Crystal structure of trans-di­aqua­bis­(1H-pyrazole-3-carboxyl­ato-κ² N,O)copper(II) dihydrate

Abstract

In the title compound, [Cu(C₄H₃N₂O₂)₂(H₂O)₂]·2H₂O, the Cu^II ion is located on an inversion centre and exhibits an axially elongated octa­hedral coordination geometry. The equatorial plane is formed by two N,O-bidentate 1H-pyrazole-3-carboxyl­ate ligands in a trans configuration. The axial positions are occupied by two water mol­ecules. The mononuclear complex mol­ecules are arranged in layers parallel to the ab plane. Each complex mol­ecule is linked to four adjacent species through inter­molecular O—H⋯O and N—H⋯O hydrogen bonds that are established between the coordinating water mol­ecules and carboxyl­ate O atoms or protonated N atoms of the organic ligands. These layers are further connected into a three-dimensional network by additional hydrogen bonds involving solvent water mol­ecules and non-coordinating carboxyl­ate O atoms.

Related literature  

For mononuclear cobalt(II), nickel(II) and zinc complexes of the 1H-pyrazole-3-carboxyl­ate ligand, see: Artetxe et al. (2015 ▸); López-Viseras et al. (2014 ▸).

Experimental  

Crystal data  

• [Cu(C₄H₃N₂O₂)₂(H₂O)₂]·2H₂O

• M _r = 357.77

• Monoclinic,

• a = 6.4780 (4) Å

• b = 21.5757 (10) Å

• c = 4.8937 (3) Å

• β = 105.856 (7)°

• V = 657.96 (6) ų

• Z = 2

• Cu Kα radiation

• μ = 2.83 mm⁻¹

• T = 100 K

• 0.09 × 0.04 × 0.02 mm

Data collection  

• Agilent SuperNova Single source at offset diffractometer

• Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2011 ▸) T _min = 0.817, T _max = 1

• 4452 measured reflections

• 1216 independent reflections

• 1089 reflections with I > 2σ(I)

• R _int = 0.031

Refinement  

• R[F ² > 2σ(F ²)] = 0.028

• wR(F ²) = 0.074

• S = 1.09

• 1216 reflections

• 109 parameters

• 4 restraints

• H atoms treated by a mixture of independent and constrained refinement

• Δρ_max = 0.36 e Å⁻³

• Δρ_min = −0.35 e Å⁻³

Data collection: CrysAlis PRO (Agilent, 2011 ▸); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: OLEX2 (Dolomanov et al., 2009 ▸); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▸); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012 ▸); software used to prepare material for publication: WinGX (Farrugia, 2012 ▸) and PLATON (Spek, 2009 ▸).

Supplementary Material

CCDC reference: 1437048

Additional supporting information: crystallographic information; 3D view; checkCIF report

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

Cu1—N2	1.9808 (16)
Cu1—O7	1.9910 (14)
Cu1—O1W	2.4501 (15)

N2—Cu1—O7	81.30 (6)
N2—Cu1—O1W	92.08 (6)
O7—Cu1—O1W	89.43 (5)

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

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1⋯O1W i	0.88	1.93	2.710 (2)	147
O1W—H1WA⋯O8ii	0.83 (2)	1.86 (2)	2.667 (2)	163 (3)
O1W—H1WB⋯O7iii	0.82 (2)	1.96 (2)	2.709 (2)	153 (3)
O2W—H2WA⋯O2W iv	0.83 (2)	1.95 (2)	2.7792 (15)	178 (3)
O2W—H2WB⋯O8	0.81 (2)	2.04 (2)	2.854 (2)	175 (3)

