Diaqua­bis(1H-1,2,4-triazole-3-carboxyl­ato)cadmium(II)

Abstract

In the title complex, [Cd(C₃H₂N₃O₂)₂(H₂O)₂], the Cd^II atom is coordinated by two N and two O atoms from two deprotonated 1H-1,2,4-triazole-3-carboxylic acid ligands (TRIA) and two water mol­ecules. The Cd atom is located on an inversion centre. In the crystal structure, mol­ecules are linked together via O—H⋯O and N—H⋯O hydrogen bonds, forming a three-dimensional network.

Related literature

For related literature, see: Guo & Wang (2005 ▶), Zhu et al. (2007 ▶, 2008 ▶).

Experimental

Crystal data

• [Cd(C₃H₂N₃O₂)₂(H₂O)₂]

• M _r = 372.58

• Monoclinic,

• a = 9.2722 (16) Å

• b = 8.8318 (14) Å

• c = 6.9714 (17) Å

• β = 92.230 (1)°

• V = 570.46 (19) ų

• Z = 2

• Mo Kα radiation

• μ = 1.95 mm⁻¹

• T = 298 (1) K

• 0.32 × 0.23 × 0.11 mm

Data collection

• Bruker SMART CCD diffractometer

• Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T _min = 0.574, T _max = 0.814

• 2791 measured reflections

• 1002 independent reflections

• 843 reflections with I > 2σ(I)

• R _int = 0.023

Refinement

• R[F ² > 2σ(F ²)] = 0.027

• wR(F ²) = 0.077

• S = 1.09

• 1002 reflections

• 88 parameters

• H-atom parameters constrained

• Δρ_max = 1.21 e Å⁻³

• Δρ_min = −0.60 e Å⁻³

Data collection: SMART (Siemens, 1996 ▶); cell refinement: SAINT (Siemens, 1996 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997a ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997a ▶); molecular graphics: SHELXTL (Sheldrick, 1997b ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

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—H3C⋯O2i	0.85	1.90	2.715 (3)	159
O3—H3B⋯O1ii	0.85	1.91	2.736 (3)	162
N3—H3⋯O2iii	0.86	1.89	2.728 (4)	164

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

supplementary crystallographic information

Comment

Recently, although the crystal structure of methyl 1H-1,2,4-triazole-3-carboxylate has been reported (Guo & Wang, 2005), metal complexes with triazole ligands have been rarely of interest for decades despite the biological importance of the triazole group. We have reported the crystal structures of two new copper(II) complexes diaquobis(1H-1,2,4-triazole-3-carboxylato)copper(II) and (1H-1,2,4-triazole-3-carboxylato)(1,10-phen)copper(II)chloride (Zhu, et al., 2007, 2008). As a further investigation, we report in this paper the crystal structure of a new cadmium(II) complex, diaquobis(1H- 1,2,4-triazole-3-carboxylato)cadmium(II).

As shown in Fig. 1, the title compound consists of a centrosymmetric mononuclear cadmium(II) complex cation. In the cation the Cd atom is six-coordinated by two N and two O atoms from two TRIA ligands and two O atoms from two water molecules. The Cd^II atom is in a slightly distorted octahedral environment. The Cd—O distances range from 2.315 (2) to 2.321 (3) Å, and the Cd—N bond length is 2.293 (3) Å, i.e. normal values. The C1—C2 bond length is 1.495 (5) Å, being in the normal C—C ranges in cadmium carboxylate complexes. The angles around Cd^II atom are from 73.57 (9) to linear. The TRIA molecule acts as a bidentate ligand.

In the title compound, the water molecules contribute to the formation of intermolecular hydrogen bonds involving carboxylate O atoms. Additional hydrogen bonds exist between the N—H groups of the triazole and carboxylate O atoms.

Experimental

1H-1,2,4-triazole-3-carboxylic acid and CdCl₂.2.5H₂O were available commercially and were used without further purification. 1H-1,2,4-triazole-3-carboxylic acid (1 mmol, 113 mg) was dissolved in distilled water (15 ml) and CdCl₂.2.5H₂O (0.5 mmol, 114.2 mg) was added in distilled water (5 ml) with stirring at 323 K. The resulting colorless solution was allowed to react for 5 h and was then filtered. Colorless crystals suitable for X-ray analysis were obtained by slow evaporation of a water solution over a period of one month (yield 75%). Anal. Calcd (%) for C₆H₈CdN₆O₆ (Mr = 372.58): C, 19.34; H, 2.16; N, 22.56. Found (%): C, 19.28; H, 2.22; N, 22.49.

