Buy article online - an online subscription or single-article purchase is required to access this article.
Download citation
Download citation
link to html
trans-Di­bromo­bis(5-tert-butyl­pyrazole-N2)copper(II), trans-[CuBr2(HpztBu)2] (HpztBu is 5-tert-butyl­pyrazole, C7H12N2), ex­hibits a distorted square-planar geometry with a significant tetrahedral twist, while trans-di­bromo­tetrakis(5-tert-butyl­pyrazole-N2)copper(II), trans-[CuBr2(HpztBu)4], adopts a distorted octahedral geometry across a crystallographic inversion centre. Both compounds exhibit intramolecular N—H...Br hydrogen-bonding interactions.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270101012653/bm1461sup1.cif
Contains datablocks I, II, global

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270101012653/bm1461Isup2.hkl
Contains datablock I

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270101012653/bm1461IIsup3.hkl
Contains datablock II

CCDC references: 175060; 175061

Comment top

We have recently discovered that complexation of CuCl2 or CuBr2 by HpztBu [HpztBu is 3(5)-tertbutylpyrazole] in basic MeOH leads to a novel heptacopper aggregate structure, which appears to be templated by N—H···X (X- = Cl-, Br-) hydrogen-bonding interactions to non-coordinated anions (Liu et al., 2001). As a result of a more in-depth study of this system, we have isolated two more adducts of CuBr2 and HpztBu, namely trans-dibromobis(5-tert-butylpyrazole-N2)copper(II), [CuBr2(HpztBu)2], (I), and trans-dibromotetrakis(5-tert-butylpyrazole-N2)copper(II), [CuBr2(HpztBu)4], (II). The Trofimenko nomenclature for substituted pyrazoles is employed throughout this discussion (Trofimenko, 1999).

The asymmetric unit of (I) contains one molecule of the complex lying on a general position. The CuII centre in (I) is four-coordinate, with trans-disposed Br- and HpztBu ligands; the latter are coordinated as the less sterically hindered 5-tert-butylpyrazole tautomer. The two Cu—N bond lengths in the molecule are crystallographically identical. However, the Cu1—Br20 bond is 0.0713 (6) Å longer than Cu1—Br21, which presumably reflects the presence of two hydrogen bonds to Br20 (see below). Although clearly derived from a square plane, the coordination sphere at Cu1 has a significant tetrahedral twist, which can be expressed by the dihedral angle of 45.71 (6)° between the Cu1/N2/Br20 and Cu1/N11/Br21 planes. This angle would be 0° for an ideal square-planar geometry and 90° for a tetrahedron. The N—H groups on each pyrazole ligand form an intramolecular hydrogen bond to Br20, leading to a distorted pyramidal geometry for this atom defined by the angles H3···Br20—Cu1 = 70.0, H12···Br20—Cu1 = 73.4 and H3···Br20···H12 = 108.2°.

Several 2:1 adducts of pyrazole derivatives with copper dihalides have been crystallographically characterized by others. Bis-pyrazole complexes of CuF2 and CuCl2 most commonly adopt dimeric structures in the solid state of general formula [{CuX(µ-X)L2}2] (X- = F-, Cl-; L is a pyrazole derivative: ten Hoedt et al., 1981; Reitmeijer et al., 1984; Keij et al., 1991; Malecka et al., 1998; Chandrasekhar et al., 2000). Two coordination polymers with this stoichiometry (Keij et al., 1988; Malecka et al., 1998) and a number of monomeric [CuCl2L2] structures (Francisco et al., 1980; Watson et al., 1989; Hergold-Brundic et al., 1991; Valle, et al., 1995; Malecka et al., 1998) have also been reported. The only CuBr2 bis-pyrazole adduct whose crystal structure has been previously determined is the mononuclear complex [CuBr2(HpzPh2)2] (HpzPh2 is 3,5-diphenylpyrazole; Murray et al., 1988). Interestingly, this compound exhibits cis-disposed Br- and HpzPh2 ligands in the solid, but otherwise adopts an almost identical coordination geometry to (I).

Compound (II) contains discrete six-coordinate CuII centres, with Cu1 lying on a crystallographic inversion centre. As for (I), the HpztBu ligands in (II) are coordinated in the 5-tert-butylpyrazole tautomer. The four pyrazole N-donor atoms are strictly coplanar and form an almost perfect square plane, although the two unique Cu1—N bond lengths differ by 0.006 (2) Å, which is of borderline crystallographic significance. The axial Cu1—Br20 distance of 3.02801 (16) Å is substantially longer than the sum of the covalent radii of Cu (1.38 Å) and Br (1.14 Å) (Gordon & Ford, 1972), so that this `bond' is probably better considered as a weak electrostatic interaction between the Br- anion and the positively charged void perpendicular to the molecular tetragonal plane. This suggestion is supported by the fact that the Cu1—Br20 `bond' fails the Hirschfeld rigid-bond test (Hirshfeld, 1976) by almost 80 s.u.'s, which implies that there is negligible covalent interaction between these two atoms. Each Br- ligand accepts two hydrogen bonds from cis-disposed pyrazole ligands, forming an approximately pyramidal geometry with the angles H3···Br20—Cu1 = 64.1 (5)°, H12···Br20—Cu1 = 63.0 (5)° and H3···Br20···H12 = and 76.1 (7)°. The crystal structures of two other 4:1 pyrazole–CuII dihalide adducts have been reported previously, namely [CuCl2(Hpz)4] (Mighell et al., 1975; Casellato et al., 2000) and catena-[{CuCl2(µ-dpm)2}n] [dpm is bis(pyrazol-4-yl)methane; Broomhead et al., 1998]. Both of these exhibit an essentially identical coordination geometry to (II) and show the same pattern of N—H···Cl intramolecular hydrogen bonding.

