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The six-membered B2H4 ring of the title compound, C36H30B2N8, adopts a slightly distorted boat conformation, with the terminal B substituents in a trans orientation. One 3-phenylpyrazolyl group is in an equatorial position, whereas the second is in an axial position with respect to the plane defined by the B atoms.
Supporting information
CCDC reference: 282215
The title compound was obtained as a co-product from the reaction of anhydrous YCl3 (0.25 g, 1.28 mmol) and potassium hydrotris(3-phenylpyrazolyl)borate (KTpph) (0.61 g, 1.28 mmol) in tetrahydrofuran. The mixture was stirred at 293 K for 7 d, over which period the amount of insoluble material decreased. Volatiles were removed under vacuum and the residue was extracted with toluene (2 × 20 ml). The resulting colourless filtrate was evaporated under vacuum and the residue washed with pentane. Crystals of (I) suitable for X-ray diffraction were grown from a 1:2 toluene–pentane solution at 239 K.
All H atoms were located in a difference Fourier synthesis, but those attached to C atoms were treated as riding on their parent C atoms with C—H = 0.93 Å and Uiso(H) = 1.2Ueq(C). The H atoms attached to B atoms were freely refined with a fixed Uiso value.
Data collection: KappaCCD Server Software (Nonius, 1999); cell refinement: SCALEPACK (Otwinowski & Minor, 1997); data reduction: SCALEPACK and DENZO (Otwinowski & Minor 1997); program(s) used to solve structure: SIR97 (Altomare et al., 1998); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 2003); software used to prepare material for publication: SHELXL97.
1,5-Diphenyl-4,8-bis(3-phenylpyrazol-1-yl)pyrazabole
top
Crystal data top
C36H30B2N8 | F(000) = 1248 |
Mr = 596.30 | Dx = 1.294 Mg m−3 |
Monoclinic, P21/n | Mo Kα radiation, λ = 0.71069 Å |
Hall symbol: -p 2yn | Cell parameters from 7153 reflections |
a = 11.3980 (2) Å | θ = 1.0–27.5° |
b = 22.6068 (4) Å | µ = 0.08 mm−1 |
c = 13.1547 (2) Å | T = 120 K |
β = 115.429 (1)° | Prism, colourless |
V = 3061.21 (9) Å3 | 0.20 × 0.18 × 0.10 mm |
Z = 4 | |
Data collection top
Nonius KappaCCD area-detector diffractometer | 5037 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.000 |
Graphite monochromator | θmax = 27.5°, θmin = 1.8° |
Detector resolution: 19.24 pixels mm-1 | h = 0→14 |
ω scans (1.4°) | k = 0→29 |
6995 measured reflections | l = −17→15 |
6995 independent reflections | |
Refinement top
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.048 | H atoms treated by a mixture of independent and constrained refinement |
wR(F2) = 0.131 | w = 1/[σ2(Fo2) + (0.0684P)2 + 0.647P] where P = (Fo2 + 2Fc2)/3 |
S = 1.05 | (Δ/σ)max < 0.001 |
6995 reflections | Δρmax = 0.22 e Å−3 |
422 parameters | Δρmin = −0.27 e Å−3 |
0 restraints | Extinction correction: SHELXL97 (Sheldrick, 1997), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.0085 (9) |
Crystal data top
C36H30B2N8 | V = 3061.21 (9) Å3 |
Mr = 596.30 | Z = 4 |
Monoclinic, P21/n | Mo Kα radiation |
a = 11.3980 (2) Å | µ = 0.08 mm−1 |
b = 22.6068 (4) Å | T = 120 K |
c = 13.1547 (2) Å | 0.20 × 0.18 × 0.10 mm |
β = 115.429 (1)° | |
Data collection top
Nonius KappaCCD area-detector diffractometer | 5037 reflections with I > 2σ(I) |
6995 measured reflections | Rint = 0.000 |
6995 independent reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.048 | 0 restraints |
