Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270100000743/gd1068sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270100000743/gd1068Isup2.hkl |
CCDC reference: 144650
Compound (I) was prepared by an improvement upon the method of Vasil'eva & Khalfina (1976). Typically, 1,2-Ph2-1,2-closo-C2B10H10 (2.96 g, 10 mmol) and sublimed I2 (1.27 g, 5 mmol) were dissolved in glacial acetic acid (40 ml) at 313 K. A mixture of concentrated nitric acid and concentrated sulfuric acid (1:1 volume ratio, 20 ml) was added very slowly to the mixture (1 ml min-1). A brown vapour was observed above the purple solution and within 90 min the solution became pale brown and then decolorized. The colourless mixture was poured into a beaker containing distilled water (300 ml), resulting in a white precipitate which was isolated by filtration, washed with distilled water, dissolved in diethyl ether and dried over MgSO4. The dried ethereal solution was evaporated and the resulting off-white residue recrystallized from hexane to give the title compound (3.02 g, 7.15 mmol, 71.5%). Found: C 39.3, H 4.3%. C14H19B10I requires C 39.8, H 4.5%. IR (KBr disc): 3060 (w, νCH) and 2597 (s, νBH) cm-1. MS (EI): (m/z)max 424 (12C141H1911B10127I). NMR (CDCl3, 298 K): δ(11B) -0.9 (1B, B12), -8.6 (6B, B4,5,7,11,8,10), -11.0 (2B, B3,6), -15.2 (1B, B9); δ(1H) 7.39 (4H, m; ortho or meta C6H5), 7.26 (2H, m; para C6H5), 7.15 (4H, m; meta or ortho C6H5), 3.33 (2H, H3,6), 3.00 (3H, H12 and H4,5 or H7,11 or H8,10), 2.83 (2H, H8,10 or H7,11 or H4,5), 2.62 (2H, H7,11 or H8,10 or H4,5); δ(13C) 130.8 (2 para C, ortho C), 130.7 (ortho C), 130.2 (ipso C), 129.8 (ipso C), 128.7 (2 meta C), 86.1 (carboranyl C), 82.2 (carboranyl C). Diffraction-quality single crystals were obtained by slow mutual diffusion of a dichloromethane solution and petroleum ether (60–80) at 243 K.
Phenyl-H atoms were set riding with C—H 0.95 Å and with isotropic displacement parameters equal to 1.2 times Ueq of the corresponding C atom. Cluster H atoms were allowed free positional refinement, but were assigned isotropic temperature factors equal to 1.2 times Ueq of the corresponding B atom.
Data collection: XSCANS (Bruker, 1996); cell refinement: XSCANS; data reduction: SHELXTL (Sheldrick, 1999); program(s) used to solve structure: SHELXTL; program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.
Fig. 1. Perspective view of (I) with displacement ellipsoids shown at the 50% probability level for non-H atoms. H atoms are drawn as small circles of arbitrary radii. |
