Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807021149/bt2352sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536807021149/bt2352Isup2.hkl |
CCDC reference: 650586
A solution of Sb2Et4 (1.5 mmol, 0.54 g) and tBu3Ga (3 mmol, 0.72 g) in 30 ml of n-hexane was stirred for 5 d at ambient temperature and then stored for 12 h at -30°C. The resulting colorless solid ([tBu2GaSbEt2]2) was isolated by filtration, the filtrate concentrated to 5 ml and again stored for 12 h at -30°C. Colorless crystals of tBu3Ga—Sb(Et)2tBu were obtained (0.56 g, 78%. m.p. 65°C), which can be further purified by sublimation at 55°C at 10-3 mbar. Spectroscopic analysis: 1H NMR (500 MHz; C6D5H; 25°C) δ = 1.13 [9H, s, (CH3)3CSb], 1.19 - 1.28 [10H, m, CH3CH2Sb], 1.24 [27H, s, (CH3)3CGa] p.p.m.. 13C{1H} NMR (125 MHz; C6D5H; 25°C) δ = 7.4 [s, CH3CH2Sb), 12.0 [s, CH3CH2Sb], 29.3 [s, (CH3)3CGa], 30.4 [s, (CH3)3CSb], 31.6 [s, (CH3)3CGa] p.p.m..
Hydrogen atoms were located in Fourier difference maps and refined at idealizeded positions, riding on their parent C atoms, with isotropic displacement parameters Uiso(H) = 1.2Ueq(C) and 1.5Ueq(C-methyl).
Lewis acidic trialkylgallanes GaR3 generally react with Lewis basic group 15 organyles ER'3 (E = N, P, As, Sb, Bi) with formation of adducts of the type R3Ga—ER'3. The acid–base interaction within the adducts becomes weaker and the thermodynamic stability decreases with increasing atomic number of the central group 15 element owing to an increase in s character of the electron lone pair. The same is true for distibine adducts with trialkylgallanes of the general type [R3Ga]2[Sb2R'4]. In solution, these adducts are stable at low temperature (253 K), whereas at ambient temperature, Sb—Sb bond cleavage occurs with subsequent formation of heterocyclic stibinogallanes [R2GaSbR'2]x and the corresponding Lewis acid–base adduct R3Ga–SbRR'2, containing a mixed substituted trialkylstibine. The thermodynamic stability of Me3Ga–EMe3 adducts (E = N, P, As, Sb) decreases from NMe3 to SbMe3, while BiMe3 did not react (Coates, 1951). Since then, numerous adducts with strong Lewis basic amines and phosphines have been prepared and structurally characterized, whereas the first completely alkyl-substituted gallane–stibine adducts tBu3Ga—SbR3 [R = Me (Kuczkowski et al., 2005), Et, iPr (Schulz & Nieger, 2000)] became only recently available. In addition, a very few gallane–distibine adducts of the type [tBu3Ga]2[Sb2R'4] [R = Me, Et (Kuczkowski et al., 2001), nPr (Schuchmann et al., 2007)], with the distibine serving as bidentate ligand, were prepared at low temperatures and structurally characterized. These adducts tend to undergo Sb–Sb bond cleavage reactions in solution at ambient temperature, yielding four- and six-membered heterocycles of the general type [R2GaSbR'2]2 and [R2GaSbR'2]3 (Kuczkowski et al., 2001; Schuchmann et al., 2007), and the corresponding adduct R3Ga—E(R)R'2. The Ga and Sb atoms show distorted tetrahedral environments with the organic substituents adopting a staggered conformation related to one other as was previously observed for such adducts. The mean Ga–C [2.037 (3) Å] and Sb–C bond lengths [2.169 (4) Å] and C–Ga–C [116.4 (1)°] and C–Sb–C bond angles [99.1 (1)°] are within typical ranges. However, the larger steric demand of the tBu substituent bound to the Sb atom is clearly reflected by the significantly larger Ga–Sb–C13 bond angle [126.75 (8)°] compared to those of the Et substituents [Ga–Sb–C17 117.5 (2), Ga–Sb–C19 110.4 (2)°]. In addition, the sum of the C–Sb–C bond angles in the title compound [297.3 (1)°] is bigger than that in the corresponding adduct tBu3Ga-SbEt3 (292.8°). The influence of bulky organic substituents on the Ga—Sb distance becomes obvious when comparing the title compound, which shows a Ga—Sb bond length of 2.9243 (5) Å, with the Ga—Sb distances reported for tBu3Ga-SbMe3 [2.8435 (3) Å], tBu3Ga-SbEt3 [2.8479 (5) Å] and tBu3Ga—Sb(iPr)3 [2.9618 (2) Å]. Sb(iPr)3 is sterically more demanding than tBuSbEt2, leading to a larger sum of the C–Sb–C bond angles, whereas SbMe3 and SbEt3 are sterically less hindered.