wR(F2) = 0.131 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.05 | Δρmax = 0.22 e Å−3 |
6995 reflections | Δρmin = −0.27 e Å−3 |
422 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. |
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 | x | y | z | Uiso*/Ueq | |
N1 | 0.16807 (12) | −0.00717 (5) | 0.46082 (11) | 0.0224 (3) | |
N2 | 0.22961 (12) | 0.03534 (5) | 0.53987 (11) | 0.0223 (3) | |
N3 | 0.21546 (12) | 0.13469 (5) | 0.44796 (11) | 0.0228 (3) | |
N4 | 0.08418 (12) | 0.13424 (6) | 0.41407 (11) | 0.0248 (3) | |
N5 | 0.36303 (12) | 0.05384 (5) | 0.43539 (11) | 0.0228 (3) | |
N6 | 0.28973 (12) | 0.01827 (5) | 0.34719 (11) | 0.0226 (3) | |
N7 | 0.13913 (12) | −0.07096 (6) | 0.30016 (11) | 0.0241 (3) | |
N8 | 0.23138 (12) | −0.11306 (5) | 0.35484 (11) | 0.0249 (3) | |
C1 | 0.11774 (15) | −0.04722 (7) | 0.50608 (14) | 0.0252 (3) | |
H1 | 0.0704 | −0.0805 | 0.4694 | 0.030* | |
C2 | 0.14715 (15) | −0.03137 (7) | 0.61555 (14) | 0.0264 (3) | |
H2 | 0.1243 | −0.0516 | 0.6660 | 0.032* | |
C3 | 0.21770 (15) | 0.02088 (7) | 0.63537 (13) | 0.0231 (3) | |
C4 | 0.27322 (14) | 0.05548 (7) | 0.74008 (13) | 0.0242 (3) | |
C5 | 0.32144 (16) | 0.02486 (7) | 0.84226 (14) | 0.0296 (4) | |
H5 | 0.3217 | −0.0163 | 0.8424 | 0.036* | |
C6 | 0.36878 (18) | 0.05535 (8) | 0.94324 (15) | 0.0358 (4) | |
H6 | 0.4007 | 0.0347 | 1.0109 | 0.043* | |
C7 | 0.36857 (18) | 0.11677 (8) | 0.94346 (15) | 0.0367 (4) | |
H7 | 0.4008 | 0.1373 | 1.0113 | 0.044* | |
C8 | 0.32029 (18) | 0.14747 (8) | 0.84242 (15) | 0.0342 (4) | |
H8 | 0.3200 | 0.1886 | 0.8426 | 0.041* | |
C9 | 0.27240 (16) | 0.11705 (7) | 0.74116 (14) | 0.0283 (4) | |
H9 | 0.2396 | 0.1379 | 0.6736 | 0.034* | |
C10 | 0.25049 (16) | 0.18295 (7) | 0.40699 (14) | 0.0299 (4) | |
H10 | 0.3348 | 0.1927 | 0.4193 | 0.036* | |
C11 | 0.14206 (16) | 0.21505 (7) | 0.34474 (14) | 0.0300 (4) | |
H11 | 0.1369 | 0.2502 | 0.3064 | 0.036* | |
C12 | 0.03989 (15) | 0.18317 (7) | 0.35135 (13) | 0.0243 (3) | |
C13 | −0.10036 (15) | 0.19676 (7) | 0.29600 (13) | 0.0262 (3) | |
C14 | −0.18310 (17) | 0.18247 (7) | 0.34539 (16) | 0.0343 (4) | |
H14 | −0.1494 | 0.1654 | 0.4166 | 0.041* | |
C15 | −0.31545 (17) | 0.19359 (8) | 0.28926 (18) | 0.0415 (5) | |
H15 | −0.3699 | 0.1833 | 0.3226 | 0.050* | |
C16 | −0.36714 (17) | 0.21999 (8) | 0.18344 (17) | 0.0386 (4) | |
H16 | −0.4559 | 0.2272 | 0.1457 | 0.046* | |
C17 | −0.28563 (17) | 0.23537 (8) | 0.13509 (15) | 0.0343 (4) | |
H17 | −0.3196 | 0.2533 | 0.0647 | 0.041* | |
C18 | −0.15322 (16) | 0.22431 (7) | 0.19060 (14) | 0.0297 (4) | |
H18 | −0.0991 | 0.2353 | 0.1574 | 0.036* | |
C19 | 0.47680 (14) | 0.06431 (7) | 0.43090 (14) | 0.0245 (3) | |
H19 | 0.5445 | 0.0870 | 0.4820 | 0.029* | |
C20 | 0.47663 (15) | 0.03584 (7) | 0.33793 (13) | 0.0256 (3) | |
H20 | 0.5429 | 0.0359 | 0.3146 | 0.031* | |
C21 | 0.35755 (15) | 0.00713 (6) | 0.28624 (13) | 0.0235 (3) | |
C22 | 0.30335 (15) | −0.02764 (7) | 0.18043 (13) | 0.0253 (3) | |
C23 | 0.36595 (17) | −0.07816 (8) | 0.16874 (15) | 0.0355 (4) | |
H23 | 0.4414 | −0.0912 | 0.2285 | 0.043* | |
C24 | 0.31579 (19) | −0.10914 (9) | 0.06770 (16) | 0.0417 (5) | |
H24 | 0.3575 | −0.1431 | 0.0603 | 0.050* | |
C25 | 0.20463 (18) | −0.08985 (8) | −0.02157 (15) | 0.0368 (4) | |
H25 | 0.1710 | −0.1108 | −0.0889 | 0.044* | |
C26 | 0.14332 (18) | −0.03917 (8) | −0.01062 (15) | 0.0362 (4) | |