Related literature top

For related literature, see: Broomhead et al. (1998); Casellato et al. (2000); Chandrasekhar et al. (2000); Flack (1983); Francisco et al. (1980); Gordon & Ford (1972); Hergold-Brundic, Kaitner, Kamenar, Leovac, Iveges & Juranic (1991); Hirshfeld (1976); Hoedt et al. (1981); Keij et al. (1988, 1991); Liu et al. (2001); Malecka et al. (1998); Mighell et al. (1975); Murray et al. (1988); Reitmeijer et al. (1984); Trofimenko (1999); Valle et al. (1995); Watson et al. (1989).

Experimental top

For the preparation of compound (I), anhydrous CuBr2 (0.22 g, 1.0 mmol) and HpztBu (0.18 g, 1.5 mmol) were stirred into a 4:1 CH2Cl2–acetone mixture (50 ml) at room temperature for 2 h. The solvent was then removed in vacuo and the residue redissolved in a minimum volume of CH2Cl2, yielding a dark-green solution and some insoluble material which was removed by filtration. Slow diffusion of pentane into the filtrate gave a brown microcrystalline product which was removed by filtration. Slow evaporation of the remaining solution yielded green crystals of (I). Analysis, found: C 35.7, H 5.1, N 12.0%; calculated for C14H24Br2CuN4: C 35.6, H 5.1, N 11.9%. For the preparation of compound (I), anhydrous CuBr2 (0.22 g, 1.0 mmol) and HpztBu (0.37 g, 3.0 mmol) were reacted in CH3OH (50 ml) at room temperature for 30 min. The solvent was then removed in vacuo and the residue redissolved in a minimum volume of CH2Cl2, yielding a dark-green solution and some insoluble material which was removed by filtration. Slow diffusion of pentane into the solution gave a mixture of deep-blue well formed crystals of (II), together with a turquoise by-product which was removed manually. Analysis, found: C 46.8, H 6.7, N 15.7%; calculated for C28H48Br2CuN8: C 46.7, H 6.7, N 15.6%.

Refinement top

The Flack parameter (Flack, 1983) for (I) was determined using Friedel 2070 pairs. One tert-butyl group in (I) was found to be disordered during refinement. Three equally occupied disorder orientations were modelled: C16A–C19A, C16B–C19B and C16C–C19C. All C—C bonds within the disordered group were restrained to 1.53 (2) Å, and non-bonded 1,3-C···C contacts within a given disorder orientation to 2.50 (2) Å. All wholly occupied non-H atoms were refined anisotropically. All H atoms were placed in calculated positions and refined using a riding model, with fixed C—H distances of 0.95 Å for Csp2—H bonds and 0.98 Å for methyl C—H bonds and an N—H distance of 0.88 Å. No disorder was detected in (II). All C-bound H atoms were placed in calculated positions and refined using a riding model, with fixed C—H distances of 0.95 Å for Csp2—H bonds and 0.98 Å for methyl C—H bonds. The N-bound H atoms H3 and H12 were located in a difference Fourier map and were allowed to refine freely.

Computing details top

For both compounds, data collection: COLLECT (Nonius, 1999); cell refinement: DENZO-SMN (Otwinowski & Minor, 1997); data reduction: DENZO-SMN; program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEX (McArdle, 1995); software used to prepare material for publication: local program.

Figures top
[Figure 1] Fig. 1. The molecular structure of (I) showing 50% probability displacement ellipsoids and the atom-numbering scheme employed. H atoms have arbitrary radii. For clarity, only one orientation of the disordered tert-butyl group (C16A—C19A) is shown, while all C-bound H atoms have been omitted.
[Figure 2] Fig. 2. The molecular structure of (II) showing 50% probability displacement ellipsoids and the atom-numbering scheme employed. H atoms have arbitrary radii. For clarity, all C-bound H atoms have been omitted. [Symmetry code: (i) -x + 0.5, -y + 0.5, -z.]
(I) trans-dibromobis(5-tert-butylpyrazole-N2)copper(II) top
Crystal data top
[CuBr2(C7H12N2)2]Dx = 1.632 Mg m3
Mr = 471.73Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, Pca21Cell parameters from 37366 reflections
a = 17.4947 (2) Åθ = 4.1–27.5°
b = 9.8730 (1) ŵ = 5.30 mm1
c = 11.1165 (1) ÅT = 150 K
V = 1920.10 (3) Å3Column, green
Z = 40.48 × 0.18 × 0.14 mm
F(000) = 940
Data collection top
Nonius KappaCCD
diffractometer
4373 independent reflections
Radiation source: fine-focus sealed tube4268 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.056
Detector resolution: 9.091 pixels mm-1θmax = 27.5°, θmin = 4.1°
area–detector scansh = 2222
Absorption correction: multi-scan
(SORTAV; Blessing, 1995)
k = 1212
Tmin = 0.185, Tmax = 0.524l = 1414
37366 measured reflections
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.024H-atom parameters constrained
wR(F2) = 0.060 w = 1/[σ2(Fo2) + (0.0351P)2 + 0.6531P]
where P = (Fo2 + 2Fc2)/3
S = 1.06(Δ/σ)max = 0.001
4373 reflectionsΔρmax = 0.25 e Å3
203 parametersΔρmin = 0.47 e Å3
31 restraintsAbsolute structure: Flack (1983)
Primary atom site location: structure-invariant direct methodsAbsolute structure parameter: 0.006 (8)
Crystal data top
[CuBr2(C7H12N2)2]V = 1920.10 (3) Å3
Mr = 471.73Z = 4
Orthorhombic, Pca21Mo Kα radiation
a = 17.4947 (2) ŵ = 5.30 mm1
b = 9.8730 (1) ÅT = 150 K
c = 11.1165 (1) Å0.48 × 0.18 × 0.14 mm
Data collection top
Nonius KappaCCD
diffractometer
4373 independent reflections
Absorption correction: multi-scan
(SORTAV; Blessing, 1995)
4268 reflections with I > 2σ(I)
Tmin = 0.185, Tmax = 0.524Rint = 0.056
37366 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.024H-atom parameters constrained
wR(F2) = 0.060Δρmax = 0.25 e Å3
S = 1.06Δρmin = 0.47 e Å3
4373 reflectionsAbsolute structure: Flack (1983)
203 parametersAbsolute structure parameter: 0.006 (8)
31 restraints
Special details top

