Diaqua­bis­(5-methyl­pyrazine-2-carboxyl­ato-κ2N1,O2)cadmium

Albanez, J.; Brito, I.; Cárdenas, A.; López-Rodríguez, M.

doi:10.1107/S1600536811035045

metal-organic compounds

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 67| Part 10| October 2011| Pages m1339-m1340

https://doi.org/10.1107/S1600536811035045

Open

access

Diaquabis(5-methylpyrazine-2-carboxylato-κ²N¹,O²)cadmium

Joselyn Albanez,^a Iván Brito,^a ^* Alejandro Cárdenas ^b and Matías López-Rodríguez ^c

^aDepartamento de Química, Facultad de Ciencias Básicas, Universidad de Antofagasta, Casilla 170, Antofagasta, Chile, ^bDepartamento de Física, Facultad de Ciencias Básicas, Universidad de Antofagasta, Casilla 170, Antofagasta, Chile, and ^cInstituto de Bio-Orgánica `Antonio González', Universidad de La Laguna, Astrofísico Francisco Sánchez N°2, La Laguna, Tenerife, Spain
^*Correspondence e-mail: ivanbritob@yahoo.com

(Received 24 August 2011; accepted 26 August 2011; online 14 September 2011)

In the title compound, [Cd(C₆H₅N₂O₂)₂(H₂O)₂], the Cd^II ion is coordinated in a severely distorted octahedral geometry. The N atoms are cis to each other, while the water O atoms and ligand O atoms are mutually trans. The crystal structure is stabilized by a network of O—H⋯O, O—H⋯N and C—H⋯O hydrogen bonds and π–π stacking interactions [centroid–centroid distances = 3.730 (3) and 3.652 (3) Å] between the 5-methylpyrazine-2-carboxylate ligands. The structure is isotypic with the manganese analog.

Related literature

For background to coordination chemistry, see: Blake et al. (1999 ); Brito et al. (2011 ). For the isotypic Mn compound see: Chapman et al. (2002 ). For similar compounds of the type [M(C₆H₅N₂O₂)₂(H₂O)₂, where M = Fe^II, Co^II, Zn^II, Ni^II] see: Fan et al. (2007a ,b , 2009 ); Shang et al. (2007 ).

Experimental

Crystal data

[Cd(C₆H₅N₂O₂)₂(H₂O)₂]
M_r = 422.67
Triclinic, $[P \overline 1]$
a = 7.2900 (15) Å
b = 7.5320 (15) Å
c = 14.090 (3) Å
α = 87.31 (3)°
β = 81.36 (3)°
γ = 80.78 (3)°
V = 754.8 (3) Å³
Z = 2
Mo Kα radiation
μ = 1.48 mm⁻¹
T = 293 K
0.44 × 0.40 × 0.22 mm

Data collection

Oxford Diffraction CCD area-detector diffractometer
Absorption correction: multi-scan (MULABS; Spek, 2009 ; Blessing, 1995 ) T_min = 0.561, T_max = 0.736
5896 measured reflections
3530 independent reflections
2778 reflections with I > 2σ(I)
R_int = 0.061

Refinement

R[F² > 2σ(F²)] = 0.058
wR(F²) = 0.159
S = 1.06
3530 reflections
226 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 2.23 e Å⁻³
Δρ_min = −1.11 e Å⁻³

Table 1
Selected geometric parameters (Å, °)

Cd1—O1	2.245 (4)
Cd1—O2	2.269 (4)
Cd1—O4	2.278 (5)
Cd1—O3	2.283 (5)
Cd1—N3	2.361 (5)
Cd1—N1	2.370 (5)

O2—Cd1—O4	154.86 (19)
O1—Cd1—O3	161.4 (2)
O2—Cd1—N3	71.25 (16)
O3—Cd1—N3	89.0 (2)
O1—Cd1—N1	72.18 (16)
N3—Cd1—N1	177.55 (14)

Table 2
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O3—H3A⋯N4ⁱ	0.75 (6)	2.12 (6)	2.875 (9)	173 (6)
O3—H3B⋯O5ⁱⁱ	0.73 (10)	2.08 (10)	2.740 (8)	150 (10)
O4—H4A⋯N2ⁱⁱⁱ	0.84 (8)	2.04 (8)	2.852 (8)	164 (8)
O4—H4B⋯O6^iv	0.93 (11)	1.99 (10)	2.811 (8)	146 (8)
C4—H4⋯O5ⁱⁱ	0.93	2.29	3.211 (7)	169
Symmetry codes: (i) -x+1, -y+2, -z+2; (ii) x, y+1, z; (iii) -x+2, -y+1, -z+1; (iv) x+1, y, z.

