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The title compound, [CuCl2(C11H16N4)], is isostructural with the previously characterized ZnII analogous complex. The CuII ion is four-coordinate in a CuCl2N2 distorted tetra­hedral geometry. In the crystal structure, weak C—H...Cl inter­actions are observed.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807048878/bh2127sup1.cif
Contains datablocks I, global

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S1600536807048878/bh2127Isup2.hkl
Contains datablock I

CCDC reference: 667198

Key indicators

  • Single-crystal X-ray study
  • T = 193 K
  • Mean [sigma](C-C) = 0.004 Å
  • R factor = 0.030
  • wR factor = 0.075
  • Data-to-parameter ratio = 16.7

checkCIF/PLATON results

No syntax errors found



Alert level C PLAT029_ALERT_3_C _diffrn_measured_fraction_theta_full Low ....... 0.97 PLAT232_ALERT_2_C Hirshfeld Test Diff (M-X) Cu1 - Cl2 .. 6.40 su PLAT232_ALERT_2_C Hirshfeld Test Diff (M-X) Cu1 - Cl3 .. 9.47 su PLAT232_ALERT_2_C Hirshfeld Test Diff (M-X) Cu1 - N1 .. 6.10 su PLAT480_ALERT_4_C Long H...A H-Bond Reported H6C .. CL3 .. 2.87 Ang. PLAT480_ALERT_4_C Long H...A H-Bond Reported H11B .. CL3 .. 2.84 Ang. PLAT480_ALERT_4_C Long H...A H-Bond Reported H11C .. CL3 .. 2.85 Ang.
Alert level G PLAT794_ALERT_5_G Check Predicted Bond Valency for Cu1 (2) 1.97
0 ALERT level A = In general: serious problem 0 ALERT level B = Potentially serious problem 7 ALERT level C = Check and explain 1 ALERT level G = General alerts; check 0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data 3 ALERT type 2 Indicator that the structure model may be wrong or deficient 1 ALERT type 3 Indicator that the structure quality may be low 3 ALERT type 4 Improvement, methodology, query or suggestion 1 ALERT type 5 Informative message, check

Comment top

There have been numerous attempts to improve the effectiveness of antitumor agent cis-platin, through the modification of its structure. A number of pyrazole and its derivatives complexes were studied with respect to their cytotoxicity, apoptosis induction ability, and DNA damaging (Ciesielska et al., 2006). While searching for new complexes with ligands similar to previously studied ones, we synthesized a new CuII complex including a dimethylpyrazole derivative as ligand, (I).

Complex (I) is isostructural with the ZnII analogue, dichloro[(3,5-dimethyl-1H-pyrazol-1-yl)methane]zinc(II), reported by Cheng et al. (2006). Ionic radii for CuII and ZnII, 0.069 and 0.074 nm respectively, compare well, allowing isomorphous compounds to be formed.

In (I), the CuII ion is four coordinated by two N atoms and two Cl atoms (Fig. 1). This [CuCl2N2] coordination environment forms a distorted tetrahedral geometry with local non-crystallographic Cs symmetry. Angles around the CuII ion range from 115.28 (6) to 89.30 (8)°. These angles are comparable with those observed in other [CuCl2N2] coordination spheres (CSD, Version 5.28; Allen, 2002). The range of angles are 97.43–128.52° and 78.95–142.27° for Cl—Cu—Cl and N—Cu—N fragments, respectively (333 observations). The Cu—Cl and Cu—N bond lengths in (I) are also comparables with those observed in [CuCl2N2] moieties, which have averages of 2.22 and 2.05 Å, respectively, in the CSD.

In the crystal structure of (I) there are extensive C—H···Cl interactions (Table 2, Fig. 2). On the other hand, heterocyclic rings N1/N2/C2/C3/C4 in the asymmetric unit and N3/N4/C7/C8/C9 at position (1/2 - x, 1 - y, 1 - z) interact through ππ stacking interactions. The interplanar spacing is 3.531 (2) Å, while centroids of the rings are separated by 3.508 Å. The ring N3···C9 also interacts with a symmetry related N3···C9 ring at (1/2 - x, 1/2 - y, 2 - z). The interplanar spacing is 3.651 (2) Å, while the centroid to centroid separation is 3.650 Å.