Experimental. Detector set at 30 mm from sample with different 2theta offsets 1 degree phi exposures for chi=0 degree settings 1 degree omega exposures for chi=90 degree settings

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. For both compounds, structure solution was achieved by direct methods using SHELXS97 (Sheldrick, 1990), while least squares refinement used SHELXL97 (Sheldrick, 1997).

One tert-butyl group is disordered over three equally occupied orientations, C16A—C19A, C16B—C19B and C16C—C19C. All C—C bonds within the disordered moiety were restrained to 1.53 (2) Å, and non-bonded 1,3-C···C contacts within a given disorder orientation to 2.50 (2) Å. All wholly occuped non-H atoms were refined anisotropically. All H atoms were placed in calculated positions and refined using a riding model, at fixed C—H distances of 0.95 Å for the sp2 C—H bonds and 0.98 Å for the methyl C—H bonds, or N—H = 0.88 Å.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/UeqOcc. (<1)
Cu10.291298 (15)0.78148 (3)0.69315 (3)0.02836 (7)
N20.21062 (12)0.6480 (2)0.7179 (2)0.0318 (5)
N30.21436 (12)0.5639 (2)0.8136 (2)0.0360 (5)
H30.25300.56250.86430.043*
C40.15308 (14)0.4826 (2)0.8236 (3)0.0330 (5)
C50.10668 (14)0.5156 (3)0.7265 (3)0.0374 (6)
H50.05880.47610.70670.045*
C60.14435 (15)0.6187 (3)0.6638 (3)0.0354 (5)
H60.12560.66160.59320.042*
C70.14560 (16)0.3788 (3)0.9217 (3)0.0389 (6)
C80.21347 (18)0.3871 (4)1.0082 (4)0.0515 (8)
H8A0.20790.31831.07110.062*
H8B0.21500.47721.04520.062*
H8C0.26100.37120.96380.062*
C90.07223 (17)0.4072 (4)0.9930 (3)0.0517 (7)
H9A0.06680.33991.05720.062*
H9B0.02810.40170.93900.062*
H9C0.07490.49801.02830.062*
C100.1408 (3)0.2378 (3)0.8645 (4)0.0612 (10)
H10A0.13630.16920.92780.073*
H10B0.18710.22080.81720.073*
H10C0.09600.23320.81180.073*
N110.34337 (11)0.9503 (2)0.73202 (18)0.0292 (4)
N120.39656 (11)0.9593 (2)0.82064 (19)0.0283 (4)
H120.41770.88840.85530.034*
C130.41341 (14)1.0869 (2)0.8495 (2)0.0302 (5)
C140.36924 (18)1.1676 (3)0.7743 (3)0.0407 (6)
H140.36801.26370.77160.049*
C150.32725 (16)1.0785 (3)0.7038 (3)0.0382 (6)
H150.29181.10530.64370.046*
C16A0.4689 (9)1.1279 (16)0.9470 (14)0.037 (8)*0.33333
C17A0.4928 (7)0.9985 (11)1.0186 (10)0.041 (3)*0.33333
H17A0.44830.96221.06120.061*0.33333
H17B0.53271.02211.07680.061*0.33333
H17C0.51240.93020.96260.061*0.33333
C18A0.5414 (6)1.1814 (13)0.8817 (12)0.052 (3)*0.33333
H18A0.56431.10800.83440.079*0.33333
H18B0.57841.21370.94130.079*0.33333
H18C0.52731.25610.82810.079*0.33333
C19A0.4339 (9)1.2289 (14)1.0317 (13)0.065 (6)*0.33333
H19A0.41831.30960.98670.097*0.33333
H19B0.47141.25441.09300.097*0.33333
H19C0.38911.18851.07060.097*0.33333
C16B0.4765 (7)1.1257 (12)0.9346 (11)0.032 (4)*0.33333
C17B0.4739 (8)1.0297 (12)1.0426 (10)0.044 (3)*0.33333
H17D0.42161.02521.07380.066*0.33333
H17E0.50831.06321.10560.066*0.33333
H17F0.49030.93901.01740.066*0.33333
C18B0.5525 (5)1.1297 (11)0.8700 (11)0.037 (3)*0.33333
H18D0.56291.04090.83410.055*0.33333
H18E0.59311.15220.92730.055*0.33333
H18F0.55081.19850.80650.055*0.33333
C19B0.4580 (6)1.2696 (10)0.9858 (11)0.049 (3)*0.33333
H19D0.45901.33600.92030.074*0.33333
H19E0.49621.29411.04650.074*0.33333
H19F0.40711.26881.02270.074*0.33333
C16C0.4693 (7)1.1147 (13)0.9533 (11)0.030 (5)*0.33333
C17C0.4749 (8)0.9973 (12)1.0404 (10)0.033 (3)*0.33333
H17G0.51061.02041.10530.050*0.33333
H17H0.49350.91680.99780.050*0.33333
H17I0.42440.97851.07450.050*0.33333
C18C0.5494 (6)1.1437 (13)0.9003 (12)0.039 (3)*0.33333
H18G0.54751.22690.85220.059*0.33333
H18H0.56511.06780.84920.059*0.33333
H18I0.58621.15490.96590.059*0.33333
C19C0.4435 (7)1.2486 (11)1.0142 (11)0.028 (2)*0.33333
