The title Cu
II complex, [Cu
2(NCS)
4(C
6H
10N
4)
2], represents the first crystal structure of a polynuclear transition metal complex with the 3,5-dimethyl-1
H-pyrazole-1-carboxamidine ligand (H
L). It is compared with previously reported crystal structures of metal complexes with the same H
L ligand. The molecule contains an eight-membered binuclear Cu
2(NCS)
2 ring, which is centrosymmetric and in a chair conformation. The Cu atom has a distorted square-pyramidal geometry with a very elongated Cu—S bond of 2.993 (2) Å. The crystal structure redetermination of the bis(3,5-dimethyl-1
H-pyrazole-1-carboxamidine-κ
2N,
N′)bis(nitrato-κ
O)copper(II)complex, [Cu(NO
3)
2(C
6H
10N
4)
2], and analysis of its hydrogen bonds confirm the significance of the NO
3 groups in the formation of a three-dimensional hydrogen-bonding network. Both complexes are centrosymmetric, the inversion centre being located at the mid-point of the Cu
Cu line in (I) and the Cu atom being located at the inversion centre in (II).
Supporting information
CCDC references: 282173; 282174
A methanolic solution of the nitrate salt of 3,5-dimethyl-1-carboxamidinepyrazole (HL·HNO3) and the CuII salt [Cu(OAc)2·H2O] in a molar ratio of 2:1, in the presence of NH4SCN, gave dark-green crystals of complex (I), formula [Cu(NCS)2(HL)]2. Elemental analysis, found (calculated): C 30.78 (30.22), N 26.73 (26.44), H 2.99% (3.18%). The molar conductivity of the complex in dimethylformamide is 45.7 S cm2 mol−1. The effective magnetic moment µeff = 1.90 µB. Please give brief details of the preparation of compound (II).
A Gaussian-type absorption correction based on the crystal morphology (PLATON; Spek, 2003) was applied in the case of the [Cu(NCS)2(HL)]2 complex, (I). All H atoms for both crystal structures were easily found in difference Fourier maps, but those attached to C atoms were placed in calculated positions and treated using a riding model, with Uiso(H) = 1.2Ueq(C), or 1.5Ueq(C) for methyl H atoms. The positions of the methyl H atoms as defined by the HFIX 137 command (SHELXL97; Sheldrick, 1997) were in very good agreement with those found in the difference Fourier maps. H atoms bonded to N atoms were located in difference Fourier maps and refined isotropically.
For both compounds, data collection: CAD-4 Software (Enraf–Nonius, 1989); cell refinement: Please provide missing details; data reduction: XCAD4 (Harms & Wocadlo, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: CAMERON (Watkin et al.) and ORTEPIII (Burnett & Johnson, 1996); software used to prepare material for publication: PARST (Nardelli, 1995) and WinGX (Farrugia, 1999).
(I) Di-µ-thiocyanato-bis[(3,5-dimethyl-1
H-pyrazole-1-carboxamidine-
κ2N,
N')(thiocyanato-
κN)copper(II)]
top
Crystal data top
[Cu2(NCS)4(C6H10N4)2]2 | Z = 1 |
Mr = 635.76 | F(000) = 322 |
Triclinic, P1 | Dx = 1.713 Mg m−3 |
a = 7.172 (2) Å | Mo Kα radiation, λ = 0.71073 Å |
b = 8.742 (3) Å | Cell parameters from 23 reflections |
c = 11.360 (3) Å | θ = 12.2–15.6° |
α = 70.35 (2)° | µ = 2.10 mm−1 |
β = 86.00 (2)° | T = 293 K |