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

supplementary crystallographic information

S1. Structural commentary

The title compound, [Cu(C₄H₃N₂O₂)₂(H₂O)₂] ·2H₂O crystallizes in the monoclinic crystal system, space group P2₁/c. The equatorial Cu—O and Cu—N distances (Table 1) are similar to those observed for the corresponding Co(II), Ni(II) and Zn(II) analogues (Artetxe et al., 2015; López-Viseras et al., 2014). However, the axial bond lenghts are much longer due to the Jahn-Teller effect operating in Cu(II) centres. The mononuclear complexes arrange in layers parallel to the ab plane through inter­molecular O—H···O and N—H···O hydrogen bonds that are established between the coordinated water molecules (O1W) and carboxyl­ate O atoms (O7, O8) or protonated N atoms (N2) of the organic ligands. These layers are further connected into a three-dimensional network by additional hydrogen bonds involving solvent water molecules (O2W) and non-coordinating carboxyl­ate O atoms (O8). Table 2 summarizes the geometrical parameters of these O—H···O and N—H···O hydrogen bonding inter­actions.

S2. Synthesis and crystallization

To a solution of CuCl₂ · 2 H₂O (51 mg, 0.3 mmol) in hot water (15 ml) 1H-pyrazole-3-carb­oxy­lic acid (74 mg, 0.6 mmol) dissolved in hot water (10 ml) was added dropwise. After stirring for 30 min at 90 °C, the final solution was left undisturbed and prismatic blue crystals suitable for X-ray diffraction were obtained upon cooling to room temperature (Yield: 68 mg, 63%).

S3. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 1. All atoms except H were refined anisotropically. H atoms of the water molecules were located in a Fourier difference map and refined isotropically with O—H bond lenghts restrained to 0.84 (2) and with U_iso(H) = 1.5U_eq(O). All pyrazole H atoms were positioned geometrically and refined using a riding model with C—H = 0.95 Å, N—H = 0.88 Å and U_iso(H) = 1.2U_eq(C,N).

Figures

Fig. 1.

Molecular structure of [Cu(C4H3N2O2)2(H2O)2] ·2H2O showing the atom labelling for the asymmetric unit and 50% probability displacement ellipsoids.

Fig. 2.

View of the crystal packing along the crystallographic a axis (above). Projection of a layer of [Cu(C4H3N2O2)2(H2O)2] complexes along the [010] direction (below). Cu(II) centres are represented as translucent octahedra and the O—H···O and N—H···O hydrogen bonds are depicted as dashed red lines.

Crystal data

[Cu(C4H3N2O2)2(H2O)2]·2H2O	F(000) = 366
Mr = 357.77	Dx = 1.806 Mg m−3
Monoclinic, P21/c	Cu Kα radiation, λ = 1.54184 Å
Hall symbol: -P 2ybc	Cell parameters from 1956 reflections
a = 6.4780 (4) Å	θ = 4.1–73.7°
b = 21.5757 (10) Å	µ = 2.83 mm−1
c = 4.8937 (3) Å	T = 100 K
β = 105.856 (7)°	Prism, blue
V = 657.96 (6) Å3	0.09 × 0.04 × 0.02 mm
Z = 2

Data collection

Agilent SuperNova Single source at offset diffractometer	1216 independent reflections
Radiation source: SuperNova (Cu) X-ray Source	1089 reflections with I > 2σ(I)
Mirror monochromator	Rint = 0.031
Detector resolution: 5.2012 pixels mm-1	θmax = 69°, θmin = 4.1°
ω scans	h = −6→7
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2011)	k = −23→26
Tmin = 0.817, Tmax = 1	l = −5→5
4452 measured reflections

Refinement

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)] = 0.028	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.074	H atoms treated by a mixture of independent and constrained refinement
S = 1.09	w = 1/[σ2(Fo2) + (0.0406P)2 + 0.2735P] where P = (Fo2 + 2Fc2)/3
1216 reflections	(Δ/σ)max < 0.001
109 parameters	Δρmax = 0.36 e Å−3
4 restraints	Δρmin = −0.35 e Å−3

