(2,9-Dimethyl-1,10-phenanthroline-κ2 N,N′)bis­(2-hydroxy­benzoato)-κO;κ2 O,O′-cobalt(II)

Pei-Zheng Zhao; Xiao-Peng Xuan; Qing-Hu Tang

doi:10.1107/S1600536808012002

. 2008 Apr 30;64(Pt 5):m740. doi: 10.1107/S1600536808012002

(2,9-Dimethyl-1,10-phenanthroline-κ² N,N′)bis(2-hydroxybenzoato)-κO;κ² O,O′-cobalt(II)

Pei-Zheng Zhao ^a,^*, Xiao-Peng Xuan ^a, Qing-Hu Tang ^a

PMCID: PMC2961220 PMID: 21202260

Abstract

In the title compound, [Co(C₇H₅O₃)₂(C₁₄H₁₂N₂)], the Co^II ion is five-coordinated by two N atoms from one 2,9-dimethyl-1,10-phenanthroline (dmphen) ligand and three O atoms from two 2-hydroxybenzoate anions in a distorted trigonal bipyramidal geometry. The carboxylate group of one of the two 2-hydroxybenzoate anions is monodentate with a normal Co—O distance [1.9804 (18) Å], while the other is bidentate with two longer Co—O bonds [2.1981 (18) and 2.1359 (19) Å]. The crystal structure is stabilized by aromatic π–π stacking interactions [centroid–centroid distances of 4.0380 (3) and 3.8216 (3) Å between dmphen/dmphen and benzene/dmphen rings, respectively] and C—H⋯π(benzene) interactions.

Related literature

For related literature, see: Naing et al. (1995 ▶); Wang et al. (1996 ▶); Wall et al. (1999 ▶). For related structures, see: Ding et al. (2006 ▶); Ren et al. (2007 ▶); Xuan & Zhao (2007 ▶); Zhong et al. (2006 ▶).

Experimental

Crystal data

[Co(C₇H₅O₃)₂(C₁₄H₁₂N₂)]
M _r = 541.41
Monoclinic,
a = 11.436 (1) Å
b = 16.528 (2) Å
c = 13.426 (2) Å
β = 105.856 (1)°
V = 2441.1 (5) Å³
Z = 4
Mo Kα radiation
μ = 0.75 mm⁻¹
T = 293 (2) K
0.46 × 0.36 × 0.30 mm

Data collection

Bruker APEX2 CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 2004 ▶) T _min = 0.779, T _max = 0.858 (expected range = 0.725–0.799)
20557 measured reflections
5998 independent reflections
4476 reflections with I > 2σ(I)
R _int = 0.023

Refinement

R[F ² > 2σ(F ²)] = 0.040
wR(F ²) = 0.127
S = 1.04
5998 reflections
338 parameters
H-atom parameters constrained
Δρ_max = 0.86 e Å⁻³
Δρ_min = −0.39 e Å⁻³

Data collection: APEX2 (Bruker, 2004 ▶); cell refinement: APEX2; 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: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536808012002/lx2038sup1.cif

e-64-0m740-sup1.cif^{(25.7KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808012002/lx2038Isup2.hkl

e-64-0m740-Isup2.hkl^{(293.6KB, 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
O3—H3O⋯O1	0.82	1.88	2.584 (3)	143
O6—H6O⋯O5	0.82	1.85	2.578 (3)	146
C3—H3⋯Cg1ⁱ	0.93	2.59	3.402 (3)	146
C25—H25⋯Cg2ⁱⁱ	0.93	3.06	3.989 (3)	172

Open in a new tab

Symmetry codes: (i) Inline graphic ; (ii) . Cg1 is the centroid of the C23–C28 benzene ring and Cg2 is the centroid of the C16–C21 benzene ring.

Acknowledgments

Financial support from the Science Fund of Henan Province for Distinguished Young Scholars (No. 074100510005) is gratefully acknowledged.

supplementary crystallographic information

Comment

Metal-phenanthroline complexes have attracted much attention because of their peculiar features during recent decades (Wang et al., 1996; Wall et al., 1999; Naing et al., 1995). A number of Co(II)-phenanthroline complexes have been synthesized and structures were determined (Ding et al., 2006; Ren et al., 2007; Zhong et al., 2006; Xuan & Zhao, 2007). Herein we report the molecular and crystal structure of the title compound, (I), Bis(2-hydroxybenzoato–κO,κ²O,O')-(2,9-dimethyl-1, 10-phenanthroline-κ²N,N')-cobalt (II) (Fig. 1).

The Co atom in (I) is coordinated by a dmphen ligand and two 2-hydroxybenzoato ligands (Fig.1). The values of Co—O1 and Co—O2 distances are larger than the normal Co—O4 bond distance. The Co—O1—C15 and Co—O2—C15 bond angles [89.23 (14)°, 92.28 (15)°] appear to be compressed in order to allow Co and O atoms to approach each other. These imply the existence of genuing bonding interactions bwtween Co and O atoms, i.e. the C15-carboxylate group coordinates to the Co atom in chelating mode. The other ligand has a larger Co—O4—C22 angle of 107.71 (16)°. The values of Co···O5 distance is 2.6624 (22) Å, suggesting no bonding between the Co and O5 atoms. Therefore, the CoO₃N₂ unit forms a distorted trigonal-bipyramidal geometry.

A partially overlapped arrangement of neighboring parallel C3-dmphen and C3^v-dmphen rings[symmetry code: (v) -x + 2, -y + 1, -z + 1] is observed in the structure of (I) (Fig. 2). The shorter face-to-face separation of 3.3881 (5) Å clearly indicates the existence of π—π stacking between the dmphen ligands. In addition, the distance between the ring centroids Cg3 (C2—C5/C13/N1) and Cg2ⁱⁱⁱ (C16ⁱⁱⁱ—C21ⁱⁱⁱ) is 3.8216 (3) Å. This value is indentical to van der Waals thickness of the π—π stacking interaction between the nearly parallel dmphen and benzene ligands [dihedral angle 0.208 (68)°], although dmphen and benzene rings are well overlapped with respect to each other (Fig. 2).

The interaction of C—H···π and hydrogen bond intrains in the compound. The crystal structure is further stablilized by C—H···π interactions between the H atom of C3-dmphen ring and C23ⁱ-benzene ring, with a C3—H3···Cg1ⁱ separation of 2.5914 (4) Å (Fig.2 and Table 1; Cg1ⁱ is the centroid of C23ⁱ—C28ⁱ benzene ring, symmmetry code as in Fig. 2).

Experimental

2-hydroxybenzoic acid (0.1396 g, 1 mmol) and NaOH (0.0377 g, 1 mmol) were dissolved in distilled water(15 ml) and Co(NO₃)₂.6H₂O (0.1460 g, 0.5 mmol) were added. This solution was added to a solution of 2,9-dimethyl-1,10-phenanthroline hemihydrate (C₁₄H₁₂N₂.0.5H₂O, 0.1087 g, 0.5 mmol) in ethanol (10 ml). The mixture was stirred at 323 K and then refluxed for 4 h, cooled to room temperature and filtered. Brown single crystals of (I) were appeared over a period of one day by slow evaporation at room temperature.