Bis(μ-4-fluoro-2,6-diformyl­phenolato)bis­[diaqua­nickel(II)] dichloride

In the title dinuclear nickel(II) complex, [Ni₂(C₈H₄FO₃)₂(H₂O)₄]Cl₂, synthesized by the reaction between 4-fluoro-2,6-diformyl­phenol and nickel(II) chloride in methanol, the coordination cation is located on an inversion center and the Ni^II atom adopts a slightly distorted octa­hedral coordination geometry. The two Ni atoms are bridged by two phenolate O atoms and the intra­molecular Ni...Ni distance is 3.0751 (9) Å. The crystal structure is stabilized by O—H...Cl hydrogen bonds.

Key indicators

• Single-crystal X-ray study
• T = 291 K
• Mean [sigma](C-C) = 0.007 Å
• R factor = 0.051
• wR factor = 0.119
• Data-to-parameter ratio = 12.9

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT341_ALERT_3_C Low Bond Precision on  C-C Bonds (x 1000) Ang ..          7
PLAT910_ALERT_3_C Missing # of FCF Reflections Below Th(Min) .....          1
PLAT911_ALERT_3_C Missing # FCF Refl Between THmin & STh/L=  0.600          2
PLAT912_ALERT_4_C Missing # of FCF Reflections Above STh/L=  0.600          2

Alert level G
PLAT860_ALERT_3_G Note: Number of Least-Squares Restraints .......          4
PLAT764_ALERT_4_G Overcomplete CIF Bond List Detected (Rep/Expd) .       1.11 Ratio

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

   0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   0 ALERT type 2 Indicator that the structure model may be wrong or deficient
   4 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

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S1. Comment

Phenoxide-bridged dinuclear complexes have been extensively studied for several decades, most of them were derived from the cyclocondensation of 2,6-diformyl-4-R-phenol and alkyldiamine in the presence of metal ions (Thompson et al.,1996; Zhou et al., 2005; Raimondi et al., 2004).With short distances between the two metal ions in the complexes, they show special electrical and magnetic properties (Mohanta et al., 1998; Wang et al., 1997). Adhikary et al. reported a phenoxide-bridged dinuclear nickel(II) complex, obtained directly from the mixture of 2,6-diformyl-4-methyl-phenol and nickel(II) perchlorate (Adhikary et al., 1987). Here we report the crystal structure of a new dinuclear Ni^II complex with fluorine substituent in the phenyl ring. The diference between the title complex and the one Adhikary reported is that they have different substituents in the phenyl ring and different counter-anions.

The coordination cation consists of two 2,6-diformyl-4-flurophenolate ligands, four water molecules, two Ni^II ions (Fig. 1). The chlorine ions do not participate in coordination to the Ni atoms. Each Ni atom has a slightly distorted octahedral coordination geometry and it deviates from the equatorial plane defined by four coordinating oxygen atoms of the organic ligand by 0.0266 (4) Å. The axial positions are occupied by two water molecules with Ni–O distances of 2.057 (4) Å and 2.067 (4) Å.The Ni—O distance in the basal plane is in the range of 1.995 (4) Å - 2.019 (3) Å. The presence of the two bridging phenolate O atoms gives rise to a short metal-metal contact of 3.0751 (9) Å that is slightly longer than those of binuclear nickel(II) complexes with macrocyclic phenoxo-bridging ligands (Zhou et al., 2007).

Related literature

For the synthesis of related compounds and their properties, see: Thompson et al. (1996); Zhou et al. (2005); Raimondi et al. (2004); Taniguchi (1984); Mohanta et al. (1998); Wang et al. (1997). For related structures, see: Adhikary et al. (1987); Zhou et al. (2007).

S2. Experimental

2, 6-Diformyl-4-fluorophenol was prepared according to the literature method (Taniguchi, 1984). To a solution of 2,6-diformyl-4-fluorinphenol (1 mmol, 0.17 g) in absolute methanol (10 ml) was added a methanol solution (10 ml) containing NiCl₂2H₂O (1 mmol, 0.17 g). The solution was stirred vigorously for 24 h at room temperature and filtrated. The dark-green block-shaped crystals suitable for X-ray diffraction analysis were obtained by slow evaporation of solvent over a period of two weeks.

