metal-organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

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Bis(2-ethyl-1H-imidazole-κN3)bis­­(nitrito-κ2O,O′)copper(II) dihydrate

aOrdered Matter Science Research Center, College of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, People's Republic of China
*Correspondence e-mail: zhurunqiang@163.com

(Received 14 May 2011; accepted 9 June 2011; online 18 June 2011)

In the title compound, [Cu(NO2)2(C5H8N2)]·2H2O, the Cu2+ ion exhibits site symmetry 2 and is hexacoordinated by four O atoms from two nitrite ions and two N atoms from two 2-ethyl-1H-imidazole mol­ecules. A free water mol­ecule assists in forming a three-dimensional network holding together the complexes via O—H⋯N, O—H⋯O and N—H⋯O hydrogen bonds.

Related literature

For general background on ferroelectric compounds with metal–organic framework structures, see: Fu et al. (2009[Fu, D.-W., Ge, J.-Z., Dai, J., Ye, H.-Y. & Qu, Z.-R. (2009). Inorg. Chem. Commun. 12, 994-997.]); Ye et al. (2006[Ye, Q., Song, Y.-M., Wang, G.-X., Chen, K. & Fu, D.-W. (2006). J. Am. Chem. Soc. 128, 6554-6555.]); Zhang et al. (2008[Zhang, W., Xiong, R.-G. & Huang, S.-P. D. (2008). J. Am. Chem. Soc. 130, 10468-10469.], 2010[Zhang, W., Ye, H.-Y., Cai, H.-L., Ge, J.-Z. & Xiong, R.-G. (2010). J. Am. Chem. Soc. 132, 7300-7302.]). For graph-set motifs of hydrogen bonds, see: Bernstein et al. (1995[Bernstein, J., Davis, R. E., Shimoni, L. & Chang, N. L. (1995). Angew. Chem. Int. Ed. Engl. 34, 1555-1573.]).

[Scheme 1]

Experimental

Crystal data
  • [Cu(NO2)2(C5H8N2)]·2H2O

  • Mr = 383.86

  • Orthorhombic, P b c n

  • a = 12.960 (6) Å

  • b = 17.635 (7) Å

  • c = 7.288 (3) Å

  • V = 1665.7 (12) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 1.35 mm−1

  • T = 293 K

  • 0.30 × 0.25 × 0.20 mm

Data collection
  • Rigaku SCXmini diffractometer

  • Absorption correction: multi-scan (CrystalClear; Rigaku, 2005[Rigaku (2005). CrystalClear. Rigaku Corporation, Tokyo, Japan.]) Tmin = 0.674, Tmax = 0.763

  • 16649 measured reflections

  • 1902 independent reflections

  • 1712 reflections with I > 2σ(I)

  • Rint = 0.032

Refinement
  • R[F2 > 2σ(F2)] = 0.031

  • wR(F2) = 0.079

  • S = 1.10

  • 1902 reflections

  • 113 parameters

  • 5 restraints

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

  • Δρmax = 0.33 e Å−3

  • Δρmin = −0.24 e Å−3

Table 1
Selected bond lengths (Å)

Cu1—N1 1.9752 (17)
Cu1—O6 2.0255 (15)
Cu1—O5 2.4501 (18)

Table 2
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
N2—H2B⋯O7 0.86 1.99 2.830 (3) 167
O7—H1⋯O6ii 0.84 (1) 2.05 (2) 2.862 (2) 163 (3)
O7—H2⋯N3iii 0.83 (1) 2.18 (1) 3.004 (3) 167 (3)
Symmetry codes: (ii) [-x+{\script{3\over 2}}, y-{\script{1\over 2}}, z]; (iii) [-x+{\script{3\over 2}}, -y+{\script{1\over 2}}, z+{\script{1\over 2}}].

Data collection: CrystalClear (Rigaku, 2005[Rigaku (2005). CrystalClear. Rigaku Corporation, Tokyo, Japan.]); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); software used to prepare material for publication: SHELXL97.

Supporting information


Comment top

We synthesized the title compound with the aim to find new ferroelectric materials (Fu et al., 2009; Ye et al., 2006; Zhang et al., 2008; Zhang et al., 2010). For the title compound no dielectric anomalies were observed in the range from 190 K to near its melting point (m.p. >400 K). A view of the title compound is shown in Fig. 1. The structure is consolidated by multiple intermolecular and intramolecular hydrogen bonds between O and N. This hydrogen bonding (Table 1, Fig. 2) produces a three-dimensional network. Hydrogen bonding is the most reliable design element in the non-covalent assembly of neutral molecules with donor and acceptor functionalities, and as such it is the most important interaction in crystal engineering (Bernstein et al., 1995). The two contact distances between Cu and the oxygens of the nitrate ion are very different (Cu1–O5=2.4501 (18) Å and Cu1–O6=2.0255 (15) Å), showing thus only moderate bonding.