Refinement

All the H atoms were placed in geometrically idealized positions and constrained to ride on their parent atoms with O—H, N—H and C—H distances of 0.85 Å, 0.86 Å and 0.93 Å, respectively, and U_iso(H) = 1.2U_eq(O), U_iso(H) = 1.2U_eq(N) and U_iso(H) = 1.2U_eq(C).

H atoms of the water molecules were located in a difference Fourier map and refined using a riding method. The highest peak in the difference map is 1.21 (1) Å from Cd1 and the largest hole is 0.60 (2) Å from Cd1.

Figures

Fig. 1.

The structure of the title compound showing 50% probability displacement ellipsoids and the atom-numbering scheme. Symmetry code: (i) -x, -y, -z.

Crystal data

[Cd(C3H2N3O2)2(H2O)2]	F000 = 364
Mr = 372.58	Dx = 2.169 Mg m−3
Monoclinic, P21/c	Mo Kα radiation λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 2042 reflections
a = 9.2722 (16) Å	θ = 2.2–28.2º
b = 8.8318 (14) Å	µ = 1.95 mm−1
c = 6.9714 (17) Å	T = 298 (1) K
β = 92.2300 (10)º	Prism, colorless
V = 570.46 (19) Å3	0.32 × 0.23 × 0.11 mm
Z = 2

Data collection

Bruker SMART CCD diffractometer	1002 independent reflections
Radiation source: fine-focus sealed tube	843 reflections with I > 2σ(I)
Monochromator: graphite	Rint = 0.023
T = 298(1) K	θmax = 25.0º
φ and ω scans	θmin = 2.2º
Absorption correction: multi-scan(SADABS; Sheldrick, 1996)	h = −9→11
Tmin = 0.574, Tmax = 0.814	k = −10→10
2791 measured reflections	l = −8→7

Refinement

Refinement on F2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.027	H-atom parameters constrained
wR(F2) = 0.077	w = 1/[σ2(Fo2) + (0.0445P)2 + 0.5043P] where P = (Fo2 + 2Fc2)/3
S = 1.09	(Δ/σ)max < 0.001
1002 reflections	Δρmax = 1.21 e Å−3
88 parameters	Δρmin = −0.60 e Å−3
Primary atom site location: structure-invariant direct methods	Extinction correction: none

Special details

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

	x	y	z	Uiso*/Ueq
Cd1	0.0000	0.0000	0.0000	0.02817 (18)
N1	0.2289 (4)	−0.0228 (3)	0.1335 (5)	0.0311 (8)
N2	0.4348 (3)	0.1039 (3)	0.2024 (4)	0.0311 (7)
N3	0.4480 (3)	−0.0451 (4)	0.2456 (5)	0.0323 (7)
H3	0.5255	−0.0865	0.2927	0.039*
O1	0.1027 (2)	0.2387 (2)	−0.0103 (3)	0.0293 (6)
O2	0.2867 (2)	0.3785 (2)	0.1013 (4)	0.0313 (6)
O3	−0.0921 (3)	0.0865 (3)	0.2849 (4)	0.0409 (7)
H3B	−0.0262	0.1228	0.3596	0.049*
H3C	−0.1369	0.0171	0.3426	0.049*
C1	0.2259 (3)	0.2549 (4)	0.0702 (5)	0.0242 (7)
C2	0.2995 (4)	0.1123 (4)	0.1356 (5)	0.0253 (7)
C3	0.3259 (4)	−0.1186 (4)	0.2057 (6)	0.0364 (9)
H3A	0.3110	−0.2215	0.2255	0.044*

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
Cd1	0.0187 (2)	0.0234 (2)	0.0416 (3)	−0.00318 (12)	−0.00840 (16)	−0.00195 (14)
N1	0.0245 (18)	0.0259 (16)	0.042 (2)	0.0022 (12)	−0.0097 (14)	−0.0001 (13)
N2	0.0212 (15)	0.0333 (16)	0.0384 (17)	0.0024 (13)	−0.0050 (13)	−0.0017 (14)
N3	0.0253 (17)	0.0296 (15)	0.0415 (19)	0.0079 (14)	−0.0077 (14)	0.0029 (14)
O1	0.0226 (12)	0.0230 (12)	0.0414 (15)	−0.0009 (9)	−0.0103 (10)	0.0046 (10)
O2	0.0237 (13)	0.0225 (12)	0.0474 (15)	−0.0025 (10)	−0.0034 (11)	0.0009 (10)
O3	0.0377 (15)	0.0390 (15)	0.0458 (16)	−0.0120 (12)	−0.0014 (12)	−0.0053 (12)
C1	0.0204 (17)	0.0246 (17)	0.0275 (18)	−0.0005 (14)	0.0001 (13)	−0.0012 (14)
C2	0.0225 (18)	0.0259 (17)	0.0274 (18)	−0.0006 (14)	−0.0006 (13)	−0.0017 (14)
C3	0.032 (2)	0.0286 (19)	0.048 (2)	0.0017 (17)	−0.0058 (17)	0.0011 (17)