For related literature, see Coates, 1951; Kuczkowski et al., 2001; Kuczkowski et al., 2005; Schulz & Nieger, 2000 and Schuchmann et al., 2007.
Data collection: SMART (Bruker, 2002); cell refinement: SAINT (Bruker, 2002); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Bruker, 2002); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.
Fig. 1. Molecular structure with hydrogen atoms omitted. Displacement ellipsoids are drawn at the 50% probability level. | |
Fig. 2. Crystal packing viewed along [100]. | |
Fig. 3. Reaction pathway. |
[GaSb(C2H5)2(C4H9)4] | F(000) = 992 |
Mr = 478.04 | Dx = 1.334 Mg m−3 |
Monoclinic, P21/n | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2yn | Cell parameters from 986 reflections |
a = 9.1138 (16) Å | θ = 2.5–26.7° |
b = 23.698 (4) Å | µ = 2.27 mm−1 |
c = 11.027 (2) Å | T = 120 K |
β = 91.479 (4)° | Block, colourless |
V = 2380.7 (7) Å3 | 0.22 × 0.20 × 0.16 mm |
Z = 4 |
Bruker SMART APEX diffractometer | 5684 independent reflections |
Radiation source: sealed tube | 4418 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.082 |
φ and ω scans | θmax = 27.9°, θmin = 1.7° |
Absorption correction: multi-scan (SADABS; Bruker, 2002) | h = −11→11 |
Tmin = 0.624, Tmax = 0.699 | k = −31→31 |
20988 measured reflections | l = −14→14 |
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)] = 0.037 | Hydrogen site location: difference Fourier map |
wR(F2) = 0.074 | H-atom parameters constrained |
S = 0.95 | w = 1/[σ2(Fo2) + (0.0303P)2] where P = (Fo2 + 2Fc2)/3 |
5684 reflections | (Δ/σ)max = 0.001 |
199 parameters | Δρmax = 0.95 e Å−3 |
0 restraints | Δρmin = −0.95 e Å−3 |
[GaSb(C2H5)2(C4H9)4] | V = 2380.7 (7) Å3 |
Mr = 478.04 | Z = 4 |
Monoclinic, P21/n | Mo Kα radiation |
a = 9.1138 (16) Å | µ = 2.27 mm−1 |
b = 23.698 (4) Å | T = 120 K |
c = 11.027 (2) Å | 0.22 × 0.20 × 0.16 mm |
β = 91.479 (4)° |
Bruker SMART APEX diffractometer | 5684 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 2002) | 4418 reflections with I > 2σ(I) |
Tmin = 0.624, Tmax = 0.699 | Rint = 0.082 |
20988 measured reflections |
R[F2 > 2σ(F2)] = 0.037 | 0 restraints |
wR(F2) = 0.074 | H-atom parameters constrained |
S = 0.95 | Δρmax = 0.95 e Å−3 |
5684 reflections | Δρmin = −0.95 e Å−3 |
199 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 | ||
Sb1 | 0.71254 (2) | 0.158353 (8) | 0.431944 (19) | 0.02535 (7) | |
Ga1 | 0.78052 (4) | 0.087011 (13) | 0.22442 (3) | 0.02383 (9) | |
