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Acta Cryst. (2007). E63, m2620-m2621    [ doi:10.1107/S1600536807046491 ]

Bromido(3,5-dimethylpyrazole-[kappa]N)[hydrotris(3,5-dimethylpyrazolyl)borato-[kappa]3N,N',N'']copper(II)

X.-J. Zhang, J. Han, C.-G. Wang and Y.-H. Xing

Abstract top

In the title copper complex, [CuBr(C15H22BN6)(C5H8N2)], the CuII atom is coordinated by one Br atom, three N atoms from the hydrotris(3,5-dimethylpyrazolyl)borate ligand and one N atom from the 3,5-dimethylpyrazole ligand, forming a distorted trigonal-bipyramidal geometry. The equatorial positions are occupied by the Br atom and the N atoms of the hydrotris(3,5-dimethylpyrazolyl)borate ligand.

Comment top

Since Trofimenko discovered poly(pyrazolyl)borate (Trofimenko, 1972), these ligands have been proven to be extremely popular for coordination chemists in a wide range of applications because of their ease of synthesis, ease of functionalization, and the steric protection which they afford to transition metal centers. So poly(pyrazolyl)borate ligands have been used for a number of different purposes, including modeling of metalloprotein active site (Trofimenko, 1993, 2004), mimicking metalloenzyme systems in bioinorganic chemistry (Puerta & Cohen, 2002), polymerization catalysts (Blosch et al., 1991) and C—H activation (Ghosh et al., 1988; Fernandez et al., 1989). The donor N atoms of pyrazole (or modified pyrazole) and poly(pyrazolyl)borate can coordinate to metal atoms together to form half sandwich structure. Based on these findings, we attempted to determine the structure of the title complex, (I).

The structure of (I) shows a distorting trigonal bipyramidal geometry of CuII, which is coordinated to one Br atom and four N atoms: three from tris(3,5-dimethylpyrazolyl)borate ligand [Cu—N(N2, N4, N6)] with bond lengths of 2.019 (3), 2.035 (3), 2.176 (3) Å and one from 3,5-dimethylpyrazole ligand (Cu—N8) with the bond distance of 2.067 (4) Å. In the structure, the atoms Br, N2 and N6 are in the triangle plane, and N4 and N8 are at the axial positions. The copper atom is in the center of the triangle double pyramide geometry (Fig. 1). Selected bond lengths and angles are listed in Table 1. It can be found that the Cu—N distances (from tris(pyrazolyl)borate ligand) are shorter than those of bis(hydrotris(3,5-dimethylpyrazolyl) borato-κ3N,N',N'')copper(II) (Kitajima et al., 1988) [2.034 (13), 2.085 (12), 2.296 (12) Å], longer than those of chloro(hydrotris(3-adamantyl-5-isopropyl-1-pyrazolyl) borato-κ3N,N',N'')copper(II) (Fujisawa et al., 2004) [2.125 (3), 2.005 (2), 1.961 (2) Å]. For the bond angles, the range of N—Cu—N (from tris(pyrazolyl)borate ligand) in the title complex is from 85.28 (13) to 95.06 (13)°, but in bis(hydrotris(3,5-dimethylpyrazolyl)borato-κ3N,N',N'')copper(II) (Kitajima et al., 1988) complex, the range of N—Cu—N (from tris(pyrazolyl)borate ligand) is from 86.7 (4) to 88.1 (4)°.

Related literature top

For related literature, see: Badura & Vahrenkamp (2002); Blosch et al. (1991); Fernandez et al. (1989); Fujisawa et al. (2004); Ghosh et al. (1988); Kitajima et al. (1988); Puerta et al. (2002); Trofimenko (1972, 1993, 2004).

Experimental top

All chemicals purchased were of reagent grade or better and were used without further purification. A methanol solution of K[HB(C5H7N2)3] (2 mmol) and 3,5-dimethylpyrazole (1 mmol) was added to an methanol solution of CuBr (1 mmol). The mixture was stirred for 4 h at room temperature, yielding a blue solution. This was set aside to crystallize, yielding analytically pure (I) as single crystals suitable for X-ray structure determination. Yield: 0.494 g, ca 72% (based on Cu). Anal. Calcd for C20H30N8BBrCu (FW: 536.78): C 44.69, H 5.63, N 20.86%. Found: C 44.71, H 5.59, N 20.87. IR (KBr, µ, cm−1): 3190, 2979, 2507, 2364, 1567, 1541, 1448, 1414, 1383, 1348, 1269, 1195, 1183, 1127, 1067, 1047, 1022, 984, 944, 911, 852, 808, 787, 693, 664, 644, 611, 593, 465, 436, 352, 303.