γ = 67.06 (2)° | Prismatic, dark green |
V = 616.2 (3) Å3 | 0.22 × 0.14 × 0.10 mm |
Data collection top
Enraf–Nonius CAD-4 diffractometer | Rint = 0.021 |
ω/2θ scans | θmax = 27.0°, θmin = 1.9° |
Absorption correction: gaussian (PLATON; Spek, 2003) | h = 0→9 |
Tmin = 0.751, Tmax = 0.825 | k = −10→11 |
2906 measured reflections | l = −14→14 |
2685 independent reflections | 3 standard reflections every 60 min |
2096 reflections with I > 2σ(I) | intensity decay: none |
Refinement top
Refinement on F2 | 0 restraints |
Least-squares matrix: full | H atoms treated by a mixture of independent and constrained refinement |
R[F2 > 2σ(F2)] = 0.042 | w = 1/[σ2(Fo2) + (0.0738P)2 + 0.1077P] where P = (Fo2 + 2Fc2)/3 |
wR(F2) = 0.125 | (Δ/σ)max = 0.001 |
S = 1.07 | Δρmax = 0.78 e Å−3 |
2685 reflections | Δρmin = −0.51 e Å−3 |
165 parameters | |
Crystal data top
[Cu2(NCS)4(C6H10N4)2]2 | γ = 67.06 (2)° |
Mr = 635.76 | V = 616.2 (3) Å3 |
Triclinic, P1 | Z = 1 |
a = 7.172 (2) Å | Mo Kα radiation |
b = 8.742 (3) Å | µ = 2.10 mm−1 |
c = 11.360 (3) Å | T = 293 K |
α = 70.35 (2)° | 0.22 × 0.14 × 0.10 mm |
β = 86.00 (2)° | |
Data collection top
Enraf–Nonius CAD-4 diffractometer | 2096 reflections with I > 2σ(I) |
Absorption correction: gaussian (PLATON; Spek, 2003) | Rint = 0.021 |
Tmin = 0.751, Tmax = 0.825 | 3 standard reflections every 60 min |
2906 measured reflections | intensity decay: none |
2685 independent reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.042 | 0 restraints |
wR(F2) = 0.125 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.07 | Δρmax = 0.78 e Å−3 |
2685 reflections | Δρmin = −0.51 e Å−3 |
165 parameters | |
Special details top
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. |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
Cu | 0.23969 (7) | 0.91961 (5) | 0.87042 (4) | 0.03903 (17) | |
S1A | 0.3429 (2) | 1.09600 (16) | 1.19374 (10) | 0.0579 (3) | |
S1B | −0.23778 (17) | 1.49593 (13) | 0.73762 (10) | 0.0573 (3) | |
N1 | 0.2346 (4) | 0.8647 (3) | 0.7152 (2) | 0.0330 (6) | |
N2 | 0.2471 (4) | 0.6952 (3) | 0.7386 (2) | 0.0319 (6) | |
N3 | 0.2776 (5) | 0.6719 (4) | 0.9417 (3) | 0.0397 (7) | |
H1N3 | 0.280 (6) | 0.618 (5) | 1.020 (4) | 0.044 (11)* | |
N4 | 0.2592 (6) | 0.4366 (4) | 0.8971 (3) | 0.0491 (8) | |
H1N4 | 0.291 (6) | 0.369 (6) | 0.974 (4) | 0.051 (12)* | |
H2N4 | 0.2056 | 0.4280 | 0.8420 | 0.075 (17)* | |
N5A | 0.2879 (6) | 0.9436 (4) | 1.0279 (3) | 0.0512 (8) | |
N5B | 0.0809 (6) | 1.1697 (4) | 0.7971 (3) | 0.0551 (9) | |
C1 | 0.2607 (5) | 0.5961 (4) | 0.8665 (3) | 0.0328 (7) | |
C2 | 0.2676 (5) | 0.6583 (4) | 0.6297 (3) | 0.0350 (7) | |
C3 | 0.2929 (7) | 0.4861 (5) | 0.6192 (4) | 0.0502 (9) | |
H3A | 0.3100 | 0.4915 | 0.5335 | 0.075* | |
H3B | 0.1747 | 0.4615 | 0.6465 | 0.075* | |
H3C | 0.4103 | 0.3942 | 0.6707 | 0.075* | |
C4 | 0.2656 (5) | 0.8063 (5) | 0.5373 (3) | 0.0373 (7) | |
H4 | 0.2766 | 0.8212 | 0.4524 | 0.045* | |
C5 | 0.2439 (5) | 0.9322 (4) | 0.5933 (3) | 0.0346 (7) | |
C6 | 0.2386 (6) | 1.1133 (4) | 0.5338 (3) | 0.0448 (9) | |