Related literature top

For details of the antitumour activity of pyrole [pyrazole?] containing complexes, see: Ciesielska et al. (2006). For the dimethylpyrazole derivative used as a ligand, see: Rüfenacht (1973). The title complex is isostructural with the Zn analogue (Cheng et al., 2006). For comparison with other complexes containing a [CuCl2N2] core, see: Allen (2002).

Experimental top

The title compound was obtained by reaction of N-hydroxymethyl-3,5-dimethylpyrazole (Rüfenacht, 1973) with CuCl2 (2:1 stoichiometric ratio) in ethanol at room temperature. Crystals were obtained by slow evaporation at room temperature. The product (green needles) was obtained in 52% yield.

Refinement top

The crystal used for data collection revealed to be twinned, and a twin-integration based on two orientations was done. A first refinement was carried out using HKLF 5 option in SHELXL97 (Sheldrick, 1997), resulting in a twin ratio 0.241 (2)/0.759 (2). Option LIST 6 was then applied in order to get a structure factors file containing merged data for a non-twinned model and the structure was refined to convergence. All H atoms were positioned geometrically and refined with a riding model; for methyl H atoms Uiso were constrained to be 1.5 times Ueq of the carrier atom and C—H = 0.98 Å; for others H atoms Uiso were constrained to be 1.2 times Ueq of the carrier atom and C—H = 0.97, 0.93, 0.86 or 0.82 Å for methylene, aromatic, amine and hydroxyl groups, respectively.

Structure description top

There have been numerous attempts to improve the effectiveness of antitumor agent cis-platin, through the modification of its structure. A number of pyrazole and its derivatives complexes were studied with respect to their cytotoxicity, apoptosis induction ability, and DNA damaging (Ciesielska et al., 2006). While searching for new complexes with ligands similar to previously studied ones, we synthesized a new CuII complex including a dimethylpyrazole derivative as ligand, (I).

Complex (I) is isostructural with the ZnII analogue, dichloro[(3,5-dimethyl-1H-pyrazol-1-yl)methane]zinc(II), reported by Cheng et al. (2006). Ionic radii for CuII and ZnII, 0.069 and 0.074 nm respectively, compare well, allowing isomorphous compounds to be formed.

In (I), the CuII ion is four coordinated by two N atoms and two Cl atoms (Fig. 1). This [CuCl2N2] coordination environment forms a distorted tetrahedral geometry with local non-crystallographic Cs symmetry. Angles around the CuII ion range from 115.28 (6) to 89.30 (8)°. These angles are comparable with those observed in other [CuCl2N2] coordination spheres (CSD, Version 5.28; Allen, 2002). The range of angles are 97.43–128.52° and 78.95–142.27° for Cl—Cu—Cl and N—Cu—N fragments, respectively (333 observations). The Cu—Cl and Cu—N bond lengths in (I) are also comparables with those observed in [CuCl2N2] moieties, which have averages of 2.22 and 2.05 Å, respectively, in the CSD.

In the crystal structure of (I) there are extensive C—H···Cl interactions (Table 2, Fig. 2). On the other hand, heterocyclic rings N1/N2/C2/C3/C4 in the asymmetric unit and N3/N4/C7/C8/C9 at position (1/2 - x, 1 - y, 1 - z) interact through ππ stacking interactions. The interplanar spacing is 3.531 (2) Å, while centroids of the rings are separated by 3.508 Å. The ring N3···C9 also interacts with a symmetry related N3···C9 ring at (1/2 - x, 1/2 - y, 2 - z). The interplanar spacing is 3.651 (2) Å, while the centroid to centroid separation is 3.650 Å.

For details of the antitumour activity of pyrole [pyrazole?] containing complexes, see: Ciesielska et al. (2006). For the dimethylpyrazole derivative used as a ligand, see: Rüfenacht (1973). The title complex is isostructural with the Zn analogue (Cheng et al., 2006). For comparison with other complexes containing a [CuCl2N2] core, see: Allen (2002).