C1 | 0.7108 (4) | 0.01031 (13) | 0.2837 (3) | 0.0325 (7) | |
C2 | 0.7744 (5) | −0.03402 (14) | 0.1981 (4) | 0.0502 (10) | |
H2A | 0.7433 | −0.0717 | 0.2233 | 0.075* | |
H2B | 0.8818 | −0.0318 | 0.2014 | 0.075* | |
H2C | 0.7385 | −0.0268 | 0.1150 | 0.075* | |
C3 | 0.7617 (4) | −0.00311 (15) | 0.4125 (3) | 0.0420 (9) | |
H3A | 0.7249 | −0.0403 | 0.4355 | 0.063* | |
H3B | 0.7240 | 0.0255 | 0.4677 | 0.063* | |
H3C | 0.8693 | −0.0032 | 0.4173 | 0.063* | |
C4 | 0.5432 (4) | 0.00410 (15) | 0.2780 (4) | 0.0433 (9) | |
H4A | 0.5160 | −0.0334 | 0.3073 | 0.065* | |
H4B | 0.5076 | 0.0088 | 0.1940 | 0.065* | |
H4C | 0.4990 | 0.0330 | 0.3291 | 0.065* | |
C5 | 0.6503 (4) | 0.12448 (13) | 0.0946 (3) | 0.0310 (7) | |
C6 | 0.6332 (5) | 0.08250 (15) | −0.0105 (3) | 0.0450 (9) | |
H6A | 0.5707 | 0.0990 | −0.0748 | 0.068* | |
H6B | 0.5881 | 0.0477 | 0.0187 | 0.068* | |
H6C | 0.7300 | 0.0739 | −0.0427 | 0.068* | |
C7 | 0.4968 (4) | 0.13883 (16) | 0.1399 (3) | 0.0414 (9) | |
H7A | 0.4388 | 0.1566 | 0.0742 | 0.062* | |
H7B | 0.5057 | 0.1649 | 0.2087 | 0.062* | |
H7C | 0.4479 | 0.1042 | 0.1656 | 0.062* | |
C8 | 0.7166 (4) | 0.17842 (14) | 0.0457 (3) | 0.0388 (8) | |
H8A | 0.6499 | 0.1948 | −0.0160 | 0.058* | |
H8B | 0.8110 | 0.1699 | 0.0093 | 0.058* | |
H8C | 0.7317 | 0.2054 | 0.1121 | 0.058* | |
C9 | 1.0008 (3) | 0.09786 (13) | 0.2096 (3) | 0.0294 (7) | |
C10 | 1.0882 (4) | 0.06349 (15) | 0.3047 (4) | 0.0447 (9) | |
H10A | 1.1934 | 0.0697 | 0.2944 | 0.067* | |
H10B | 1.0659 | 0.0233 | 0.2943 | 0.067* | |
H10C | 1.0611 | 0.0755 | 0.3861 | 0.067* | |
C11 | 1.0439 (4) | 0.07810 (17) | 0.0837 (4) | 0.0515 (11) | |
H11A | 1.1500 | 0.0828 | 0.0749 | 0.077* | |
H11B | 0.9916 | 0.1006 | 0.0219 | 0.077* | |
H11C | 1.0179 | 0.0382 | 0.0734 | 0.077* | |
C12 | 1.0490 (4) | 0.15945 (13) | 0.2228 (3) | 0.0342 (7) | |
H12A | 1.1557 | 0.1620 | 0.2152 | 0.051* | |
H12B | 1.0216 | 0.1736 | 0.3026 | 0.051* | |
H12C | 1.0007 | 0.1822 | 0.1592 | 0.051* | |
C13 | 0.8331 (4) | 0.16198 (13) | 0.6069 (3) | 0.0325 (7) | |
C14 | 0.9914 (4) | 0.17754 (19) | 0.5847 (4) | 0.0559 (11) | |
H14A | 1.0460 | 0.1793 | 0.6624 | 0.084* | |
H14B | 0.9951 | 0.2144 | 0.5448 | 0.084* | |
H14C | 1.0356 | 0.1490 | 0.5327 | 0.084* | |
C15 | 0.8294 (5) | 0.10403 (16) | 0.6651 (4) | 0.0538 (11) | |
H15A | 0.8829 | 0.1051 | 0.7434 | 0.081* | |
H15B | 0.8757 | 0.0765 | 0.6118 | 0.081* | |
H15C | 0.7273 | 0.0930 | 0.6778 | 0.081* | |
