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

Cuiping Zhai; Feng-mei Yan; Pei-zheng Zhao

doi:10.1107/S1600536808036283

. 2008 Nov 13;64(Pt 12):m1526–m1527. doi: 10.1107/S1600536808036283

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

Cuiping Zhai ^a, Feng-mei Yan ^b, Pei-zheng Zhao ^c,^*

PMCID: PMC2959880 PMID: 21581143

Abstract

The Cu^II atoms in the two independent molecules of the title compound, [Cu(C₇H₅O₃)₂(C₁₄H₁₂N₂)], are each coordinated by a bidentate 2,9-dimethyl-1,10-phenanthroline (dmphen) molecule and two monodentate 2-hydroxybenzoate anions in a distorted tetrahedral geometry. The crystal packing is stabilized by intramolecular hydrogen bonding and π–π interactions between the dmphen rings of neighboring molecules, with distances between their ring planes of 3.5670 (4) and 3.5181 (9) Å.

Related literature

For the features of metal–phenanthroline complexes, see: Naing et al. (1995 ▶); Wang et al. (1996 ▶); Wall et al. (1999 ▶). For related structures, see: Cheng et al. (2007 ▶); Xuan et al. (2007 ▶); Zhao et al. (2007 ▶).

Experimental

Crystal data

[Cu(C₇H₅O₃)₂(C₁₄H₁₂N₂)]
M _r = 546.02
Monoclinic,
a = 23.819 (2) Å
b = 12.2576 (11) Å
c = 17.9084 (17) Å
β = 112.023 (1)°
V = 4847.0 (8) Å³
Z = 8
Mo Kα radiation
μ = 0.95 mm⁻¹
T = 291 (2) K
0.30 × 0.21 × 0.19 mm

Data collection

Bruker APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 2004 ▶) T _min = 0.765, T _max = 0.837
30637 measured reflections
8932 independent reflections
5274 reflections with I > 2σ(I)
R _int = 0.060

Refinement

R[F ² > 2σ(F ²)] = 0.045
wR(F ²) = 0.121
S = 1.01
8932 reflections
675 parameters
H-atom parameters constrained
Δρ_max = 0.38 e Å⁻³
Δρ_min = −0.45 e Å⁻³

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

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536808036283/hg2438sup1.cif

e-64-m1526-sup1.cif^{(38.9KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808036283/hg2438Isup2.hkl

e-64-m1526-Isup2.hkl^{(436.9KB, hkl)}

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

Table 1. Selected geometric parameters (Å, °).

Cu1—O2	1.931 (2)
Cu1—O4	1.946 (2)
Cu1—N2	1.994 (3)
Cu1—N1	2.022 (3)
Cu2—O10	1.945 (2)
Cu2—O8	1.956 (3)
Cu2—N4	1.992 (3)
Cu2—N3	2.044 (3)

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O2—Cu1—O4	91.00 (11)
O2—Cu1—N2	152.67 (12)
O4—Cu1—N2	97.15 (11)
O2—Cu1—N1	104.90 (11)
O4—Cu1—N1	144.27 (11)
N2—Cu1—N1	83.30 (11)
O10—Cu2—O8	90.72 (11)
O10—Cu2—N4	94.59 (12)
O8—Cu2—N4	155.88 (12)
O10—Cu2—N3	143.61 (12)
O8—Cu2—N3	106.20 (12)
N4—Cu2—N3	82.98 (13)

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

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O12—H12⋯O11	0.82	1.82	2.549 (4)	147
O9—H9⋯O7	0.82	1.84	2.561 (4)	146
O6—H6⋯O5	0.82	1.85	2.572 (4)	146
O3—H3⋯O1	0.82	1.82	2.553 (5)	148

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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 (Wang et al., 1996; Wall et al., 1999; Naing et al., 1995). Some Cu(II)-phenanthroline complexes have been synthesized and structures were determined (Cheng et al., 2007; Xuan et al., 2007; Zhao et al., 2007). Recently, we obtained the title compound copper(II) complex (I), by reaction of 2,9-dimethyl-1,10-phenanthroline, 2-hydroxybenzoic acid and Cu(NO₃)₂ in an ethanol/water mixture. The structure of the title compound, Cu(C₁₄H₁₂N₂)(C₆H₄OHCOO)₂,(I), is shown below.

There are two independent molecules in the asymmetric unit. Each Cu^II ion is four-coordinated by two N atoms from a 2,9-dimethyl-1,10-phenanthroline ligand, and two O atoms from two 2-hydroxybenzoic anions. The Cu^II ion locates in the center, and CuO₂N₂ unit forms a distorted tetrahedral geometry (Fig.1). The Cu—N and Cu—O bond lengths in two independent molecules different slightly (Table 1). The hydroxy directions of 2-hydroxybenzoic anions in the two independent molecules are also different.

An intramolecular hydrogen bond between the hydroxy group and uncoordinated carboxyl O atom stabilizes the conformation of the hydroxybenzoate ligands (Table 2). A partially overlapped arrangement of neighboring parallel Cu1A-dmphen [symmetry code: (Cu1A) x, y - 1, z] and Cu1B-dmphen rings [symmetry code: (Cu1B) -x + 1, -y + 1, -z + 1], Cu2A-dmphen [symmetry code: (Cu2A) -x + 2, y - 1/2, -z + 3/2] and Cu2C-dmphen rings [symmetry code: (Cu2C) x, -y - 1/2, z + 3/2] are observed in the structure of (I) (Fig.2). The shorter face-to-face separation of 3.5670 (4)Å and 3.5181 (9)Å indicates the existence of π—π stacking between the dmphen ligands.

Experimental

2-hydroxybenzoic acid (0.1389 g, 1 mmol) and NaOH (0.0370 g, 1 mmol) were dissolved in distilled water(10 ml) and Cu(NO₃)₂.3H₂O (0.1222 g, 0.5 mmol) were added. This solution was added to a solution of 2,9-dimethyl-1,10-phenanthroline hemihydrate (C₁₄H₁₂N₂.0.5H₂O, 0.1090 g, 0.5 mmol) in ethanol (10 ml). The mixture was stirred at 323 K and then refluxed for 5 h, cooled to room temperature and filtered. Green single crystals of (I) were appeared over a period of eighteen days by slow evaporation at room temperature.