.19 × 0.10 mm

Data collection

Bruker APEXII CCD diffractometer	2466 independent reflections
Radiation source: fine-focus sealed tube	1536 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.089
Detector resolution: 10.0 pixels mm^-1	θmax = 27.5°, θmin = 2.5°
ϕ and ω scans	h = −15→16
Absorption correction: multi-scan (APEX2; Bruker, 2005)	k = −13→10
Tmin = 0.821, Tmax = 0.902	l = −20→19
10055 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)] = 0.044	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.102	H-atom parameters constrained
S = 1.02	w = 1/[σ^2(Fo^2) + (0.0372P)^2 + 0.0108P] where P = (Fo^2 + 2Fc^2)/3
2466 reflections	(Δ/σ)max < 0.001
160 parameters	Δρmax = 0.26 e Å^−3
0 restraints	Δρmin = −0.38 e Å^−3

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq
Ni1	0.5000	0.46011 (4)	0.2500	0.03546 (17)
O1	0.56048 (15)	0.31353 (15)	0.17633 (10)	0.0439 (5)
O2	0.6016 (2)	0.0512 (2)	0.12408 (16)	0.1053 (10)
O3	0.5000	−0.1097 (3)	0.2500	0.0700 (9)
N1	0.45364 (18)	0.58822 (19)	0.34037 (12)	0.0397 (5)
N2	0.63184 (17)	0.46676 (19)	0.32573 (12)	0.0419 (6)
C1	0.3650 (3)	0.6535 (3)	0.34092 (17)	0.0531 (8)
H1	0.3173	0.6410	0.2970	0.064*
C2	0.3402 (3)	0.7384 (3)	0.4029 (2)	0.0717 (10)
H2	0.2774	0.7824	0.4013	0.086*
C3	0.4114 (4)	0.7561 (3)	0.4673 (2)	0.0742 (11)
H3	0.3977	0.8142	0.5097	0.089*
C4	0.5025 (3)	0.6888 (3)	0.46926 (18)	0.0570 (9)
H4	0.5502	0.6989	0.5135	0.068*
C5	0.5226 (2)	0.6052 (2)	0.40425 (15)	0.0406 (7)
C6	0.6200 (2)	0.5320 (2)	0.39824 (16)	0.0431 (7)
C7	0.6964 (3)	0.5264 (3)	0.4613 (2)	0.0638 (9)
H7	0.6872	0.5696	0.5119	0.077*
C8	0.7854 (3)	0.4569 (4)	0.4486 (2)	0.0770 (12)
H8	0.8367	0.4526	0.4906	0.092*
C9	0.7982 (2)	0.3940 (3)	0.3737 (2)	0.0679 (10)
H9	0.8587	0.3479	0.3633	0.081*
C10	0.7195 (2)	0.4008 (3)	0.31437 (19)	0.0575 (8)
H10	0.7276	0.3572	0.2637	0.069*
C11	0.5300 (2)	0.2129 (3)	0.21214 (15)	0.0393 (6)
C12	0.5511 (3)	0.0864 (3)	0.18605 (18)	0.0530 (8)
C13	0.5000	0.0035 (4)	0.2500	0.0487 (10)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Ni1	0.0404 (3)	0.0388 (3)	0.0271 (2)	0.000	−0.0053 (2)	0.000
O1	0.0587 (13)	0.0418 (11)	0.0310 (9)	−0.0040 (10)	0.0083 (9)	0.0013 (8)
O2	0.167 (3)	0.0586 (15)	0.0903 (17)	−0.0026 (15)	0.0769 (19)	−0.0177 (13)
O3	0.086 (2)	0.0405 (17)	0.084 (2)	0.000	0.0118 (18)	0.000
N1	0.0510 (14)	0.0360 (12)	0.0322 (11)	−0.0008 (12)	−0.0020 (11)	0.0015 (10)
N2	0.0437 (14)	0.0480 (14)	0.0340 (12)	0.0003 (12)	−0.0082 (10)	0.0017 (10)
C1	0.064 (2)	0.0507 (18)	0.0443 (16)	0.0138 (17)	0.0003 (16)	0.0011 (14)
C2	0.098 (3)	0.057 (2)	0.060 (2)	0.024 (2)	0.022 (2)	−0.0018 (17)
C3	0.119 (3)	0.048 (2)	0.056 (2)	−0.002 (2)	0.028 (2)	−0.0121 (16)
C4	0.084 (2)	0.0514 (17)	0.0359 (15)	−0.022 (2)	0.0095 (16)	−0.0076 (13)
C5	0.0582 (19)	0.0341 (14)	0.0295 (13)	−0.0130 (14)	0.0012 (12)	0.0026 (11)
C6	0.0535 (18)	0.0442 (16)	0.0317 (14)	−0.0198 (15)	−0.0080 (13)	0.0070 (13)
C7	0.076 (2)	0.068 (2)	0.0482 (18)	−0.023 (2)	−0.0272 (17)	0.0038 (15)
C8	0.065 (2)	0.090 (3)	0.076 (3)	−0.023 (2)	−0.041 (2)	0.033 (2)
C9	0.0442 (18)	0.080 (3)	0.079 (2)	0.0036 (19)	−0.0144 (18)	0.026 (2)
C10	0.0494 (19)	0.067 (2)	0.0555 (19)	0.0078 (18)	−0.0081 (15)	0.0055 (16)
C11	0.0431 (17)	0.0439 (16)	0.0309 (13)	−0.0025 (14)	−0.0005 (11)	−0.0019 (12)
C12	0.066 (2)	0.0462 (17)	0.0463 (17)	−0.0038 (17)	0.0129 (16)	−0.0085 (14)
C13	0.052 (2)	0.042 (2)	0.052 (2)	0.000	0.000 (2)	0.000