S3. Refinement

The H atoms of water molecules were found in a difference Fourier map, and the O—H distances were restrained to 0.85 (1) Å; their temperature factor was set to 1.2U_eq(O). All other H atoms were placed in calculated positions with C—H = 0.93 Å and included in the refinement in the riding-model approximation with U(H) set to 1.2U_eq(C).

Computing details

Data collection: SMART (Bruker, 2007); cell refinement: SAINT (Bruker, 2007); data reduction: SAINT (Bruker, 2007); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures

Fig. 1. A view of the title complex, showing the labeling of the non-H atoms and 30% probability displacement ellipsoids. Atoms with the suffix (*) are generated by the symmetry operation 1-x, 1-y, 1-z.

Bis(µ-4-fluoro-2,6-diformylphenolato)bis[diaquanickel(II)] dichloride

Crystal data

[Ni2(C8H4FO3)2(H2O)4]Cl2	F(000) = 600
Mr = 594.61	Dx = 1.922 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 3902 reflections
a = 8.3299 (14) Å	θ = 2.2–28.0°
b = 13.576 (2) Å	µ = 2.16 mm^−1
c = 9.9965 (17) Å	T = 291 K
β = 114.623 (3)°	Block, green
V = 1027.6 (3) Å^3	0.26 × 0.22 × 0.20 mm
Z = 2

Data collection

Bruker SMART APEX CCD diffractometer	2018 independent reflections
Radiation source: sealed tube	1708 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.041
phi and ω scans	θmax = 26.0°, θmin = 2.7°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −10→7
Tmin = 0.603, Tmax = 0.672	k = −15→16
5827 measured reflections	l = −8→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)] = 0.051	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.119	H atoms treated by a mixture of independent and constrained refinement
S = 1.05	w = 1/[σ^2(Fo^2) + (0.06P)^2 + 1.99P] where P = (Fo^2 + 2Fc^2)/3
2018 reflections	(Δ/σ)max < 0.001
157 parameters	Δρmax = 0.42 e Å^−3
4 restraints	Δρmin = −0.94 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 > 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
C1	0.2077 (6)	0.3085 (3)	0.2584 (5)	0.0349 (11)
H1	0.1159	0.2647	0.2095	0.042*
C2	0.2373 (6)	0.3811 (3)	0.1689 (5)	0.0281 (9)