H26 | 0.0688 | −0.0258 | −0.0711 | 0.043* | |
C27 | 0.19214 (16) | −0.00817 (8) | 0.08963 (14) | 0.0316 (4) | |
H27 | 0.1503 | 0.0259 | 0.0963 | 0.038* | |
C28 | 0.02639 (15) | −0.09686 (7) | 0.22889 (14) | 0.0278 (4) | |
H28 | −0.0498 | −0.0772 | 0.1833 | 0.033* | |
C29 | 0.04360 (16) | −0.15660 (7) | 0.23529 (14) | 0.0300 (4) | |
H29 | −0.0171 | −0.1855 | 0.1960 | 0.036* | |
C30 | 0.17356 (15) | −0.16513 (7) | 0.31457 (13) | 0.0241 (3) | |
C31 | 0.24415 (15) | −0.22149 (7) | 0.35403 (13) | 0.0255 (3) | |
C32 | 0.18141 (16) | −0.27526 (7) | 0.31364 (15) | 0.0295 (4) | |
H32 | 0.0952 | −0.2753 | 0.2605 | 0.035* | |
C33 | 0.24523 (17) | −0.32873 (7) | 0.35133 (16) | 0.0341 (4) | |
H33 | 0.2014 | −0.3641 | 0.3238 | 0.041* | |
C34 | 0.37358 (18) | −0.32961 (7) | 0.42946 (15) | 0.0344 (4) | |
H34 | 0.4162 | −0.3654 | 0.4554 | 0.041* | |
C35 | 0.43830 (17) | −0.27647 (7) | 0.46885 (15) | 0.0337 (4) | |
H35 | 0.5252 | −0.2767 | 0.5205 | 0.040* | |
C36 | 0.37458 (16) | −0.22315 (7) | 0.43195 (15) | 0.0308 (4) | |
H36 | 0.4191 | −0.1879 | 0.4594 | 0.037* | |
B1 | 0.15716 (17) | −0.00705 (8) | 0.33798 (15) | 0.0239 (4) | |
H1A | 0.072 (2) | 0.0208 (9) | 0.2827 (17) | 0.050* | |
B2 | 0.30691 (17) | 0.08375 (7) | 0.51296 (15) | 0.0222 (4) | |
H2A | 0.393 (2) | 0.1003 (9) | 0.5896 (18) | 0.050* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
N1 | 0.0215 (6) | 0.0190 (6) | 0.0263 (7) | −0.0005 (5) | 0.0098 (5) | −0.0010 (5) |
N2 | 0.0213 (6) | 0.0207 (6) | 0.0244 (7) | −0.0002 (5) | 0.0093 (5) | −0.0009 (5) |
N3 | 0.0219 (6) | 0.0222 (6) | 0.0250 (7) | −0.0013 (5) | 0.0108 (6) | −0.0003 (5) |
N4 | 0.0213 (7) | 0.0232 (6) | 0.0315 (7) | 0.0014 (5) | 0.0128 (6) | 0.0005 (5) |
N5 | 0.0209 (6) | 0.0210 (6) | 0.0253 (7) | −0.0010 (5) | 0.0089 (5) | −0.0018 (5) |
N6 | 0.0217 (6) | 0.0212 (6) | 0.0237 (7) | −0.0011 (5) | 0.0086 (5) | −0.0007 (5) |
N7 | 0.0205 (6) | 0.0245 (7) | 0.0258 (7) | −0.0001 (5) | 0.0084 (6) | −0.0013 (5) |
N8 | 0.0233 (7) | 0.0226 (6) | 0.0283 (7) | 0.0009 (5) | 0.0107 (6) | −0.0008 (5) |
C1 | 0.0240 (8) | 0.0214 (7) | 0.0315 (9) | −0.0015 (6) | 0.0129 (7) | 0.0011 (6) |
C2 | 0.0268 (8) | 0.0250 (8) | 0.0298 (9) | 0.0015 (6) | 0.0143 (7) | 0.0036 (6) |
C3 | 0.0224 (7) | 0.0223 (7) | 0.0267 (8) | 0.0040 (6) | 0.0124 (6) | 0.0035 (6) |
C4 | 0.0222 (8) | 0.0258 (8) | 0.0270 (8) | 0.0006 (6) | 0.0129 (7) | 0.0003 (6) |
C5 | 0.0320 (9) | 0.0288 (8) | 0.0296 (9) | 0.0009 (7) | 0.0149 (7) | 0.0023 (7) |
C6 | 0.0397 (10) | 0.0412 (10) | 0.0274 (9) | −0.0005 (8) | 0.0152 (8) | 0.0032 (7) |
C7 | 0.0399 (10) | 0.0427 (10) | 0.0305 (10) | −0.0055 (8) | 0.0180 (8) | −0.0075 (8) |
C8 | 0.0419 (10) | 0.0283 (8) | 0.0372 (10) | −0.0027 (7) | 0.0216 (8) | −0.0062 (7) |
C9 | 0.0317 (9) | 0.0272 (8) | 0.0291 (9) | 0.0006 (7) | 0.0158 (7) | 0.0006 (7) |
C10 | 0.0256 (8) | 0.0276 (8) | 0.0372 (10) | −0.0034 (7) | 0.0142 (7) | 0.0059 (7) |
C11 | 0.0294 (8) | 0.0265 (8) | 0.0346 (9) | 0.0012 (7) | 0.0142 (7) | 0.0090 (7) |
C12 | 0.0274 (8) | 0.0216 (7) | 0.0258 (8) | 0.0007 (6) | 0.0131 (7) | −0.0015 (6) |
C13 | 0.0268 (8) | 0.0209 (7) | 0.0308 (9) | 0.0016 (6) | 0.0122 (7) | −0.0020 (6) |
C14 | 0.0336 (9) | 0.0280 (9) | 0.0444 (11) | 0.0066 (7) | 0.0199 (8) | 0.0108 (7) |
C15 | 0.0311 (9) | 0.0373 (10) | 0.0619 (13) | 0.0048 (8) | 0.0254 (9) | 0.0120 (9) |
C16 | 0.0251 (9) | 0.0346 (10) | 0.0498 (12) | 0.0037 (7) | 0.0100 (8) | 0.0006 (8) |