Geometric parameters (Å, º)

Ni1—N2	2.059 (2)	C3—C4	1.367 (4)
Ni1—N2^i	2.059 (2)	C3—H3	0.9300
Ni1—N1	2.066 (2)	C4—C5	1.385 (4)
Ni1—N1^i	2.066 (2)	C4—H4	0.9300
Ni1—O1^i	2.1022 (18)	C5—C6	1.472 (4)
Ni1—O1	2.1022 (18)	C6—C7	1.389 (4)
O1—C11	1.280 (3)	C7—C8	1.371 (5)
O2—C12	1.227 (3)	C7—H7	0.9300
O3—C13	1.217 (5)	C8—C9	1.369 (5)
N1—C1	1.328 (3)	C8—H8	0.9300
N1—C5	1.347 (3)	C9—C10	1.370 (4)
N2—C10	1.334 (3)	C9—H9	0.9300
N2—C6	1.347 (3)	C10—H10	0.9300
C1—C2	1.372 (4)	C11—C11^i	1.415 (5)
C1—H1	0.9300	C11—C12	1.446 (4)
C2—C3	1.373 (5)	C12—C13	1.493 (4)
C2—H2	0.9300	C13—C12^i	1.493 (4)
N2—Ni1—N2^i	176.02 (12)	C3—C4—C5	118.9 (3)
N2—Ni1—N1	79.12 (9)	C3—C4—H4	120.6
N2^i—Ni1—N1	98.19 (8)	C5—C4—H4	120.6
N2—Ni1—N1^i	98.19 (8)	N1—C5—C4	121.3 (3)
N2^i—Ni1—N1^i	79.12 (9)	N1—C5—C6	115.4 (2)
N1—Ni1—N1^i	96.35 (11)	C4—C5—C6	123.3 (3)
N2—Ni1—O1^i	90.30 (8)	N2—C6—C7	120.2 (3)
N2^i—Ni1—O1^i	92.68 (8)	N2—C6—C5	115.3 (2)
N1—Ni1—O1^i	90.91 (8)	C7—C6—C5	124.5 (3)
N1^i—Ni1—O1^i	169.72 (7)	C8—C7—C6	119.8 (3)
N2—Ni1—O1	92.68 (8)	C8—C7—H7	120.1
N2^i—Ni1—O1	90.30 (8)	C6—C7—H7	120.1
N1—Ni1—O1	169.72 (7)	C9—C8—C7	119.5 (3)
N1^i—Ni1—O1	90.91 (8)	C9—C8—H8	120.2
O1^i—Ni1—O1	82.88 (10)	C7—C8—H8	120.2
C11—O1—Ni1	106.29 (15)	C8—C9—C10	118.2 (3)
C1—N1—C5	118.5 (2)	C8—C9—H9	120.9
C1—N1—Ni1	126.82 (19)	C10—C9—H9	120.9
C5—N1—Ni1	114.72 (18)	N2—C10—C9	123.2 (3)
C10—N2—C6	118.9 (2)	N2—C10—H10	118.4
C10—N2—Ni1	125.83 (19)	C9—C10—H10	118.4
C6—N2—Ni1	114.66 (19)	O1—C11—C11^i	122.26 (14)
N1—C1—C2	123.5 (3)	O1—C11—C12	127.9 (2)
N1—C1—H1	118.3	C11^i—C11—C12	109.83 (15)
C2—C1—H1	118.3	O2—C12—C11	127.8 (3)
C1—C2—C3	117.7 (3)	O2—C12—C13	125.4 (3)
C1—C2—H2	121.1	C11—C12—C13	106.8 (2)
C3—C2—H2	121.1	O3—C13—C12^i	126.64 (17)
C4—C3—C2	120.2 (3)	O3—C13—C12	126.64 (17)