Computing details top

Data collection: IPDS2 (Stoe & Cie, 2000); cell refinement: IPDS2 (Stoe & Cie, 2000); data reduction: IPDS2 (Stoe & Cie, 2000); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 2003); software used to prepare material for publication: PARST97 (Nardelli, 1996).

Figures top
[Figure 1] Fig. 1. Molecular structure and atomic numbering scheme showing 50% probability displacement ellipsoids in (I).
[Figure 2] Fig. 2. Packing in the unit cell.
Dichlorido[(3,5-dimethyl-1H-pyrazol-1-yl)methane]copper(II) top
Crystal data top
[CuCl2(C11H16N4)]F(000) = 1384
Mr = 338.72Dx = 1.585 Mg m3
Monoclinic, C2/cMelting point: 471 K
Hall symbol: -C 2ycMo Kα radiation, λ = 0.71073 Å
a = 14.8120 (7) ÅCell parameters from 2790 reflections
b = 16.7384 (9) Åθ = 1.0–26.2°
c = 12.4943 (6) ŵ = 1.90 mm1
β = 113.58 (1)°T = 193 K
V = 2839.0 (3) Å3Needle, green
Z = 80.2 × 0.1 × 0.1 mm
Data collection top
Stoe IPDSII
diffractometer
2619 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.431
Graphite monochromatorθmax = 26.3°, θmin = 1.9°
Detector resolution: 150 pixels mm-1h = 1816
ω scansk = 020
39701 measured reflectionsl = 015
2790 independent reflections
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)] = 0.030Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.075H-atom parameters constrained
S = 1.11 w = 1/[σ2(Fo2) + (0.0335P)2 + 8.2559P]
where P = (Fo2 + 2Fc2)/3
2790 reflections(Δ/σ)max < 0.001
167 parametersΔρmax = 0.49 e Å3
0 restraintsΔρmin = 0.37 e Å3
Crystal data top
[CuCl2(C11H16N4)]V = 2839.0 (3) Å3
Mr = 338.72Z = 8
Monoclinic, C2/cMo Kα radiation
a = 14.8120 (7) ŵ = 1.90 mm1
b = 16.7384 (9) ÅT = 193 K
c = 12.4943 (6) Å0.2 × 0.1 × 0.1 mm
β = 113.58 (1)°
Data collection top
Stoe IPDSII
diffractometer
2619 reflections with I > 2σ(I)
39701 measured reflectionsRint = 0.431
2790 independent reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0300 restraints
wR(F2) = 0.075H-atom parameters constrained
S = 1.11Δρmax = 0.49 e Å3
2790 reflectionsΔρmin = 0.37 e Å3
167 parameters
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
Cu10.22280 (2)0.382801 (16)0.73912 (2)0.01924 (10)
Cl20.38607 (4)0.38971 (4)0.81853 (6)0.03166 (15)
Cl30.15000 (4)0.50151 (3)0.70045 (5)0.02650 (14)
N40.18202 (15)0.22504 (12)0.81646 (18)0.0246 (4)
N20.18482 (15)0.22408 (12)0.62680 (18)0.0234 (4)
N10.17654 (15)0.30433 (12)0.60113 (18)0.0239 (4)
N30.17098 (15)0.30531 (12)0.83008 (18)0.0228 (4)
C10.23608 (18)0.20058 (15)0.7477 (2)0.0243 (5)
H1A0.30230.22530.78010.029*
H1B0.24460.14180.75240.029*
C20.12575 (18)0.30910 (15)0.4853 (2)0.0248 (5)
C90.13452 (18)0.18129 (16)0.8687 (2)0.0272 (5)
C40.14092 (17)0.17955 (15)0.5294 (2)0.0257 (5)
C100.1347 (2)0.09174 (17)0.8698 (3)0.0378 (6)
H10A0.10200.07180.78970.057*
H10B0.09950.07260.91660.057*
H10C0.20280.07230.90400.057*
C70.11546 (18)0.31124 (15)0.8915 (2)0.0243 (5)
C30.10333 (18)0.23234 (16)0.4379 (2)0.0265 (5)
H30.06870.21920.35780.032*
C80.09196 (19)0.23490 (16)0.9179 (2)0.0285 (5)
H80.05390.22250.96150.034*
C50.1358 (2)0.09069 (16)0.5300 (3)0.0354 (6)
H5A0.20100.06900.57770.053*
H5B0.11420.07060.44990.053*
H5C0.08870.07400.56280.053*
C110.0867 (2)0.39044 (16)0.9220 (2)0.0321 (6)
H11A0.11740.43290.89410.048*
H11B0.10890.39451.00700.048*
H11C0.01490.39610.88510.048*
C60.1003 (2)0.38793 (16)0.4253 (2)0.0323 (6)