H6A | 0.1126 | 1.1969 | 0.5480 | 0.067* | |
H6B | 0.2505 | 1.1374 | 0.4453 | 0.067* | |
H6C | 0.3494 | 1.1228 | 0.5695 | 0.067* | |
C7A | 0.3107 (6) | 1.0059 (4) | 1.0968 (3) | 0.0390 (8) | |
C7B | −0.0553 (6) | 1.3030 (5) | 0.7727 (3) | 0.0385 (8) | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Cu | 0.0583 (3) | 0.0285 (2) | 0.0341 (2) | −0.0180 (2) | 0.00501 (19) | −0.01405 (17) |
S1A | 0.0864 (8) | 0.0712 (7) | 0.0408 (5) | −0.0453 (6) | 0.0145 (5) | −0.0335 (5) |
S1B | 0.0575 (6) | 0.0409 (5) | 0.0486 (6) | −0.0042 (5) | 0.0064 (5) | −0.0031 (4) |
N1 | 0.0450 (16) | 0.0232 (12) | 0.0306 (13) | −0.0150 (11) | −0.0008 (12) | −0.0061 (10) |
N2 | 0.0451 (16) | 0.0255 (12) | 0.0267 (13) | −0.0168 (12) | 0.0006 (11) | −0.0065 (10) |
N3 | 0.061 (2) | 0.0310 (14) | 0.0266 (14) | −0.0196 (14) | 0.0002 (13) | −0.0068 (12) |
N4 | 0.082 (3) | 0.0375 (16) | 0.0342 (16) | −0.0349 (17) | −0.0022 (16) | −0.0050 (13) |
N5A | 0.075 (2) | 0.0543 (19) | 0.0434 (17) | −0.0385 (18) | 0.0156 (16) | −0.0259 (15) |
N5B | 0.069 (2) | 0.0332 (16) | 0.058 (2) | −0.0160 (16) | 0.0181 (17) | −0.0157 (15) |
C1 | 0.0415 (18) | 0.0263 (15) | 0.0277 (15) | −0.0132 (13) | 0.0004 (13) | −0.0053 (12) |
C2 | 0.0409 (18) | 0.0370 (17) | 0.0343 (16) | −0.0202 (14) | 0.0034 (14) | −0.0147 (14) |
C3 | 0.077 (3) | 0.046 (2) | 0.044 (2) | −0.036 (2) | 0.0151 (19) | −0.0244 (17) |
C4 | 0.0457 (19) | 0.0461 (19) | 0.0278 (15) | −0.0254 (16) | 0.0056 (14) | −0.0133 (14) |
C5 | 0.0388 (18) | 0.0322 (16) | 0.0294 (15) | −0.0154 (14) | −0.0012 (13) | −0.0034 (13) |
C6 | 0.057 (2) | 0.0344 (18) | 0.0402 (19) | −0.0238 (17) | 0.0025 (17) | −0.0016 (15) |
C7A | 0.058 (2) | 0.0344 (16) | 0.0297 (16) | −0.0242 (16) | 0.0103 (15) | −0.0107 (14) |
C7B | 0.055 (2) | 0.0371 (18) | 0.0316 (16) | −0.0254 (17) | 0.0101 (15) | −0.0136 (14) |
Geometric parameters (Å, º) top
Cu—S1Ai | 2.993 (2) | N4—H2N4 | 0.795 |
Cu—N1 | 1.983 (3) | N5A—C7A | 1.144 (5) |
Cu—N3 | 1.952 (3) | N5B—C7B | 1.151 (5) |
Cu—N5A | 1.939 (3) | C2—C3 | 1.490 (5) |
Cu—N5B | 1.933 (3) | C2—C4 | 1.360 (5) |
S1A—C7A | 1.627 (4) | C3—H3A | 0.9600 |
S1B—C7B | 1.617 (4) | C3—H3B | 0.9600 |
N1—N2 | 1.382 (3) | C3—H3C | 0.9600 |
N1—C5 | 1.318 (4) | C4—C5 | 1.402 (5) |
N2—C1 | 1.407 (4) | C4—H4 | 0.9300 |
N2—C2 | 1.364 (4) | C5—C6 | 1.484 (4) |
N3—C1 | 1.281 (4) | C6—H6A | 0.9600 |
N3—H1N3 | 0.85 (4) | C6—H6B | 0.9600 |
N4—C1 | 1.323 (4) | C6—H6C | 0.9600 |
N4—H1N4 | 0.86 (4) | | |
| | | |
N5B—Cu—N5A | 91.99 (15) | C4—C2—N2 | 106.3 (3) |
N5B—Cu—N3 | 154.40 (16) | C4—C2—C3 | 128.4 (3) |
N5A—Cu—N3 | 95.67 (13) | N2—C2—C3 | 125.3 (3) |
N5B—Cu—N1 | 95.62 (13) | C2—C3—H3A | 109.5 |
N5A—Cu—N1 | 170.81 (13) | C2—C3—H3B | 109.5 |
N3—Cu—N1 | 79.60 (11) | H3A—C3—H3B | 109.5 |
C5—N1—N2 | 106.5 (3) | C2—C3—H3C | 109.5 |
C5—N1—Cu | 140.1 (2) | H3A—C3—H3C | 109.5 |
N2—N1—Cu | 112.92 (18) | H3B—C3—H3C | 109.5 |
C2—N2—N1 | 110.1 (2) | C2—C4—C5 | 107.5 (3) |
C2—N2—C1 | 135.0 (3) | C2—C4—H4 | 126.3 |
N1—N2—C1 | 114.3 (2) | C5—C4—H4 | 126.3 |
C1—N3—Cu | 117.7 (2) | N1—C5—C4 | 109.5 (3) |
C1—N3—H1N3 | 117 (3) | N1—C5—C6 | 121.7 (3) |