C17 | 0.0326 (9) | 0.0349 (9) | 0.0306 (9) | 0.0065 (7) | 0.0089 (8) | −0.0024 (7) |
C18 | 0.0297 (9) | 0.0314 (9) | 0.0288 (9) | 0.0048 (7) | 0.0132 (7) | −0.0006 (7) |
C19 | 0.0205 (8) | 0.0227 (7) | 0.0299 (9) | −0.0002 (6) | 0.0105 (7) | 0.0014 (6) |
C20 | 0.0241 (8) | 0.0249 (8) | 0.0311 (9) | 0.0025 (6) | 0.0150 (7) | 0.0020 (6) |
C21 | 0.0238 (8) | 0.0218 (7) | 0.0258 (8) | 0.0026 (6) | 0.0116 (7) | 0.0032 (6) |
C22 | 0.0262 (8) | 0.0264 (8) | 0.0259 (8) | −0.0017 (6) | 0.0136 (7) | −0.0005 (6) |
C23 | 0.0301 (9) | 0.0382 (10) | 0.0336 (10) | 0.0069 (7) | 0.0093 (8) | −0.0041 (8) |
C24 | 0.0417 (11) | 0.0412 (11) | 0.0420 (11) | 0.0046 (8) | 0.0180 (9) | −0.0121 (8) |
C25 | 0.0414 (10) | 0.0406 (10) | 0.0307 (9) | −0.0096 (8) | 0.0177 (8) | −0.0084 (8) |
C26 | 0.0346 (10) | 0.0395 (10) | 0.0289 (9) | −0.0015 (8) | 0.0083 (8) | 0.0032 (7) |
C27 | 0.0332 (9) | 0.0299 (9) | 0.0301 (9) | 0.0042 (7) | 0.0120 (8) | 0.0029 (7) |
C28 | 0.0220 (8) | 0.0311 (8) | 0.0270 (8) | −0.0028 (6) | 0.0074 (7) | −0.0011 (7) |
C29 | 0.0269 (8) | 0.0275 (8) | 0.0319 (9) | −0.0060 (7) | 0.0092 (7) | −0.0036 (7) |
C30 | 0.0265 (8) | 0.0232 (8) | 0.0255 (8) | −0.0036 (6) | 0.0138 (7) | −0.0033 (6) |
C31 | 0.0274 (8) | 0.0249 (8) | 0.0281 (9) | −0.0016 (6) | 0.0155 (7) | −0.0014 (6) |
C32 | 0.0265 (8) | 0.0288 (8) | 0.0345 (9) | −0.0042 (7) | 0.0142 (7) | −0.0037 (7) |
C33 | 0.0389 (10) | 0.0232 (8) | 0.0430 (11) | −0.0057 (7) | 0.0201 (9) | −0.0043 (7) |
C34 | 0.0403 (10) | 0.0245 (8) | 0.0411 (10) | 0.0029 (7) | 0.0199 (9) | 0.0030 (7) |
C35 | 0.0296 (9) | 0.0305 (9) | 0.0362 (10) | 0.0005 (7) | 0.0095 (8) | 0.0013 (7) |
C36 | 0.0305 (9) | 0.0232 (8) | 0.0360 (10) | −0.0037 (6) | 0.0118 (8) | −0.0028 (7) |
B1 | 0.0216 (8) | 0.0225 (8) | 0.0270 (9) | 0.0004 (7) | 0.0097 (7) | −0.0002 (7) |
B2 | 0.0220 (8) | 0.0205 (8) | 0.0245 (9) | −0.0003 (7) | 0.0103 (7) | −0.0007 (7) |
Geometric parameters (Å, º) top
N1—C1 | 1.3403 (19) | C14—H14 | 0.9300 |
N1—N2 | 1.3677 (17) | C15—C16 | 1.392 (3) |
N1—B1 | 1.567 (2) | C15—H15 | 0.9300 |
N2—C3 | 1.360 (2) | C16—C17 | 1.377 (3) |
N2—B2 | 1.539 (2) | C16—H16 | 0.9300 |
N3—C10 | 1.351 (2) | C17—C18 | 1.388 (2) |
N3—N4 | 1.3657 (17) | C17—H17 | 0.9300 |
N3—B2 | 1.542 (2) | C18—H18 | 0.9300 |
N4—C12 | 1.342 (2) | C19—C20 | 1.381 (2) |
N5—C19 | 1.3441 (19) | C19—H19 | 0.9300 |
N5—N6 | 1.3633 (17) | C20—C21 | 1.390 (2) |
N5—B2 | 1.571 (2) | C20—H20 | 0.9300 |
N6—C21 | 1.3550 (19) | C21—C22 | 1.483 (2) |
N6—B1 | 1.571 (2) | C22—C27 | 1.388 (2) |
N7—C28 | 1.356 (2) | C22—C23 | 1.390 (2) |
N7—N8 | 1.3708 (18) | C23—C24 | 1.390 (3) |
N7—B1 | 1.513 (2) | C23—H23 | 0.9300 |
N8—C30 | 1.3420 (19) | C24—C25 | 1.377 (3) |
C1—C2 | 1.378 (2) | C24—H24 | 0.9300 |
C1—H1 | 0.9300 | C25—C26 | 1.381 (3) |
C2—C3 | 1.389 (2) | C25—H25 | 0.9300 |
C2—H2 | 0.9300 | C26—C27 | 1.382 (2) |
C3—C4 | 1.470 (2) | C26—H26 | 0.9300 |
C4—C9 | 1.392 (2) | C27—H27 | 0.9300 |
C4—C5 | 1.398 (2) | C28—C29 | 1.362 (2) |
C5—C6 | 1.384 (2) | C28—H28 | 0.9300 |
C5—H5 | 0.9300 | C29—C30 | 1.411 (2) |
C6—C7 | 1.388 (3) | C29—H29 | 0.9300 |
C6—H6 | 0.9300 | C30—C31 | 1.477 (2) |
C7—C8 | 1.387 (3) | C31—C32 | 1.395 (2) |
C7—H7 | 0.9300 | C31—C36 | 1.398 (2) |
C8—C9 | 1.386 (2) | C32—C33 | 1.388 (2) |
C8—H8 | 0.9300 | C32—H32 | 0.9300 |
C9—H9 | 0.9300 | C33—C34 | 1.380 (3) |
C10—C11 | 1.362 (2) | C33—H33 | 0.9300 |
C10—H10 | 0.9300 | C34—C35 | 1.388 (2) |
C11—C12 | 1.404 (2) | C34—H34 | 0.9300 |
C11—H11 | 0.9300 | C35—C36 | 1.383 (2) |
C12—C13 | 1.477 (2) | C35—H35 | 0.9300 |
C13—C14 | 1.394 (2) | C36—H36 | 0.9300 |
C13—C18 | 1.399 (2) | B1—H1A | 1.12 (2) |
C14—C15 | 1.388 (2) | B2—H2A | 1.13 (2) |
| | | |
C1—N1—N2 | 108.33 (12) | C18—C17—H17 | 119.7 |
C1—N1—B1 | 126.86 (13) | C17—C18—C13 | 120.66 (16) |
N2—N1—B1 | 124.80 (12) | C17—C18—H18 | 119.7 |
C3—N2—N1 | 108.14 (12) | C13—C18—H18 | 119.7 |
C3—N2—B2 | 132.66 (13) | N5—C19—C20 | 108.80 (14) |
N1—N2—B2 | 118.83 (12) | N5—C19—H19 | 125.6 |
C10—N3—N4 | 110.24 (12) | C20—C19—H19 | 125.6 |
C10—N3—B2 | 125.39 (13) | C19—C20—C21 | 106.28 (13) |
N4—N3—B2 | 124.08 (12) | C19—C20—H20 | 126.9 |
C12—N4—N3 | 105.34 (12) | C21—C20—H20 | 126.9 |
C19—N5—N6 | 108.47 (12) | N6—C21—C20 | 108.01 (13) |
C19—N5—B2 | 128.48 (13) | N6—C21—C22 | 122.71 (13) |
N6—N5—B2 | 122.34 (12) | C20—C21—C22 | 129.22 (14) |
C21—N6—N5 | 108.44 (12) | C27—C22—C23 | 119.20 (15) |
C21—N6—B1 | 131.37 (13) | C27—C22—C21 | 119.87 (14) |
N5—N6—B1 | 119.88 (12) | C23—C22—C21 | 120.85 (14) |
C28—N7—N8 | 110.41 (12) | C22—C23—C24 | 120.00 (16) |
C28—N7—B1 | 126.45 (13) | C22—C23—H23 | 120.0 |
N8—N7—B1 | 121.68 (12) | C24—C23—H23 | 120.0 |
C30—N8—N7 | 105.42 (12) | C25—C24—C23 | 120.40 (17) |
N1—C1—C2 | 109.27 (14) | C25—C24—H24 | 119.8 |
N1—C1—H1 | 125.4 | C23—C24—H24 | 119.8 |
C2—C1—H1 | 125.4 | C24—C25—C26 | 119.67 (17) |
C1—C2—C3 | 106.17 (14) | C24—C25—H25 | 120.2 |
C1—C2—H2 | 126.9 | C26—C25—H25 | 120.2 |
C3—C2—H2 | 126.9 | C25—C26—C27 | 120.38 (17) |
N2—C3—C2 | 108.08 (14) | C25—C26—H26 | 119.8 |
N2—C3—C4 | 124.34 (14) | C27—C26—H26 | 119.8 |
C2—C3—C4 | 127.58 (14) | C26—C27—C22 | 120.34 (16) |
C9—C4—C5 | 119.14 (15) | C26—C27—H27 | 119.8 |
C9—C4—C3 | 122.65 (14) | C22—C27—H27 | 119.8 |
C5—C4—C3 | 118.10 (14) | N7—C28—C29 | 108.47 (14) |
C6—C5—C4 | 120.44 (16) | N7—C28—H28 | 125.8 |
C6—C5—H5 | 119.8 | C29—C28—H28 | 125.8 |
C4—C5—H5 | 119.8 | C28—C29—C30 | 104.99 (14) |
C5—C6—C7 | 119.99 (16) | C28—C29—H29 | 127.5 |
C5—C6—H6 | 120.0 | C30—C29—H29 | 127.5 |
C7—C6—H6 | 120.0 | N8—C30—C29 | 110.70 (14) |
C8—C7—C6 | 119.92 (16) | N8—C30—C31 | 121.13 (14) |
C8—C7—H7 | 120.0 | C29—C30—C31 | 128.17 (14) |
C6—C7—H7 | 120.0 | C32—C31—C36 | 117.77 (15) |
C9—C8—C7 | 120.21 (16) | C32—C31—C30 | 120.34 (14) |
C9—C8—H8 | 119.9 | C36—C31—C30 | 121.89 (14) |
C7—C8—H8 | 119.9 | C33—C32—C31 | 121.24 (16) |
C8—C9—C4 | 120.29 (16) | C33—C32—H32 | 119.4 |
C8—C9—H9 | 119.9 | C31—C32—H32 | 119.4 |
C4—C9—H9 | 119.9 | C34—C33—C32 | 120.26 (16) |
N3—C10—C11 | 108.83 (14) | C34—C33—H33 | 119.9 |
N3—C10—H10 | 125.6 | C32—C33—H33 | 119.9 |
C11—C10—H10 | 125.6 | C33—C34—C35 | 119.26 (16) |
C10—C11—C12 | 104.60 (14) | C33—C34—H34 | 120.4 |
C10—C11—H11 | 127.7 | C35—C34—H34 | 120.4 |
C12—C11—H11 | 127.7 | C36—C35—C34 | 120.55 (16) |
N4—C12—C11 | 110.99 (14) | C36—C35—H35 | 119.7 |
N4—C12—C13 | 121.08 (14) | C34—C35—H35 | 119.7 |
C11—C12—C13 | 127.88 (14) | C35—C36—C31 | 120.91 (15) |
C14—C13—C18 | 118.40 (15) | C35—C36—H36 | 119.5 |
C14—C13—C12 | 121.87 (14) | C31—C36—H36 | 119.5 |
C18—C13—C12 | 119.72 (14) | N7—B1—N1 | 106.07 (12) |
C15—C14—C13 | 120.56 (17) | N7—B1—N6 | 111.31 (13) |
C15—C14—H14 | 119.7 | N1—B1—N6 | 105.87 (12) |
C13—C14—H14 | 119.7 | N7—B1—H1A | 111.3 (11) |
C14—C15—C16 | 120.41 (17) | N1—B1—H1A | 109.3 (10) |