H6A0.13710.43020.47950.048*
H6B0.02950.39760.39960.048*
H6C0.11770.38780.35740.048*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cu10.01992 (16)0.01714 (15)0.01992 (15)0.00007 (10)0.00719 (11)0.00023 (10)
Cl20.0218 (3)0.0354 (3)0.0340 (3)0.0002 (2)0.0072 (2)0.0008 (3)
Cl30.0277 (3)0.0202 (3)0.0299 (3)0.0015 (2)0.0096 (2)0.0004 (2)
N40.0268 (10)0.0203 (10)0.0275 (11)0.0018 (8)0.0118 (9)0.0021 (8)
N20.0260 (10)0.0191 (10)0.0253 (10)0.0023 (8)0.0105 (8)0.0002 (8)
N10.0276 (10)0.0199 (10)0.0243 (10)0.0024 (8)0.0106 (8)0.0022 (8)
N30.0249 (10)0.0185 (10)0.0237 (10)0.0014 (8)0.0083 (8)0.0004 (8)
C10.0255 (12)0.0225 (12)0.0241 (12)0.0038 (9)0.0092 (10)0.0019 (9)
C20.0231 (12)0.0283 (13)0.0230 (12)0.0007 (10)0.0093 (10)0.0001 (10)
C90.0245 (12)0.0260 (13)0.0289 (12)0.0002 (10)0.0085 (10)0.0056 (10)
C40.0212 (11)0.0249 (13)0.0300 (13)0.0001 (9)0.0091 (10)0.0058 (10)
C100.0448 (17)0.0252 (14)0.0472 (17)0.0000 (12)0.0224 (14)0.0067 (12)
C70.0245 (12)0.0279 (13)0.0195 (11)0.0018 (10)0.0076 (9)0.0011 (9)
C30.0249 (12)0.0286 (13)0.0241 (12)0.0027 (10)0.0077 (10)0.0039 (10)
C80.0291 (13)0.0322 (13)0.0271 (13)0.0005 (11)0.0142 (11)0.0024 (11)
C50.0365 (15)0.0232 (13)0.0400 (15)0.0031 (11)0.0082 (12)0.0056 (11)
C110.0354 (14)0.0339 (14)0.0314 (14)0.0034 (11)0.0181 (12)0.0033 (11)
C60.0407 (15)0.0287 (14)0.0278 (13)0.0020 (11)0.0139 (12)0.0034 (11)
Geometric parameters (Å, º) top
Cu1—N12.055 (2)C4—C31.374 (4)
Cu1—N32.064 (2)C4—C51.490 (4)
Cu1—Cl22.2195 (9)C10—H10A0.9800
Cu1—Cl32.2197 (7)C10—H10B0.9800
N4—C91.351 (3)C10—H10C0.9800
N4—N31.372 (3)C7—C81.398 (4)
N4—C11.448 (3)C7—C111.488 (4)
N2—C41.352 (3)C3—H30.9500
N2—N11.375 (3)C8—H80.9500
N2—C11.448 (3)C5—H5A0.9800
N1—C21.340 (3)C5—H5B0.9800
N3—C71.334 (3)C5—H5C0.9800
C1—H1A0.9900C11—H11A0.9800
C1—H1B0.9900C11—H11B0.9800
C2—C31.398 (4)C11—H11C0.9800
C2—C61.490 (4)C6—H6A0.9800
C9—C81.375 (4)C6—H6B0.9800
C9—C101.499 (4)C6—H6C0.9800
N1—Cu1—N389.30 (8)C9—C10—H10A109.5
N1—Cu1—Cl2110.26 (7)C9—C10—H10B109.5
N3—Cu1—Cl2111.42 (6)H10A—C10—H10B109.5
N1—Cu1—Cl3114.82 (6)C9—C10—H10C109.5
N3—Cu1—Cl3115.28 (6)H10A—C10—H10C109.5
Cl2—Cu1—Cl3113.46 (3)H10B—C10—H10C109.5
C9—N4—N3111.1 (2)N3—C7—C8109.7 (2)
C9—N4—C1130.7 (2)N3—C7—C11121.3 (2)
N3—N4—C1118.2 (2)C8—C7—C11129.0 (2)
C4—N2—N1111.3 (2)C4—C3—C2106.9 (2)
C4—N2—C1130.7 (2)C4—C3—H3126.6
N1—N2—C1118.00 (19)C2—C3—H3126.6
C2—N1—N2105.6 (2)C9—C8—C7106.8 (2)
C2—N1—Cu1136.29 (17)C9—C8—H8126.6
N2—N1—Cu1117.39 (15)C7—C8—H8126.6
C7—N3—N4106.0 (2)C4—C5—H5A109.5
C7—N3—Cu1136.09 (17)C4—C5—H5B109.5
N4—N3—Cu1117.25 (15)H5A—C5—H5B109.5
N2—C1—N4111.01 (19)C4—C5—H5C109.5
N2—C1—H1A109.4H5A—C5—H5C109.5
N4—C1—H1A109.4H5B—C5—H5C109.5
N2—C1—H1B109.4C7—C11—H11A109.5
N4—C1—H1B109.4C7—C11—H11B109.5
H1A—C1—H1B108.0H11A—C11—H11B109.5
N1—C2—C3109.8 (2)C7—C11—H11C109.5
N1—C2—C6121.1 (2)H11A—C11—H11C109.5
C3—C2—C6129.2 (2)H11B—C11—H11C109.5
N4—C9—C8106.4 (2)C2—C6—H6A109.5
N4—C9—C10123.2 (2)C2—C6—H6B109.5
C8—C9—C10130.4 (2)H6A—C6—H6B109.5
N2—C4—C3106.5 (2)C2—C6—H6C109.5
N2—C4—C5123.6 (2)H6A—C6—H6C109.5
C3—C4—C5129.9 (2)H6B—C6—H6C109.5
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C1—H1B···Cl3i0.992.753.674 (2)155
C6—H6C···Cl3ii0.982.873.676 (3)140
C11—H11B···Cl3iii0.982.843.692 (3)146
C11—H11C···Cl3iv0.982.853.714 (2)147
Symmetry codes: (i) x+1/2, y1/2, z+3/2; (ii) x, y+1, z1/2; (iii) x, y+1, z+1/2; (iv) x, y, z+3/2.