Cu—N3—H1N3 | 124 (3) | C4—C5—C6 | 128.7 (3) |
C1—N4—H1N4 | 118 (3) | C5—C6—H6A | 109.5 |
C1—N4—H2N4 | 111.0 | C5—C6—H6B | 109.5 |
H1N4—N4—H2N4 | 130 | H6A—C6—H6B | 109.5 |
C7A—N5A—Cu | 159.6 (3) | C5—C6—H6C | 109.5 |
C7B—N5B—Cu | 160.1 (3) | H6A—C6—H6C | 109.5 |
N3—C1—N4 | 126.9 (3) | H6B—C6—H6C | 109.5 |
N3—C1—N2 | 114.8 (3) | N5A—C7A—S1A | 179.5 (3) |
N4—C1—N2 | 118.2 (3) | N5B—C7B—S1B | 176.7 (4) |
Symmetry code: (i) −x+1, −y+2, −z+2. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N4—H1N4···S1Aii | 0.86 (4) | 2.74 (4) | 3.567 (4) | 162 (4) |
N3—H1N3···S1Biii | 0.85 (4) | 2.63 (4) | 3.477 (3) | 170 (4) |
Symmetry codes: (ii) x, y−1, z; (iii) −x, −y+2, −z+2. |
(II) bis(3,5-dimethyl-1
H-pyrazole-1-carboxamidine-
κ2N,
N')bis(nitrato-
κO)copper(II)
top
Crystal data top
[Cu(NO3)2(C6H10N4)2] | Z = 1 |
Mr = 463.92 | F(000) = 239 |
Triclinic, P1 | Dx = 1.670 Mg m−3 |
a = 5.476 (2) Å | Mo Kα radiation, λ = 0.71073 Å |
b = 9.379 (3) Å | Cell parameters from 24 reflections |
c = 9.529 (3) Å | θ = 13.4–17.7° |
α = 76.99 (2)° | µ = 1.24 mm−1 |
β = 75.38 (2)° | T = 293 K |
γ = 86.96 (2)° | Prismatic, blue |
V = 461.4 (3) Å3 | 0.16 × 0.14 × 0.14 mm |
Data collection top
Enraf–Nonius CAD-4 diffractometer | θmax = 30.0°, θmin = 2.2° |
ω/2θ scans | h = −7→7 |
4799 measured reflections | k = −12→13 |
2691 independent reflections | l = −10→13 |
2311 reflections with I > 2σ(I) | 3 standard reflections every 60 min |
Rint = 0.019 | intensity decay: none |
Refinement top
Refinement on F2 | 0 restraints |
Least-squares matrix: full | H atoms treated by a mixture of independent and constrained refinement |
R[F2 > 2σ(F2)] = 0.030 | w = 1/[σ2(Fo2) + (0.0453P)2 + 0.1115P] where P = (Fo2 + 2Fc2)/3 |
wR(F2) = 0.083 | (Δ/σ)max < 0.001 |
S = 1.05 | Δρmax = 0.43 e Å−3 |
2691 reflections | Δρmin = −0.47 e Å−3 |
147 parameters | |
Crystal data top
[Cu(NO3)2(C6H10N4)2] | γ = 86.96 (2)° |
Mr = 463.92 | V = 461.4 (3) Å3 |
Triclinic, P1 | Z = 1 |
a = 5.476 (2) Å | Mo Kα radiation |
b = 9.379 (3) Å | µ = 1.24 mm−1 |
c = 9.529 (3) Å | T = 293 K |
α = 76.99 (2)° | 0.16 × 0.14 × 0.14 mm |
β = 75.38 (2)° | |
Data collection top
Enraf–Nonius CAD-4 diffractometer | Rint = 0.019 |
4799 measured reflections | 3 standard reflections every 60 min |
2691 independent reflections | intensity decay: none |
2311 reflections with I > 2σ(I) | |
Refinement top
R[F2 > 2σ(F2)] = 0.030 | 0 restraints |
wR(F2) = 0.083 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.05 | Δρmax = 0.43 e Å−3 |
2691 reflections | Δρmin = −0.47 e Å−3 |
147 parameters | |
Special details top
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. |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
Cu | 0.0000 | 0.0000 | 0.0000 | 0.02888 (10) | |
N1 | 0.0004 (2) | −0.17639 (14) | −0.08910 (15) | 0.0290 (3) | |
N2 | 0.2059 (2) | −0.17615 (14) | −0.20765 (14) | 0.0287 (3) | |
N3 | 0.3319 (3) | 0.01890 (16) | −0.13792 (16) | 0.0326 (3) | |
H1N3 | 0.450 (5) | 0.074 (3) | −0.153 (3) | 0.048 (6)* | |
N4 | 0.6014 (3) | −0.06673 (18) | −0.33310 (17) | 0.0377 (3) | |
