trans-Diaqua­bis­(4-fluoro­benzoato-κO)bis­(nicotinamide-κN 1)nickel(II)

Hacali Necefoğlu; Vijdan Öztürk; Füreya Elif Özbek; Vedat Adıgüzel; Tuncer Hökelek

doi:10.1107/S1600536811044771

. 2011 Oct 29;67(Pt 11):m1638–m1639. doi: 10.1107/S1600536811044771

trans-Diaquabis(4-fluorobenzoato-κO)bis(nicotinamide-κN ¹)nickel(II)

Hacali Necefoğlu ^a, Vijdan Öztürk ^a, Füreya Elif Özbek ^a, Vedat Adıgüzel ^a, Tuncer Hökelek ^b,^*

PMCID: PMC3247555 PMID: 22219860

Abstract

In the mononuclear Ni^II title complex, [Ni(C₇H₄FO₂)₂(C₆H₆N₂O)₂(H₂O)₂], the Ni^II atom, located on an inversion center, is coordinated by two nicotinamide and two 4-fluorobenzoate ligands and two water molecules in a distorted N₂O₄ octahedral geometry. The dihedral angle between the carboxylate group and the adjacent benzene ring is 8.95 (8)°, while the pyridine ring and the benzene ring are oriented at a dihedral angle of 75.01 (7)°. The water molecule links the adjacent carboxylate O atom via an intramolecular O—H⋯O hydrogen bond. In the crystal, O—H⋯O, N—H⋯O, C—H⋯O and C—H⋯F hydrogen bonds link the molecules into a three-dimensional network. π–π stacking between parallel pyridine rings [centroid–centroid distance = 3.7287 (11) Å] is also observed.

Related literature

For literature on niacin, see: Krishnamachari (1974 ▶). For information on the nicotinic acid derivative N,N-diethylnicotinamide, see: Bigoli et al. (1972 ▶). For related structures, see: Hökelek et al. (1996 ▶, 2009a ▶,b ▶); Hökelek & Necefoğlu (1998 ▶, 2007) ▶; Necefoğlu et al. (2011 ▶). For bond-length data, see: Allen et al. (1987 ▶).

Experimental

Crystal data

[Ni(C₇H₄FO₂)₂(C₆H₆N₂O)₂(H₂O)₂]
M _r = 617.18
Monoclinic,
a = 12.2001 (5) Å
b = 8.8473 (4) Å
c = 17.1341 (5) Å
β = 136.080 (2)°
V = 1282.86 (10) Å³
Z = 2
Mo Kα radiation
μ = 0.83 mm⁻¹
T = 100 K
0.29 × 0.22 × 0.18 mm

Data collection

Bruker Kappa APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2005 ▶) T _min = 0.803, T _max = 0.861
11926 measured reflections
3220 independent reflections
2874 reflections with I > 2σ(I)
R _int = 0.028

Refinement

R[F ² > 2σ(F ²)] = 0.030
wR(F ²) = 0.077
S = 1.04
3220 reflections
203 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.46 e Å⁻³
Δρ_min = −0.57 e Å⁻³

Data collection: APEX2 (Bruker, 2007 ▶); cell refinement: SAINT (Bruker, 2007 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶) and PLATON (Spek, 2009 ▶).

Supplementary Material

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536811044771/xu5359sup1.cif

e-67-m1638-sup1.cif^{(18.6KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811044771/xu5359Isup2.hkl

e-67-m1638-Isup2.hkl^{(154.8KB, hkl)}

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Selected bond lengths (Å).

Ni1—O1	2.0500 (9)
Ni1—O4	2.0872 (10)
Ni1—N1	2.1033 (13)

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Table 2. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N2—H21⋯O3ⁱ	0.84 (3)	2.15 (3)	2.8363 (19)	139 (2)
N2—H22⋯O4ⁱⁱ	0.86 (3)	2.28 (3)	2.955 (2)	135 (2)
O4—H41⋯O3ⁱⁱⁱ	0.841 (18)	1.94 (2)	2.7654 (16)	166 (3)
O4—H42⋯O2	0.88 (3)	1.70 (2)	2.5663 (14)	168 (4)
C6—H6⋯O4^iv	0.93	2.52	3.402 (3)	159
C8—H8⋯F1^v	0.93	2.53	3.1358 (18)	123
C9—H9⋯F1^v	0.93	2.55	3.129 (2)	121
C10—H10⋯O2^vi	0.93	2.57	3.4060 (19)	150

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) ; (iv) ; (v) ; (vi) .