H19G0.43731.31910.95290.042*0.33333
H19H0.48221.27711.07270.042*0.33333
H19I0.39471.23411.05540.042*0.33333
Br200.391135 (14)0.63896 (2)0.78137 (3)0.03398 (7)
Br210.243097 (17)0.85958 (3)0.50569 (3)0.04032 (8)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cu10.02511 (13)0.03068 (13)0.02930 (13)0.00248 (10)0.00408 (12)0.00108 (12)
N20.0290 (10)0.0337 (10)0.0327 (12)0.0030 (7)0.0058 (9)0.0012 (8)
N30.0312 (10)0.0373 (11)0.0395 (12)0.0091 (8)0.0092 (9)0.0045 (9)
C40.0285 (11)0.0291 (11)0.0415 (14)0.0050 (9)0.0015 (10)0.0036 (10)
C50.0288 (12)0.0382 (13)0.0451 (15)0.0064 (10)0.0080 (10)0.0040 (12)
C60.0289 (12)0.0375 (12)0.0399 (14)0.0019 (10)0.0066 (10)0.0032 (11)
C70.0354 (13)0.0357 (13)0.0457 (15)0.0095 (10)0.0050 (13)0.0014 (12)
C80.0435 (16)0.0523 (17)0.059 (2)0.0136 (13)0.0127 (16)0.0166 (17)
C90.0412 (15)0.073 (2)0.0408 (16)0.0105 (15)0.0026 (13)0.0050 (16)
C100.086 (3)0.0321 (14)0.066 (2)0.0157 (16)0.0002 (19)0.0008 (14)
N110.0276 (9)0.0349 (10)0.0252 (9)0.0023 (8)0.0046 (8)0.0027 (8)
N120.0259 (9)0.0314 (10)0.0277 (10)0.0027 (7)0.0024 (8)0.0019 (8)
C130.0297 (11)0.0326 (11)0.0281 (11)0.0045 (9)0.0011 (10)0.0005 (10)
C140.0510 (15)0.0292 (11)0.0420 (15)0.0020 (11)0.0066 (14)0.0040 (12)
C150.0452 (14)0.0327 (12)0.0368 (13)0.0000 (10)0.0107 (12)0.0055 (11)
Br200.02716 (12)0.03378 (12)0.04101 (15)0.00362 (8)0.00407 (10)0.00189 (11)
Br210.03937 (14)0.04965 (15)0.03193 (14)0.00396 (10)0.01137 (12)0.00457 (11)
Geometric parameters (Å, º) top
Cu1—N21.951 (2)C16A—C19A1.502 (15)
Cu1—N111.948 (2)C16A—C18A1.554 (15)
Cu1—Br202.4479 (4)C16A—C17A1.562 (15)
Cu1—Br212.3766 (4)C17A—H17A0.9800
N2—C61.338 (3)C17A—H17B0.9800
N2—N31.351 (3)C17A—H17C0.9800
N3—C41.344 (3)C18A—H18A0.9800
N3—H30.8800C18A—H18B0.9800
C4—C51.389 (4)C18A—H18C0.9800
C4—C71.503 (4)C19A—H19A0.9800
C5—C61.398 (4)C19A—H19B0.9800
C5—H50.9500C19A—H19C0.9800
C6—H60.9500C16B—C18B1.512 (13)
C7—C81.530 (4)C16B—C17B1.530 (13)
C7—C101.533 (4)C16B—C19B1.565 (13)
C7—C91.534 (4)C17B—H17D0.9800
C8—H8A0.9800C17B—H17E0.9800
C8—H8B0.9800C17B—H17F0.9800
C8—H8C0.9800C18B—H18D0.9800
C9—H9A0.9800C18B—H18E0.9800
C9—H9B0.9800C18B—H18F0.9800
C9—H9C0.9800C19B—H19D0.9800
C10—H10A0.9800C19B—H19E0.9800
C10—H10B0.9800C19B—H19F0.9800
C10—H10C0.9800C16C—C17C1.514 (14)
N11—C151.334 (3)C16C—C18C1.547 (13)
N11—N121.358 (3)C16C—C19C1.552 (13)
N12—C131.333 (3)C17C—H17G0.9800
N12—H120.8800C17C—H17H0.9800
C13—C141.390 (4)C17C—H17I0.9800
C13—C16B1.503 (11)C18C—H18G0.9800
C13—C16A1.510 (14)C18C—H18H0.9800
C13—C16C1.537 (12)C18C—H18I0.9800
C14—C151.388 (4)C19C—H19G0.9800
C14—H140.9500C19C—H19H0.9800
C15—H150.9500C19C—H19I0.9800
N2—Cu1—N11152.26 (9)C13—C16A—C17A108.5 (10)
N2—Cu1—Br2094.09 (6)C18A—C16A—C17A107.3 (11)
N2—Cu1—Br2194.96 (7)C16A—C17A—H17A109.5
N11—Cu1—Br2093.97 (6)C16A—C17A—H17B109.5
N11—Cu1—Br2194.75 (6)H17A—C17A—H17B109.5
Br20—Cu1—Br21142.27 (2)C16A—C17A—H17C109.5
C6—N2—N3105.3 (2)H17A—C17A—H17C109.5
C6—N2—Cu1135.20 (19)H17B—C17A—H17C109.5
N3—N2—Cu1119.44 (16)C16A—C18A—H18A109.5
C4—N3—N2113.2 (2)C16A—C18A—H18B109.5
C4—N3—H3123.4H18A—C18A—H18B109.5
N2—N3—H3123.4C16A—C18A—H18C109.5
N3—C4—C5105.2 (2)H18A—C18A—H18C109.5
N3—C4—C7122.5 (2)H18B—C18A—H18C109.5
C5—C4—C7132.3 (2)C16A—C19A—H19A109.5
C4—C5—C6106.4 (2)C16A—C19A—H19B109.5
C4—C5—H5126.8H19A—C19A—H19B109.5
C6—C5—H5126.8C16A—C19A—H19C109.5
N2—C6—C5110.0 (2)H19A—C19A—H19C109.5
N2—C6—H6125.0H19B—C19A—H19C109.5
C5—C6—H6125.0C13—C16B—C18B110.7 (9)
C4—C7—C8110.6 (2)C13—C16B—C17B108.3 (8)
C4—C7—C10108.8 (3)C18B—C16B—C17B114.5 (10)
C8—C7—C10110.6 (3)C13—C16B—C19B107.9 (8)
C4—C7—C9108.9 (3)C18B—C16B—C19B109.4 (9)
C8—C7—C9108.4 (3)C17B—C16B—C19B105.7 (9)
C10—C7—C9109.5 (3)C16B—C17B—H17D109.5