H1N4 | 0.719 (5) | −0.002 (3) | −0.341 (3) | 0.059 (7)* | |
H2N4 | 0.620 (4) | −0.120 (3) | −0.388 (3) | 0.045 (6)* | |
N5 | 0.0101 (3) | −0.21882 (17) | 0.32868 (17) | 0.0382 (3) | |
O1 | −0.0386 (3) | −0.14197 (19) | 0.42255 (18) | 0.0578 (4) | |
O2 | 0.1713 (3) | −0.1718 (2) | 0.20914 (17) | 0.0558 (4) | |
O3 | −0.1010 (5) | −0.3323 (2) | 0.3480 (3) | 0.0886 (7) | |
C1 | 0.3896 (3) | −0.06854 (17) | −0.22861 (17) | 0.0280 (3) | |
C2 | 0.1988 (3) | −0.29558 (18) | −0.26744 (19) | 0.0330 (3) | |
C3 | 0.3894 (4) | −0.3321 (2) | −0.3969 (2) | 0.0486 (5) | |
H3A | 0.3285 | −0.4122 | −0.4262 | 0.073* | |
H3B | 0.5452 | −0.3591 | −0.3694 | 0.073* | |
H3C | 0.4170 | −0.2483 | −0.4784 | 0.073* | |
C4 | −0.0147 (3) | −0.37158 (18) | −0.1850 (2) | 0.0372 (4) | |
H5 | −0.0718 | −0.4578 | −0.1989 | 0.045* | |
C5 | −0.1322 (3) | −0.29485 (18) | −0.07493 (19) | 0.0322 (3) | |
C6 | −0.3656 (4) | −0.3354 (2) | 0.0458 (2) | 0.0438 (4) | |
H6A | −0.3406 | −0.3183 | 0.1368 | 0.066* | |
H6B | −0.4030 | −0.4370 | 0.0585 | 0.066* | |
H6C | −0.5037 | −0.2769 | 0.0200 | 0.066* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Cu | 0.02459 (14) | 0.02945 (15) | 0.03360 (16) | −0.00277 (9) | 0.00146 (10) | −0.01807 (11) |
N1 | 0.0271 (6) | 0.0292 (6) | 0.0309 (6) | −0.0021 (5) | 0.0000 (5) | −0.0142 (5) |
N2 | 0.0283 (6) | 0.0279 (6) | 0.0299 (6) | −0.0020 (5) | −0.0006 (5) | −0.0137 (5) |
N3 | 0.0274 (6) | 0.0332 (7) | 0.0380 (7) | −0.0058 (5) | 0.0015 (5) | −0.0190 (6) |
N4 | 0.0317 (7) | 0.0422 (8) | 0.0380 (8) | −0.0052 (6) | 0.0052 (6) | −0.0207 (7) |
N5 | 0.0338 (7) | 0.0414 (8) | 0.0388 (7) | −0.0029 (6) | −0.0002 (6) | −0.0168 (6) |
O1 | 0.0570 (9) | 0.0672 (10) | 0.0519 (8) | −0.0090 (8) | 0.0052 (7) | −0.0375 (8) |
O2 | 0.0339 (7) | 0.0835 (12) | 0.0449 (8) | −0.0063 (7) | 0.0063 (6) | −0.0201 (8) |
O3 | 0.1023 (16) | 0.0593 (11) | 0.0951 (15) | −0.0404 (11) | 0.0170 (12) | −0.0359 (11) |
C1 | 0.0265 (7) | 0.0290 (7) | 0.0281 (7) | 0.0004 (5) | −0.0032 (5) | −0.0094 (6) |
C2 | 0.0360 (8) | 0.0298 (7) | 0.0356 (8) | 0.0018 (6) | −0.0038 (6) | −0.0179 (6) |
C3 | 0.0493 (11) | 0.0472 (11) | 0.0500 (11) | −0.0041 (8) | 0.0064 (8) | −0.0320 (9) |
C4 | 0.0369 (8) | 0.0302 (8) | 0.0470 (10) | −0.0018 (6) | −0.0032 (7) | −0.0209 (7) |
C5 | 0.0306 (7) | 0.0276 (7) | 0.0390 (8) | −0.0012 (6) | −0.0042 (6) | −0.0133 (6) |
C6 | 0.0356 (9) | 0.0371 (9) | 0.0562 (11) | −0.0083 (7) | 0.0043 (8) | −0.0208 (8) |
Geometric parameters (Å, º) top
Cu—N1i | 2.0220 (14) | N4—H2N4 | 0.79 (2) |
Cu—N1 | 2.0221 (14) | N5—O1 | 1.241 (2) |
Cu—N3 | 1.9457 (15) | N5—O2 | 1.256 (2) |
Cu—N3i | 1.9457 (15) | N5—O3 | 1.209 (2) |
Cu—O1 | 3.901 (2) | C2—C3 | 1.494 (2) |
Cu—O2 | 2.6049 (19) | C2—C4 | 1.366 (2) |
Cu—O3 | 3.952 (3) | C3—H3A | 0.9600 |
N1—N2 | 1.3781 (17) | C3—H3B | 0.9600 |
N1—C5 | 1.323 (2) | C3—H3C | 0.9600 |
N2—C1 | 1.409 (2) | C4—C5 | 1.408 (2) |
N2—C2 | 1.3725 (19) | C4—H5 | 0.9300 |
N3—C1 | 1.293 (2) | C5—C6 | 1.488 (2) |
N3—H1N3 | 0.81 (3) | C6—H6A | 0.9600 |
N4—C1 | 1.322 (2) | C6—H6B | 0.9600 |
N4—H1N4 | 0.89 (3) | C6—H6C | 0.9600 |