Data collection: CrysAlis PRO (Agilent, 2010 ); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: OLEX2 (Dolomanov et al., 2009 ) and PLATON (Spek, 2009); software used to prepare material for publication: publCIF (Westrip, 2010 ) and WinGX (Farrugia, 1999 ).

Supporting information

Crystal structure: contains datablocks I, global. DOI: https://doi.org/10.1107/S1600536811035045/bt5630sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536811035045/bt5630Isup2.hkl

checkCIF report

Comment top

The design of polymeric organic-inorganic materials with novel topologies and structural motifs is of current interest in the field of coordination chemistry, (Blake et al., 1999). This paper forms part of our continuing study of the synthesis, structural characterization and physical properties of coordination polymers (Brito et al., 2011). The title compound was isolated during attempts to synthesize a mixed-ligand coordination polymer by a condensation reaction between the title compound and pyrazine. The crystal structure of the title compound, contains discrete mononuclear complex molecules in which Cd ^II ions, are chelated by two 2-methylpyrazine- 5-carboxylate ligands in a trans-cis mode and bonded by two water molecules. The coordination geometry around the Cd^II ion is severely distorted octahedral. The ligand chelation proceeds via its N,O-bonding group. The organic ligands are essentially planar [r.m.s. deviation 0.0765 (3) Å mean] and form a dihedral angle of 89.71 (18)°. The molecular structure is shown in Fig. 1 and relevant bond distances and angles for the Cd^II coordination octahedron are listed in Table 1. All molecular geometry parameters lie within the normal ranges, except the C1—C6 bond distance (1.532 (8) Å) which is longer than Csp²—Csp² bond distance, possibly due to the coordination effect of the Cd atom. This effect is observed in Mn analog. The coordination geometry and geometric parameters of the title compound match closely those found in the analog compound (Chapman et al., 2002).The crystal structure is stabilized by a network of O—H···O, O—H···N, C—H···O, hydrogen bonds, forming an infinite 3-D network, Fig. 2, Table 2, and π-π stacking interactions between the 5-methylpyrazine-2-carboxylate ligand, Fig. 3, Table 3.

Related literature top

For background to coordination chemistry, see: Blake et al. (1999); Brito et al. (2011). For the isotypic Mn compound see: Chapman et al. (2002). For similar compounds of the type [M(C₆H₅N₂O₂)₂(H₂O)₂, wher M = Fe^II, Co^II, Zn^II, Ni^II] see: Fan et al. (2007a,b, 2009); Shang et al. (2007).

Experimental top

5-methylpyrazine-2-carboxylic acid (1113 mg, 8.0 mmol) was added to 20 ml solution of NaOH (322 mg, 8.0 mmol) in water. The mixture was stirred for 30 minutes at room temperature. CdCl₂ (739 mg, 4.0 mmol) was added slowly to the above solution and upon heating, a yellow precipitate was formed. After filtration the yellow material was washed several times with water and dried in air. The title compound was obtained by hydrothermal synthesis of a mixture of the yellow precipitate (105.6 mg, 0.25 mmol) and pyrazine (40.0 mg, 0.5 mmol) in 6 ml H₂O, in an acid digestion bomb, heated at 130 °C for 72 h. Suitable single crystals grew upon cooling of the solution to room temperature. C₁₂H₁₄CdN₄O₆; IR (KBr, cm^-1): ν = 3427 s, 1631 s,1580 s, 1520 m, 1483 m, 1449 s, 1395 s, 1322 s, 1290 m, 1171 m, 1042 s, 871 s, 413 s.