C14H19B10I | Dx = 1.497 Mg m−3 |
Mr = 422.29 | Melting point: 176 - 177 °C K |
Monoclinic, P21/n | Mo Kα radiation, λ = 0.71073 Å |
a = 9.0913 (9) Å | Cell parameters from 32 reflections |
b = 11.4168 (11) Å | θ = 4.8–12.5° |
c = 18.0817 (17) Å | µ = 1.70 mm−1 |
β = 93.460 (7)° | T = 160 K |
V = 1873.3 (3) Å3 | Block, colourless |
Z = 4 | 0.40 × 0.15 × 0.12 mm |
F(000) = 824 |
Bruker P4 diffractometer | 2628 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.033 |
Graphite monochromator | θmax = 25.0°, θmin = 2.1° |
ω scans | h = −1→10 |
Absorption correction: empirical (using intensity measurements) (SHELXTL; Sheldrick, 1999) | k = −13→1 |
Tmin = 0.746, Tmax = 0.815 | l = −21→21 |
4407 measured reflections | 3 standard reflections every 97 reflections |
3304 independent reflections | intensity decay: 1.2% |
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.035 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.085 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.02 | w = 1/[σ2(Fo2) + (0.0259P)2 + 1.7031P] where P = (Fo2 + 2Fc2)/3 |
3304 reflections | (Δ/σ)max = 0.001 |
253 parameters | Δρmax = 0.77 e Å−3 |
0 restraints | Δρmin = −0.58 e Å−3 |
C14H19B10I | V = 1873.3 (3) Å3 |
Mr = 422.29 | Z = 4 |
Monoclinic, P21/n | Mo Kα radiation |
a = 9.0913 (9) Å | µ = 1.70 mm−1 |
b = 11.4168 (11) Å | T = 160 K |
c = 18.0817 (17) Å | 0.40 × 0.15 × 0.12 mm |
β = 93.460 (7)° |
Bruker P4 diffractometer | 2628 reflections with I > 2σ(I) |
Absorption correction: empirical (using intensity measurements) (SHELXTL; Sheldrick, 1999) | Rint = 0.033 |
Tmin = 0.746, Tmax = 0.815 | 3 standard reflections every 97 reflections |
4407 measured reflections | intensity decay: 1.2% |
3304 independent reflections |
R[F2 > 2σ(F2)] = 0.035 | 0 restraints |
wR(F2) = 0.085 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.02 | Δρmax = 0.77 e Å−3 |
3304 reflections | Δρmin = −0.58 e Å−3 |
253 parameters |
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. |
x | y | z | Uiso*/Ueq | ||
C1 | 1.0902 (4) | 0.6085 (3) | 0.27551 (18) | 0.0218 (7) | |
C2 | 0.9113 (4) | 0.6240 (3) | 0.23945 (18) | 0.0226 (7) | |
B3 | 1.0333 (4) | 0.7399 (4) | 0.2348 (2) | 0.0259 (8) | |
H3 | 1.019 (4) | 0.815 (3) | 0.267 (2) | 0.031* | |
B4 | 1.2090 (5) | 0.6780 (4) | 0.2200 (2) | 0.0274 (8) | |
H4 | 1.308 (4) | 0.715 (3) | 0.244 (2) | 0.033* | |
B5 | 1.1870 (4) | 0.5219 (4) | 0.2183 (2) | 0.0263 (8) | |
H5 | 1.270 (4) | 0.472 (4) | 0.245 (2) | 0.032* | |