C16 | 0.7661 (5) | 0.20555 (18) | 0.6891 (4) | 0.0656 (13) | |
H16A | 0.8212 | 0.2066 | 0.7666 | 0.098* | |
H16B | 0.6637 | 0.1955 | 0.7035 | 0.098* | |
H16C | 0.7700 | 0.2427 | 0.6505 | 0.098* | |
C17 | 0.6764 (4) | 0.24674 (14) | 0.3980 (4) | 0.0439 (9) | |
H17A | 0.5912 | 0.2506 | 0.3411 | 0.053* | |
H17B | 0.6499 | 0.2650 | 0.4752 | 0.053* | |
C18 | 0.8048 (5) | 0.27849 (14) | 0.3462 (4) | 0.0504 (10) | |
H18A | 0.8904 | 0.2749 | 0.4013 | 0.076* | |
H18B | 0.7790 | 0.3184 | 0.3369 | 0.076* | |
H18C | 0.8281 | 0.2627 | 0.2669 | 0.076* | |
C19 | 0.4982 (4) | 0.13805 (17) | 0.4982 (4) | 0.0548 (11) | |
H19A | 0.4616 | 0.1046 | 0.4529 | 0.066* | |
H19B | 0.5105 | 0.1267 | 0.5843 | 0.066* | |
C20 | 0.3854 (5) | 0.1806 (3) | 0.4913 (6) | 0.103 (2) | |
H20A | 0.4240 | 0.2161 | 0.5244 | 0.154* | |
H20B | 0.3013 | 0.1684 | 0.5383 | 0.154* | |
H20C | 0.3543 | 0.1861 | 0.4064 | 0.154* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Sb1 | 0.02265 (11) | 0.02651 (10) | 0.02678 (12) | 0.00206 (8) | −0.00157 (8) | 0.00041 (9) |
Ga1 | 0.02381 (18) | 0.02428 (16) | 0.02328 (18) | −0.00316 (14) | −0.00149 (14) | −0.00031 (14) |
C1 | 0.0339 (19) | 0.0278 (15) | 0.0354 (19) | −0.0046 (14) | −0.0043 (15) | 0.0041 (14) |
C2 | 0.061 (3) | 0.0312 (18) | 0.058 (3) | −0.0046 (18) | −0.004 (2) | −0.0080 (17) |
C3 | 0.047 (2) | 0.0367 (18) | 0.042 (2) | −0.0112 (16) | −0.0090 (18) | 0.0092 (16) |
C4 | 0.045 (2) | 0.0392 (19) | 0.046 (2) | −0.0183 (17) | −0.0044 (18) | 0.0081 (17) |
C5 | 0.0309 (18) | 0.0373 (17) | 0.0244 (16) | −0.0037 (14) | −0.0061 (14) | 0.0018 (13) |
C6 | 0.055 (3) | 0.049 (2) | 0.0304 (19) | −0.0116 (18) | −0.0093 (18) | −0.0045 (16) |
C7 | 0.031 (2) | 0.054 (2) | 0.039 (2) | −0.0018 (17) | −0.0083 (16) | 0.0111 (17) |
C8 | 0.042 (2) | 0.0387 (17) | 0.035 (2) | −0.0038 (16) | −0.0075 (17) | 0.0076 (15) |
C9 | 0.0228 (16) | 0.0322 (16) | 0.0334 (18) | −0.0038 (13) | 0.0008 (13) | −0.0040 (14) |
C10 | 0.0277 (19) | 0.0413 (19) | 0.065 (3) | 0.0013 (15) | −0.0022 (18) | 0.0065 (18) |
C11 | 0.041 (2) | 0.061 (2) | 0.053 (3) | −0.0050 (19) | 0.015 (2) | −0.019 (2) |
C12 | 0.0272 (17) | 0.0366 (17) | 0.0390 (19) | −0.0053 (14) | 0.0008 (15) | 0.0046 (15) |
C13 | 0.0357 (19) | 0.0355 (17) | 0.0261 (17) | 0.0045 (15) | −0.0028 (14) | −0.0049 (14) |
C14 | 0.045 (3) | 0.084 (3) | 0.039 (2) | −0.014 (2) | −0.0093 (19) | −0.002 (2) |