Structure description top

For background to coordination chemistry, see: Blake et al. (1999); Brito et al. (2011). For the isotypic Mn compound see: Chapman et al. (2002). For similar compounds of the type [M(C₆H₅N₂O₂)₂(H₂O)₂, wher M = Fe^II, Co^II, Zn^II, Ni^II] see: Fan et al. (2007a,b, 2009); Shang et al. (2007).

Computing details top

Data collection: CrysAlis PRO (Agilent, 2010); cell refinement: CrysAlis PRO (Agilent, 2010); data reduction: CrysAlis PRO (Agilent, 2010); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: OLEX2 (Dolomanov et al., 2009) and PLATON (Spek, 2009); software used to prepare material for publication: publCIF (Westrip, 2010) and WinGX (Farrugia, 1999).

Figures top

	Fig. 1. The molecule of (I), showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 30% probability level. H atoms are represented by circles of arbitrary radius.
	Fig. 2. A view of title compound showing the hydrogen bonds and are indicated by dashed lines. [Symmetry codes: (i) -x + 1, -y + 2, -z + 2; (ii) x, y + 1, z; (iii) -x + 2, -y + 1, -z + 1; (iv) x + 1, y, z].
	Fig. 3. A partial packing diagram (I), showing molecules stacked view along ab plane. Ring centroids (Cg1 and Cg2 for the 2-methylpyrazine rings) involved in the π-π interactions are joined by dashed lines. [Symmetry codes: (i) -x + 2, -y + 1, -z + 1; (ii) -x + 1, -y + 2, -z + 2]

Diaquabis(5-methylpyrazine-2-carboxylato- κ²N¹,O²)cadmium top

Crystal data top

[Cd(C₆H₅N₂O₂)₂(H₂O)₂]	Z = 2
M_r = 422.67	F(000) = 420
Triclinic, P1	D_x = 1.860 Mg m⁻³
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 7.2900 (15) Å	Cell parameters from 5011 reflections
b = 7.5320 (15) Å	θ = 3.4–29.7°
c = 14.090 (3) Å	µ = 1.48 mm⁻¹
α = 87.31 (3)°	T = 293 K
β = 81.36 (3)°	Block, yellow
γ = 80.78 (3)°	0.44 × 0.40 × 0.22 mm
V = 754.8 (3) Å³

Data collection top

Oxford Diffraction CCD area-detector diffractometer	3530 independent reflections
Radiation source: fine-focus sealed tube	2778 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.061
ω scans	θ_max = 29.7°, θ_min = 3.4°
Absorption correction: multi-scan (MULABS; Spek, 2009; Blessing, 1995)	h = −8→9
T_min = 0.561, T_max = 0.736	k = −9→5
5896 measured reflections	l = −17→17

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.058	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.159	H atoms treated by a mixture of independent and constrained refinement
S = 1.06	w = 1/[σ²(F_o²) + (0.0751P)²] where P = (F_o² + 2F_c²)/3
3530 reflections	(Δ/σ)_max = 0.002
226 parameters	Δρ_max = 2.23 e Å⁻³
0 restraints	Δρ_min = −1.11 e Å⁻³

Crystal data top

[Cd(C₆H₅N₂O₂)₂(H₂O)₂]	γ = 80.78 (3)°
M_r = 422.67	V = 754.8 (3) Å³
Triclinic, P1	Z = 2
a = 7.2900 (15) Å	Mo Kα radiation
b = 7.5320 (15) Å	µ = 1.48 mm⁻¹
c = 14.090 (3) Å	T = 293 K
α = 87.31 (3)°	0.44 × 0.40 × 0.22 mm
β = 81.36 (3)°

Data collection top

Oxford Diffraction CCD area-detector diffractometer	3530 independent reflections
Absorption correction: multi-scan (MULABS; Spek, 2009; Blessing, 1995)	2778 reflections with I > 2σ(I)
T_min = 0.561, T_max = 0.736	R_int = 0.061
5896 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.058	0 restraints
wR(F²) = 0.159	H atoms treated by a mixture of independent and constrained refinement
S = 1.06	Δρ_max = 2.23 e Å⁻³
3530 reflections	Δρ_min = −1.11 e Å⁻³
226 parameters