B6 | 0.9994 (5) | 0.4896 (3) | 0.2330 (2) | 0.0253 (8) | |
H6 | 0.959 (4) | 0.422 (3) | 0.264 (2) | 0.030* | |
B7 | 0.9093 (5) | 0.7029 (4) | 0.1588 (2) | 0.0290 (9) | |
H7 | 0.819 (4) | 0.761 (4) | 0.147 (2) | 0.035* | |
B8 | 1.0976 (5) | 0.7370 (4) | 0.1442 (2) | 0.0309 (9) | |
H8 | 1.131 (4) | 0.817 (4) | 0.117 (2) | 0.037* | |
B9 | 1.1913 (5) | 0.6012 (4) | 0.1344 (2) | 0.0291 (9) | |
I1 | 1.38279 (3) | 0.58482 (3) | 0.068280 (15) | 0.04696 (11) | |
B10 | 1.0638 (5) | 0.4837 (4) | 0.1427 (2) | 0.0292 (9) | |
H10 | 1.080 (4) | 0.399 (3) | 0.113 (2) | 0.035* | |
B11 | 0.8893 (5) | 0.5485 (4) | 0.1569 (2) | 0.0279 (8) | |
H11 | 0.786 (4) | 0.515 (4) | 0.141 (2) | 0.033* | |
B12 | 1.0079 (5) | 0.6166 (4) | 0.0958 (2) | 0.0320 (9) | |
H12 | 0.968 (5) | 0.617 (4) | 0.032 (2) | 0.038* | |
C101 | 1.1231 (4) | 0.6047 (3) | 0.35857 (18) | 0.0244 (7) | |
C102 | 1.1340 (4) | 0.4973 (3) | 0.3946 (2) | 0.0333 (9) | |
H102 | 1.1154 | 0.4270 | 0.3675 | 0.040* | |
C103 | 1.1719 (5) | 0.4922 (4) | 0.4703 (2) | 0.0466 (11) | |
H103 | 1.1795 | 0.4188 | 0.4950 | 0.056* | |
C104 | 1.1985 (5) | 0.5953 (4) | 0.5093 (2) | 0.0447 (10) | |
H104 | 1.2231 | 0.5923 | 0.5611 | 0.054* | |
C105 | 1.1898 (4) | 0.7016 (4) | 0.4741 (2) | 0.0397 (10) | |
H105 | 1.2090 | 0.7716 | 0.5015 | 0.048* | |
C106 | 1.1527 (4) | 0.7071 (4) | 0.3983 (2) | 0.0318 (8) | |
H106 | 1.1476 | 0.7807 | 0.3738 | 0.038* | |
C201 | 0.7898 (4) | 0.6314 (3) | 0.29228 (18) | 0.0234 (7) | |
C202 | 0.6820 (4) | 0.5448 (3) | 0.2902 (2) | 0.0300 (8) | |
H202 | 0.6860 | 0.4820 | 0.2559 | 0.036* | |
C203 | 0.5680 (4) | 0.5498 (4) | 0.3383 (2) | 0.0373 (9) | |
H203 | 0.4942 | 0.4908 | 0.3363 | 0.045* | |
C204 | 0.5615 (4) | 0.6401 (4) | 0.3889 (2) | 0.0365 (9) | |
H204 | 0.4837 | 0.6432 | 0.4217 | 0.044* | |
C205 | 0.6691 (4) | 0.7258 (3) | 0.39156 (19) | 0.0316 (8) | |
H205 | 0.6652 | 0.7879 | 0.4264 | 0.038* | |
C206 | 0.7829 (4) | 0.7220 (3) | 0.34364 (18) | 0.0276 (7) | |
H206 | 0.8563 | 0.7813 | 0.3459 | 0.033* |
U11 | U22 | U33 | U12 | U13 | U23 | |
C1 | 0.0196 (15) | 0.0217 (18) | 0.0243 (16) | 0.0008 (13) | 0.0024 (13) | 0.0004 (13) |
C2 | 0.0219 (16) | 0.0205 (16) | 0.0251 (16) | −0.0004 (14) | −0.0010 (13) | 0.0004 (14) |
B3 | 0.0257 (19) | 0.022 (2) | 0.0297 (19) | 0.0018 (17) | 0.0038 (16) | 0.0032 (17) |
B4 | 0.025 (2) | 0.026 (2) | 0.031 (2) | −0.0039 (17) | 0.0042 (17) | −0.0020 (17) |
B5 | 0.025 (2) | 0.028 (2) | 0.0266 (19) | 0.0045 (17) | 0.0040 (16) | −0.0030 (17) |