| | | |
N3—Cu—N3i | 180.0 | H1N4—N4—H2N4 | 121 (2) |
N3—Cu—N1i | 100.73 (6) | O3—N5—O1 | 121.46 (18) |
N3i—Cu—N1i | 79.27 (6) | O3—N5—O2 | 120.59 (18) |
N3—Cu—N1 | 79.27 (6) | O1—N5—O2 | 117.87 (17) |
N3i—Cu—N1 | 100.73 (6) | N5—O1—Cu | 55.02 (11) |
N1i—Cu—N1 | 180.00 (10) | N5—O2—Cu | 115.73 (12) |
N3—Cu—O2 | 92.11 (6) | N5—O3—Cu | 52.07 (13) |
N3i—Cu—O2 | 87.89 (6) | N3—C1—N4 | 126.24 (15) |
N1i—Cu—O2 | 92.82 (6) | N3—C1—N2 | 114.60 (13) |
N1—Cu—O2 | 87.18 (6) | N4—C1—N2 | 119.15 (14) |
N3—Cu—O1 | 118.06 (6) | C4—C2—N2 | 106.13 (14) |
N3i—Cu—O1 | 61.94 (6) | C4—C2—C3 | 128.00 (15) |
N1i—Cu—O1 | 72.32 (5) | N2—C2—C3 | 125.88 (16) |
N1—Cu—O1 | 107.68 (5) | C2—C3—H3A | 109.5 |
O2—Cu—O1 | 30.97 (4) | C2—C3—H3B | 109.5 |
N3—Cu—O3 | 116.76 (6) | H3A—C3—H3B | 109.5 |
N3i—Cu—O3 | 63.24 (6) | C2—C3—H3C | 109.5 |
N1i—Cu—O3 | 103.52 (5) | H3A—C3—H3C | 109.5 |
N1—Cu—O3 | 76.48 (5) | H3B—C3—H3C | 109.5 |
O2—Cu—O3 | 30.07 (5) | C2—C4—C5 | 107.09 (14) |
O1—Cu—O3 | 31.57 (4) | C2—C4—H5 | 126.5 |
C5—N1—N2 | 106.27 (12) | C5—C4—H5 | 126.5 |
C5—N1—Cu | 141.85 (11) | N1—C5—C4 | 109.94 (14) |
N2—N1—Cu | 111.87 (9) | N1—C5—C6 | 121.98 (15) |
C2—N2—N1 | 110.57 (13) | C4—C5—C6 | 128.06 (15) |
C2—N2—C1 | 133.81 (13) | C5—C6—H6A | 109.5 |
N1—N2—C1 | 114.96 (12) | C5—C6—H6B | 109.5 |
C1—N3—Cu | 118.36 (11) | H6A—C6—H6B | 109.5 |
C1—N3—H1N3 | 109.1 (18) | C5—C6—H6C | 109.5 |
Cu—N3—H1N3 | 132.5 (18) | H6A—C6—H6C | 109.5 |
C1—N4—H1N4 | 117.8 (17) | H6B—C6—H6C | 109.5 |
C1—N4—H2N4 | 120.7 (18) | | |
Symmetry code: (i) −x, −y, −z. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N3—H1N3···O2ii | 0.81 (3) | 2.20 (3) | 2.993 (2) | 164 (2) |
N4—H1N4···O1ii | 0.89 (3) | 2.14 (3) | 3.001 (2) | 163 (2) |
N4—H2N4···O1iii | 0.79 (2) | 2.28 (2) | 2.843 (2) | 129 (2) |
Symmetry codes: (ii) −x+1, −y, −z; (iii) x+1, y, z−1. |
Experimental details
| (I) | (II) |
Crystal data |
Chemical formula | [Cu2(NCS)4(C6H10N4)2]2 | [Cu(NO3)2(C6H10N4)2] |
Mr | 635.76 | 463.92 |
Crystal system, space group | Triclinic, P1 | Triclinic, P1 |
Temperature (K) | 293 | 293 |
a, b, c (Å) | 7.172 (2), 8.742 (3), 11.360 (3) | 5.476 (2), 9.379 (3), 9.529 (3) |
α, β, γ (°) | 70.35 (2), 86.00 (2), 67.06 (2) | 76.99 (2), 75.38 (2), 86.96 (2) |
V (Å3) | 616.2 (3) | 461.4 (3) |
Z | 1 | 1 |
Radiation type | Mo Kα | Mo Kα |
µ (mm−1) | 2.10 | 1.24 |
Crystal size (mm) | 0.22 × 0.14 × 0.10 | 0.16 × 0.14 × 0.14 |
|
Data collection |
Diffractometer | Enraf–Nonius CAD-4 diffractometer | Enraf–Nonius CAD-4 diffractometer |
Absorption correction | Gaussian (PLATON; Spek, 2003) | – |
Tmin, Tmax | 0.751, 0.825 | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 2906, 2685, 2096 | 4799, 2691, 2311 |
Rint | 0.021 | 0.019 |
(sin θ/λ)max (Å−1) | 0.639 | 0.703 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.042, 0.125, 1.07 | 0.030, 0.083, 1.05 |
No. of reflections | 2685 | 2691 |
No. of parameters | 165 | 147 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.78, −0.51 | 0.43, −0.47 |
Selected geometric parameters (Å, º) for (I) topCu—S1Ai | 2.993 (2) | N1—C5 | 1.318 (4) |