C3	0.1336 (6)	0.3705 (3)	0.0166 (5)	0.0331 (10)
H3	0.0559	0.3178	−0.0182	0.040*
C4	0.1475 (7)	0.4376 (4)	−0.0792 (5)	0.0401 (12)
C5	0.2548 (7)	0.5179 (4)	−0.0329 (5)	0.0370 (11)
H5	0.2609	0.5630	−0.1007	0.044*
C6	0.3552 (6)	0.5318 (3)	0.1172 (5)	0.0276 (9)
C7	0.3474 (5)	0.4643 (3)	0.2223 (5)	0.0228 (8)
C8	0.4651 (6)	0.6193 (4)	0.1539 (6)	0.0356 (11)
H8	0.4680	0.6545	0.0752	0.043*
Cl1	0.16724 (17)	0.66791 (9)	0.64475 (15)	0.0406 (3)
F1	0.0499 (5)	0.4245 (3)	−0.2256 (3)	0.0555 (9)
Ni1	0.43045 (7)	0.40202 (4)	0.53212 (6)	0.02194 (18)
O1	0.2874 (4)	0.2955 (2)	0.3923 (4)	0.0318 (7)
O2	0.4438 (4)	0.4760 (2)	0.3627 (3)	0.0249 (6)
O3	0.5544 (5)	0.6519 (2)	0.2770 (4)	0.0351 (8)
O4	0.1900 (5)	0.4629 (3)	0.4960 (4)	0.0415 (8)
H4A	0.201 (8)	0.502 (4)	0.565 (5)	0.050*
H4B	0.116 (6)	0.417 (3)	0.484 (7)	0.050*
O5	0.6594 (5)	0.3234 (3)	0.5759 (4)	0.0402 (8)
H5C	0.725 (7)	0.313 (4)	0.6662 (18)	0.048*
H5A	0.717 (7)	0.354 (4)	0.535 (6)	0.048*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.034 (2)	0.032 (2)	0.034 (3)	−0.0109 (19)	0.008 (2)	−0.002 (2)
C2	0.024 (2)	0.025 (2)	0.035 (2)	−0.0003 (17)	0.0122 (18)	−0.0051 (18)
C3	0.028 (2)	0.032 (2)	0.034 (3)	0.0002 (19)	0.0079 (19)	−0.010 (2)
C4	0.050 (3)	0.042 (3)	0.019 (2)	0.012 (2)	0.006 (2)	−0.001 (2)
C5	0.055 (3)	0.035 (3)	0.018 (2)	0.001 (2)	0.012 (2)	0.0028 (19)
C6	0.031 (2)	0.027 (2)	0.024 (2)	−0.0020 (17)	0.0109 (17)	0.0029 (17)
C7	0.0206 (19)	0.0228 (19)	0.028 (2)	0.0044 (15)	0.0127 (17)	0.0059 (17)
C8	0.039 (3)	0.036 (3)	0.036 (3)	0.004 (2)	0.020 (2)	0.011 (2)
Cl1	0.0417 (7)	0.0394 (6)	0.0449 (7)	0.0017 (5)	0.0222 (6)	−0.0033 (5)
F1	0.066 (2)	0.0570 (19)	0.0244 (15)	−0.0102 (17)	−0.0007 (14)	−0.0047 (14)
Ni1	0.0241 (3)	0.0209 (3)	0.0230 (3)	−0.0028 (2)	0.0120 (2)	0.0000 (2)
O1	0.0358 (16)	0.0266 (16)	0.0336 (18)	−0.0065 (13)	0.0149 (14)	−0.0018 (13)
O2	0.0303 (15)	0.0256 (14)	0.0188 (14)	−0.0044 (12)	0.0103 (12)	0.0019 (11)
O3	0.0455 (19)	0.0349 (18)	0.0282 (18)	−0.0055 (15)	0.0186 (15)	0.0046 (14)
O4	0.0335 (18)	0.040 (2)	0.053 (2)	0.0004 (15)	0.0196 (17)	−0.0023 (17)
O5	0.0359 (18)	0.051 (2)	0.0361 (19)	0.0158 (16)	0.0178 (15)	0.0147 (17)