Geometric parameters (Å, °)

Cd1—N1	2.293 (3)	N2—N3	1.355 (4)
Cd1—N1i	2.293 (3)	N3—C3	1.325 (5)
Cd1—O1i	2.315 (2)	N3—H3	0.8600
Cd1—O1	2.315 (2)	O1—C1	1.261 (4)
Cd1—O3i	2.321 (3)	O2—C1	1.244 (4)
Cd1—O3	2.321 (3)	O3—H3B	0.8500
N1—C3	1.321 (5)	O3—H3C	0.8500
N1—C2	1.361 (4)	C1—C2	1.495 (5)
N2—C2	1.323 (4)	C3—H3A	0.9300
N1—Cd1—N1i	180.00 (17)	C2—N2—N3	102.0 (3)
N1—Cd1—O1i	106.43 (9)	C3—N3—N2	111.2 (3)
N1i—Cd1—O1i	73.57 (9)	C3—N3—H3	124.4
N1—Cd1—O1	73.57 (9)	N2—N3—H3	124.4
N1i—Cd1—O1	106.43 (9)	C1—O1—Cd1	117.1 (2)
O1i—Cd1—O1	180.0	Cd1—O3—H3B	111.7
N1—Cd1—O3i	87.30 (11)	Cd1—O3—H3C	111.8
N1i—Cd1—O3i	92.70 (11)	H3B—O3—H3C	109.5
O1i—Cd1—O3i	83.82 (9)	O2—C1—O1	125.0 (3)
O1—Cd1—O3i	96.18 (9)	O2—C1—C2	119.2 (3)
N1—Cd1—O3	92.70 (11)	O1—C1—C2	115.8 (3)
N1i—Cd1—O3	87.30 (11)	N2—C2—N1	113.8 (3)
O1i—Cd1—O3	96.18 (9)	N2—C2—C1	124.7 (3)
O1—Cd1—O3	83.82 (9)	N1—C2—C1	121.4 (3)
O3i—Cd1—O3	180.00 (12)	N1—C3—N3	109.2 (3)
C3—N1—C2	103.7 (3)	N1—C3—H3A	125.4
C3—N1—Cd1	144.8 (3)	N3—C3—H3A	125.4
C2—N1—Cd1	111.4 (2)
O1i—Cd1—N1—C3	4.2 (5)	Cd1—O1—C1—C2	9.1 (4)
O1—Cd1—N1—C3	−175.8 (5)	N3—N2—C2—N1	−0.5 (4)
O3i—Cd1—N1—C3	−78.6 (5)	N3—N2—C2—C1	178.4 (3)
O3—Cd1—N1—C3	101.4 (5)	C3—N1—C2—N2	0.9 (5)
O1i—Cd1—N1—C2	−179.7 (2)	Cd1—N1—C2—N2	−176.8 (2)
O1—Cd1—N1—C2	0.3 (2)	C3—N1—C2—C1	−178.1 (3)
O3i—Cd1—N1—C2	97.5 (3)	Cd1—N1—C2—C1	4.2 (4)
O3—Cd1—N1—C2	−82.5 (3)	O2—C1—C2—N2	−9.7 (5)
C2—N2—N3—C3	−0.1 (4)	O1—C1—C2—N2	171.8 (3)
N1—Cd1—O1—C1	−5.4 (2)	O2—C1—C2—N1	169.2 (3)
N1i—Cd1—O1—C1	174.6 (2)	O1—C1—C2—N1	−9.3 (5)
O3i—Cd1—O1—C1	−90.8 (2)	C2—N1—C3—N3	−0.9 (5)
O3—Cd1—O1—C1	89.2 (2)	Cd1—N1—C3—N3	175.3 (3)
Cd1—O1—C1—O2	−169.3 (3)	N2—N3—C3—N1	0.7 (5)

Symmetry codes: (i) −x, −y, −z.

Hydrogen-bond geometry (Å, °)

D—H···A	D—H	H···A	D···A	D—H···A
O3—H3C···O2ii	0.85	1.90	2.715 (3)	159
O3—H3B···O1iii	0.85	1.91	2.736 (3)	162
N3—H3···O2iv	0.86	1.89	2.728 (4)	164

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