Special details

Experimental. IR (KBr pellets, cm-1): 3487(s), 3340(s), 3140(s), 3075(s), 2854(s), 2795(s), 1695(s), 1501(m), 1451(w), 1358(s), 1263(w), 1132(w), 1069(w), 1015(w), 943(m), 899(m), 839(m), 785(m), 648(m), 615(w), 500(w).TGA/DTA (synthetic air, 5°C min-1): The initial endothermic dehydration proccess (calcd/found for 4H2O: 20.1 /20.2%) is completed at c.a. 85°C and is followed by a thermal stability range for the anydrous phase that extends up to c.a. 210°C. The highly exothermic ligand combustion results in the final residue at 370°C (calcd/found for CuO: 22.1/21.8%).CHN (%m, calcd/found): C (26.8/27.2), H (3.9/3.9), N(15.7/15.5).

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
Cu1	0.5	0.5	0	0.01043 (15)
N1	0.5203 (3)	0.37840 (7)	−0.3376 (4)	0.0113 (4)
H1	0.6239	0.3877	−0.4153	0.014*
N2	0.4416 (3)	0.41696 (7)	−0.1769 (4)	0.0111 (4)
C3	0.2890 (3)	0.38581 (9)	−0.0975 (4)	0.0105 (4)
C4	0.2691 (3)	0.32597 (9)	−0.2127 (4)	0.0124 (4)
H4	0.1732	0.2942	−0.1909	0.015*
C5	0.4182 (3)	0.32329 (9)	−0.3637 (4)	0.0137 (4)
H5	0.4452	0.2886	−0.4687	0.016*
C6	0.1815 (3)	0.42089 (9)	0.0858 (4)	0.0107 (4)
O7	0.2562 (2)	0.47569 (6)	0.1520 (3)	0.0118 (3)
O8	0.0330 (2)	0.39735 (6)	0.1641 (3)	0.0144 (3)
O1W	0.2455 (2)	0.54965 (6)	−0.4047 (3)	0.0134 (3)
O2W	−0.1631 (3)	0.28054 (7)	0.2052 (4)	0.0219 (4)
H1WA	0.140 (4)	0.5615 (13)	−0.353 (6)	0.033*
H1WB	0.208 (5)	0.5252 (12)	−0.536 (5)	0.033*
H2WA	−0.167 (5)	0.2621 (13)	0.054 (5)	0.033*
H2WB	−0.102 (4)	0.3132 (10)	0.201 (6)	0.033*

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
Cu1	0.0144 (2)	0.0066 (2)	0.0126 (2)	−0.00226 (14)	0.00748 (17)	−0.00236 (15)
N1	0.0134 (8)	0.0095 (8)	0.0118 (8)	0.0020 (6)	0.0049 (7)	−0.0013 (6)
N2	0.0139 (8)	0.0095 (8)	0.0105 (8)	0.0006 (6)	0.0046 (7)	−0.0006 (6)
C3	0.0101 (9)	0.0116 (9)	0.0091 (9)	−0.0005 (7)	0.0016 (7)	0.0019 (7)
C4	0.0147 (10)	0.0089 (9)	0.0136 (10)	−0.0006 (8)	0.0039 (8)	0.0008 (7)
C5	0.0162 (10)	0.0094 (9)	0.0149 (10)	0.0008 (7)	0.0035 (8)	−0.0019 (7)
C6	0.0124 (9)	0.0098 (9)	0.0093 (10)	0.0026 (7)	0.0021 (8)	0.0013 (7)
O7	0.0153 (7)	0.0087 (6)	0.0132 (7)	−0.0015 (5)	0.0071 (5)	−0.0020 (5)
O8	0.0159 (7)	0.0106 (7)	0.0198 (8)	−0.0013 (5)	0.0103 (6)	0.0000 (6)
O1W	0.0153 (7)	0.0130 (7)	0.0140 (7)	−0.0010 (6)	0.0076 (6)	−0.0037 (6)
O2W	0.0313 (9)	0.0143 (7)	0.0209 (9)	−0.0057 (7)	0.0084 (7)	0.0011 (7)

Geometric parameters (Å, º)