Related literature top

For general background on ferroelectric metal–organic frameworks, see: Fu et al. (2009); Ye et al. (2006); Zhang et al. (2008, 2010). For graph-set motifs of hydrogen bonds, see: Bernstein et al. (1995).

Experimental top

An aqueous solution of 2-ethyl imidazole (2.4 g, 25 mmol) and H2SO4(12.5 mmol) was treated with CuSO4 (250 g, 12.5 mmol). After the mixture was churned for a few minutes, Ba(NO2)2 (6.18 g, 25 mmol) was added to give a blue solution. Slow evaporation of the solution yielded blue crystals after a few days.

Refinement top

Positional parameters of all H atoms except H1 and H2 were calculated geometrically and the H atoms were set to ride the C atoms and N atoms to which they are bonded, with Uiso(H)= 1.2 Uiso(C, N) and 1.5 Uiso(C) for methyl H atoms. The H atoms of the water molecule were restrained with O—H = 0.84 Å yielding O7—H1 = 0.835 (11) Å and O7—H2 = 0.834 (11) Å.

Computing details top

Data collection: CrystalClear (Rigaku, 2005); cell refinement: CrystalClear (Rigaku, 2005); data reduction: CrystalClear (Rigaku, 2005); 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: SHELXL97 (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. The molecular structure of the title compound, with the displacement ellipsoids drawn at the 30% probability level. The weak Cu—O interactions and the hydrogen bonds are shown as dashed lines. [Symmetry code: (A) - 1-x, y, 1/2-z]
[Figure 2] Fig. 2. A view of the N—H···O, O—H···N and O—H···O interactions (dotted lines) in the crystal structure of the title compound. [Symmetry codes: (i)-x + 3/2, y - 1/2, z (ii)-x + 3/2, -y + 1/2, z + 1/2]
Bis(2-ethyl-1H-imidazole-κN3)bis(nitrito- κ2O,O')copper(II) dihydrate top
Crystal data top
[Cu(NO2)2(C5H8N2)]·2H2OF(000) = 796
Mr = 383.86Dx = 1.531 Mg m3
Orthorhombic, PbcnMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2n 2abCell parameters from 3875 reflections
a = 12.960 (6) Åθ = 2.8–27.5°
b = 17.635 (7) ŵ = 1.35 mm1
c = 7.288 (3) ÅT = 293 K
V = 1665.7 (12) Å3Block, blue
Z = 40.30 × 0.25 × 0.20 mm
Data collection top
Rigaku, SCXmini
diffractometer
1902 independent reflections
Radiation source: fine-focus sealed tube1712 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.032
ω scansθmax = 27.5°, θmin = 3.6°
Absorption correction: multi-scan
(CrystalClear; Rigaku, 2005)
h = 1616
Tmin = 0.674, Tmax = 0.763k = 2222
16649 measured reflectionsl = 99
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.031Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.079H atoms treated by a mixture of independent and constrained refinement
S = 1.10 w = 1/[σ2(Fo2) + (0.0424P)2 + 0.3653P]
where P = (Fo2 + 2Fc2)/3
1902 reflections(Δ/σ)max = 0.001
113 parametersΔρmax = 0.33 e Å3
5 restraintsΔρmin = 0.24 e Å3
Crystal data top
[Cu(NO2)2(C5H8N2)]·2H2OV = 1665.7 (12) Å3
Mr = 383.86Z = 4
Orthorhombic, PbcnMo Kα radiation
a = 12.960 (6) ŵ = 1.35 mm1
b = 17.635 (7) ÅT = 293 K
c = 7.288 (3) Å0.30 × 0.25 × 0.20 mm
Data collection top
Rigaku, SCXmini
diffractometer
1902 independent reflections
Absorption correction: multi-scan
(CrystalClear; Rigaku, 2005)
1712 reflections with I > 2σ(I)
Tmin = 0.674, Tmax = 0.763Rint = 0.032
16649 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0315 restraints
wR(F2) = 0.079H atoms treated by a mixture of independent and constrained refinement
S = 1.10Δρmax = 0.33 e Å3
1902 reflectionsΔρmin = 0.24 e Å3
113 parameters
Special details top

Geometry. All e.s.d.'s 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 and angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry.