Geometric parameters (Å, º)

C1—O1	1.234 (6)	C8—O3	1.226 (6)
C1—C2	1.421 (7)	C8—H8	0.9300
C1—H1	0.9300	Ni1—O3^i	1.998 (3)
C2—C3	1.410 (6)	Ni1—O2^i	2.007 (3)
C2—C7	1.412 (6)	Ni1—O2	2.012 (3)
C3—C4	1.361 (7)	Ni1—O1	2.019 (3)
C3—H3	0.9300	Ni1—O4	2.054 (4)
C4—F1	1.358 (5)	Ni1—O5	2.067 (3)
C4—C5	1.364 (7)	O2—Ni1^i	2.007 (3)
C5—C6	1.393 (6)	O3—Ni1^i	1.998 (3)
C5—H5	0.9300	O4—H4A	0.85 (5)
C6—C7	1.416 (6)	O4—H4B	0.85 (5)
C6—C8	1.450 (6)	O5—H5C	0.85 (2)
C7—O2	1.304 (5)	O5—H5A	0.86 (6)
O1—C1—C2	128.7 (4)	O3^i—Ni1—O2	169.53 (13)
O1—C1—H1	115.6	O2^i—Ni1—O2	80.18 (13)
C2—C1—H1	115.6	O3^i—Ni1—O1	100.54 (14)
C3—C2—C1	114.8 (4)	O2^i—Ni1—O1	169.22 (12)
C3—C2—C7	119.9 (4)	O2—Ni1—O1	89.91 (13)
C1—C2—C7	125.0 (4)	O3^i—Ni1—O4	89.11 (15)
C4—C3—C2	119.9 (4)	O2^i—Ni1—O4	91.02 (14)
C4—C3—H3	120.1	O2—Ni1—O4	92.46 (14)
C2—C3—H3	120.1	O1—Ni1—O4	85.14 (14)
F1—C4—C3	118.9 (5)	O3^i—Ni1—O5	85.59 (15)
F1—C4—C5	118.9 (5)	O2^i—Ni1—O5	94.66 (15)
C3—C4—C5	122.2 (4)	O2—Ni1—O5	93.79 (13)
C4—C5—C6	119.2 (5)	O1—Ni1—O5	90.19 (15)
C4—C5—H5	120.4	O4—Ni1—O5	172.19 (15)
C6—C5—H5	120.4	C1—O1—Ni1	123.0 (3)
C5—C6—C7	121.3 (4)	C7—O2—Ni1^i	128.1 (3)
C5—C6—C8	114.5 (4)	C7—O2—Ni1	128.3 (3)
C7—C6—C8	124.1 (4)	Ni1^i—O2—Ni1	99.82 (13)
O2—C7—C2	121.1 (4)	C8—O3—Ni1^i	126.6 (3)
O2—C7—C6	121.5 (4)	Ni1—O4—H4A	110 (4)
C2—C7—C6	117.4 (4)	Ni1—O4—H4B	109 (4)
O3—C8—C6	127.3 (4)	H4A—O4—H4B	114 (6)
O3—C8—H8	116.4	Ni1—O5—H5C	116 (4)
C6—C8—H8	116.4	Ni1—O5—H5A	108 (4)
O3^i—Ni1—O2^i	89.45 (13)	H5C—O5—H5A	111 (6)
O1—C1—C2—C3	174.3 (5)	O3^i—Ni1—O1—C1	161.0 (4)
O1—C1—C2—C7	−11.6 (8)	O2^i—Ni1—O1—C1	3.4 (9)
C1—C2—C3—C4	178.2 (5)	O2—Ni1—O1—C1	−19.6 (4)
C7—C2—C3—C4	3.7 (7)	O4—Ni1—O1—C1	72.9 (4)
C2—C3—C4—F1	178.3 (4)	O5—Ni1—O1—C1	−113.4 (4)
C2—C3—C4—C5	−2.4 (8)	C2—C7—O2—Ni1^i	−166.2 (3)
F1—C4—C5—C6	180.0 (5)	C6—C7—O2—Ni1^i	16.8 (6)
C3—C4—C5—C6	0.7 (8)	C2—C7—O2—Ni1	−12.6 (5)
C4—C5—C6—C7	−0.3 (8)	C6—C7—O2—Ni1	170.5 (3)
C4—C5—C6—C8	179.7 (5)	O3^i—Ni1—O2—C7	−167.1 (7)
C3—C2—C7—O2	179.7 (4)	O2^i—Ni1—O2—C7	−159.3 (4)
C1—C2—C7—O2	5.8 (7)	O1—Ni1—O2—C7	16.5 (3)
C3—C2—C7—C6	−3.3 (6)	O4—Ni1—O2—C7	−68.7 (3)
C1—C2—C7—C6	−177.1 (4)	O5—Ni1—O2—C7	106.7 (3)
C5—C6—C7—O2	178.6 (4)	O3^i—Ni1—O2—Ni1^i	−7.8 (8)
C8—C6—C7—O2	−1.4 (7)	O2^i—Ni1—O2—Ni1^i	0.0
C5—C6—C7—C2	1.6 (6)	O1—Ni1—O2—Ni1^i	175.74 (14)
C8—C6—C7—C2	−178.4 (4)	O4—Ni1—O2—Ni1^i	90.61 (15)
C5—C6—C8—O3	173.9 (5)	O5—Ni1—O2—Ni1^i	−94.08 (16)
C7—C6—C8—O3	−6.1 (8)	C6—C8—O3—Ni1^i	−2.9 (7)
C2—C1—O1—Ni1	21.3 (7)

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
O4—H4A···Cl1	0.85 (5)	2.44 (3)	3.198 (4)	149 (6)
O4—H4B···Cl1^ii	0.85 (5)	2.45 (3)	3.241 (4)	154 (5)
O5—H5C···Cl1^iii	0.85 (2)	2.61 (4)	3.313 (4)	141 (5)
O5—H5A···Cl1^i	0.86 (6)	2.39 (4)	3.101 (4)	142 (5)

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