Cu1—N2	1.9808 (16)	C3—C6	1.484 (3)
Cu1—N2i	1.9808 (16)	C4—C5	1.369 (3)
Cu1—O7i	1.9910 (14)	C4—H4	0.95
Cu1—O7	1.9910 (14)	C5—H5	0.95
Cu1—O1W	2.4501 (15)	C6—O8	1.238 (3)
Cu1—O1Wi	2.4501 (15)	C6—O7	1.285 (2)
N1—N2	1.338 (2)	O1W—H1WA	0.833 (18)
N1—C5	1.350 (3)	O1W—H1WB	0.817 (18)
N1—H1	0.88	O2W—H2WA	0.834 (18)
N2—C3	1.338 (3)	O2W—H2WB	0.813 (17)
C3—C4	1.401 (3)
N2—Cu1—N2i	180.00 (4)	N1—N2—Cu1	139.59 (13)
N2—Cu1—O7i	98.70 (6)	N2—C3—C4	109.90 (18)
N2i—Cu1—O7i	81.30 (6)	N2—C3—C6	115.16 (17)
N2—Cu1—O7	81.30 (6)	C4—C3—C6	134.95 (18)
N2i—Cu1—O7	98.70 (6)	C4—C3—Cu1	150.27 (15)
O7i—Cu1—O7	180	C6—C3—Cu1	74.67 (11)
N2—Cu1—O1W	92.08 (6)	C5—C4—C3	104.79 (17)
N2i—Cu1—O1W	87.92 (6)	C5—C4—H4	127.6
O7i—Cu1—O1W	90.57 (5)	C3—C4—H4	127.6
O7—Cu1—O1W	89.43 (5)	N1—C5—C4	108.16 (18)
N2—Cu1—O1Wi	87.92 (6)	N1—C5—H5	125.9
N2i—Cu1—O1Wi	92.08 (6)	C4—C5—H5	125.9
O7i—Cu1—O1Wi	89.43 (5)	O8—C6—O7	124.79 (19)
O7—Cu1—O1Wi	90.57 (5)	O8—C6—C3	120.69 (17)
O1W—Cu1—O1Wi	180.00 (6)	O7—C6—C3	114.52 (17)
N2—N1—C5	110.36 (17)	O8—C6—Cu1	164.75 (15)
C5—N1—Cu1	134.42 (13)	C3—C6—Cu1	74.54 (11)
N2—N1—H1	124.8	C6—O7—Cu1	115.51 (13)
C5—N1—H1	124.8	Cu1—O1W—H1WA	108 (2)
Cu1—N1—H1	100.7	Cu1—O1W—H1WB	110 (2)
C3—N2—N1	106.79 (16)	H1WA—O1W—H1WB	110 (3)
C3—N2—Cu1	113.30 (14)	H2WA—O2W—H2WB	107 (3)
N2i—Cu1—N1—N2	180	O7—Cu1—C3—C6	−0.48 (10)
O7i—Cu1—N1—N2	−176.5 (2)	O1W—Cu1—C3—C6	−87.49 (11)
O7—Cu1—N1—N2	3.5 (2)	O1Wi—Cu1—C3—C6	92.51 (11)
O1W—Cu1—N1—N2	−86.4 (2)	N2—C3—C4—C5	0.2 (2)
O1Wi—Cu1—N1—N2	93.6 (2)	C6—C3—C4—C5	−180.0 (2)
N2—Cu1—N1—C5	−8.9 (2)	Cu1—C3—C4—C5	−6.1 (3)
N2i—Cu1—N1—C5	171.1 (2)	N2—N1—C5—C4	−0.5 (2)
O7i—Cu1—N1—C5	174.58 (18)	Cu1—N1—C5—C4	3.4 (3)
O7—Cu1—N1—C5	−5.42 (18)	C3—C4—C5—N1	0.2 (2)
O1W—Cu1—N1—C5	−95.26 (18)	N2—C3—C6—O8	177.59 (17)
O1Wi—Cu1—N1—C5	84.74 (18)	C4—C3—C6—O8	−2.3 (3)