B6 | 0.027 (2) | 0.021 (2) | 0.0276 (19) | 0.0011 (16) | 0.0006 (16) | −0.0025 (16) |
B7 | 0.031 (2) | 0.030 (2) | 0.0260 (19) | 0.0058 (18) | 0.0042 (16) | 0.0042 (17) |
B8 | 0.033 (2) | 0.030 (2) | 0.031 (2) | 0.0025 (19) | 0.0091 (17) | 0.0074 (18) |
B9 | 0.027 (2) | 0.033 (2) | 0.0288 (19) | −0.0001 (18) | 0.0078 (16) | 0.0015 (17) |
I1 | 0.04321 (17) | 0.05530 (19) | 0.04485 (16) | 0.00590 (14) | 0.02312 (12) | 0.00002 (14) |
B10 | 0.028 (2) | 0.028 (2) | 0.031 (2) | 0.0006 (18) | 0.0014 (17) | −0.0038 (17) |
B11 | 0.029 (2) | 0.027 (2) | 0.0274 (19) | 0.0003 (17) | −0.0011 (16) | −0.0016 (16) |
B12 | 0.034 (2) | 0.035 (2) | 0.026 (2) | 0.0061 (19) | 0.0008 (17) | 0.0033 (17) |
C101 | 0.0198 (16) | 0.0286 (19) | 0.0247 (16) | 0.0032 (14) | −0.0007 (13) | 0.0000 (14) |
C102 | 0.037 (2) | 0.036 (2) | 0.0264 (18) | 0.0048 (17) | −0.0046 (16) | 0.0007 (16) |
C103 | 0.054 (3) | 0.051 (3) | 0.033 (2) | 0.004 (2) | −0.007 (2) | 0.0096 (19) |
C104 | 0.043 (2) | 0.065 (3) | 0.0253 (18) | 0.002 (2) | −0.0053 (16) | −0.004 (2) |
C105 | 0.031 (2) | 0.051 (3) | 0.036 (2) | 0.0044 (19) | −0.0042 (17) | −0.0154 (19) |
C106 | 0.0249 (17) | 0.036 (2) | 0.0346 (19) | 0.0029 (16) | 0.0003 (15) | −0.0060 (17) |
C201 | 0.0207 (16) | 0.0233 (16) | 0.0261 (16) | 0.0035 (14) | −0.0003 (13) | 0.0045 (14) |
C202 | 0.0249 (18) | 0.0282 (19) | 0.0369 (19) | −0.0020 (15) | 0.0027 (15) | −0.0007 (16) |
C203 | 0.0250 (18) | 0.038 (2) | 0.048 (2) | −0.0064 (17) | 0.0021 (17) | 0.0046 (18) |
C204 | 0.0275 (19) | 0.044 (2) | 0.039 (2) | 0.0071 (18) | 0.0088 (16) | 0.0067 (19) |
C205 | 0.0293 (18) | 0.037 (2) | 0.0286 (17) | 0.0073 (17) | 0.0029 (15) | −0.0015 (16) |
C206 | 0.0236 (17) | 0.0283 (19) | 0.0307 (17) | 0.0005 (15) | −0.0006 (14) | 0.0018 (15) |
C1—C101 | 1.514 (4) | B8—H8 | 1.08 (4) |
C1—B5 | 1.713 (5) | B9—B12 | 1.777 (6) |
C1—B4 | 1.713 (5) | B9—B10 | 1.786 (6) |
C1—C2 | 1.724 (4) | B9—I1 | 2.178 (4) |
C1—B3 | 1.736 (5) | B10—B11 | 1.784 (6) |
C1—B6 | 1.744 (5) | B10—B12 | 1.797 (6) |
C2—C201 | 1.506 (5) | B10—H10 | 1.12 (4) |
C2—B7 | 1.714 (5) | B11—B12 | 1.769 (6) |
C2—B11 | 1.724 (5) | B11—H11 | 1.04 (4) |
C2—B3 | 1.732 (5) | B12—H12 | 1.21 (3) |
C2—B6 | 1.738 (5) | C101—C102 | 1.388 (5) |
B3—B8 | 1.773 (5) | C101—C106 | 1.390 (5) |
B3—B7 | 1.776 (6) | C102—C103 | 1.393 (5) |
B3—B4 | 1.783 (6) | C102—H102 | 0.9500 |
B3—H3 | 1.05 (4) | C103—C104 | 1.387 (6) |
B4—B9 | 1.779 (6) | C103—H103 | 0.9500 |
B4—B8 | 1.787 (6) | C104—C105 | 1.370 (6) |