Special details top

Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > 2σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
Cd1	0.61134 (5)	0.67712 (5)	0.73978 (3)	0.03763 (19)
O1	0.6127 (6)	0.3946 (6)	0.6951 (3)	0.0472 (11)
O2	0.2944 (6)	0.7316 (6)	0.7793 (3)	0.0475 (10)
O3	0.6360 (9)	0.9759 (7)	0.7328 (5)	0.0593 (14)
H3A	0.625 (7)	1.019 (8)	0.781 (4)	0.020 (15)*
H3B	0.607 (14)	1.024 (13)	0.690 (7)	0.09 (4)*
O4	0.9122 (7)	0.6009 (8)	0.7706 (4)	0.0581 (13)
H4A	0.995 (10)	0.560 (10)	0.726 (6)	0.06 (2)*
H4B	0.943 (13)	0.705 (14)	0.793 (7)	0.10 (3)*
O5	0.6558 (8)	0.2045 (6)	0.5758 (3)	0.0561 (12)
O6	0.0540 (6)	0.8123 (8)	0.8930 (4)	0.0607 (13)
N1	0.6959 (7)	0.6675 (6)	0.5708 (3)	0.0354 (10)
N2	0.8477 (7)	0.5928 (7)	0.3815 (4)	0.0421 (12)
N3	0.5370 (6)	0.6945 (6)	0.9084 (3)	0.0346 (10)
N4	0.4226 (7)	0.8321 (7)	1.0909 (4)	0.0411 (12)
C1	0.7138 (7)	0.5011 (7)	0.5376 (4)	0.0344 (12)
C2	0.7863 (8)	0.4661 (8)	0.4434 (4)	0.0398 (13)
H2	0.7933	0.3503	0.4215	0.048*
C3	0.8288 (8)	0.7586 (8)	0.4138 (4)	0.0418 (13)
C4	0.7530 (9)	0.7945 (8)	0.5084 (4)	0.0417 (13)
H4	0.7412	0.9115	0.5295	0.050*
C5	0.8947 (11)	0.9043 (10)	0.3470 (5)	0.0591 (18)
H5A	0.9502	0.9833	0.3817	0.089*
H5B	0.7898	0.9714	0.3207	0.089*
H5C	0.9862	0.8512	0.2958	0.089*
C6	0.6543 (8)	0.3540 (8)	0.6091 (5)	0.0400 (13)
C7	0.6558 (8)	0.6841 (8)	0.9727 (4)	0.0405 (13)
H7	0.7798	0.6306	0.9555	0.049*
C8	0.6001 (8)	0.7502 (8)	1.0637 (4)	0.0392 (13)
C9	0.3029 (8)	0.8382 (8)	1.0262 (4)	0.0425 (14)
H9	0.1785	0.8906	1.0433	0.051*
C10	0.3579 (7)	0.7703 (8)	0.9364 (4)	0.0365 (12)
C11	0.2241 (8)	0.7717 (8)	0.8637 (5)	0.0424 (14)
C12	0.7340 (10)	0.7352 (10)	1.1345 (5)	0.0532 (17)
H12A	0.7154	0.8453	1.1688	0.080*
H12B	0.8603	0.7131	1.1015	0.080*
H12C	0.7127	0.6375	1.1789	0.080*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Cd1	0.0420 (3)	0.0324 (3)	0.0377 (3)	−0.00852 (18)	0.00199 (18)	−0.00820 (19)
O1	0.069 (3)	0.033 (2)	0.041 (2)	−0.019 (2)	0.003 (2)	−0.0051 (19)
O2	0.042 (2)	0.058 (3)	0.042 (2)	−0.005 (2)	−0.0048 (18)	−0.010 (2)
O3	0.102 (4)	0.035 (3)	0.041 (3)	−0.021 (3)	−0.001 (3)	−0.011 (3)
O4	0.037 (3)	0.070 (4)	0.066 (3)	−0.003 (2)	−0.001 (2)	−0.032 (3)
O5	0.092 (4)	0.027 (2)	0.050 (3)	−0.017 (2)	−0.003 (2)	−0.008 (2)
O6	0.031 (2)	0.086 (4)	0.066 (3)	−0.009 (2)	−0.002 (2)	−0.015 (3)
N1	0.048 (3)	0.023 (2)	0.036 (3)	−0.0080 (19)	−0.004 (2)	−0.005 (2)
N2	0.048 (3)	0.035 (3)	0.042 (3)	−0.003 (2)	−0.002 (2)	−0.007 (2)
N3	0.034 (2)	0.033 (3)	0.036 (3)	−0.0069 (19)	0.0004 (19)	−0.005 (2)
N4	0.049 (3)	0.036 (3)	0.038 (3)	−0.008 (2)	−0.002 (2)	−0.004 (2)
C1	0.037 (3)	0.023 (3)	0.043 (3)	−0.003 (2)	−0.005 (2)	−0.008 (2)
C2	0.042 (3)	0.030 (3)	0.047 (4)	−0.004 (2)	−0.004 (2)	−0.011 (3)
C3	0.049 (3)	0.036 (3)	0.040 (3)	−0.007 (3)	−0.008 (3)	0.000 (3)
C4	0.057 (4)	0.023 (3)	0.044 (3)	−0.005 (2)	0.000 (3)	−0.007 (2)
C5	0.076 (5)	0.053 (4)	0.050 (4)	−0.017 (4)	−0.006 (3)	0.002 (3)
C6	0.043 (3)	0.030 (3)	0.047 (4)	−0.006 (2)	−0.006 (3)	−0.006 (3)
C7	0.032 (3)	0.044 (4)	0.044 (3)	−0.007 (2)	−0.001 (2)	0.002 (3)
C8	0.041 (3)	0.036 (3)	0.042 (3)	−0.014 (2)	−0.003 (2)	0.003 (3)
C9	0.036 (3)	0.041 (3)	0.047 (4)	−0.005 (2)	0.005 (2)	−0.012 (3)
C10	0.033 (3)	0.032 (3)	0.043 (3)	−0.010 (2)	0.005 (2)	−0.003 (2)
C11	0.038 (3)	0.035 (3)	0.055 (4)	−0.009 (2)	−0.004 (3)	−0.008 (3)
C12	0.060 (4)	0.055 (4)	0.050 (4)	−0.017 (3)	−0.016 (3)	−0.004 (3)

