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Acta Crystallogr Sect E Struct Rep Online. 2010 January 1; 66(Pt 1): m64.
Published online 2009 December 16. doi:  10.1107/S1600536809050995
PMCID: PMC2980159

Chlorido[3,3′-dibutyl-5,5′-(pyridine-2,6-di­yl)dipyrazol-1-ido]gold(III)

Abstract

The Au atom in the C2-symmetric pincer-type title complex, [AuCl(C19H23N5)], is in the +3 oxidation state. The ligand is composed of one pyridine unit and two n-butyl-substituted pyrazoles (pyrz). Both pyrazoles are deprotonated, thus forming a neutral compound. To the best of our knowledge, this is the first AuIII–bis­pyrazolate complex. According to the special geometry in the N,N′,N′′-tridentate ligand, containing two five-membered heterocycles, the complex deviates from an ideal square-planar coordination geometry; the Npyrz—Au—Npyrz angle is 160.8 (3)°, indicating a distortion of nearly 20°.

Related literature

For the importance of gold catalysis, see: Hashmi & Hutchings (2006a [triangle],b [triangle]); Hashmi (2007 [triangle]). For the role of the gold(I) oxidation state, see: Ito et al. (1986 [triangle]) and for the use of gold(III) pre-catalysts, see: Hashmi et al. (2004a [triangle],b [triangle]).

An external file that holds a picture, illustration, etc.
Object name is e-66-00m64-scheme1.jpg

Experimental

Crystal data

  • [AuCl(C19H23N5)]
  • M r = 553.84
  • Monoclinic, An external file that holds a picture, illustration, etc.
Object name is e-66-00m64-efi1.jpg
  • a = 9.0003 (3) Å
  • b = 24.2220 (7) Å
  • c = 9.3042 (3) Å
  • β = 101.372 (1)°
  • V = 1988.54 (11) Å3
  • Z = 4
  • Mo Kα radiation
  • μ = 7.55 mm−1
  • T = 200 K
  • 0.16 × 0.04 × 0.04 mm

Data collection

  • Bruker SMART CCD diffractometer
  • Absorption correction: multi-scan SADABS (Sheldrick, 2008b [triangle]) T min = 0.378, T max = 0.752
  • 19560 measured reflections
  • 4539 independent reflections
  • 3103 reflections with I > 2σ(I)
  • R int = 0.091

Refinement

  • R[F 2 > 2σ(F 2)] = 0.048
  • wR(F 2) = 0.089
  • S = 1.07
  • 4539 reflections
  • 235 parameters
  • H-atom parameters constrained
  • Δρmax = 0.91 e Å−3
  • Δρmin = −1.01 e Å−3

Data collection: SMART (Siemens, 1996 [triangle]); cell refinement: SAINT (Siemens, 1996 [triangle]); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008a [triangle]); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809050995/hg2593sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809050995/hg2593Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Acknowledgments

Gold salts were donated by Umicore AG & Co. KG.

supplementary crystallographic information

Comment

Catalysis of organic reactions by gold complexes has become a very important area of research in the past decade (Hashmi & Hutchings, 2006a, 2006b; Hashmi, 2007). While the field is dominated by gold(I) complexes (Ito et al., 1986), the use of gold(III) pre-catalysts is also of interest (Hashmi et al., 2004a, 2004b). Here we report the structural details of a new representative of the gold(III) pre-catalysts. The main feature of this structure is the ring strain of the two 5-membered metallacycles that were built up by the pincer ligand and the gold center. The theoretical sum of the bond angles in these flat 5-membered metallacycles is 540.0°, as it was observed in both cases. For a hypothetic strain-free (ring-opened) molecule simple geometrical considerations result an angle sum of about 582° (90° at Au1, 120° at N1, C2, C6, and 126° at C11, N12 C21, N22). The required adaption of 42° is achieved by bending the bond angles (mean values over both rings) at Au1 (9.7°), N1 (2.4°), C2/C6 (7.6°), C11/C21 (10.3°), and N12/N22 (12.0°). As expected the bending at the pyridin nitrogen atom N1 is by far least, as the aromatic ring itself is rigid and cannot bend on two sides simultaneously.