C7—C8—H8A109.5C16B—C17B—H17E109.5
C7—C8—H8B109.5H17D—C17B—H17E109.5
H8A—C8—H8B109.5C16B—C17B—H17F109.5
C7—C8—H8C109.5H17D—C17B—H17F109.5
H8A—C8—H8C109.5H17E—C17B—H17F109.5
H8B—C8—H8C109.5C16B—C18B—H18D109.5
C7—C9—H9A109.5C16B—C18B—H18E109.5
C7—C9—H9B109.5H18D—C18B—H18E109.5
H9A—C9—H9B109.5C16B—C18B—H18F109.5
C7—C9—H9C109.5H18D—C18B—H18F109.5
H9A—C9—H9C109.5H18E—C18B—H18F109.5
H9B—C9—H9C109.5C16B—C19B—H19D109.5
C7—C10—H10A109.5C16B—C19B—H19E109.5
C7—C10—H10B109.5H19D—C19B—H19E109.5
H10A—C10—H10B109.5C16B—C19B—H19F109.5
C7—C10—H10C109.5H19D—C19B—H19F109.5
H10A—C10—H10C109.5H19E—C19B—H19F109.5
H10B—C10—H10C109.5C17C—C16C—C13112.6 (9)
C15—N11—N12104.7 (2)C17C—C16C—C18C109.0 (10)
C15—N11—Cu1131.37 (18)C13—C16C—C18C108.8 (9)
N12—N11—Cu1122.50 (16)C17C—C16C—C19C113.1 (10)
C13—N12—N11112.8 (2)C13—C16C—C19C107.1 (8)
C13—N12—H12123.6C18C—C16C—C19C105.8 (10)
N11—N12—H12123.6C16C—C17C—H17G109.5
N12—C13—C14105.9 (2)C16C—C17C—H17H109.5
N12—C13—C16B123.7 (5)H17G—C17C—H17H109.5
C14—C13—C16B129.9 (5)C16C—C17C—H17I109.5
N12—C13—C16A124.6 (6)H17G—C17C—H17I109.5
C14—C13—C16A129.5 (6)H17H—C17C—H17I109.5
N12—C13—C16C119.4 (5)C16C—C18C—H18G109.5
C14—C13—C16C134.7 (6)C16C—C18C—H18H109.5
C15—C14—C13105.7 (2)H18G—C18C—H18H109.5
C15—C14—H14127.1C16C—C18C—H18I109.5
C13—C14—H14127.1H18G—C18C—H18I109.5
N11—C15—C14110.9 (2)H18H—C18C—H18I109.5
N11—C15—H15124.5C16C—C19C—H19G109.5
C14—C15—H15124.5C16C—C19C—H19H109.5
C19A—C16A—C13111.4 (11)H19G—C19C—H19H109.5
C19A—C16A—C18A113.6 (12)C16C—C19C—H19I109.5
C13—C16A—C18A106.3 (10)H19G—C19C—H19I109.5
C19A—C16A—C17A109.4 (11)H19H—C19C—H19I109.5
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N3—H3···Br200.882.693.200 (2)118
N12—H12···Br200.882.643.194 (2)122
(II) trans-dibromotetrakis(5-tert-butylpyrazole-N2)copper(II) top
Crystal data top
[CuBr2(C7H12N2)4]F(000) = 1484
Mr = 720.10Dx = 1.359 Mg m3
Monoclinic, C2/cMo Kα radiation, λ = 0.71073 Å
a = 19.5985 (3) ÅCell parameters from 29739 reflections
b = 11.9918 (2) Åθ = 3.7–27.5°
c = 15.9131 (2) ŵ = 2.92 mm1
β = 109.8260 (6)°T = 150 K
V = 3518.24 (9) Å3Rectangular prism, deep blue
Z = 40.49 × 0.34 × 0.17 mm
Data collection top
Nonius KappaCCD
diffractometer
4019 independent reflections
Radiation source: fine-focus sealed tube3655 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.077
Detector resolution: 9.091 pixels mm-1θmax = 27.5°, θmin = 3.7°
area–detector scansh = 2525
Absorption correction: multi-scan
(SORTAV; Blessing, 1995)
k = 1515
Tmin = 0.329, Tmax = 0.637l = 2020
29739 measured reflections
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: see text
R[F2 > 2σ(F2)] = 0.026H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.070 w = 1/[σ2(Fo2) + (0.0327P)2 + 2.2831P]
where P = (Fo2 + 2Fc2)/3
S = 1.07(Δ/σ)max = 0.001
4019 reflectionsΔρmax = 0.26 e Å3
187 parametersΔρmin = 0.44 e Å3
0 restraintsExtinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methodsExtinction coefficient: 0.0027 (2)
Crystal data top
[CuBr2(C7H12N2)4]V = 3518.24 (9) Å3
Mr = 720.10Z = 4
Monoclinic, C2/cMo Kα radiation
a = 19.5985 (3) ŵ = 2.92 mm1
b = 11.9918 (2) ÅT = 150 K
c = 15.9131 (2) Å0.49 × 0.34 × 0.17 mm
β = 109.8260 (6)°
Data collection top
Nonius KappaCCD
diffractometer
4019 independent reflections
Absorption correction: multi-scan
(SORTAV; Blessing, 1995)
3655 reflections with I > 2σ(I)
Tmin = 0.329, Tmax = 0.637Rint = 0.077
29739 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0260 restraints
wR(F2) = 0.070H atoms treated by a mixture of independent and constrained refinement
S = 1.07Δρmax = 0.26 e Å3
4019 reflectionsΔρmin = 0.44 e Å3
187 parameters
Special details top