Cu—N1 | 1.983 (3) | N2—C2 | 1.364 (4) |
Cu—N3 | 1.952 (3) | N3—C1 | 1.281 (4) |
Cu—N5A | 1.939 (3) | N4—C1 | 1.323 (4) |
Cu—N5B | 1.933 (3) | C2—C4 | 1.360 (5) |
N1—N2 | 1.382 (3) | C4—C5 | 1.402 (5) |
| | | |
N5B—Cu—N5A | 91.99 (15) | N5B—Cu—N1 | 95.62 (13) |
N5B—Cu—N3 | 154.40 (16) | N5A—Cu—N1 | 170.81 (13) |
N5A—Cu—N3 | 95.67 (13) | N3—Cu—N1 | 79.60 (11) |
Symmetry code: (i) −x+1, −y+2, −z+2. |
Hydrogen-bond geometry (Å, º) for (I) top
D—H···A | D—H | H···A | D···A | D—H···A |
N4—H1N4···S1Aii | 0.86 (4) | 2.74 (4) | 3.567 (4) | 162 (4) |
N3—H1N3···S1Biii | 0.85 (4) | 2.63 (4) | 3.477 (3) | 170 (4) |
Symmetry codes: (ii) x, y−1, z; (iii) −x, −y+2, −z+2. |
Selected geometric parameters (Å, º) for (II) topCu—N1 | 2.0221 (14) | N2—C2 | 1.3725 (19) |
Cu—N3 | 1.9457 (15) | N3—C1 | 1.293 (2) |
Cu—O2 | 2.6049 (19) | N4—C1 | 1.322 (2) |
N1—N2 | 1.3781 (17) | C2—C4 | 1.366 (2) |
N1—C5 | 1.323 (2) | C4—C5 | 1.408 (2) |
N2—C1 | 1.409 (2) | | |
| | | |
N3—Cu—N1 | 79.27 (6) | N1—Cu—O2 | 87.18 (6) |
N3—Cu—O2 | 92.11 (6) | | |
Hydrogen-bond geometry (Å, º) for (II) top
D—H···A | D—H | H···A | D···A | D—H···A |
N3—H1N3···O2i | 0.81 (3) | 2.20 (3) | 2.993 (2) | 164 (2) |
N4—H1N4···O1i | 0.89 (3) | 2.14 (3) | 3.001 (2) | 163 (2) |
N4—H2N4···O1ii | 0.79 (2) | 2.28 (2) | 2.843 (2) | 129 (2) |
Symmetry codes: (i) −x+1, −y, −z; (ii) x+1, y, z−1. |
Metal complexes with pyrazole-derived ligands have been the subject of research interest because of their interesting coordination chemistry and potential applications (Trofimenko, 1986, 1993; Mukherjee, 2000, and references therein). Pyrazole-based compounds find uses in the chemistry of antipyretics, antirheumatics, herbicides and fungicides (Goslar et al., 1988; Ding et al., 1994). Copper complexes containing pyrazole-based ligands are of particular interest in bioinorganic chemistry, since they can be used as models for the active sites in copper proteins, such as haemocyanin and tyrosinase (Karlin & Tyeklar, 1993). Furthermore, polynuclear transition metal complexes (such as the Cu complex presented in this work) are used in the important research area of molecular magnetism (Kahn, 1993).
We have synthesized and characterized a number of transition metal complexes containing pyrazole-based ligands (Jaćimović et al., 1999, 2003, 2004; Mészáros Szécsényi, Leovac, Jaćimović, Češljević, Kovács & Pokol, 2001; Mészáros Szécsényi, Leovac, Jaćimović, Češljević, Kovács, Pokol & Gal, 2001; Mészáros Szécsényi et al., 2003; Tomić et al., 2000; Radosavljević Evans, Howard, Howard et al., 2004; Radosavljević Evans, Howard, Mészáros Szécsényi et al., 2004), with the aim of investigating the influence of the pyrazole ring substituents on the formation and properties of the complexes. The crystal structure of the pyrazole-derived ligand HL·HNO3 (HL is 3,5-dimethyl-1-carboxamidine pyrazole) was reported by Khudoyarov et al. (1995). In this paper, we present the synthesis and molecular and crystal structures of the title novel copper complex, [Cu(NCS)2(HL)]2, (I), containing this ligand.