C5—N1—N2—C3	0.6 (2)	Cu1—C3—C6—O8	−179.15 (18)
Cu1—N1—N2—C3	−172.7 (3)	N2—C3—C6—O7	−2.6 (3)
C5—N1—N2—Cu1	173.24 (16)	C4—C3—C6—O7	177.6 (2)
O7i—Cu1—N2—C3	175.82 (13)	Cu1—C3—C6—O7	0.68 (14)
O7—Cu1—N2—C3	−4.18 (13)	N2—C3—C6—Cu1	−3.26 (14)
O1W—Cu1—N2—C3	−93.28 (14)	C4—C3—C6—Cu1	176.9 (2)
O1Wi—Cu1—N2—C3	86.72 (14)	N2—Cu1—C6—O8	179.6 (6)
O7i—Cu1—N2—N1	3.5 (2)	N2i—Cu1—C6—O8	−0.4 (6)
O7—Cu1—N2—N1	−176.5 (2)	O7i—Cu1—C6—O8	176.3 (5)
O1W—Cu1—N2—N1	94.4 (2)	O7—Cu1—C6—O8	−3.7 (5)
O1Wi—Cu1—N2—N1	−85.6 (2)	O1W—Cu1—C6—O8	−88.9 (5)
N1—N2—C3—C4	−0.4 (2)	O1Wi—Cu1—C6—O8	91.1 (5)
Cu1—N2—C3—C4	−175.27 (13)	N2—Cu1—C6—O7	−176.66 (15)
N1—N2—C3—C6	179.66 (15)	N2i—Cu1—C6—O7	3.34 (15)
Cu1—N2—C3—C6	4.8 (2)	O7i—Cu1—C6—O7	180
N1—N2—C3—Cu1	174.8 (2)	O1W—Cu1—C6—O7	−85.20 (13)
N2i—Cu1—C3—N2	180	O1Wi—Cu1—C6—O7	94.80 (13)
O7i—Cu1—C3—N2	−5.02 (16)	N2—Cu1—C6—C3	2.38 (10)
O7—Cu1—C3—N2	174.98 (16)	N2i—Cu1—C6—C3	−177.62 (10)
O1W—Cu1—C3—N2	87.97 (14)	O7i—Cu1—C6—C3	−0.96 (19)
O1Wi—Cu1—C3—N2	−92.03 (14)	O7—Cu1—C6—C3	179.04 (19)
N2—Cu1—C3—C4	9.0 (2)	O1W—Cu1—C6—C3	93.84 (10)
N2i—Cu1—C3—C4	−171.0 (2)	O1Wi—Cu1—C6—C3	−86.16 (10)
O7i—Cu1—C3—C4	4.0 (3)	O8—C6—O7—Cu1	178.80 (15)
O7—Cu1—C3—C4	−176.0 (3)	C3—C6—O7—Cu1	−1.0 (2)
O1W—Cu1—C3—C4	97.0 (3)	N2—Cu1—O7—C6	2.83 (13)
O1Wi—Cu1—C3—C4	−83.0 (3)	N2i—Cu1—O7—C6	−177.17 (13)
N2—Cu1—C3—C6	−175.5 (2)	O1W—Cu1—O7—C6	95.02 (13)
N2i—Cu1—C3—C6	4.5 (2)	O1Wi—Cu1—O7—C6	−84.98 (13)
O7i—Cu1—C3—C6	179.52 (10)

Symmetry code: (i) −x+1, −y+1, −z.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···O1Wii	0.88	1.93	2.710 (2)	147
O1W—H1WA···O8iii	0.83 (2)	1.86 (2)	2.667 (2)	163 (3)
O1W—H1WB···O7iv	0.82 (2)	1.96 (2)	2.709 (2)	153 (3)
O2W—H2WA···O2Wv	0.83 (2)	1.95 (2)	2.7792 (15)	178 (3)
O2W—H2WB···O8	0.81 (2)	2.04 (2)	2.854 (2)	175 (3)

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