Refinement top

Hydrogen atoms were placed at calculated positions (C—H = 0.93–0.96, N—H = 0.86 and B—H = 0.98 Å) and refined as riding, with Uiso(H) = 1.2Ueq(C, B, N) or 1.5Ueq(methyl C).

Computing details top

Data collection: APEX2 (Bruker, 2005); cell refinement: APEX2 (Bruker, 2005); data reduction: APEX2 (Bruker, 2005); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997a); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997a); molecular graphics: SHELXTL (Sheldrick, 1997b); software used to prepare material for publication: SHELXTL (Sheldrick, 1997b).

Figures top
[Figure 1] Fig. 1. The molecular structure of the title complex. Displacement ellipsoids are drawn at the 50% probability level. H atoms have been omitted.
Bromido(3,5-dimethylpyrazole-κN)[hydrotris(3,5-dimethylpyrazolyl)\ borato-κ3N,N',N'']copper(II) top
Crystal data top
[CuBr(C15H22BN6)(C5H8N2)]F000 = 1100
Mr = 536.78Dx = 1.425 Mg m−3
Monoclinic, P21/cMo Kα radiation
λ = 0.71073 Å
Hall symbol: -p 2ybcCell parameters from 4917 reflections
a = 17.223 (4) Åθ = 2.2–26.0º
b = 7.9231 (18) ŵ = 2.49 mm−1
c = 19.236 (4) ÅT = 293 (2) K
β = 107.618 (3)ºPlate, green
V = 2501.7 (10) Å30.21 × 0.16 × 0.13 mm
Z = 4
Data collection top
Bruker P4
diffractometer		4917 independent reflections
Radiation source: fine-focus sealed tube3349 reflections with I > 2σ(I)
Monochromator: graphiteRint = 0.055
T = 293(2) Kθmax = 26.0º
ω scansθmin = 2.2º
Absorption correction: multi-scan
(SADABS; Sheldrick, 2003)		h = −13→21
Tmin = 0.626, Tmax = 0.723k = −9→9
4917 measured reflectionsl = −23→21
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)] = 0.050H-atom parameters constrained
wR(F2) = 0.136  w = 1/[σ2(Fo2) + (0.0625P)2]
where P = (Fo2 + 2Fc2)/3
S = 1.03(Δ/σ)max < 0.001
4917 reflectionsΔρmax = 0.75 e Å−3
280 parametersΔρmin = −0.65 e Å−3
Primary atom site location: structure-invariant direct methodsExtinction correction: none
Crystal data top
[CuBr(C15H22BN6)(C5H8N2)]V = 2501.7 (10) Å3
Mr = 536.78Z = 4
Monoclinic, P21/cMo Kα
a = 17.223 (4) ŵ = 2.49 mm−1
b = 7.9231 (18) ÅT = 293 (2) K
c = 19.236 (4) Å0.21 × 0.16 × 0.13 mm
β = 107.618 (3)º
Data collection top
Bruker P4
diffractometer		4917 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 2003)		3349 reflections with I > 2σ(I)
Tmin = 0.626, Tmax = 0.723Rint = 0.055
4917 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.050280 parameters
wR(F2) = 0.136H-atom parameters constrained
S = 1.03Δρmax = 0.75 e Å−3
4917 reflectionsΔρmin = −0.65 e Å−3
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.