Besides the uncoordinated HL·HNO3 ligand, three additional crystal structures of metal complexes containing the same ligand have been reported to date. The crystal structure of [Ni(HL)2(H2O)2](NO3)2 was originally determined at 298 K (Podder et al., 1989), but has been redetermined at 120 K and published recently, together with the isostructural CoII complex, [Co(HL)2(H2O)2](NO3)2 (Jaćimović et al., 2004). The CuII complex of composition [Cu(NO3)2(HL)2], (II), has also been characterized previously by X-ray analysis (Podder, Dattagupta et al., 1986, or Podder, Mukhopadhyay et al., 1986 Please provide unique citation), but that crystal structure was published with the wrong number of H atoms and without a precise description of the hydrogen-bonding interactions (specifically, the N4H2 group was determined as an NH group, with only one H atom; cf. Fig. 2). For this reason, we have performed a new X-ray analysis of (II) with crystallographically more relevant results, and this is also presented in this article.
In all three complexes cited above from the literature, as well as in [Cu(NCS)2(HL)]2 presented in this work (Fig. 1), the HL ligand is bonded to the metal atom as a bidentate chelate ligand, with the difference that the three previously published complexes are bis(bidentate)–MII mononuclear complexes, while the present complex, (I), is binuclear, with one HL ligand per metal atom. Furthermore, all three previously published complexes have the transition metal atom in an octahedral geometry, while the Cu atom in (I) is coordinated by five atoms.
Complex (I) is centrosymmetric, with an inversion centre located on the mid-point of the Cu···Cui line [symmetry code: (i) 1 − x, 2 − y, 2 − z]. The coordination geometry of CuII is significantly deformed. According to the value of 0.27 calculated for the geometrical parameter τ = (β - α)/60 (Addison et al., 1984), where α = N3—Cu—N5B and β = N1—Cu—N5A, the structure is about 27% distorted from ideal square-pyramidal geometry. The Cu—S bond formed through the NCS ligand is very elongated (Table 1). Searching crystal structures of penta-coordinated Cu complexes with two equivalent NCS bridging ligands, we found 30 examples with Cu···S bond lengths ranging from 2.41 to 3.23 Å [Please give details of source of search, software and reference]. Compound (I) contains an eight-membered binuclear Cu2(NCS)2 ring, which is centrosymmetric and in a chair conformation. The two NCS ligands are practically coplanar, forming the base of the chair conformation. The Cu atom is displaced from this (NCS)2 plane by about 0.60 Å. A very similar form of eight-membered Cu2(NCS)2 ring is identified in the additional 16 crystal structures mentioned above. This ring is centrosymmetric in all complexes, but the position of the Cu atom relative to the (NCS)2 plane is different and consequently the Cu···Cu distance varies. In complex (I), the Cu···Cu distance is 5.744 (2) Å. However, the shortest Cu···Cu distance [4.480 (2) Å] in the present structure is outside the ring, i.e. it involves a neighbouring molecule in the symmetry position (−x, 2 − y, 2 − z).
Bond distances within the 3,5-dimethyl-1-carboxamidine pyrazole ligand are very similar for all four metal complexes, as well as the corresponding bonds in the uncoordinated HL·HNO3. Within the pyrazole ring in all the crystal structures, the longest and shortest bonds are always C4—C5 and N1—C5, respectively. When HL is bonded to the metal atom, the C1—N3 bond is significantly shorter then the C1—N4 bond in all complexes. It is interesting to analyze the metal–HL bonds, which show remarkable differences. The M—N1 and M—N3 bond lengths in [Ni(HL)2(H2O)2](NO3)2 and [Co(HL)2(H2O)2](NO3)2 are nearly the same, while in [Cu(NO3)2(HL)2], the M—N1 bond is about 0.08 Å longer (Table 3). It is worth mentioning again that all three complexes are bis(bidentate)–MII mononuclear complexes with octahedral coordination geometry. In the binuclear CuII complex presented in this work, the M—N1 bond is almost 0.04 Å longer than the M—N3 bond (Table 1).
No significant hydrogen bonds or intermolecular interactions exist in the crystal packing of (I), except for two weak N—H···S hydrogen bonds, the details of which are given in Table 2. The hydrogen-bonding network of (II) is much more interesting. Two axially coordinated NO3 groups with elongated Cu—O bonds (Fig. 2) playa dominant role in the formation of a three-dimensional network of hydrogen bonds. Only three hydrogen bonds are listed in Table 4, but since the molecule of (II) is centrosymmetric (with the Cu atom located on an inversion centre), each molecule is hydrogen bonded to eight neighbouring molecules (four from the same layer and 2 + 2 from two neighbouring layers). Thus, the crystal packing consists of parallel layers (Fig. 3) which are composed of equatorial coordination planes created by HL pyrazole ligands, and NO3 groups bonded to Cu atoms in neighbouring layers. In this way, the layers are interconnected by Cu—O2 bonds, while the equatorial coordination planes within the layers are interconnected by NO3 groups. This interesting role of NO3 in the formation of the hydrogen-bonding network has also been reported by us for a previous CuII complex (Leovac et al., 2002).