Experimental. Detector set at 30 mm from sample with different 2theta offsets 1 degree phi exposures for chi=0 degree settings 1 degree omega exposures for chi=90 degree settings

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. For both compounds, structure solution was achieved by direct methods using SHELXS97 (Sheldrick, 1990), while least squares refinement used SHELXL97 (Sheldrick, 1997).

No disorder was detected during refinement. All C-bound H atoms were placed in calculated positions and refined using a riding model, at fixed C—H distances of 0.95 Å for the sp2 C—H bonds and 0.98 Å for the methyl C—H bonds. All N-bound H atoms were located in the difference map and allowed to refine freely. All non-H atoms were refined anisotropically, and no restraints were applied.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
Cu10.25000.25000.00000.03027 (10)
N20.35090 (8)0.31214 (12)0.05144 (9)0.0314 (3)
N30.41078 (8)0.24737 (13)0.06997 (10)0.0303 (3)
H30.4028 (11)0.1775 (18)0.0576 (13)0.031 (5)*
C40.47233 (9)0.30750 (15)0.09398 (12)0.0331 (4)
C50.45117 (11)0.41710 (17)0.09161 (17)0.0488 (5)
H50.48120.47940.10520.059*
C60.37558 (11)0.41606 (17)0.06466 (15)0.0457 (5)
H60.34660.47930.05700.055*
C70.54601 (10)0.25549 (16)0.11226 (13)0.0381 (4)
C80.56461 (15)0.2589 (3)0.02676 (18)0.0686 (8)
H8A0.61150.22610.03760.082*
H8B0.56520.33490.00810.082*
H8C0.52890.21780.01920.082*
C90.60229 (13)0.3221 (2)0.18558 (18)0.0640 (7)
H9A0.64930.28930.19760.077*
H9B0.58980.32100.23890.077*
H9C0.60300.39780.16620.077*
C100.54679 (14)0.1342 (2)0.1417 (2)0.0708 (8)
H10A0.59430.10340.15310.085*
H10B0.51200.09220.09530.085*
H10C0.53460.13080.19520.085*
N110.24815 (8)0.20208 (12)0.11981 (9)0.0303 (3)
N120.20697 (8)0.25908 (12)0.15857 (10)0.0284 (3)
H120.1929 (11)0.3200 (18)0.1395 (13)0.031 (5)*
C130.19824 (9)0.20293 (14)0.22722 (10)0.0282 (3)
C140.23621 (11)0.10438 (16)0.23377 (12)0.0370 (4)
H140.24110.04750.27510.044*
C150.26576 (10)0.10787 (16)0.16548 (12)0.0363 (4)
H150.29400.05170.15360.044*
C160.15555 (10)0.24795 (15)0.28280 (12)0.0346 (4)
C170.11354 (12)0.35283 (18)0.24082 (14)0.0451 (5)
H17A0.08690.37960.27740.054*
H17B0.08040.33560.18230.054*
H17C0.14690.40930.23640.054*
C180.10189 (17)0.1578 (2)0.2878 (2)0.0751 (9)
H18A0.07380.18450.32270.090*
H18B0.12800.09210.31510.090*
H18C0.07010.14020.22860.090*
C190.20784 (15)0.2747 (2)0.37618 (14)0.0625 (7)
H19A0.18120.30360.41200.075*
H19B0.24240.32930.37210.075*
H19C0.23290.20800.40320.075*
Br200.181354 (10)0.468494 (13)0.023977 (11)0.03249 (8)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cu10.02651 (16)0.04470 (19)0.02063 (15)0.00107 (12)0.00933 (11)0.00212 (11)
N20.0284 (7)0.0351 (7)0.0308 (7)0.0029 (6)0.0102 (6)0.0009 (6)
N30.0290 (7)0.0309 (8)0.0314 (7)0.0022 (6)0.0108 (6)0.0003 (6)
C40.0300 (8)0.0380 (9)0.0322 (8)0.0014 (7)0.0115 (7)0.0002 (7)
C50.0348 (10)0.0371 (10)0.0706 (14)0.0033 (8)0.0131 (9)0.0069 (10)
C60.0356 (10)0.0357 (10)0.0624 (13)0.0052 (8)0.0122 (9)0.0059 (9)
C70.0307 (9)0.0458 (10)0.0393 (10)0.0065 (8)0.0136 (8)0.0020 (8)
C80.0549 (15)0.108 (2)0.0508 (14)0.0288 (15)0.0284 (11)0.0071 (14)
C90.0361 (11)0.0804 (17)0.0656 (15)0.0069 (11)0.0042 (10)0.0158 (13)
C100.0458 (13)0.0585 (14)0.111 (2)0.0187 (11)0.0306 (14)0.0262 (15)