Experimental

2,6-bis(5-butyl-1H-pyrazol-3-yl)pyridine (200 mg, µmol) was dissolved in acetone (5 ml). After this HAuCl4*xH2O (248 mg, 618 µmol, 49% metal content) in acetonitrile (3 ml) and NaOH (2.5 M in H2O, 741 µl) were added consecutively. The mixture was warmed to 60 °C for 20 min, during this time the initially formed yellow precipitate dissolved. The mixture was subjected to hot filtration and the solvent was removed under reduced pressure. The crude complex was purified by recrystallization from acetone to yield the title compound as red crystals (96.0 mg, 173 µmol, 28%). The compound is stable at RT in air.

1H NMR (300 MHz, acetone): δ=0.93 (t, J=7.3 Hz, 6H, CH3), 1.4 (dm, J=8.5, 7.1 Hz, 4H, CH2), 1.65 (m, 4H, CH2), 2.66 (t, J=7.5 Hz, 4H, CH2), 7.71 (d, J=7.9 Hz, 2H, ArH), 8.25 (t, J=7.9 Hz, 1H, ArH); 13C NMR (75 MHz, acetone): δ = 14.27, 23.13, 32.87, 106.97, 116.38 (no further signals observed, one signal overlapping with solvent at about 29 p.p.m.)

Refinement

Carbon-bound H-atoms were placed in calculated positions (C–H 0.95– 0.99 Å) and were included in the refinement in the riding model approximation with Uiso(H) set to 1.2–1.5Ueq(C). A staggered group model was used for the methyl groups.

Figures

Fig. 1.
Thermal ellipsoid representation of the title compound. Displacement ellipsoids were plotted at 50% probability level.

Crystal data

[AuCl(C19H23N5)]Z = 4
Mr = 553.84F(000) = 1072
Monoclinic, P21/cDx = 1.850 Mg m3
Hall symbol: -P 2ybcMo Kα radiation, λ = 0.71073 Å
a = 9.0003 (3) ÅCell parameters from 6701 reflections
b = 24.2220 (7) ŵ = 7.55 mm1
c = 9.3042 (3) ÅT = 200 K
β = 101.372 (1)°Polyhedron, orange
V = 1988.54 (11) Å30.16 × 0.04 × 0.04 mm

Data collection

Bruker SMART CCD diffractometer4539 independent reflections
Radiation source: fine-focus sealed tube3103 reflections with I > 2σ(I)
graphiteRint = 0.091
ω scansθmax = 27.5°, θmin = 1.7°
Absorption correction: multi-scan SADABS (Sheldrick, 2008b)h = −11→11
Tmin = 0.378, Tmax = 0.752k = −31→31
19560 measured reflectionsl = −12→12

Refinement

Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.048Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.089H-atom parameters constrained
S = 1.07w = 1/[σ2(Fo2) + (0.0241P)2 + 2.5681P] where P = (Fo2 + 2Fc2)/3
4539 reflections(Δ/σ)max = 0.001
235 parametersΔρmax = 0.91 e Å3
0 restraintsΔρmin = −1.01 e Å3

Special details

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 (Å2)

xyzUiso*/Ueq
Au10.28448 (3)0.481560 (12)0.61190 (3)0.03110 (10)
Cl10.3449 (3)0.44522 (9)0.8400 (2)0.0514 (6)
N10.2300 (7)0.5101 (2)0.4082 (6)0.0347 (15)
C20.1273 (8)0.5513 (3)0.3826 (8)0.0328 (17)
C30.0815 (9)0.5696 (3)0.2393 (8)0.040 (2)
H30.00690.59770.21560.048*
C40.1478 (11)0.5458 (3)0.1317 (9)0.050 (2)
H40.11660.55780.03310.060*
C50.2585 (10)0.5050 (3)0.1635 (9)0.044 (2)
H50.30700.49060.08970.053*
C60.2952 (8)0.4865 (3)0.3063 (8)0.0344 (18)
C110.0767 (8)0.5693 (3)0.5158 (7)0.0316 (18)
N120.1375 (7)0.5411 (2)0.6419 (6)0.0319 (14)
N130.0917 (6)0.5633 (2)0.7583 (6)0.0293 (14)
C14−0.0014 (8)0.6050 (3)0.7037 (8)0.0311 (17)
C15−0.0165 (8)0.6099 (3)0.5537 (8)0.0328 (18)
H15−0.07730.63550.49060.039*
C16−0.0734 (9)0.6395 (3)0.8036 (8)0.040 (2)
H16A0.00090.64580.89580.048*
H16B−0.16010.61900.82840.048*
C17−0.1289 (9)0.6948 (3)0.7383 (9)0.042 (2)
H17A−0.20640.68820.64850.050*
H17B−0.04290.71420.70850.050*
C18−0.1964 (9)0.7326 (3)0.8389 (9)0.048 (2)
H18A−0.12240.73700.93220.057*
H18B−0.28810.71490.86180.057*
C19−0.2390 (11)0.7898 (4)0.7739 (11)0.066 (3)
H19A−0.14660.81080.77090.098*
H19B−0.29900.80940.83490.098*
H19C−0.29860.78580.67430.098*
C210.3986 (9)0.4418 (3)0.3670 (8)0.041 (2)
N220.4106 (7)0.4319 (3)0.5137 (7)0.0386 (16)
N230.5062 (8)0.3898 (3)0.5598 (8)0.0465 (18)
C240.5559 (9)0.3730 (3)0.4398 (11)0.049 (2)
C250.4926 (9)0.4040 (3)0.3161 (10)0.049 (2)
H250.50990.40020.21910.058*
C260.6668 (11)0.3245 (4)0.4558 (13)0.071 (3)
H26A0.72270.32610.37440.085*
H26B0.74160.32910.54840.085*
C270.6011 (12)0.2719 (4)0.4563 (15)0.093 (4)
H27A0.53520.26560.35920.112*
H27B0.53530.27180.52990.112*
C280.7134 (12)0.2229 (5)0.4898 (16)0.094 (4)
H28A0.78560.22440.42210.113*
H28B0.77230.22650.59110.113*
C290.6347 (14)0.1689 (5)0.4739 (15)0.114 (5)
H29A0.55260.16930.52930.171*
H29B0.70690.13960.51190.171*
H29C0.59240.16200.37010.171*

Atomic displacement parameters (Å2)

U11U22U33U12U13U23
Au10.03813 (17)0.03202 (16)0.02527 (15)0.00177 (16)0.01141 (11)−0.00274 (16)
Cl10.0686 (15)0.0563 (14)0.0304 (11)0.0218 (12)0.0125 (10)0.0075 (10)
N10.051 (4)0.032 (4)0.024 (3)−0.006 (3)0.015 (3)−0.003 (3)
C20.039 (5)0.034 (4)0.029 (4)−0.008 (4)0.016 (3)−0.001 (3)
C30.053 (5)0.040 (5)0.026 (4)0.001 (4)0.005 (4)0.005 (4)
C40.079 (7)0.041 (5)0.032 (5)−0.014 (5)0.019 (5)−0.003 (4)
C50.072 (6)0.039 (5)0.030 (4)−0.021 (4)0.031 (4)−0.012 (4)
C60.045 (5)0.040 (5)0.024 (4)−0.014 (4)0.021 (3)−0.010 (4)
C110.043 (5)0.034 (4)0.019 (4)−0.003 (3)0.010 (3)0.008 (3)
N120.038 (4)0.033 (3)0.027 (3)0.007 (3)0.013 (3)−0.002 (3)
N130.029 (3)0.039 (4)0.022 (3)0.001 (3)0.010 (3)−0.008 (3)
C140.032 (4)0.037 (5)0.024 (4)0.000 (3)0.007 (3)0.000 (3)
C150.041 (5)0.035 (4)0.021 (4)0.005 (4)0.003 (3)0.002 (3)
C160.041 (5)0.048 (5)0.031 (4)0.005 (4)0.006 (4)−0.003 (4)
C170.045 (5)0.041 (5)0.038 (5)0.011 (4)0.004 (4)−0.006 (4)
C180.051 (6)0.050 (5)0.039 (5)0.009 (4)0.003 (4)−0.014 (4)
C190.080 (7)0.042 (6)0.067 (7)0.018 (5)−0.005 (5)−0.018 (5)
C210.054 (5)0.041 (5)0.031 (5)−0.012 (4)0.020 (4)−0.014 (4)
N220.046 (4)0.032 (4)0.041 (4)0.002 (3)0.018 (3)−0.007 (3)
N230.047 (4)0.034 (4)0.067 (5)0.001 (3)0.031 (4)0.001 (4)
C240.046 (5)0.031 (5)0.079 (7)−0.007 (4)0.036 (5)−0.016 (5)
C250.050 (6)0.040 (5)0.064 (6)−0.007 (4)0.031 (5)−0.016 (5)
C260.075 (7)0.041 (6)0.106 (9)−0.002 (5)0.041 (6)−0.018 (6)
C270.055 (7)0.064 (8)0.170 (13)0.009 (6)0.042 (7)0.025 (8)
C280.062 (7)0.071 (9)0.152 (12)0.032 (6)0.027 (7)0.030 (8)
C290.104 (11)0.092 (11)0.141 (13)0.044 (9)0.011 (9)0.018 (10)

Geometric parameters (Å, °)

Au1—N11.985 (6)C17—H17B0.9900
Au1—N221.994 (6)C18—C191.529 (11)
Au1—N122.014 (6)C18—H18A0.9900
Au1—Cl12.263 (2)C18—H18B0.9900
N1—C61.338 (8)C19—H19A0.9800
N1—C21.349 (9)C19—H19B0.9800
C2—C31.389 (10)C19—H19C0.9800
C2—C111.469 (9)C21—N221.369 (9)
C3—C41.387 (11)C21—C251.390 (11)
C3—H30.9500N22—N231.349 (9)
C4—C51.394 (12)N23—C241.346 (10)
C4—H40.9500C24—C251.398 (12)
C5—C61.379 (10)C24—C261.530 (12)
C5—H50.9500C25—H250.9500
C6—C211.466 (11)C26—C271.403 (12)
C11—N121.374 (9)C26—H26A0.9900
C11—C151.383 (10)C26—H26B0.9900
N12—N131.345 (7)C27—C281.551 (13)
N13—C141.346 (9)C27—H27A0.9900
C14—C151.381 (9)C27—H27B0.9900
C14—C161.490 (10)C28—C291.482 (15)
C15—H150.9500C28—H28A0.9900
C16—C171.515 (10)C28—H28B0.9900
C16—H16A0.9900C29—H29A0.9800
C16—H16B0.9900C29—H29B0.9800
C17—C181.519 (10)C29—H29C0.9800
C17—H17A0.9900
N1—Au1—N2280.1 (3)C17—C18—C19113.6 (7)
N1—Au1—N1280.6 (2)C17—C18—H18A108.8
N22—Au1—N12160.8 (3)C19—C18—H18A108.8
N1—Au1—Cl1177.47 (18)C17—C18—H18B108.8
N22—Au1—Cl198.2 (2)C19—C18—H18B108.8
N12—Au1—Cl1101.06 (18)H18A—C18—H18B107.7
C6—N1—C2124.9 (6)C18—C19—H19A109.5
C6—N1—Au1117.9 (5)C18—C19—H19B109.5
C2—N1—Au1117.3 (5)H19A—C19—H19B109.5
N1—C2—C3118.0 (7)C18—C19—H19C109.5
N1—C2—C11112.7 (6)H19A—C19—H19C109.5
C3—C2—C11129.2 (7)H19B—C19—H19C109.5
C4—C3—C2118.1 (8)N22—C21—C25106.9 (8)
C4—C3—H3120.9N22—C21—C6115.6 (6)
C2—C3—H3120.9C25—C21—C6137.5 (8)
C3—C4—C5122.2 (8)N23—N22—C21111.6 (6)
C3—C4—H4118.9N23—N22—Au1134.0 (5)
C5—C4—H4118.9C21—N22—Au1114.3 (5)
C6—C5—C4117.5 (7)C24—N23—N22105.1 (7)
C6—C5—H5121.3N23—C24—C25111.9 (7)
C4—C5—H5121.3N23—C24—C26117.9 (9)
N1—C6—C5119.2 (8)C25—C24—C26130.2 (8)
N1—C6—C21112.1 (6)C21—C25—C24104.5 (8)
C5—C6—C21128.7 (7)C21—C25—H25127.8
N12—C11—C15107.2 (6)C24—C25—H25127.8
N12—C11—C2115.8 (7)C27—C26—C24115.5 (9)
C15—C11—C2137.0 (7)C27—C26—H26A108.4
N13—N12—C11110.8 (6)C24—C26—H26A108.4
N13—N12—Au1135.4 (5)C27—C26—H26B108.4
C11—N12—Au1113.6 (5)C24—C26—H26B108.4
N12—N13—C14105.2 (5)H26A—C26—H26B107.5
N13—C14—C15112.1 (6)C26—C27—C28115.9 (9)
N13—C14—C16120.0 (6)C26—C27—H27A108.3
C15—C14—C16127.9 (7)C28—C27—H27A108.3
C14—C15—C11104.6 (6)C26—C27—H27B108.3
C14—C15—H15127.7C28—C27—H27B108.3
C11—C15—H15127.7H27A—C27—H27B107.4
C14—C16—C17113.3 (6)C29—C28—C27112.1 (9)
C14—C16—H16A108.9C29—C28—H28A109.2
C17—C16—H16A108.9C27—C28—H28A109.2
C14—C16—H16B108.9C29—C28—H28B109.2
C17—C16—H16B108.9C27—C28—H28B109.2
H16A—C16—H16B107.7H28A—C28—H28B107.9
C16—C17—C18115.2 (7)C28—C29—H29A109.5
C16—C17—H17A108.5C28—C29—H29B109.5
C18—C17—H17A108.5H29A—C29—H29B109.5
C16—C17—H17B108.5C28—C29—H29C109.5
C18—C17—H17B108.5H29A—C29—H29C109.5
H17A—C17—H17B107.5H29B—C29—H29C109.5

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: HG2593).

References

  • Hashmi, A. S. K. (2007). Chem. Rev.107, 3180–3211. [PubMed]
  • Hashmi, A. S. K. & Hutchings, G. J. (2006a). Angew. Chem.118, 8064–8105.
  • Hashmi, A. S. K. & Hutchings, G. J. (2006b). Angew. Chem. Int. Ed.45, 7896–7936. [PubMed]
  • Hashmi, A. S. K., Weyrauch, J. P., Rudolph, M. & Kurpejovic, E. (2004a). Angew. Chem.116, 6707–6709.
  • Hashmi, A. S. K., Weyrauch, J. P., Rudolph, M. & Kurpejovic, E. (2004b). Angew. Chem. Int. Ed.43, 6545–6547. [PubMed]
  • Ito, Y., Sawamura, M. & Hayashi, T. (1986). J. Am. Chem. Soc.108, 6405–6406.
  • Sheldrick, G. M. (2008a). Acta Cryst. A64, 112–122. [PubMed]
  • Sheldrick, G. M. (2008b). SADABS University of Göttingen, Germany.
  • Siemens (1996). SMART and SAINT Siemens Analytical X-ray Instruments Inc. Madison, Wisconsin, USA.

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