C15 | 0.069 (3) | 0.048 (2) | 0.043 (2) | −0.005 (2) | −0.020 (2) | 0.0085 (18) |
C16 | 0.082 (3) | 0.073 (3) | 0.041 (2) | 0.035 (3) | −0.009 (2) | −0.019 (2) |
C17 | 0.052 (2) | 0.0342 (17) | 0.045 (2) | 0.0094 (17) | −0.0066 (18) | 0.0023 (16) |
C18 | 0.062 (3) | 0.0332 (18) | 0.055 (2) | −0.0087 (18) | −0.015 (2) | 0.0036 (17) |
C19 | 0.028 (2) | 0.061 (2) | 0.076 (3) | −0.0029 (18) | 0.012 (2) | 0.013 (2) |
C20 | 0.038 (3) | 0.119 (5) | 0.153 (6) | 0.023 (3) | 0.030 (3) | 0.025 (4) |
Sb1—C17 | 2.152 (3) | C10—H10A | 0.9800 |
Sb1—C19 | 2.158 (4) | C10—H10B | 0.9800 |
Sb1—C13 | 2.197 (3) | C10—H10C | 0.9800 |
Sb1—Ga1 | 2.9243 (5) | C11—H11A | 0.9800 |
Ga1—C9 | 2.034 (3) | C11—H11B | 0.9800 |
Ga1—C1 | 2.039 (3) | C11—H11C | 0.9800 |
Ga1—C5 | 2.039 (3) | C12—H12A | 0.9800 |
C1—C3 | 1.516 (5) | C12—H12B | 0.9800 |
C1—C4 | 1.534 (5) | C12—H12C | 0.9800 |
C1—C2 | 1.536 (5) | C13—C16 | 1.513 (5) |
C2—H2A | 0.9800 | C13—C14 | 1.515 (5) |
C2—H2B | 0.9800 | C13—C15 | 1.517 (5) |
C2—H2C | 0.9800 | C14—H14A | 0.9800 |
C3—H3A | 0.9800 | C14—H14B | 0.9800 |
C3—H3B | 0.9800 | C14—H14C | 0.9800 |
C3—H3C | 0.9800 | C15—H15A | 0.9800 |
C4—H4A | 0.9800 | C15—H15B | 0.9800 |
C4—H4B | 0.9800 | C15—H15C | 0.9800 |
C4—H4C | 0.9800 | C16—H16A | 0.9800 |
C5—C8 | 1.519 (4) | C16—H16B | 0.9800 |
C5—C6 | 1.532 (4) | C16—H16C | 0.9800 |
C5—C7 | 1.536 (5) | C17—C18 | 1.516 (5) |
C6—H6A | 0.9800 | C17—H17A | 0.9900 |
C6—H6B | 0.9800 | C17—H17B | 0.9900 |
C6—H6C | 0.9800 | C18—H18A | 0.9800 |
C7—H7A | 0.9800 | C18—H18B | 0.9800 |
C7—H7B | 0.9800 | C18—H18C | 0.9800 |
C7—H7C | 0.9800 | C19—C20 | 1.440 (6) |
C8—H8A | 0.9800 | C19—H19A | 0.9900 |
C8—H8B | 0.9800 | C19—H19B | 0.9900 |
C8—H8C | 0.9800 | C20—H20A | 0.9800 |
C9—C11 | 1.527 (5) | C20—H20B | 0.9800 |
C9—C12 | 1.530 (4) | C20—H20C | 0.9800 |
C9—C10 | 1.534 (5) | ||
C17—Sb1—C19 | 98.05 (15) | C9—C10—H10A | 109.5 |
C17—Sb1—C13 | 100.69 (14) | C9—C10—H10B | 109.5 |
C19—Sb1—C13 | 98.53 (15) | H10A—C10—H10B | 109.5 |
C17—Sb1—Ga1 | 117.47 (11) | C9—C10—H10C | 109.5 |
C19—Sb1—Ga1 | 110.36 (12) | H10A—C10—H10C | 109.5 |
C13—Sb1—Ga1 | 126.75 (8) | H10B—C10—H10C | 109.5 |
C9—Ga1—C1 | 117.05 (13) | C9—C11—H11A | 109.5 |
C9—Ga1—C5 | 116.50 (13) | C9—C11—H11B | 109.5 |
C1—Ga1—C5 | 115.65 (13) | H11A—C11—H11B | 109.5 |
C9—Ga1—Sb1 | 102.65 (9) | C9—C11—H11C | 109.5 |
C1—Ga1—Sb1 | 100.97 (10) | H11A—C11—H11C | 109.5 |
C5—Ga1—Sb1 | 99.58 (9) | H11B—C11—H11C | 109.5 |