Geometric parameters (Å, º) top

Cd1—O1	2.245 (4)	N4—C9	1.347 (8)
Cd1—O2	2.269 (4)	N4—C8	1.349 (8)
Cd1—O4	2.278 (5)	C1—C2	1.374 (8)
Cd1—O3	2.283 (5)	C1—C6	1.532 (8)
Cd1—N3	2.361 (5)	C2—H2	0.9300
Cd1—N1	2.370 (5)	C3—C4	1.385 (8)
O1—C6	1.244 (7)	C3—C5	1.502 (9)
O2—C11	1.253 (8)	C4—H4	0.9300
O3—H3A	0.75 (6)	C5—H5A	0.9600
O3—H3B	0.73 (9)	C5—H5B	0.9600
O4—H4A	0.83 (8)	C5—H5C	0.9600
O4—H4B	0.93 (11)	C7—C8	1.376 (8)
O5—C6	1.238 (7)	C7—H7	0.9300
O6—C11	1.240 (7)	C8—C12	1.486 (8)
N1—C1	1.339 (7)	C9—C10	1.366 (8)
N1—C4	1.342 (7)	C9—H9	0.9300
N2—C3	1.329 (8)	C10—C11	1.516 (8)
N2—C2	1.346 (8)	C12—H12A	0.9600
N3—C7	1.335 (7)	C12—H12B	0.9600
N3—C10	1.347 (7)	C12—H12C	0.9600