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
Cu0.23841 (3)0.86990 (6)0.30904 (3)0.03100 (17)
Br10.26691 (3)1.02181 (7)0.20786 (3)0.0571 (2)
C10.1549 (3)0.5592 (6)0.4415 (2)0.0433 (11)
C20.1719 (3)0.4300 (6)0.4000 (3)0.0491 (13)
H2A0.16810.31490.40790.059*
C30.1953 (3)0.5040 (6)0.3447 (2)0.0424 (11)
C40.0315 (3)1.0552 (6)0.3462 (2)0.0410 (11)
C50.0068 (3)1.1021 (6)0.2754 (3)0.0460 (12)
H5A−0.04121.15810.25130.055*
C60.0667 (3)1.0510 (6)0.2457 (2)0.0390 (11)
C70.2787 (3)1.0521 (6)0.5238 (2)0.0469 (12)
C80.3505 (3)1.1191 (7)0.5189 (3)0.0557 (14)
H8A0.39021.17450.55550.067*
C90.3520 (3)1.0874 (6)0.4479 (3)0.0454 (12)
C100.4449 (3)0.6283 (8)0.2855 (4)0.0704 (17)
C110.4591 (3)0.5844 (7)0.3563 (4)0.0702 (17)
H11A0.50260.52040.38440.084*
C120.3964 (3)0.6531 (6)0.3791 (3)0.0490 (12)
C130.1268 (4)0.5499 (7)0.5069 (3)0.0633 (16)
H13A0.12040.66190.52330.095*
H13B0.16620.48970.54480.095*
H13C0.07540.49190.49480.095*
C140.2180 (3)0.4232 (7)0.2831 (3)0.0636 (15)
H14A0.23130.50920.25340.095*
H14B0.17290.35780.25400.095*
H14C0.26420.35100.30240.095*
C15−0.0100 (3)1.0777 (8)0.4035 (3)0.0680 (16)
H15A0.02311.03010.44860.102*
H15B−0.06181.02170.38860.102*
H15C−0.01801.19590.41010.102*
C160.0640 (3)1.0668 (8)0.1676 (2)0.0608 (15)
H16A0.11291.02050.16130.091*
H16B0.05961.18370.15380.091*
H16C0.01771.00630.13740.091*
C170.2459 (4)1.0483 (8)0.5871 (3)0.0795 (19)
H17A0.19420.99190.57330.119*
H17B0.23921.16170.60200.119*
H17C0.28320.98890.62690.119*
C180.4151 (3)1.1289 (8)0.4123 (3)0.0637 (16)
H18A0.39771.08940.36280.096*
H18B0.46541.07510.43830.096*
H18C0.42281.24890.41280.096*
C190.4902 (4)0.5946 (10)0.2306 (5)0.121 (3)
H19A0.46100.64470.18470.181*
H19B0.49440.47510.22450.181*
H19C0.54380.64280.24780.181*
C200.3829 (3)0.6372 (7)0.4518 (3)0.0665 (16)
H20A0.33450.69780.45150.100*
H20B0.42880.68340.48860.100*
H20C0.37670.52030.46210.100*
N10.1701 (2)0.7062 (4)0.41197 (17)0.0336 (8)
N20.1952 (2)0.6716 (4)0.35195 (17)0.0331 (8)
N30.1048 (2)0.9768 (4)0.35979 (17)0.0322 (8)
N40.1276 (2)0.9762 (4)0.29746 (17)0.0329 (8)
N50.2399 (2)0.9827 (4)0.45886 (17)0.0352 (9)
N60.2847 (2)1.0044 (4)0.41192 (17)0.0356 (9)
N70.3765 (2)0.7205 (5)0.2677 (2)0.0506 (10)
H7A0.35440.76280.22510.061*
N80.3461 (2)0.7391 (5)0.32409 (19)0.0407 (9)
B10.1575 (3)0.8903 (6)0.4308 (3)0.0339 (11)
H10.12910.89420.46790.041*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cu0.0280 (3)0.0343 (3)0.0322 (3)0.0016 (2)0.0114 (2)0.0010 (2)
Br10.0572 (4)0.0688 (4)0.0551 (3)0.0191 (3)0.0319 (3)0.0230 (3)
C10.040 (3)0.041 (3)0.048 (3)−0.003 (2)0.012 (2)0.010 (2)
C20.054 (3)0.027 (3)0.062 (3)−0.006 (2)0.011 (3)0.014 (2)
C30.034 (3)0.038 (3)0.051 (3)−0.003 (2)0.006 (2)−0.005 (2)
C40.030 (2)0.045 (3)0.050 (3)0.003 (2)0.015 (2)−0.006 (2)
C50.028 (2)0.050 (3)0.056 (3)0.012 (2)0.007 (2)0.006 (2)