Experimental details

Crystal data
Chemical formula[CuCl2(C11H16N4)]
Mr338.72
Crystal system, space groupMonoclinic, C2/c
Temperature (K)193
a, b, c (Å)14.8120 (7), 16.7384 (9), 12.4943 (6)
β (°) 113.58 (1)
V3)2839.0 (3)
Z8
Radiation typeMo Kα
µ (mm1)1.90
Crystal size (mm)0.2 × 0.1 × 0.1
Data collection
DiffractometerStoe IPDSII
Absorption correction
No. of measured, independent and
observed [I > 2σ(I)] reflections
39701, 2790, 2619
Rint0.431
(sin θ/λ)max1)0.623
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.030, 0.075, 1.11
No. of reflections2790
No. of parameters167
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.49, 0.37

Computer programs: IPDS2 (Stoe & Cie, 2000), SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), PLATON (Spek, 2003), PARST97 (Nardelli, 1996).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C1—H1B···Cl3i0.992.753.674 (2)155
C6—H6C···Cl3ii0.982.873.676 (3)140
C11—H11B···Cl3iii0.982.843.692 (3)146
C11—H11C···Cl3iv0.982.853.714 (2)147
Symmetry codes: (i) x+1/2, y1/2, z+3/2; (ii) x, y+1, z1/2; (iii) x, y+1, z+1/2; (iv) x, y, z+3/2.
 

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