O1—Cd1—O2	93.45 (17)	N2—C3—C4	120.1 (6)
O1—Cd1—O4	90.14 (19)	N2—C3—C5	119.0 (6)
O2—Cd1—O4	154.86 (19)	C4—C3—C5	120.9 (6)
O1—Cd1—O3	161.4 (2)	N1—C4—C3	122.7 (5)
O2—Cd1—O3	92.9 (2)	N1—C4—H4	118.6
O4—Cd1—O3	91.5 (2)	C3—C4—H4	118.6
O1—Cd1—N3	109.65 (16)	C3—C5—H5A	109.5
O2—Cd1—N3	71.25 (16)	C3—C5—H5B	109.5
O4—Cd1—N3	84.11 (18)	H5A—C5—H5B	109.5
O3—Cd1—N3	89.0 (2)	C3—C5—H5C	109.5
O1—Cd1—N1	72.18 (16)	H5A—C5—H5C	109.5
O2—Cd1—N1	110.48 (16)	H5B—C5—H5C	109.5
O4—Cd1—N1	94.30 (19)	O5—C6—O1	126.1 (6)
O3—Cd1—N1	89.2 (2)	O5—C6—C1	116.6 (6)
N3—Cd1—N1	177.55 (14)	O1—C6—C1	117.2 (5)
C6—O1—Cd1	120.4 (4)	N3—C7—C8	122.0 (5)
C11—O2—Cd1	119.5 (4)	N3—C7—H7	119.0
Cd1—O3—H3A	114 (4)	C8—C7—H7	119.0
Cd1—O3—H3B	115 (8)	N4—C8—C7	120.9 (5)
H3A—O3—H3B	124 (10)	N4—C8—C12	118.0 (6)
Cd1—O4—H4A	119 (5)	C7—C8—C12	121.1 (6)
Cd1—O4—H4B	105 (6)	N4—C9—C10	122.3 (5)
H4A—O4—H4B	109 (8)	N4—C9—H9	118.8
C1—N1—C4	116.9 (5)	C10—C9—H9	118.8
C1—N1—Cd1	112.5 (4)	N3—C10—C9	120.8 (5)
C4—N1—Cd1	129.8 (4)	N3—C10—C11	116.2 (5)
C3—N2—C2	117.3 (5)	C9—C10—C11	123.0 (5)
C7—N3—C10	117.3 (5)	O6—C11—O2	125.5 (6)
C7—N3—Cd1	127.7 (4)	O6—C11—C10	117.1 (6)
C10—N3—Cd1	112.4 (4)	O2—C11—C10	117.4 (5)
C9—N4—C8	116.6 (5)	C8—C12—H12A	109.5
N1—C1—C2	120.3 (5)	C8—C12—H12B	109.5
N1—C1—C6	117.3 (5)	H12A—C12—H12B	109.5
C2—C1—C6	122.4 (5)	C8—C12—H12C	109.5
N2—C2—C1	122.7 (6)	H12A—C12—H12C	109.5
N2—C2—H2	118.7	H12B—C12—H12C	109.5
C1—C2—H2	118.7