B4—B5 | 1.793 (6) | C104—H104 | 0.9500 |
B4—H4 | 1.06 (3) | C105—C106 | 1.394 (5) |
B5—B10 | 1.768 (6) | C105—H105 | 0.9500 |
B5—B9 | 1.770 (6) | C106—H106 | 0.9500 |
B5—B6 | 1.781 (6) | C201—C202 | 1.391 (5) |
B5—H5 | 1.04 (4) | C201—C206 | 1.394 (5) |
B6—B10 | 1.770 (6) | C202—C203 | 1.393 (5) |
B6—B11 | 1.784 (6) | C202—H202 | 0.9500 |
B6—H6 | 1.02 (3) | C203—C204 | 1.383 (6) |
B7—B11 | 1.771 (6) | C203—H203 | 0.9500 |
B7—B12 | 1.787 (6) | C204—C205 | 1.383 (6) |
B7—B8 | 1.791 (6) | C204—H204 | 0.9500 |
B7—H7 | 1.07 (4) | C205—C206 | 1.390 (5) |
B8—B9 | 1.783 (6) | C205—H205 | 0.9500 |
B8—B12 | 1.799 (6) | C206—H206 | 0.9500 |
C101—C1—B5 | 120.3 (3) | B3—B8—B7 | 59.8 (2) |
C101—C1—B4 | 120.0 (3) | B9—B8—B7 | 107.0 (3) |
B5—C1—B4 | 63.1 (2) | B4—B8—B7 | 107.9 (3) |
C101—C1—C2 | 120.2 (3) | B3—B8—B12 | 107.3 (3) |
B5—C1—C2 | 109.7 (3) | B9—B8—B12 | 59.5 (2) |
B4—C1—C2 | 110.2 (3) | B4—B8—B12 | 107.7 (3) |
C101—C1—B3 | 118.8 (3) | B7—B8—B12 | 59.7 (2) |
B5—C1—B3 | 113.2 (3) | B3—B8—H8 | 121 (2) |
B4—C1—B3 | 62.2 (2) | B9—B8—H8 | 123 (2) |
C2—C1—B3 | 60.1 (2) | B4—B8—H8 | 120 (2) |
C101—C1—B6 | 118.3 (3) | B7—B8—H8 | 123 (2) |
B5—C1—B6 | 62.0 (2) | B12—B8—H8 | 124 (2) |
B4—C1—B6 | 113.6 (3) | B5—B9—B12 | 108.6 (3) |
C2—C1—B6 | 60.2 (2) | B5—B9—B4 | 60.7 (2) |
B3—C1—B6 | 111.4 (3) | B12—B9—B4 | 109.1 (3) |
C201—C2—B7 | 122.7 (3) | B5—B9—B8 | 108.9 (3) |
C201—C2—B11 | 121.7 (3) | B12—B9—B8 | 60.7 (2) |
B7—C2—B11 | 62.0 (2) | B4—B9—B8 | 60.2 (2) |
C201—C2—C1 | 118.5 (3) | B5—B9—B10 | 59.7 (2) |
B7—C2—C1 | 109.7 (3) | B12—B9—B10 | 60.6 (2) |
B11—C2—C1 | 109.5 (3) | B4—B9—B10 | 108.8 (3) |
C201—C2—B3 | 118.9 (3) | B8—B9—B10 | 109.2 (3) |
B7—C2—B3 | 62.0 (2) | B5—B9—I1 | 119.1 (2) |
B11—C2—B3 | 112.4 (3) | B12—B9—I1 | 123.7 (2) |
C1—C2—B3 | 60.3 (2) | B4—B9—I1 | 119.1 (2) |
C201—C2—B6 | 116.8 (3) | B8—B9—I1 | 122.1 (2) |
B7—C2—B6 | 112.9 (3) | B10—B9—I1 | 121.7 (3) |
B11—C2—B6 | 62.0 (2) | B5—B10—B6 | 60.4 (2) |
C1—C2—B6 | 60.5 (2) | B5—B10—B11 | 108.2 (3) |
B3—C2—B6 | 111.9 (3) | B6—B10—B11 | 60.3 (2) |
C2—B3—C1 | 59.6 (2) | B5—B10—B9 | 59.7 (2) |
C2—B3—B8 | 106.2 (3) | B6—B10—B9 | 107.6 (3) |
C1—B3—B8 | 105.6 (3) | B11—B10—B9 | 106.7 (3) |
C2—B3—B7 | 58.5 (2) | B5—B10—B12 | 107.7 (3) |
C1—B3—B7 | 106.4 (3) | B6—B10—B12 | 107.7 (3) |
B8—B3—B7 | 60.6 (2) | B11—B10—B12 | 59.2 (2) |
C2—B3—B4 | 106.7 (3) | B9—B10—B12 | 59.5 (2) |
C1—B3—B4 | 58.3 (2) | B5—B10—H10 | 119 (2) |
B8—B3—B4 | 60.4 (2) | B6—B10—H10 | 123 (2) |
B7—B3—B4 | 108.8 (3) | B11—B10—H10 | 125 (2) |