Acknowledgments

The authors are indebted to Anadolu University and the Medicinal Plants and Medicine Research Centre of Anadolu University, Eskişehir, Turkey, for the use of the X-ray diffractometer. This work was supported financially by the Scientific and Technological Research Council of Turkey (grant No. 106 T472).

supplementary crystallographic information

Comment

As a part of our ongoing investigations of transition metal complexes of nicotinamide (NA), one form of niacin (Krishnamachari, 1974), and/or the nicotinic acid derivative N,N-diethylnicotinamide (DENA), an important respiratory stimulant (Bigoli et al., 1972), the title compound was synthesized and its crystal structure is reported herein.

The asymmetric unit of the title mononuclear Ni^II complex, (Fig. 1), contains one-half molecule, the Ni^II atom being located on an inversion center. It consists of two nicotinamide (NA), two 4-fluorobenzoate (PFB) ligands and two coordinated water molecules, all ligands coordinating in a monodentate manner. The crystal structures of similar omplexes of Cu^II, Co^II, Ni^II, Mn^II and Zn^II ions, [Cu(C₇H₅O₂)₂(C₁₀H₁₄N₂O)₂] (Hökelek et al., 1996), [Co(C₆H₆N₂O)₂(C₇H₄NO₄)₂(H₂O)₂] (Hökelek & Necefouglu, 1998), [Co(C₉H₉O₂)₂(C₁₀H₁₄N₂O)₂(H₂O)₂] (Necefoğlu et al., 2011), [Ni(C₇H₄ClO₂)₂(C₆H₆N₂O)₂(H₂O)₂] (Hökelek et al., 2009a), [Mn(C₉H₁₀NO₂)₂(H₂O)₄].2H₂O (Hökelek & Necefoğlu, 2007) and [Zn(C₇H₄BrO₂)₂(C₆H₆N₂O)₂(H₂O)₂] (Hökelek et al., 2009b) have also been reported. In the copper(II) complex mentioned above the two benzoate ions coordinate to the Cu^II atom as bidentate ligands, while in the other structures all the ligands coordinate in a monodentate manner.

In the title complex, the four symmetry related O atoms (O1, O1', O4 and O4') in the equatorial plane around the Ni^II ion form a slightly distorted square-planar arrangement, while the slightly distorted octahedral coordination is completed by the two N atoms of the NA ligands (N1 and N1') in the axial positions. The near equalities of the C1—O1 [1.2695 (18) Å] and C1—O2 [1.2560 (16) Å] bonds in the carboxylate groups indicate delocalized bonding arrangements, rather than localized single and double bonds. The Ni—O bond lengths are 2.0500 (9) Å (for benzoate oxygen) and 2.0872 (10) Å (for water oxygen), and the Ni—N bond length is 2.1033 (13) Å, close to standard values (Allen et al., 1987). The intramolecular O—H···O hydrogen bonds (Table 1) link the water molecules to the carboxylate groups. The Ni atom is displaced out of the mean-plane of the carboxylate group (O1/C1/O2) by 0.5609 (1) Å. The dihedral angle between the planar carboxylate group and the adjacent benzene ring A (C2—C7) is 8.95 (8)°. The benzene A (C2—C7) and the pyridine B (N1/C8—C12) rings are oriented at a dihedral angle of A/B = 75.01 (7)°.

In the crystal, intermolecular O—H···O, N—H···O, C—H···O and C—H···F hydrogen bonds (Table 1) link the molecules into a three-dimensional network. There also exists a π–π contact between the pyridine rings, Cg2—Cg2ⁱ, may further stabilize the structure [centroid-centroid distance = 3.729 (1) Å; symmetry code: (i) 2 - x, -y, 1 - z; Cg2 is the centroid of the ring B (N1/C8—C12)].

Experimental

The title compound was prepared by the reaction of NiSO₄.6H₂O (1.31 g, 5 mmol) in H₂O (25 ml) and NA (1.22 g, 10 mmol) in H₂O (25 ml) with sodium 4-fluorobenzoate (1.62 g, 10 mmol) in H₂O (100 ml) at room temperature. The mixture was filtered and set aside to crystallize at ambient temperature for two weeks, giving blue single crystals.