N110.0327 (7)0.0366 (7)0.0237 (6)0.0043 (6)0.0125 (6)0.0010 (6)
N120.0338 (8)0.0285 (7)0.0265 (7)0.0039 (6)0.0148 (6)0.0029 (6)
C130.0307 (8)0.0318 (8)0.0231 (7)0.0028 (6)0.0102 (6)0.0002 (6)
C140.0502 (11)0.0332 (9)0.0317 (9)0.0072 (8)0.0191 (8)0.0077 (7)
C150.0454 (10)0.0367 (9)0.0299 (8)0.0127 (8)0.0166 (7)0.0041 (7)
C160.0393 (10)0.0388 (9)0.0319 (9)0.0029 (7)0.0201 (8)0.0026 (7)
C170.0479 (11)0.0497 (11)0.0441 (11)0.0141 (9)0.0237 (9)0.0035 (9)
C180.092 (2)0.0581 (14)0.111 (2)0.0127 (14)0.082 (2)0.0027 (15)
C190.0680 (16)0.0860 (17)0.0318 (10)0.0301 (13)0.0146 (10)0.0101 (11)
Br200.04245 (13)0.02641 (11)0.03100 (11)0.00415 (6)0.01558 (8)0.00061 (6)
Geometric parameters (Å, º) top
Cu1—N22.0094 (14)N11—C151.324 (2)
Cu1—N112.0032 (14)N11—N121.355 (2)
Cu1—Br203.0280 (2)N12—C131.343 (2)
N2—C61.328 (3)N12—H120.80 (2)
N2—N31.354 (2)C13—C141.382 (3)
N3—C41.345 (2)C13—C161.509 (2)
N3—H30.86 (2)C14—C151.395 (3)
C4—C51.375 (3)C14—H140.9300
C4—C71.508 (2)C15—H150.9300
C5—C61.396 (3)C16—C191.526 (3)
C5—H50.9300C16—C171.527 (3)
C6—H60.9300C16—C181.528 (3)
C7—C81.524 (3)C17—H17A0.9600
C7—C101.526 (3)C17—H17B0.9600
C7—C91.531 (3)C17—H17C0.9600
C8—H8A0.9600C18—H18A0.9600
C8—H8B0.9600C18—H18B0.9600
C8—H8C0.9600C18—H18C0.9600
C9—H9A0.9600C19—H19A0.9600
C9—H9B0.9600C19—H19B0.9600
C9—H9C0.9600C19—H19C0.9600
C10—H10A0.9600Br20—H3i2.45 (2)
C10—H10B0.9600Br20—H122.51 (2)
C10—H10C0.9600
N2—Cu1—N1192.96 (6)C7—C10—H10C109.5
N2—Cu1—Br2092.62 (4)H10A—C10—H10C109.5
N11—Cu1—Br2088.63 (4)H10B—C10—H10C109.5
N2—Cu1—N11i87.04 (6)C15—N11—N12105.36 (14)
N11i—Cu1—Br2091.37 (4)C15—N11—Cu1132.97 (12)
N2i—Cu1—Br2087.38 (4)N12—N11—Cu1119.62 (11)
N2i—Cu1—N2180C13—N12—N11112.17 (14)
N11i—Cu1—N11180C13—N12—H12129.9 (15)
Br20i—Cu1—Br20180N11—N12—H12117.9 (15)
C6—N2—N3105.17 (14)N12—C13—C14106.03 (15)
C6—N2—Cu1131.92 (13)N12—C13—C16123.14 (15)
N3—N2—Cu1122.46 (11)C14—C13—C16130.82 (16)
C4—N3—N2112.47 (15)C13—C14—C15105.72 (15)
C4—N3—H3131.5 (13)C13—C14—H14127.1
N2—N3—H3115.5 (13)C15—C14—H14127.1
N3—C4—C5105.76 (16)N11—C15—C14110.70 (16)
N3—C4—C7122.76 (16)N11—C15—H15124.6
C5—C4—C7131.36 (18)C14—C15—H15124.6
C4—C5—C6106.18 (18)C13—C16—C19108.86 (16)
C4—C5—H5126.9C13—C16—C17111.23 (15)
C6—C5—H5126.9C19—C16—C17109.71 (17)
N2—C6—C5110.42 (17)C13—C16—C18107.78 (16)
N2—C6—H6124.8C19—C16—C18110.2 (2)
C5—C6—H6124.8C17—C16—C18109.06 (19)
C4—C7—C8108.67 (16)C16—C17—H17A109.5
C4—C7—C10111.25 (17)C16—C17—H17B109.5
C8—C7—C10108.6 (2)H17A—C17—H17B109.5
C4—C7—C9109.05 (17)C16—C17—H17C109.5
C8—C7—C9109.7 (2)H17A—C17—H17C109.5
C10—C7—C9109.5 (2)H17B—C17—H17C109.5
C7—C8—H8A109.5C16—C18—H18A109.5
C7—C8—H8B109.5C16—C18—H18B109.5
H8A—C8—H8B109.5H18A—C18—H18B109.5
C7—C8—H8C109.5C16—C18—H18C109.5
H8A—C8—H8C109.5H18A—C18—H18C109.5
H8B—C8—H8C109.5H18B—C18—H18C109.5
C7—C9—H9A109.5C16—C19—H19A109.5
C7—C9—H9B109.5C16—C19—H19B109.5
H9A—C9—H9B109.5H19A—C19—H19B109.5
C7—C9—H9C109.5C16—C19—H19C109.5
H9A—C9—H9C109.5H19A—C19—H19C109.5
H9B—C9—H9C109.5H19B—C19—H19C109.5
C7—C10—H10A109.5H3i—Br20—H1276.1 (6)
C7—C10—H10B109.5H3i—Br20—Cu164.1 (5)
H10A—C10—H10B109.5H12—Br20—Cu163.0 (5)
Symmetry code: (i) x+1/2, y+1/2, z.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N3—H3···Br20i0.86 (2)2.45 (2)3.2195 (15)148 (2)
N12—H12···Br200.80 (2)2.51 (2)3.2275 (15)149 (2)
Symmetry code: (i) x+1/2, y+1/2, z.