C2—B3—H3 | 120 (2) | B9—B10—H10 | 120 (2) |
C1—B3—H3 | 121 (2) | B12—B10—H10 | 123 (2) |
B8—B3—H3 | 126 (2) | C2—B11—B12 | 106.1 (3) |
B7—B3—H3 | 122 (2) | C2—B11—B7 | 58.7 (2) |
B4—B3—H3 | 123 (2) | B12—B11—B7 | 60.6 (2) |
C1—B4—B9 | 104.8 (3) | C2—B11—B10 | 105.9 (3) |
C1—B4—B3 | 59.5 (2) | B12—B11—B10 | 60.7 (2) |
B9—B4—B3 | 106.9 (3) | B7—B11—B10 | 108.9 (3) |
C1—B4—B8 | 106.0 (3) | C2—B11—B6 | 59.3 (2) |
B9—B4—B8 | 60.0 (2) | B12—B11—B6 | 108.2 (3) |
B3—B4—B8 | 59.6 (2) | B7—B11—B6 | 108.0 (3) |
C1—B4—B5 | 58.4 (2) | B10—B11—B6 | 59.5 (2) |
B9—B4—B5 | 59.4 (2) | C2—B11—H11 | 119 (2) |
B3—B4—B5 | 107.2 (3) | B12—B11—H11 | 124 (2) |
B8—B4—B5 | 107.7 (3) | B7—B11—H11 | 118 (2) |
C1—B4—H4 | 119 (2) | B10—B11—H11 | 127 (2) |
B9—B4—H4 | 126 (2) | B6—B11—H11 | 122 (2) |
B3—B4—H4 | 121 (2) | B11—B12—B9 | 107.7 (3) |
B8—B4—H4 | 126 (2) | B11—B12—B7 | 59.8 (2) |
B5—B4—H4 | 120 (2) | B9—B12—B7 | 107.4 (3) |
C1—B5—B10 | 106.6 (3) | B11—B12—B10 | 60.0 (2) |
C1—B5—B9 | 105.2 (3) | B9—B12—B10 | 60.0 (2) |
B10—B5—B9 | 60.6 (2) | B7—B12—B10 | 107.7 (3) |
C1—B5—B6 | 59.8 (2) | B11—B12—B8 | 107.9 (3) |
B10—B5—B6 | 59.8 (2) | B9—B12—B8 | 59.8 (2) |
B9—B5—B6 | 107.8 (3) | B7—B12—B8 | 59.9 (2) |
C1—B5—B4 | 58.4 (2) | B10—B12—B8 | 108.0 (3) |
B10—B5—B4 | 108.9 (3) | B11—B12—H12 | 117 (2) |
B9—B5—B4 | 59.9 (2) | B9—B12—H12 | 127 (2) |
B6—B5—B4 | 108.1 (3) | B7—B12—H12 | 119 (2) |
C1—B5—H5 | 115 (2) | B10—B12—H12 | 122 (2) |
B10—B5—H5 | 129 (2) | B8—B12—H12 | 125 (2) |
B9—B5—H5 | 128 (2) | C102—C101—C106 | 119.6 (3) |
B6—B5—H5 | 120 (2) | C102—C101—C1 | 119.7 (3) |
B4—B5—H5 | 117 (2) | C106—C101—C1 | 120.5 (3) |
C2—B6—C1 | 59.36 (19) | C101—C102—C103 | 120.3 (4) |
C2—B6—B10 | 105.9 (3) | C101—C102—H102 | 119.8 |
C1—B6—B10 | 105.2 (3) | C103—C102—H102 | 119.8 |
C2—B6—B5 | 106.0 (3) | C104—C103—C102 | 119.3 (4) |
C1—B6—B5 | 58.1 (2) | C104—C103—H103 | 120.4 |
B10—B6—B5 | 59.8 (2) | C102—C103—H103 | 120.4 |
C2—B6—B11 | 58.6 (2) | C105—C104—C103 | 120.9 (3) |
C1—B6—B11 | 105.9 (3) | C105—C104—H104 | 119.5 |
B10—B6—B11 | 60.2 (2) | C103—C104—H104 | 119.5 |
B5—B6—B11 | 107.7 (3) | C104—C105—C106 | 120.0 (4) |
C2—B6—H6 | 116 (2) | C104—C105—H105 | 120.0 |
C1—B6—H6 | 121 (2) | C106—C105—H105 | 120.0 |
B10—B6—H6 | 128 (2) | C101—C106—C105 | 119.9 (4) |
B5—B6—H6 | 128 (2) | C101—C106—H106 | 120.0 |
B11—B6—H6 | 120 (2) | C105—C106—H106 | 120.0 |
C2—B7—B11 | 59.3 (2) | C202—C201—C206 | 119.0 (3) |
C2—B7—B3 | 59.5 (2) | C202—C201—C2 | 119.1 (3) |
B11—B7—B3 | 108.1 (3) | C206—C201—C2 | 121.9 (3) |