C3—C1—C4 | 107.4 (3) | C9—C12—H12A | 109.5 |
C3—C1—C2 | 108.7 (3) | C9—C12—H12B | 109.5 |
C4—C1—C2 | 107.5 (3) | H12A—C12—H12B | 109.5 |
C3—C1—Ga1 | 113.4 (2) | C9—C12—H12C | 109.5 |
C4—C1—Ga1 | 113.0 (2) | H12A—C12—H12C | 109.5 |
C2—C1—Ga1 | 106.7 (2) | H12B—C12—H12C | 109.5 |
C1—C2—H2A | 109.5 | C16—C13—C14 | 109.3 (3) |
C1—C2—H2B | 109.5 | C16—C13—C15 | 110.5 (3) |
H2A—C2—H2B | 109.5 | C14—C13—C15 | 108.7 (3) |
C1—C2—H2C | 109.5 | C16—C13—Sb1 | 110.6 (2) |
H2A—C2—H2C | 109.5 | C14—C13—Sb1 | 109.0 (2) |
H2B—C2—H2C | 109.5 | C15—C13—Sb1 | 108.7 (2) |
C1—C3—H3A | 109.5 | C13—C14—H14A | 109.5 |
C1—C3—H3B | 109.5 | C13—C14—H14B | 109.5 |
H3A—C3—H3B | 109.5 | H14A—C14—H14B | 109.5 |
C1—C3—H3C | 109.5 | C13—C14—H14C | 109.5 |
H3A—C3—H3C | 109.5 | H14A—C14—H14C | 109.5 |
H3B—C3—H3C | 109.5 | H14B—C14—H14C | 109.5 |
C1—C4—H4A | 109.5 | C13—C15—H15A | 109.5 |
C1—C4—H4B | 109.5 | C13—C15—H15B | 109.5 |
H4A—C4—H4B | 109.5 | H15A—C15—H15B | 109.5 |
C1—C4—H4C | 109.5 | C13—C15—H15C | 109.5 |
H4A—C4—H4C | 109.5 | H15A—C15—H15C | 109.5 |
H4B—C4—H4C | 109.5 | H15B—C15—H15C | 109.5 |
C8—C5—C6 | 108.1 (3) | C13—C16—H16A | 109.5 |
C8—C5—C7 | 107.7 (3) | C13—C16—H16B | 109.5 |
C6—C5—C7 | 108.3 (3) | H16A—C16—H16B | 109.5 |
C8—C5—Ga1 | 112.7 (2) | C13—C16—H16C | 109.5 |
C6—C5—Ga1 | 107.1 (2) | H16A—C16—H16C | 109.5 |
C7—C5—Ga1 | 112.8 (2) | H16B—C16—H16C | 109.5 |
C5—C6—H6A | 109.5 | C18—C17—Sb1 | 115.6 (3) |
C5—C6—H6B | 109.5 | C18—C17—H17A | 108.4 |
H6A—C6—H6B | 109.5 | Sb1—C17—H17A | 108.4 |
C5—C6—H6C | 109.5 | C18—C17—H17B | 108.4 |
H6A—C6—H6C | 109.5 | Sb1—C17—H17B | 108.4 |
H6B—C6—H6C | 109.5 | H17A—C17—H17B | 107.4 |
C5—C7—H7A | 109.5 | C17—C18—H18A | 109.5 |
C5—C7—H7B | 109.5 | C17—C18—H18B | 109.5 |
H7A—C7—H7B | 109.5 | H18A—C18—H18B | 109.5 |
C5—C7—H7C | 109.5 | C17—C18—H18C | 109.5 |
H7A—C7—H7C | 109.5 | H18A—C18—H18C | 109.5 |
H7B—C7—H7C | 109.5 | H18B—C18—H18C | 109.5 |
C5—C8—H8A | 109.5 | C20—C19—Sb1 | 118.5 (3) |
C5—C8—H8B | 109.5 | C20—C19—H19A | 107.7 |
H8A—C8—H8B | 109.5 | Sb1—C19—H19A | 107.7 |
C5—C8—H8C | 109.5 | C20—C19—H19B | 107.7 |
H8A—C8—H8C | 109.5 | Sb1—C19—H19B | 107.7 |
H8B—C8—H8C | 109.5 | H19A—C19—H19B | 107.1 |
C11—C9—C12 | 107.4 (3) | C19—C20—H20A | 109.5 |
C11—C9—C10 | 108.5 (3) | C19—C20—H20B | 109.5 |
C12—C9—C10 | 107.4 (3) | H20A—C20—H20B | 109.5 |
C11—C9—Ga1 | 108.2 (2) | C19—C20—H20C | 109.5 |
C12—C9—Ga1 | 113.2 (2) | H20A—C20—H20C | 109.5 |
C10—C9—Ga1 | 112.0 (2) | H20B—C20—H20C | 109.5 |
C17—Sb1—Ga1—C9 | 83.96 (15) | Sb1—Ga1—C5—C7 | −43.5 (2) |
C19—Sb1—Ga1—C9 | −164.86 (15) | C1—Ga1—C9—C11 | 87.7 (3) |
C13—Sb1—Ga1—C9 | −46.52 (14) | C5—Ga1—C9—C11 | −55.2 (3) |
C17—Sb1—Ga1—C1 | −154.82 (15) | Sb1—Ga1—C9—C11 | −162.8 (2) |
C19—Sb1—Ga1—C1 | −43.65 (15) | C1—Ga1—C9—C12 | −153.4 (2) |
C13—Sb1—Ga1—C1 | 74.69 (15) | C5—Ga1—C9—C12 | 63.7 (3) |
C17—Sb1—Ga1—C5 | −36.15 (15) | Sb1—Ga1—C9—C12 | −43.9 (2) |
C19—Sb1—Ga1—C5 | 75.02 (15) | C1—Ga1—C9—C10 | −31.8 (3) |
C13—Sb1—Ga1—C5 | −166.63 (14) | C5—Ga1—C9—C10 | −174.7 (2) |
C9—Ga1—C1—C3 | 64.0 (3) | Sb1—Ga1—C9—C10 | 77.7 (2) |
C5—Ga1—C1—C3 | −152.7 (2) | C17—Sb1—C13—C16 | 41.6 (3) |
Sb1—Ga1—C1—C3 | −46.4 (3) | C19—Sb1—C13—C16 | −58.3 (3) |
C9—Ga1—C1—C4 | −173.5 (2) | Ga1—Sb1—C13—C16 | 178.2 (2) |
C5—Ga1—C1—C4 | −30.2 (3) | C17—Sb1—C13—C14 | −78.6 (3) |
Sb1—Ga1—C1—C4 | 76.1 (2) | C19—Sb1—C13—C14 | −178.6 (3) |
C9—Ga1—C1—C2 | −55.6 (3) | Ga1—Sb1—C13—C14 | 58.0 (3) |
C5—Ga1—C1—C2 | 87.6 (3) | C17—Sb1—C13—C15 | 163.1 (3) |
Sb1—Ga1—C1—C2 | −166.1 (2) | C19—Sb1—C13—C15 | 63.2 (3) |
C9—Ga1—C5—C8 | −30.7 (3) | Ga1—Sb1—C13—C15 | −60.3 (3) |
C1—Ga1—C5—C8 | −174.2 (2) | C19—Sb1—C17—C18 | −178.9 (3) |
Sb1—Ga1—C5—C8 | 78.7 (2) | C13—Sb1—C17—C18 | 80.7 (3) |
C9—Ga1—C5—C6 | 88.1 (2) | Ga1—Sb1—C17—C18 | −60.9 (3) |
C1—Ga1—C5—C6 | −55.3 (3) | C17—Sb1—C19—C20 | 7.2 (5) |
Sb1—Ga1—C5—C6 | −162.5 (2) | C13—Sb1—C19—C20 | 109.4 (5) |
C9—Ga1—C5—C7 | −152.9 (2) | Ga1—Sb1—C19—C20 | −116.1 (4) |
C1—Ga1—C5—C7 | 63.7 (3) |
Experimental details
Crystal data | |
Chemical formula | [GaSb(C2H5)2(C4H9)4] |
Mr | 478.04 |
Crystal system, space group | Monoclinic, P21/n |
Temperature (K) | 120 |
a, b, c (Å) | 9.1138 (16), 23.698 (4), 11.027 (2) |
β (°) | 91.479 (4) |
V (Å3) | 2380.7 (7) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 2.27 |
Crystal size (mm) | 0.22 × 0.20 × 0.16 |
Data collection | |
Diffractometer | Bruker SMART APEX |
Absorption correction | Multi-scan (SADABS; Bruker, 2002) |
Tmin, Tmax | 0.624, 0.699 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 20988, 5684, 4418 |
Rint | 0.082 |
(sin θ/λ)max (Å−1) | 0.658 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.037, 0.074, 0.95 |
No. of reflections | 5684 |
No. of parameters | 199 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.95, −0.95 |
Computer programs: SMART (Bruker, 2002), SAINT (Bruker, 2002), SAINT, SHELXTL (Bruker, 2002), SHELXTL.