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 (Å2) top
xyzUiso*/Ueq
C10.65105 (15)0.16593 (12)0.2425 (3)0.0354 (4)
C20.63010 (17)0.21323 (12)0.0306 (3)0.0429 (5)
H2A0.60670.24360.12620.051*
C30.69903 (18)0.15687 (14)0.0455 (3)0.0502 (6)
H3A0.73210.14110.15210.060*
C40.64560 (18)0.15017 (13)0.4424 (3)0.0451 (5)
H4A0.60910.19140.50210.054*
H4B0.71510.14880.49170.054*
C50.5918 (2)0.07583 (15)0.4881 (4)0.0637 (7)
H5A0.59230.06830.61850.096*
H5B0.62740.03470.42930.096*
H5C0.52180.07760.44530.096*
N10.59959 (13)0.21864 (9)0.1508 (2)0.0342 (4)
N20.71115 (13)0.12722 (11)0.1257 (3)0.0465 (4)
H2B0.75080.08990.15410.056*
Cu10.50000.292843 (17)0.25000.02994 (13)
O60.57539 (11)0.37719 (8)0.1173 (2)0.0460 (4)
O70.82902 (14)0.00761 (11)0.2776 (3)0.0563 (5)
O50.44637 (13)0.34927 (11)0.0420 (2)0.0604 (5)
N30.52032 (17)0.39184 (12)0.0252 (3)0.0528 (5)
H10.848 (2)0.0289 (14)0.213 (4)0.088 (12)*
H20.8774 (18)0.0299 (17)0.330 (5)0.104 (13)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C10.0307 (9)0.0311 (10)0.0443 (11)0.0003 (8)0.0020 (8)0.0012 (8)
C20.0446 (12)0.0477 (12)0.0364 (11)0.0071 (9)0.0052 (9)0.0002 (9)
C30.0488 (12)0.0564 (14)0.0455 (13)0.0086 (10)0.0094 (10)0.0069 (11)
C40.0462 (11)0.0459 (12)0.0434 (12)0.0009 (9)0.0055 (10)0.0050 (10)
C50.0735 (17)0.0546 (15)0.0631 (16)0.0072 (13)0.0031 (14)0.0163 (12)
N10.0349 (8)0.0324 (8)0.0352 (9)0.0022 (6)0.0032 (7)0.0002 (7)
N20.0405 (9)0.0434 (10)0.0557 (12)0.0136 (8)0.0012 (9)0.0035 (9)
Cu10.0318 (2)0.0253 (2)0.0327 (2)0.0000.00267 (12)0.000
O60.0511 (8)0.0358 (7)0.0512 (9)0.0066 (6)0.0063 (7)0.0036 (7)
O70.0532 (10)0.0438 (10)0.0720 (12)0.0097 (8)0.0056 (9)0.0079 (9)
O50.0549 (10)0.0723 (12)0.0541 (10)0.0012 (9)0.0072 (8)0.0181 (9)
N30.0633 (13)0.0455 (11)0.0497 (12)0.0011 (9)0.0107 (10)0.0131 (9)
Geometric parameters (Å, º) top
C1—N11.325 (3)C5—H5B0.9600
C1—N21.341 (3)C5—H5C0.9600
C1—C41.485 (3)N1—Cu11.9752 (17)
C2—C31.341 (3)N2—H2B0.8600
C2—N11.383 (3)Cu1—N1i1.9752 (17)
C2—H2A0.9300Cu1—O62.0255 (15)
C3—N21.362 (3)Cu1—O6i2.0255 (15)
C3—H3A0.9300Cu1—O52.4501 (18)
C4—C51.522 (3)O6—N31.287 (3)
C4—H4A0.9700O7—H10.835 (11)
C4—H4B0.9700O7—H20.834 (11)
C5—H5A0.9600O5—N31.223 (3)
N1—C1—N2109.23 (18)C1—N1—C2106.86 (17)
N1—C1—C4127.04 (19)C1—N1—Cu1127.51 (14)
N2—C1—C4123.73 (19)C2—N1—Cu1125.63 (14)
C3—C2—N1108.6 (2)C1—N2—C3108.61 (18)
C3—C2—H2A125.7C1—N2—H2B125.7
N1—C2—H2A125.7C3—N2—H2B125.7
C2—C3—N2106.7 (2)N1i—Cu1—N197.01 (10)
C2—C3—H3A126.7N1i—Cu1—O6167.58 (7)
N2—C3—H3A126.7N1—Cu1—O689.80 (7)
C1—C4—C5113.4 (2)N1i—Cu1—O6i89.80 (7)
C1—C4—H4A108.9N1—Cu1—O6i167.58 (7)
C5—C4—H4A108.9O6—Cu1—O6i85.48 (9)
C1—C4—H4B108.9N1i—Cu1—O5113.70 (7)
C5—C4—H4B108.9N1—Cu1—O597.84 (7)
H4A—C4—H4B107.7O6—Cu1—O554.81 (6)
C4—C5—H5A109.5O6i—Cu1—O588.83 (7)
C4—C5—H5B109.5N3—O6—Cu1105.39 (13)
H5A—C5—H5B109.5H1—O7—H2113.6 (19)
C4—C5—H5C109.5N3—O5—Cu186.57 (13)
H5A—C5—H5C109.5O5—N3—O6113.08 (18)
H5B—C5—H5C109.5
Symmetry code: (i) x+1, y, z+1/2.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N2—H2B···O70.861.992.830 (3)167
O7—H1···O6ii0.84 (1)2.05 (2)2.862 (2)163 (3)
O7—H2···N3iii0.83 (1)2.18 (1)3.004 (3)167 (3)
Symmetry codes: (ii) x+3/2, y1/2, z; (iii) x+3/2, y+1/2, z+1/2.