C2—B7—B12 | 105.8 (3) | C201—C202—C203 | 120.2 (4) |
B11—B7—B12 | 59.6 (2) | C201—C202—H202 | 119.9 |
B3—B7—B12 | 107.8 (3) | C203—C202—H202 | 119.9 |
C2—B7—B8 | 106.2 (3) | C204—C203—C202 | 120.5 (4) |
B11—B7—B8 | 108.2 (3) | C204—C203—H203 | 119.8 |
B3—B7—B8 | 59.6 (2) | C202—C203—H203 | 119.8 |
B12—B7—B8 | 60.4 (2) | C203—C204—C205 | 119.5 (3) |
C2—B7—H7 | 118 (2) | C203—C204—H204 | 120.3 |
B11—B7—H7 | 123 (2) | C205—C204—H204 | 120.3 |
B3—B7—H7 | 117 (2) | C204—C205—C206 | 120.5 (3) |
B12—B7—H7 | 129 (2) | C204—C205—H205 | 119.7 |
B8—B7—H7 | 124 (2) | C206—C205—H205 | 119.7 |
B3—B8—B9 | 107.1 (3) | C205—C206—C201 | 120.3 (3) |
B3—B8—B4 | 60.1 (2) | C205—C206—H206 | 119.9 |
B9—B8—B4 | 59.7 (2) | C201—C206—H206 | 119.9 |
C1—C2—C201—C202 | −117.3 (3) | C2—C1—C101—C102 | 94.3 (4) |
C1—C2—C201—C206 | 62.1 (4) | C2—C1—C101—C106 | −90.2 (4) |
Experimental details
Crystal data | |
Chemical formula | C14H19B10I |
Mr | 422.29 |
Crystal system, space group | Monoclinic, P21/n |
Temperature (K) | 160 |
a, b, c (Å) | 9.0913 (9), 11.4168 (11), 18.0817 (17) |
β (°) | 93.460 (7) |
V (Å3) | 1873.3 (3) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 1.70 |
Crystal size (mm) | 0.40 × 0.15 × 0.12 |
Data collection | |
Diffractometer | Bruker P4 diffractometer |
Absorption correction | Empirical (using intensity measurements) (SHELXTL; Sheldrick, 1999) |
Tmin, Tmax | 0.746, 0.815 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 4407, 3304, 2628 |
Rint | 0.033 |
(sin θ/λ)max (Å−1) | 0.594 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.035, 0.085, 1.02 |
No. of reflections | 3304 |
No. of parameters | 253 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.77, −0.58 |
Computer programs: XSCANS (Bruker, 1996), XSCANS, SHELXTL (Sheldrick, 1999), SHELXTL.
C1—C101 | 1.514 (4) | C2—C201 | 1.506 (5) |
C1—C2 | 1.724 (4) | B9—I1 | 2.178 (4) |
B5—B9—I1 | 119.1 (2) | B8—B9—I1 | 122.1 (2) |
B12—B9—I1 | 123.7 (2) | B10—B9—I1 | 121.7 (3) |
B4—B9—I1 | 119.1 (2) | ||
C1—C2—C201—C202 | −117.3 (3) | C2—C1—C101—C102 | 94.3 (4) |
C1—C2—C201—C206 | 62.1 (4) | C2—C1—C101—C106 | −90.2 (4) |
We are currently investigating the mechanism of the isomerization of closo-12-vertex dicarbametallaboranes (3,1,2-closo-MC2B9), wherein we exploit steric crowding to facilitate isomerization at reduced temperatures. This process models the well known thermal rearrangement (450 °) of the parent ortho-carborane to meta-carborane (Grafstein & Dvorak, 1963).