Experimental details

(I)(II)
Crystal data
Chemical formula[CuBr2(C7H12N2)2][CuBr2(C7H12N2)4]
Mr471.73720.10
Crystal system, space groupOrthorhombic, Pca21Monoclinic, C2/c
Temperature (K)150150
a, b, c (Å)17.4947 (2), 9.8730 (1), 11.1165 (1)19.5985 (3), 11.9918 (2), 15.9131 (2)
α, β, γ (°)90, 90, 9090, 109.8260 (6), 90
V3)1920.10 (3)3518.24 (9)
Z44
Radiation typeMo KαMo Kα
µ (mm1)5.302.92
Crystal size (mm)0.48 × 0.18 × 0.140.49 × 0.34 × 0.17
Data collection
DiffractometerNonius KappaCCD
diffractometer
Nonius KappaCCD
diffractometer
Absorption correctionMulti-scan
(SORTAV; Blessing, 1995)
Multi-scan
(SORTAV; Blessing, 1995)
Tmin, Tmax0.185, 0.5240.329, 0.637
No. of measured, independent and
observed [I > 2σ(I)] reflections
37366, 4373, 4268 29739, 4019, 3655
Rint0.0560.077
(sin θ/λ)max1)0.6490.649
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.024, 0.060, 1.06 0.026, 0.070, 1.07
No. of reflections43734019
No. of parameters203187
No. of restraints310
H-atom treatmentH-atom parameters constrainedH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.25, 0.470.26, 0.44
Absolute structureFlack (1983)?
Absolute structure parameter0.006 (8)?

Computer programs: COLLECT (Nonius, 1999), DENZO-SMN (Otwinowski & Minor, 1997), DENZO-SMN, SHELXS97 (Sheldrick, 1990), SHELXL97 (Sheldrick, 1997), ORTEX (McArdle, 1995), local program.

Selected geometric parameters (Å, º) for (I) top
Cu1—N21.951 (2)Cu1—Br202.4479 (4)
Cu1—N111.948 (2)Cu1—Br212.3766 (4)
N2—Cu1—N11152.26 (9)N11—Cu1—Br2093.97 (6)
N2—Cu1—Br2094.09 (6)N11—Cu1—Br2194.75 (6)
N2—Cu1—Br2194.96 (7)Br20—Cu1—Br21142.27 (2)
Hydrogen-bond geometry (Å, º) for (I) top
D—H···AD—HH···AD···AD—H···A
N3—H3···Br200.882.693.200 (2)118
N12—H12···Br200.882.643.194 (2)122
Selected geometric parameters (Å, º) for (II) top
Cu1—N22.0094 (14)Cu1—Br203.0280 (2)
Cu1—N112.0032 (14)
N2—Cu1—N1192.96 (6)N11—Cu1—Br2088.63 (4)
N2—Cu1—Br2092.62 (4)
Hydrogen-bond geometry (Å, º) for (II) top
D—H···AD—HH···AD···AD—H···A
N3—H3···Br20i0.86 (2)2.45 (2)3.2195 (15)148 (2)
N12—H12···Br200.80 (2)2.51 (2)3.2275 (15)149 (2)
Symmetry code: (i) x+1/2, y+1/2, z.
 

Subscribe to Acta Crystallographica Section C: Structural Chemistry

The full text of this article is available to subscribers to the journal.

If you have already registered and are using a computer listed in your registration details, please email support@iucr.org for assistance.

Buy online

You may purchase this article in PDF and/or HTML formats. For purchasers in the European Community who do not have a VAT number, VAT will be added at the local rate. Payments to the IUCr are handled by WorldPay, who will accept payment by credit card in several currencies. To purchase the article, please complete the form below (fields marked * are required), and then click on `Continue'.
E-mail address* 
Repeat e-mail address* 
(for error checking) 

Format*   PDF (US $40)
   HTML (US $40)
   PDF+HTML (US $50)
In order for VAT to be shown for your country javascript needs to be enabled.

VAT number 
(non-UK EC countries only) 
Country* 
 

Terms and conditions of use
Contact us

Follow Acta Cryst. C
Sign up for e-alerts
Follow Acta Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds