μ-Aqua-κ2 O:O-di-μ-4-methyl­benzoato-κ4 O:O′-bis­[(4-methyl­benzoato-κO)(1,10-phenanthroline-κ2 N,N′)nickel(II)]

Wen-Dong Song; Jian-Bin Yan; Xiao-Min Hao

doi:10.1107/S1600536808017285

. 2008 Jun 13;64(Pt 7):m919–m920. doi: 10.1107/S1600536808017285

μ-Aqua-κ² O:O-di-μ-4-methylbenzoato-κ⁴ O:O′-bis[(4-methylbenzoato-κO)(1,10-phenanthroline-κ² N,N′)nickel(II)]

Wen-Dong Song ^a,^*, Jian-Bin Yan ^a, Xiao-Min Hao ^a

PMCID: PMC2961858 PMID: 21202777

Abstract

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].

Related literature

For the coordination chemistry of 4-methylbenzoate 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

Crystal data

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

Data collection

Bruker APEXII area-detector diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T _min = 0.612, T _max = 0.801
23989 measured reflections
5125 independent reflections
3585 reflections with I > 2σ(I)
R _int = 0.077

Refinement

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

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

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536808017285/zl2119sup1.cif

e-64-0m919-sup1.cif^{(21.5KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808017285/zl2119Isup2.hkl

e-64-0m919-Isup2.hkl^{(264.1KB, hkl)}

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

Table 1. Hydrogen-bond geometry (Å, °).

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	0.830 (10)	1.746 (12)	2.560 (2)	166 (3)

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

Acknowledgments

The authors thank Guang Dong Ocean University for supporting this study.

supplementary crystallographic information

Comment

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).

Experimental

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.