Experimental details

Crystal data
Chemical formula[Cu(NO2)2(C5H8N2)]·2H2O
Mr383.86
Crystal system, space groupOrthorhombic, Pbcn
Temperature (K)293
a, b, c (Å)12.960 (6), 17.635 (7), 7.288 (3)
V3)1665.7 (12)
Z4
Radiation typeMo Kα
µ (mm1)1.35
Crystal size (mm)0.30 × 0.25 × 0.20
Data collection
DiffractometerRigaku, SCXmini
diffractometer
Absorption correctionMulti-scan
(CrystalClear; Rigaku, 2005)
Tmin, Tmax0.674, 0.763
No. of measured, independent and
observed [I > 2σ(I)] reflections
16649, 1902, 1712
Rint0.032
(sin θ/λ)max1)0.649
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.031, 0.079, 1.10
No. of reflections1902
No. of parameters113
No. of restraints5
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.33, 0.24

Computer programs: CrystalClear (Rigaku, 2005), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).

Selected bond lengths (Å) top
N1—Cu11.9752 (17)Cu1—O6i2.0255 (15)
Cu1—N1i1.9752 (17)Cu1—O52.4501 (18)
Cu1—O62.0255 (15)
Symmetry code: (i) x+1, y, z+1/2.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N2—H2B···O70.861.992.830 (3)166.7
O7—H1···O6ii0.835 (11)2.053 (15)2.862 (2)163 (3)
O7—H2···N3iii0.834 (11)2.184 (12)3.004 (3)167 (3)
Symmetry codes: (ii) x+3/2, y1/2, z; (iii) x+3/2, y+1/2, z+1/2.
 

Acknowledgements

This work was supported by Southeast University.

References

First citationBernstein, J., Davis, R. E., Shimoni, L. & Chang, N. L. (1995). Angew. Chem. Int. Ed. Engl. 34, 1555–1573.  CrossRef CAS Web of Science Google Scholar
First citationFu, D.-W., Ge, J.-Z., Dai, J., Ye, H.-Y. & Qu, Z.-R. (2009). Inorg. Chem. Commun. 12, 994–997.  Web of Science CSD CrossRef CAS Google Scholar
First citationRigaku (2005). CrystalClear. Rigaku Corporation, Tokyo, Japan.  Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationYe, Q., Song, Y.-M., Wang, G.-X., Chen, K. & Fu, D.-W. (2006). J. Am. Chem. Soc. 128, 6554–6555.  Web of Science CSD CrossRef PubMed CAS Google Scholar
First citationZhang, W., Xiong, R.-G. & Huang, S.-P. D. (2008). J. Am. Chem. Soc. 130, 10468–10469.  Web of Science CSD CrossRef PubMed CAS Google Scholar
First citationZhang, W., Ye, H.-Y., Cai, H.-L., Ge, J.-Z. & Xiong, R.-G. (2010). J. Am. Chem. Soc. 132, 7300–7302.  Web of Science CSD CrossRef CAS PubMed Google Scholar

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