C14—C15—H15 | 119.8 | N6—B1—H1A | 112.6 (11) |
C16—C15—H15 | 119.8 | N2—B2—N3 | 109.95 (12) |
C17—C16—C15 | 119.38 (16) | N2—B2—N5 | 106.05 (12) |
C17—C16—H16 | 120.3 | N3—B2—N5 | 109.15 (12) |
C15—C16—H16 | 120.3 | N2—B2—H2A | 113.3 (11) |
C16—C17—C18 | 120.55 (17) | N3—B2—H2A | 111.7 (10) |
C16—C17—H17 | 119.7 | N5—B2—H2A | 106.4 (11) |
| | | |
C1—N1—N2—C3 | 0.48 (16) | B1—N6—C21—C22 | 10.0 (2) |
B1—N1—N2—C3 | 179.19 (13) | C19—C20—C21—N6 | −0.15 (17) |
C1—N1—N2—B2 | 174.39 (13) | C19—C20—C21—C22 | 176.81 (15) |
B1—N1—N2—B2 | −6.89 (19) | N6—C21—C22—C27 | 60.3 (2) |
C10—N3—N4—C12 | 0.14 (17) | C20—C21—C22—C27 | −116.23 (19) |
B2—N3—N4—C12 | −173.90 (13) | N6—C21—C22—C23 | −122.82 (17) |
C19—N5—N6—C21 | −0.86 (16) | C20—C21—C22—C23 | 60.6 (2) |
B2—N5—N6—C21 | 170.25 (13) | C27—C22—C23—C24 | −1.1 (3) |
C19—N5—N6—B1 | 173.43 (13) | C21—C22—C23—C24 | −178.02 (16) |
B2—N5—N6—B1 | −15.46 (19) | C22—C23—C24—C25 | 0.5 (3) |
C28—N7—N8—C30 | 0.84 (16) | C23—C24—C25—C26 | 0.4 (3) |
B1—N7—N8—C30 | 167.89 (13) | C24—C25—C26—C27 | −0.7 (3) |
N2—N1—C1—C2 | −0.53 (16) | C25—C26—C27—C22 | 0.0 (3) |
B1—N1—C1—C2 | −179.21 (14) | C23—C22—C27—C26 | 0.9 (2) |
N1—C1—C2—C3 | 0.38 (17) | C21—C22—C27—C26 | 177.82 (15) |
N1—N2—C3—C2 | −0.24 (16) | N8—N7—C28—C29 | −0.46 (18) |
B2—N2—C3—C2 | −172.99 (14) | B1—N7—C28—C29 | −166.76 (15) |
N1—N2—C3—C4 | 178.95 (13) | N7—C28—C29—C30 | −0.09 (18) |
B2—N2—C3—C4 | 6.2 (2) | N7—N8—C30—C29 | −0.89 (17) |
C1—C2—C3—N2 | −0.08 (17) | N7—N8—C30—C31 | 179.70 (13) |
C1—C2—C3—C4 | −179.24 (14) | C28—C29—C30—N8 | 0.63 (18) |
N2—C3—C4—C9 | 40.2 (2) | C28—C29—C30—C31 | 179.99 (15) |
C2—C3—C4—C9 | −140.82 (17) | N8—C30—C31—C32 | 178.16 (15) |
N2—C3—C4—C5 | −143.78 (15) | C29—C30—C31—C32 | −1.1 (2) |
C2—C3—C4—C5 | 35.3 (2) | N8—C30—C31—C36 | −2.0 (2) |
C9—C4—C5—C6 | −0.5 (2) | C29—C30—C31—C36 | 178.71 (16) |
C3—C4—C5—C6 | −176.75 (15) | C36—C31—C32—C33 | 1.4 (2) |
C4—C5—C6—C7 | 0.0 (3) | C30—C31—C32—C33 | −178.70 (15) |
C5—C6—C7—C8 | 0.3 (3) | C31—C32—C33—C34 | −0.6 (3) |
C6—C7—C8—C9 | −0.1 (3) | C32—C33—C34—C35 | −0.7 (3) |
C7—C8—C9—C4 | −0.5 (3) | C33—C34—C35—C36 | 1.2 (3) |
C5—C4—C9—C8 | 0.8 (2) | C34—C35—C36—C31 | −0.3 (3) |
C3—C4—C9—C8 | 176.80 (15) | C32—C31—C36—C35 | −1.0 (2) |
N4—N3—C10—C11 | −0.26 (19) | C30—C31—C36—C35 | 179.15 (15) |
B2—N3—C10—C11 | 173.69 (14) | C28—N7—B1—N1 | 103.45 (17) |
N3—C10—C11—C12 | 0.26 (19) | N8—N7—B1—N1 | −61.42 (17) |
N3—N4—C12—C11 | 0.03 (17) | C28—N7—B1—N6 | −141.85 (15) |
N3—N4—C12—C13 | 177.75 (13) | N8—N7—B1—N6 | 53.28 (19) |
C10—C11—C12—N4 | −0.18 (19) | C1—N1—B1—N7 | −26.4 (2) |
C10—C11—C12—C13 | −177.71 (15) | N2—N1—B1—N7 | 155.12 (12) |
N4—C12—C13—C14 | 34.6 (2) | C1—N1—B1—N6 | −144.77 (14) |
C11—C12—C13—C14 | −148.13 (17) | N2—N1—B1—N6 | 36.75 (18) |
N4—C12—C13—C18 | −144.92 (15) | C21—N6—B1—N7 | 33.8 (2) |
C11—C12—C13—C18 | 32.4 (2) | N5—N6—B1—N7 | −138.94 (13) |
C18—C13—C14—C15 | 2.2 (3) | C21—N6—B1—N1 | 148.66 (14) |
C12—C13—C14—C15 | −177.33 (16) | N5—N6—B1—N1 | −24.12 (17) |
C13—C14—C15—C16 | −1.0 (3) | C3—N2—B2—N3 | −102.42 (18) |
C14—C15—C16—C17 | −0.4 (3) | N1—N2—B2—N3 | 85.45 (15) |
C15—C16—C17—C18 | 0.5 (3) | C3—N2—B2—N5 | 139.71 (15) |
C16—C17—C18—C13 | 0.7 (3) | N1—N2—B2—N5 | −32.42 (17) |
C14—C13—C18—C17 | −2.1 (2) | C10—N3—B2—N2 | −176.88 (14) |
C12—C13—C18—C17 | 177.45 (15) | N4—N3—B2—N2 | −3.7 (2) |
N6—N5—C19—C20 | 0.77 (17) | C10—N3—B2—N5 | −60.95 (19) |
B2—N5—C19—C20 | −169.63 (14) | N4—N3—B2—N5 | 112.19 (15) |
N5—C19—C20—C21 | −0.39 (17) | C19—N5—B2—N2 | −145.76 (14) |
N5—N6—C21—C20 | 0.62 (16) | N6—N5—B2—N2 | 45.02 (17) |
B1—N6—C21—C20 | −172.79 (14) | C19—N5—B2—N3 | 95.83 (18) |
N5—N6—C21—C22 | −176.59 (13) | N6—N5—B2—N3 | −73.38 (16) |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
C19—H19···N8i | 0.93 | 2.60 | 3.489 (2) | 160 |
Symmetry code: (i) −x+1, −y, −z+1. |
Experimental details
Crystal data |
Chemical formula | C36H30B2N8 |
Mr | 596.30 |
Crystal system, space group | Monoclinic, P21/n |
Temperature (K) | 120 |
a, b, c (Å) | 11.3980 (2), 22.6068 (4), 13.1547 (2) |
β (°) | 115.429 (1) |
V (Å3) | 3061.21 (9) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.08 |
Crystal size (mm) | 0.20 × 0.18 × 0.10 |
|
Data collection |
Diffractometer | Nonius KappaCCD area-detector diffractometer |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 6995, 6995, 5037 |
Rint | 0.000 |
(sin θ/λ)max (Å−1) | 0.649 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.048, 0.131, 1.05 |
No. of reflections | 6995 |
No. of parameters | 422 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.22, −0.27 |
Selected geometric parameters (Å, º) topN1—C1 | 1.3403 (19) | N6—B1 | 1.571 (2) |
N1—N2 | 1.3677 (17) | N7—C28 | 1.356 (2) |
N1—B1 | 1.567 (2) | N7—N8 | 1.3708 (18) |
N2—C3 | 1.360 (2) | N7—B1 | 1.513 (2) |
N2—B2 | 1.539 (2) | N8—C30 | 1.3420 (19) |
N3—C10 | 1.351 (2) | C1—C2 | 1.378 (2) |
N3—N4 | 1.3657 (17) | C2—C3 | 1.389 (2) |
N3—B2 | 1.542 (2) | C10—C11 | 1.362 (2) |
N4—C12 | 1.342 (2) | C11—C12 | 1.404 (2) |
N5—C19 | 1.3441 (19) | C19—C20 | 1.381 (2) |
N5—N6 | 1.3633 (17) | C20—C21 | 1.390 (2) |
N5—B2 | 1.571 (2) | C28—C29 | 1.362 (2) |
N6—C21 | 1.3550 (19) | C29—C30 | 1.411 (2) |
| | | |
C1—N1—N2 | 108.33 (12) | C21—N6—N5 | 108.44 (12) |
C1—N1—B1 | 126.86 (13) | C21—N6—B1 | 131.37 (13) |
N2—N1—B1 | 124.80 (12) | N5—N6—B1 | 119.88 (12) |
C3—N2—N1 | 108.14 (12) | C28—N7—N8 | 110.41 (12) |
C3—N2—B2 | 132.66 (13) | C28—N7—B1 | 126.45 (13) |
N1—N2—B2 | 118.83 (12) | N8—N7—B1 | 121.68 (12) |
C10—N3—N4 | 110.24 (12) | C30—N8—N7 | 105.42 (12) |
C10—N3—B2 | 125.39 (13) | N1—C1—C2 | 109.27 (14) |
N4—N3—B2 | 124.08 (12) | C1—C2—C3 | 106.17 (14) |
C12—N4—N3 | 105.34 (12) | C10—C11—C12 | 104.60 (14) |
C19—N5—N6 | 108.47 (12) | C19—C20—C21 | 106.28 (13) |
C19—N5—B2 | 128.48 (13) | C28—C29—C30 | 104.99 (14) |
N6—N5—B2 | 122.34 (12) | | |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
C19—H19···N8i | 0.93 | 2.60 | 3.489 (2) | 160 |
Symmetry code: (i) −x+1, −y, −z+1. |
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First introduced by Trofimenko (1967), pyrazaboles constitutes a unique class of heterocyclic compounds containing a B—N bond, mainly due to their high chemical and thermal stability (Trofimenko, 1999). In recent decades, a series of pyrazaboles have been reported in the literature (Niedenzu, 1988), and used as building blocks for discotic liquid crystals (Barberá et al., 1994) and as bridges for ansa-ferrocenes to form active container molecules for supramolecular applications (Jäkle et al., 1996; Herdtweck et al., 1996). The structural characterization of these compounds has become an important tool in order to define their conformational structures in the solid state. Fig. 1 represents the possible conformations of pyrazaboles.