Our recent isolation and structural characterization of an intermediate in this process (Dunn et al., 1997) combine with our present vertex-labelling studies (Dunn et al., 1998, 1999) to provide evidence whereby a reliable picture of the rearrangement pathway may ultimately be built up.
As part of these labelling experiments, we have prepared the title compound (I) and are embarking upon studies of its metal complexes. However, the structure of the parent carborane reported here serves as a useful reference, and provides confirmation both of the position and of the structural `innocence' of the iodine substituent. [In fact, (I) was briefly reported over 20 years ago (Vasil'eva & Khalfina, 1976), but detailed structural and spectroscopic characterization are only now presented herein.] \sch
A view of a molecule of (I) is shown in Figure 1, along with the atomic numbering scheme. The carborane skeleton clearly has the anticipated pseudo-icosahedral architecture, with the two adjacent Ccage atoms C1 and C2 bearing phenyl substituents, and the molecule overall having the approximate molecular Cs symmetry mirrored in the solution NMR data. The boron atom B9, antipodal to one of the Ccage atoms, has undergone electrophilic substitution and bears the iodine atom I1 [B9—I1 2.178 (4) Å]. Cluster B—B and C—B distances are unremarkable, whilst the Ccage—Ccage separation, 1.724 (4) Å, is comparable to that in the parent 1,2-Ph2-1,2-closo-C2B10H10 (Lewis & Welch, 1993) where the corresponding parameter is 1.733 (4) (molecule A) and 1.720 (4) Å (molecule B).
The major deviation from molecular mirror symmetry in the structure of (I) lies in twisting of the planes of the aryl substitutents away from orthogonality with the notional molecular mirror plane. This twisting may be described by the angle θ, the modulus of the average Ccage—Ccage—CPh(ipso)—CPh(ortho) torsion angles (Cowie et al., 1994). In (I), the phenyl ring bound to C1 has θ = 2.0 (6)° and that at C2 has θ = 27.6 (5)°. The former value compares well with θ values in the parent compound [2.3 and 2.4° (molecule A) and 9.2 and 8.0° (molecule B): Lewis & Welch (1993)]; whereas the latter is quite unusually large. In such compounds, the magnitude of θ appears to be a consequence of weak intermolecular Ph···Ph interactions and/or packing in the solid state. In (I) the phenyl ring bound at C1 has a closest interplanar approach of over 3.3 Å to a neighbouring parallel ring, related to it by an inversion centre; whilst the ring bound at C2 is approximately orthogonal to the phenyl ring at C1 in a neighbouring molecule, with H103 and H104 within 3.0 Å of the plane of the former ring. It has in any case been shown previously that at lower θ different conformations are very similar in energy (Brain et al., 1996), and that in 1,2-Ph2-1,2-closo-C2B10H10 θ values of up to ca 40° can be tolerated without any destabilizing intramolecular Ph···Ph interaction (Lewis & Welch, 1993).
Another molecular feature of interest is that the B9—I1 vector is not symmetrically disposed with respect to the five boron atoms to which B9 is bound, but `bends' slightly towards C1. Thus B4—B9—I1 and B5—B9—I1 are both 119.1 (2)° whilst the other three B—B9—I1 angles lie in the range 121.7 (3) to 123.7 (2)°. (A similar effect can be seen, albeit less reliably, in a bending of the B12—H12 vector towards C2.) This perhaps reveals an interesting structural-electronic effect of the mutual steric crowding between the two phenyl groups. In the unsubstituted parent compound 1,2-closo-C2B10H12, the Ccage—Ccage distance is typically 1.629 (5) Å (Davidson et al., 1996). Thus, as the C···C connectivity extends in compounds such as (I) or its non-halogenated parent, the directions of the exo-radial orbitals forming the Ccage—CPh bonds mutually diverge and this is mirrored in the bending of the antipodal B9—X or B12—X vectors.