O2—Cd1—O1—C6	110.9 (5)	C6—C1—C2—N2	−176.5 (5)
O4—Cd1—O1—C6	−94.0 (5)	C2—N2—C3—C4	1.6 (8)
O3—Cd1—O1—C6	1.2 (9)	C2—N2—C3—C5	−179.7 (5)
N3—Cd1—O1—C6	−177.8 (4)	C1—N1—C4—C3	−0.5 (8)
N1—Cd1—O1—C6	0.5 (4)	Cd1—N1—C4—C3	168.3 (4)
O1—Cd1—O2—C11	119.9 (5)	N2—C3—C4—N1	0.0 (9)
O4—Cd1—O2—C11	22.2 (7)	C5—C3—C4—N1	−178.7 (6)
O3—Cd1—O2—C11	−77.7 (5)	Cd1—O1—C6—O5	−178.3 (5)
N3—Cd1—O2—C11	10.3 (5)	Cd1—O1—C6—C1	3.2 (7)
N1—Cd1—O2—C11	−167.9 (4)	N1—C1—C6—O5	173.8 (5)
O1—Cd1—N1—C1	−4.4 (3)	C2—C1—C6—O5	−7.4 (8)
O2—Cd1—N1—C1	−91.4 (4)	N1—C1—C6—O1	−7.5 (8)
O4—Cd1—N1—C1	84.3 (4)	C2—C1—C6—O1	171.2 (5)
O3—Cd1—N1—C1	175.8 (4)	C10—N3—C7—C8	−1.1 (8)
O1—Cd1—N1—C4	−173.7 (5)	Cd1—N3—C7—C8	159.3 (4)
O2—Cd1—N1—C4	99.3 (5)	C9—N4—C8—C7	2.7 (8)
O4—Cd1—N1—C4	−84.9 (5)	C9—N4—C8—C12	−177.8 (5)
O3—Cd1—N1—C4	6.5 (5)	N3—C7—C8—N4	−1.3 (9)
O1—Cd1—N3—C7	96.2 (5)	N3—C7—C8—C12	179.2 (5)
O2—Cd1—N3—C7	−176.9 (5)	C8—N4—C9—C10	−1.8 (9)
O4—Cd1—N3—C7	8.2 (5)	C7—N3—C10—C9	1.9 (8)
O3—Cd1—N3—C7	−83.5 (5)	Cd1—N3—C10—C9	−161.4 (5)
O1—Cd1—N3—C10	−102.6 (4)	C7—N3—C10—C11	−177.0 (5)
O2—Cd1—N3—C10	−15.7 (4)	Cd1—N3—C10—C11	19.7 (6)
O4—Cd1—N3—C10	169.4 (4)	N4—C9—C10—N3	−0.5 (9)
O3—Cd1—N3—C10	77.7 (4)	N4—C9—C10—C11	178.4 (5)
C4—N1—C1—C2	−0.5 (8)	Cd1—O2—C11—O6	176.5 (5)
Cd1—N1—C1—C2	−171.3 (4)	Cd1—O2—C11—C10	−3.6 (7)
C4—N1—C1—C6	178.3 (5)	N3—C10—C11—O6	168.1 (5)
Cd1—N1—C1—C6	7.5 (6)	C9—C10—C11—O6	−10.8 (9)
C3—N2—C2—C1	−2.7 (8)	N3—C10—C11—O2	−11.8 (8)
N1—C1—C2—N2	2.2 (9)	C9—C10—C11—O2	169.3 (6)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O3—H3A···N4ⁱ	0.75 (6)	2.12 (6)	2.875 (9)	173 (6)
O3—H3B···O5ⁱⁱ	0.73 (10)	2.08 (10)	2.740 (8)	150 (10)
O4—H4A···N2ⁱⁱⁱ	0.84 (8)	2.04 (8)	2.852 (8)	164 (8)
O4—H4B···O6^iv	0.93 (11)	1.99 (10)	2.811 (8)	146 (8)
C4—H4···O5ⁱⁱ	0.93	2.29	3.211 (7)	169

Symmetry codes: (i) −x+1, −y+2, −z+2; (ii) x, y+1, z; (iii) −x+2, −y+1, −z+1; (iv) x+1, y, z.

Experimental details

Crystal data
Chemical formula	[Cd(C₆H₅N₂O₂)₂(H₂O)₂]
M_r	422.67
Crystal system, space group	Triclinic, P1
Temperature (K)	293
a, b, c (Å)	7.2900 (15), 7.5320 (15), 14.090 (3)
α, β, γ (°)	87.31 (3), 81.36 (3), 80.78 (3)
V (Å³)	754.8 (3)
Z	2
Radiation type	Mo Kα
µ (mm⁻¹)	1.48
Crystal size (mm)	0.44 × 0.40 × 0.22

Data collection
Diffractometer	Oxford Diffraction CCD area-detector
Absorption correction	Multi-scan (MULABS; Spek, 2009; Blessing, 1995)
T_min, T_max	0.561, 0.736
No. of measured, independent and observed [I > 2σ(I)] reflections	5896, 3530, 2778
R_int	0.061
(sin θ/λ)_max (Å⁻¹)	0.697

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.058, 0.159, 1.06
No. of reflections	3530
No. of parameters	226
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	2.23, −1.11

Computer programs: CrysAlis PRO (Agilent, 2010), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), OLEX2 (Dolomanov et al., 2009) and PLATON (Spek, 2009), publCIF (Westrip, 2010) and WinGX (Farrugia, 1999).