C60.030 (2)0.043 (3)0.040 (2)0.002 (2)0.003 (2)0.006 (2)
C70.055 (3)0.049 (3)0.033 (2)−0.003 (3)0.007 (2)−0.011 (2)
C80.052 (3)0.060 (4)0.045 (3)−0.020 (3)0.001 (2)−0.019 (2)
C90.041 (3)0.038 (3)0.053 (3)−0.010 (2)0.009 (2)−0.002 (2)
C100.049 (3)0.061 (4)0.115 (5)0.016 (3)0.047 (4)0.016 (4)
C110.037 (3)0.060 (4)0.112 (5)0.017 (3)0.021 (3)0.025 (4)
C120.032 (3)0.045 (3)0.065 (3)0.003 (2)0.008 (2)0.014 (2)
C130.078 (4)0.061 (4)0.056 (3)−0.016 (3)0.028 (3)0.017 (3)
C140.069 (4)0.043 (3)0.082 (4)−0.005 (3)0.028 (3)−0.024 (3)
C150.057 (4)0.086 (5)0.071 (4)0.024 (3)0.035 (3)0.002 (3)
C160.045 (3)0.089 (4)0.041 (3)0.006 (3)0.002 (2)0.014 (3)
C170.090 (5)0.109 (5)0.040 (3)−0.020 (4)0.021 (3)−0.028 (3)
C180.041 (3)0.078 (4)0.070 (3)−0.021 (3)0.014 (3)−0.002 (3)
C190.104 (6)0.118 (7)0.179 (8)0.062 (5)0.101 (6)0.037 (6)
C200.048 (3)0.074 (4)0.061 (3)0.005 (3)−0.009 (3)0.014 (3)
N10.0305 (19)0.035 (2)0.0337 (18)−0.0037 (16)0.0079 (15)0.0022 (16)
N20.033 (2)0.033 (2)0.0360 (18)−0.0016 (16)0.0138 (16)−0.0001 (15)
N30.030 (2)0.035 (2)0.0342 (18)0.0026 (16)0.0135 (16)−0.0002 (15)
N40.030 (2)0.037 (2)0.0340 (18)0.0004 (16)0.0130 (16)0.0008 (15)
N50.039 (2)0.038 (2)0.0291 (18)−0.0030 (17)0.0106 (16)−0.0055 (15)
N60.034 (2)0.037 (2)0.0339 (19)−0.0065 (16)0.0083 (16)−0.0034 (16)
N70.040 (2)0.050 (3)0.071 (3)0.010 (2)0.030 (2)0.007 (2)
N80.032 (2)0.043 (2)0.048 (2)0.0019 (18)0.0134 (18)0.0019 (18)
B10.032 (3)0.041 (3)0.032 (2)−0.001 (2)0.014 (2)−0.002 (2)
Geometric parameters (Å, °) top
Cu—N22.019 (3)C13—H13A0.9600
Cu—N42.035 (3)C13—H13B0.9600
Cu—N82.067 (4)C13—H13C0.9600
Cu—N62.176 (3)C14—H14A0.9600
Cu—Br12.4607 (8)C14—H14B0.9600
C1—N11.355 (5)C14—H14C0.9600
C1—C21.383 (7)C15—H15A0.9600
C1—C131.480 (6)C15—H15B0.9600
C2—C31.378 (7)C15—H15C0.9600
C2—H2A0.9300C16—H16A0.9600
C3—N21.335 (5)C16—H16B0.9600
C3—C141.499 (7)C16—H16C0.9600
C4—C51.350 (6)C17—H17A0.9600
C4—N31.360 (5)C17—H17B0.9600
C4—C151.495 (6)C17—H17C0.9600
C5—C61.382 (6)C18—H18A0.9600
C5—H5A0.9300C18—H18B0.9600
C6—N41.346 (5)C18—H18C0.9600
C6—C161.494 (6)C19—H19A0.9600
C7—N51.343 (5)C19—H19B0.9600
C7—C81.374 (7)C19—H19C0.9600
C7—C171.491 (6)C20—H20A0.9600
C8—C91.396 (6)C20—H20B0.9600
C8—H8A0.9300C20—H20C0.9600
C9—N61.331 (5)N1—N21.378 (4)
C9—C181.485 (6)N1—B11.534 (6)
C10—N71.340 (6)N3—N41.370 (4)
C10—C111.353 (8)N3—B11.552 (6)
C10—C191.514 (8)N5—N61.364 (4)
C11—C121.394 (7)N5—B11.542 (6)
C11—H11A0.9300N7—N81.348 (5)
C12—N81.333 (5)N7—H7A0.8600
C12—C201.491 (7)B1—H10.9800
N2—Cu—N485.28 (13)H15A—C15—H15C109.5
N2—Cu—N888.77 (14)H15B—C15—H15C109.5
N4—Cu—N8174.01 (14)C6—C16—H16A109.5
N2—Cu—N695.06 (13)C6—C16—H16B109.5
N4—Cu—N688.27 (13)H16A—C16—H16B109.5
N8—Cu—N692.99 (14)C6—C16—H16C109.5
N2—Cu—Br1152.93 (10)H16A—C16—H16C109.5
N4—Cu—Br196.65 (9)H16B—C16—H16C109.5