C4—C3—H3	119.9	C12^i—C13—C12	106.7 (3)
C2—C3—H3	119.9
N2—Ni1—O1—C11	90.49 (17)	C1—N1—C5—C6	−178.6 (2)
N2^i—Ni1—O1—C11	−92.14 (18)	Ni1—N1—C5—C6	1.2 (3)
N1—Ni1—O1—C11	53.7 (5)	C3—C4—C5—N1	−1.0 (4)
N1^i—Ni1—O1—C11	−171.27 (17)	C3—C4—C5—C6	177.3 (3)
O1^i—Ni1—O1—C11	0.52 (13)	C10—N2—C6—C7	−2.5 (4)
N2—Ni1—N1—C1	174.7 (2)	Ni1—N2—C6—C7	169.1 (2)
N2^i—Ni1—N1—C1	−2.3 (2)	C10—N2—C6—C5	178.1 (2)
N1^i—Ni1—N1—C1	77.5 (2)	Ni1—N2—C6—C5	−10.3 (3)
O1^i—Ni1—N1—C1	−95.2 (2)	N1—C5—C6—N2	6.1 (3)
O1—Ni1—N1—C1	−147.8 (4)	C4—C5—C6—N2	−172.3 (2)
N2—Ni1—N1—C5	−5.04 (17)	N1—C5—C6—C7	−173.3 (2)
N2^i—Ni1—N1—C5	177.93 (18)	C4—C5—C6—C7	8.3 (4)
N1^i—Ni1—N1—C5	−102.20 (19)	N2—C6—C7—C8	1.8 (4)
O1^i—Ni1—N1—C5	85.09 (18)	C5—C6—C7—C8	−178.8 (3)
O1—Ni1—N1—C5	32.5 (5)	C6—C7—C8—C9	0.2 (5)
N1—Ni1—N2—C10	179.3 (2)	C7—C8—C9—C10	−1.5 (5)
N1^i—Ni1—N2—C10	−85.7 (2)	C6—N2—C10—C9	1.2 (4)
O1^i—Ni1—N2—C10	88.5 (2)	Ni1—N2—C10—C9	−169.4 (2)
O1—Ni1—N2—C10	5.6 (2)	C8—C9—C10—N2	0.8 (5)
N1—Ni1—N2—C6	8.43 (17)	Ni1—O1—C11—C11^i	−1.5 (4)
N1^i—Ni1—N2—C6	103.37 (17)	Ni1—O1—C11—C12	−179.9 (2)
O1^i—Ni1—N2—C6	−82.44 (17)	O1—C11—C12—O2	−0.7 (5)
O1—Ni1—N2—C6	−165.32 (17)	C11^i—C11—C12—O2	−179.3 (3)
C5—N1—C1—C2	0.6 (4)	O1—C11—C12—C13	178.9 (2)
Ni1—N1—C1—C2	−179.1 (2)	C11^i—C11—C12—C13	0.3 (4)
N1—C1—C2—C3	0.1 (5)	O2—C12—C13—O3	−0.6 (4)
C1—C2—C3—C4	−1.2 (5)	C11—C12—C13—O3	179.89 (13)
C2—C3—C4—C5	1.7 (5)	O2—C12—C13—C12^i	179.4 (4)
C1—N1—C5—C4	−0.1 (4)	C11—C12—C13—C12^i	−0.11 (13)
Ni1—N1—C5—C4	179.63 (19)

Symmetry code: (i) −x+1, y, −z+1/2.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C4—H4···O1^ii	0.93	2.57	3.340 (4)	141
C8—H8···O2^iii	0.93	2.24	3.114 (4)	156
C9—H9···O3^iv	0.93	2.57	3.222 (4)	127

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