Most of the pyrazabole derivatives which have been structurally characterized to date are related to symmetrical pyrazaboles, R2B(µ-Pz)2BR2 (R = H, Et, Pz, Ph, F or Br, and Pz = pyrazol-1-yl) (Barberá et al., 2000; Clarke et al., 1987; Hanecker et al., 1985; Atwood et al., 1992) or R1RB(µ-pz)2BRR1 (R = Et or Ph, and R1 = Pz or Br) (Niedenzu & Nöth, 1983; Bielawski et al., 1986) and asymmetrical ones, such as R2B(µ-pz)2BR12 (R = H or Cl, and R1 = Pz or Ph) (Clarke et al., 1987) or R2B(µ-pz)2BR1R2 (R = H, R1 = H, and R2 = Br) (Hodgkins & Powell, 1992; Niedenzu et al., 1985). On the other hand, although several papers report the synthesis and spectroscopic characterization of symmetrical disubstituted 4,8-bis(pyrazolyl-1-yl)pyrazaboles, H(Pz')B(µ-pz)2B(Pz')H (Pz'= pyrazol-1-yl or 3,5-dimethylpyrazol-1-yl) (Trofimenko, 1987; Blosch et al., 1992), only the structural characterization of H(Pz)B(µ-pz)2B(Pz)H (Pz = pyrazol-1-yl), (II) has been described to date (Kresinski, 1999). Here, we describe the crystal and molecular structure of the novel H(Pz')B(µ-Pz)2B(Pz')H compound (Pz' = 3-phenylpyrazol-1-yl), (I). Selected bond distances and angles are listed in Table 1.
Fig. 2 shows that the six-membered B2N4 ring adopts a slightly distorted boat conformation, with the terminal B substituents in a trans orientation. The B atoms are tetracoordinated, as confirmed by the almost ideal sp3-hybrydization sphere around them. The two terminal pyrazolyl groups (at the 4- and 8-positions) occupy one axial position and one equatorial position. The dihedral angles between the least-squares plane through the four central atoms of the ring (N1, N2, N5 and N6) and the N2/B2/N5 and N1/B1/N6 planes are 32.42 (2) and 24.11 (2)°, respectively. The B—N [average B—N = 1.550 Å, range 1.513 (2)–1.571 (2) Å] and N—N [average N—N = 1.367 Å, range 1.3633 (17)–1.3708 (18) Å] bond distances are comparable with those found in the related compound, (II) (average B—N = 1.541 Å and average N—N = 1.360 Å; Kresinski, 1999). In contrast with what is observed in (II), the B—H bond distances in the pseudo-equatorial (pe) and pseudo-axial (pa) positions of (I) are very similar [B—Hpe = 1.12 (2) Å and B—Hpa = 1.13 (2) Å], suggesting that the negative charges on the H atoms are equally distributed. One of the four 3-phenylpyrazolyl groups features the pyrazolyl and the phenyl rings in a coplanar orientation (torsion angle N8—C30—C31—C36 = −1.98°), while the others display torsion angles from 34.55 to 60.33°.
The overall structure of (I) is extended through self-complementary C—H···N hydrogen bonds that involve the bridging pyrazolyl group (C19—H19) of one molecule and an N atom (N8) of the terminal pyrazolyl unit of a second molecule. As shown in Fig. 3, this results in the formation of a dimer, with the pyrazabole rings in a mirror-like array across the centre of symmetry. The intermolecular C19—H19···N8 contacts of 2.60 Å (Table 2) are within the sum of the van der Waals radii for the H and N atoms (2.75 Å; Kresinski, 1999) and are longer than the C—H···N contacts [2.41 (2) and 2.52 (2) Å for the two independent molecules] observed in the related pyrazabole compound, (II), which has no phenyl substituent on the pyrazolyl rings (Kresinski, 1999). Steric crowding induced by the phenyl substituents likely accounts for the longer C—H···N contacts in (I).
Despite the presence of many aromatic rings in (I), i.e. the four phenyl substituents and the four pyrazolyl rings, only minimal π–π interactions are observed, which involve the C22–C27 phenyl ring and the N7–N8 pyrazolyl ring (Fig. 3). These observations suggest that the overall distorted-boat conformation of 4,8-disubstituted pyrazaboles, in particular the presence of pseudo-equatorial and pseudo-axial substituents, is mainly governed by the aforementioned C—H···N interactions.