N8—Cu—Br188.31 (10)C7—C17—H17A109.5
N6—Cu—Br1111.97 (10)C7—C17—H17B109.5
N1—C1—C2107.1 (4)H17A—C17—H17B109.5
N1—C1—C13123.6 (4)C7—C17—H17C109.5
C2—C1—C13129.3 (5)H17A—C17—H17C109.5
C3—C2—C1107.0 (4)H17B—C17—H17C109.5
C3—C2—H2A126.5C9—C18—H18A109.5
C1—C2—H2A126.5C9—C18—H18B109.5
N2—C3—C2109.4 (4)H18A—C18—H18B109.5
N2—C3—C14121.1 (4)C9—C18—H18C109.5
C2—C3—C14129.5 (5)H18A—C18—H18C109.5
C5—C4—N3108.0 (4)H18B—C18—H18C109.5
C5—C4—C15129.5 (4)C10—C19—H19A109.5
N3—C4—C15122.5 (4)C10—C19—H19B109.5
C4—C5—C6106.9 (4)H19A—C19—H19B109.5
C4—C5—H5A126.5C10—C19—H19C109.5
C6—C5—H5A126.5H19A—C19—H19C109.5
N4—C6—C5109.5 (4)H19B—C19—H19C109.5
N4—C6—C16124.1 (4)C12—C20—H20A109.5
C5—C6—C16126.3 (4)C12—C20—H20B109.5
N5—C7—C8107.5 (4)H20A—C20—H20B109.5
N5—C7—C17123.1 (5)C12—C20—H20C109.5
C8—C7—C17129.4 (4)H20A—C20—H20C109.5
C7—C8—C9106.3 (4)H20B—C20—H20C109.5
C7—C8—H8A126.8C1—N1—N2109.2 (3)
C9—C8—H8A126.8C1—N1—B1131.2 (4)
N6—C9—C8109.0 (4)N2—N1—B1119.3 (3)
N6—C9—C18120.9 (4)C3—N2—N1107.2 (3)
C8—C9—C18130.1 (4)C3—N2—Cu136.0 (3)
N7—C10—C11106.0 (5)N1—N2—Cu115.8 (2)
N7—C10—C19121.1 (6)C4—N3—N4109.2 (3)
C11—C10—C19133.0 (6)C4—N3—B1129.2 (4)
C10—C11—C12107.1 (5)N4—N3—B1121.5 (3)
C10—C11—H11A126.4C6—N4—N3106.3 (3)
C12—C11—H11A126.4C6—N4—Cu139.3 (3)
N8—C12—C11109.2 (5)N3—N4—Cu114.4 (2)
N8—C12—C20122.6 (4)C7—N5—N6109.9 (4)
C11—C12—C20128.2 (5)C7—N5—B1131.8 (4)
C1—C13—H13A109.5N6—N5—B1118.2 (3)
C1—C13—H13B109.5C9—N6—N5107.3 (3)
H13A—C13—H13B109.5C9—N6—Cu137.4 (3)
C1—C13—H13C109.5N5—N6—Cu114.6 (2)
H13A—C13—H13C109.5C10—N7—N8112.3 (4)
H13B—C13—H13C109.5C10—N7—H7A123.9
C3—C14—H14A109.5N8—N7—H7A123.9
C3—C14—H14B109.5C12—N8—N7105.4 (4)
H14A—C14—H14B109.5C12—N8—Cu135.0 (3)
C3—C14—H14C109.5N7—N8—Cu119.5 (3)
H14A—C14—H14C109.5N1—B1—N5110.7 (4)
H14B—C14—H14C109.5N1—B1—N3107.4 (3)
C4—C15—H15A109.5N5—B1—N3109.2 (4)
C4—C15—H15B109.5N1—B1—H1109.8
H15A—C15—H15B109.5N5—B1—H1109.8
C4—C15—H15C109.5N3—B1—H1109.8
Hydrogen-bond geometry (Å, °) top
D—H···AD—HH···AD···AD—H···A
N7—H7A···Br10.862.513.045 (4)121
Table 1
Selected geometric parameters (Å, °) top
Cu—N22.019 (3)Cu—N62.176 (3)
Cu—N42.035 (3)Cu—Br12.4607 (8)
Cu—N82.067 (4)
N2—Cu—N485.28 (13)N8—Cu—N692.99 (14)
N2—Cu—N888.77 (14)N2—Cu—Br1152.93 (10)
N4—Cu—N8174.01 (14)N4—Cu—Br196.65 (9)
N2—Cu—N695.06 (13)N8—Cu—Br188.31 (10)
N4—Cu—N688.27 (13)N6—Cu—Br1111.97 (10)
Table 2
Hydrogen-bond geometry (Å, °) top
D—H···AD—HH···AD···AD—H···A
N7—H7A···Br10.862.513.045 (4)121
Acknowledgements top

The authors are grateful to the National Natural Science Foundation of China (grant No. 20771051), the Education Foundation of Liaoning Province (grant No. 05 L212) and SRF for ROCS, SEM for financial assistance. Author please give these abbreviations in full.

references
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