Bis(2,5-dihydroxy­benzoato-κO)bis­(1,10-phenathroline-κ2 N,N′)cadmium(II) 1.25-hydrate

Bing-Yu Zhang; Jing-Jing Nie; Duan-Jun Xu

doi:10.1107/S1600536808018126

. 2008 Jun 19;64(Pt 7):m937. doi: 10.1107/S1600536808018126

Bis(2,5-dihydroxybenzoato-κO)bis(1,10-phenathroline-κ² N,N′)cadmium(II) 1.25-hydrate

Bing-Yu Zhang ^a, Jing-Jing Nie ^a, Duan-Jun Xu ^a,^*

PMCID: PMC2961672 PMID: 21202790

Abstract

In the crystal structure of the title compound, [Cd(C₇H₅O₄)₂(C₁₂H₈N₂)₂]·1.25H₂O, the Cd²⁺ cation is coordinated by two phenanthroline (phen) molecules and two 2,5-dihydroxybenzoate (dhba) anions in a distorted octahedral geometry. The centroid–centroid distances of 3.809 (2) and 3.680 (2) Å between nearly parallel pyridine rings of the phen ligands and the benzene rings of dhba anions indicate that the dhba anions are involved in π–π stacking in the crystal structure. The face-to-face separation of 3.35 (3) Å between parallel phen ring systems also suggests π–π stacking between adjacent complex molecules. The crystal structure contains extensive O—H⋯O and C—H⋯O hydrogen bonding.

Related literature

For general background, see: Su & Xu (2004 ▶); Li et al. (2005 ▶). For a related structure, see: Huang et al. (2006 ▶).

Experimental

Crystal data

[Cd(C₇H₅O₄)₂(C₁₂H₈N₂)₂]·1.25H₂O
M _r = 801.55
Monoclinic,
a = 10.8992 (18) Å
b = 27.300 (2) Å
c = 11.4218 (12) Å
β = 93.700 (6)°
V = 3391.5 (7) Å³
Z = 4
Mo Kα radiation
μ = 0.71 mm⁻¹
T = 295 (2) K
0.20 × 0.16 × 0.12 mm

Data collection

Rigaku R-AXIS RAPID IP diffractometer
Absorption correction: multi-scan (ABSCOR; Higashi, 1995 ▶) T _min = 0.875, T _max = 0.928
25199 measured reflections
6639 independent reflections
4509 reflections with I > 2σ(I)
R _int = 0.064

Refinement

R[F ² > 2σ(F ²)] = 0.042
wR(F ²) = 0.092
S = 1.03
6639 reflections
478 parameters
H-atom parameters constrained
Δρ_max = 0.53 e Å⁻³
Δρ_min = −0.51 e Å⁻³

Data collection: PROCESS-AUTO (Rigaku, 1998 ▶); cell refinement: PROCESS-AUTO; data reduction: CrystalStructure (Rigaku/MSC, 2002 ▶); program(s) used to solve structure: SIR92 (Altomare et al., 1993 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶).

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536808018126/rk2092sup1.cif

e-64-0m937-sup1.cif^{(25.7KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808018126/rk2092Isup2.hkl

e-64-0m937-Isup2.hkl^{(318.4KB, 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
O1W—H1A⋯O1	0.94	2.09	2.974 (6)	155
O1W—H1B⋯O6	0.92	2.03	2.892 (6)	155
O2W—H2A⋯O2	0.88	1.99	2.869 (18)	175
O2W—H2B⋯O8ⁱ	0.86	2.42	3.28 (2)	173
O3—H3A⋯O2	0.82	1.81	2.540 (3)	147
O4—H4A⋯O7ⁱⁱ	0.82	2.09	2.877 (3)	160
O7—H7A⋯O6	0.82	1.82	2.546 (3)	147
O8—H8A⋯O3ⁱⁱⁱ	0.82	2.10	2.917 (4)	171
C23—H23⋯O1W^iv	0.93	2.49	3.339 (6)	153
C25—H25⋯O6^v	0.93	2.50	3.285 (5)	143
C30—H30⋯O1	0.93	2.56	3.155 (5)	122
C33—H33⋯O5	0.93	2.50	3.105 (5)	123
C38—H38⋯O2^vi	0.93	2.36	3.182 (5)	147
C42—H42⋯O4^vii	0.93	2.58	3.231 (5)	127

Open in a new tab

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

Acknowledgments

The work was supported by the ZIJIN project of Zhejiang University, China.

supplementary crystallographic information

Comment

As part of investigation on the nature of π-π stacking between aromatic rings (Su & Xu, 2004; Li et al., 2005), the title complex recently has been prepared and its crystal structure is reported here.

The molecular structure of the title compound is shown on Fig. 1. The Cd²⁺ cation is coordinated by two phenanthroline (phen) ligands and two 2,5-dihydroxybenzoate (dhba) anions with a distorted octahedral geometry. The centroid-to-centroid distance of 3.809 (2)Å between nearly parallel N1-pyridine and C2ⁱ-benzene rings (dihedral angle 4.89 (17)°; symmetry code: (i) x-1, y, z) and the centroid-to-centroid distance of 3.680 (2)Å between nearly parallel N4-pyridine and C12ⁱⁱ-benzene rings (dihedral angle 5.33 (11)°; symmetry code: (ii) x, y, z-1) indicate that dhba anions are involved in π-π stacking in the crystal structure (Fig. 2), which agrees with the situation found in the 3,5-dihydroxybenzoate complex of Cu²⁺ (Huang et al., 2006). The face-to-face separation of 3.35 (3)Å suggests the existence of π-π stacking between parallel C31-phen and C31ⁱⁱⁱ-phen ring systems (Fig. 3) (symmetry code: (iii) -x, 1-y, 1-z). The crystal structure contains extensive O–H···O and C–H···O hydrogen bonding (Table 1).

Experimental

Cd(NO₃)₂^.4H₂O (0.31 g, 1 mmol), dhba (0.31 g, 2 mmol), phen (0.36 g, 2 mmol) and Na₂CO₃ (0.10 g, 1 mmol) were dissolved in a water-ethanol mixture (20 ml, 2:1). The solution was refluxed for 2 h. After cooling to room temperature the solution was filtered. Single crystals of the title compound were obtained from the filtrate after 4 weeks.