Selected geometric parameters (Å, º) top

Cd1—O1	2.245 (4)	Cd1—O3	2.283 (5)
Cd1—O2	2.269 (4)	Cd1—N3	2.361 (5)
Cd1—O4	2.278 (5)	Cd1—N1	2.370 (5)

O2—Cd1—O4	154.86 (19)	O3—Cd1—N3	89.0 (2)
O1—Cd1—O3	161.4 (2)	O1—Cd1—N1	72.18 (16)
O2—Cd1—N3	71.25 (16)	N3—Cd1—N1	177.55 (14)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O3—H3A···N4ⁱ	0.75 (6)	2.12 (6)	2.875 (9)	173 (6)
O3—H3B···O5ⁱⁱ	0.73 (10)	2.08 (10)	2.740 (8)	150 (10)
O4—H4A···N2ⁱⁱⁱ	0.84 (8)	2.04 (8)	2.852 (8)	164 (8)
O4—H4B···O6^iv	0.93 (11)	1.99 (10)	2.811 (8)	146 (8)
C4—H4···O5ⁱⁱ	0.93	2.29	3.211 (7)	169

Symmetry codes: (i) −x+1, −y+2, −z+2; (ii) x, y+1, z; (iii) −x+2, −y+1, −z+1; (iv) x+1, y, z.

π–π stacking interactions (Å) in the title compound top

Notes: α is the dihedral angle (°) between the planes of the rings, d is the distance (Å) between the ring centroids and Δ is the displacement (Å) of the centroid of ring 2 relative to the intersection point of the normal to the centroid of ring 1 and the least-squares plane of ring 2.

Ring 1	Ring 2	α	d	Δ
N1/C1/C2/N2/C3/C4	(N1/C1/C2/N2/C3/C4)ⁱ	0	3.730 (3)	1.237
N3/C7/C8/N4/C9/C10	(N3/C7/C8/N4/C9/C10)ⁱⁱ	0	3.652 (3)	1.307

Symmetry codes: (i) -x+2, -y+1, -z+1; (ii) -x+1, -y+2, -z+2.

Acknowledgements

We thank the Spanish Research Council (CSIC) for providing us with a free-of-charge licence for the CSD system. JA thanks the Universidad de Antofagasta for a PhD fellowship.

References

Agilent (2010). CrysAlis PRO. Agilent Technologies, Yarnton, England. Google Scholar
Blake, A. J., Champness, N. R., Hubberstey, P., Li, W. S., Withersby, M. A. & Schröder, M. (1999). Coord. Chem. Rev. 183, 117–138. Web of Science CrossRef CAS Google Scholar
Blessing, R. H. (1995). Acta Cryst. A51, 33–38. CrossRef CAS Web of Science IUCr Journals Google Scholar
Brito, I., Vallejos, J., Cárdenas, A., López-Rodríguez, M., Bolte, M. & Llanos, J. (2011). Inorg. Chem. Commun. 14, 897–901. Web of Science CSD CrossRef CAS Google Scholar
Chapman, C. T., Ciurtin, D. M., Smith, M. D. & zur Loye, H.-C. (2002). Solid State Sci. 4, 1187–1191. Web of Science CSD CrossRef CAS Google Scholar
Dolomanov, O. V., Bourhis, L. J., Gildea, R. J., Howard, J. A. K. & Puschmann, H. (2009). J. Appl. Cryst. 42, 339–341. Web of Science CrossRef CAS IUCr Journals Google Scholar
Fan, G., Chen, S.-P. & Gao, S.-L. (2007a). Acta Cryst. E63, m772–m773. Web of Science CSD CrossRef IUCr Journals Google Scholar
Fan, G., Chen, S.-P. & Gao, S.-L. (2007b). Acta Cryst. E63, m774–m775. Web of Science CSD CrossRef IUCr Journals Google Scholar
Fan, G., Sun, J.-J., Zhang, J.-C., Ma, Z.-Y. & Gao, S.-L. (2009). Acta Cryst. E65, m107. Web of Science CSD CrossRef IUCr Journals Google Scholar
Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837–838. CrossRef CAS IUCr Journals Google Scholar
Shang, R.-L., Liu, F.-Y., Du, L., Li, X.-B. & Sun, B.-W. (2007). Acta Cryst. E63, m190–m192. Web of Science CSD CrossRef IUCr Journals Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Spek, A. L. (2009). Acta Cryst. D65, 148–155. Web of Science CrossRef CAS IUCr Journals Google Scholar
Westrip, S. P. (2010). J. Appl. Cryst. 43, 920–925. Web of Science CrossRef CAS IUCr Journals Google Scholar