Sb1—C17 | 2.152 (3) | Ga1—C9 | 2.034 (3) |
Sb1—C19 | 2.158 (4) | Ga1—C1 | 2.039 (3) |
Sb1—C13 | 2.197 (3) | Ga1—C5 | 2.039 (3) |
Sb1—Ga1 | 2.9243 (5) | ||
C17—Sb1—C19 | 98.05 (15) | C13—Sb1—Ga1 | 126.75 (8) |
C17—Sb1—C13 | 100.69 (14) | C9—Ga1—C1 | 117.05 (13) |
C19—Sb1—C13 | 98.53 (15) | C9—Ga1—C5 | 116.50 (13) |
C17—Sb1—Ga1 | 117.47 (11) | C1—Ga1—C5 | 115.65 (13) |
C19—Sb1—Ga1 | 110.36 (12) |
Lewis acidic trialkylgallanes GaR3 generally react with Lewis basic group 15 organyles ER'3 (E = N, P, As, Sb, Bi) with formation of adducts of the type R3Ga—ER'3. The acid–base interaction within the adducts becomes weaker and the thermodynamic stability decreases with increasing atomic number of the central group 15 element owing to an increase in s character of the electron lone pair. The same is true for distibine adducts with trialkylgallanes of the general type [R3Ga]2[Sb2R'4]. In solution, these adducts are stable at low temperature (253 K), whereas at ambient temperature, Sb—Sb bond cleavage occurs with subsequent formation of heterocyclic stibinogallanes [R2GaSbR'2]x and the corresponding Lewis acid–base adduct R3Ga–SbRR'2, containing a mixed substituted trialkylstibine. The thermodynamic stability of Me3Ga–EMe3 adducts (E = N, P, As, Sb) decreases from NMe3 to SbMe3, while BiMe3 did not react (Coates, 1951). Since then, numerous adducts with strong Lewis basic amines and phosphines have been prepared and structurally characterized, whereas the first completely alkyl-substituted gallane–stibine adducts tBu3Ga—SbR3 [R = Me (Kuczkowski et al., 2005), Et, iPr (Schulz & Nieger, 2000)] became only recently available. In addition, a very few gallane–distibine adducts of the type [tBu3Ga]2[Sb2R'4] [R = Me, Et (Kuczkowski et al., 2001), nPr (Schuchmann et al., 2007)], with the distibine serving as bidentate ligand, were prepared at low temperatures and structurally characterized. These adducts tend to undergo Sb–Sb bond cleavage reactions in solution at ambient temperature, yielding four- and six-membered heterocycles of the general type [R2GaSbR'2]2 and [R2GaSbR'2]3 (Kuczkowski et al., 2001; Schuchmann et al., 2007), and the corresponding adduct R3Ga—E(R)R'2. The Ga and Sb atoms show distorted tetrahedral environments with the organic substituents adopting a staggered conformation related to one other as was previously observed for such adducts. The mean Ga–C [2.037 (3) Å] and Sb–C bond lengths [2.169 (4) Å] and C–Ga–C [116.4 (1)°] and C–Sb–C bond angles [99.1 (1)°] are within typical ranges. However, the larger steric demand of the tBu substituent bound to the Sb atom is clearly reflected by the significantly larger Ga–Sb–C13 bond angle [126.75 (8)°] compared to those of the Et substituents [Ga–Sb–C17 117.5 (2), Ga–Sb–C19 110.4 (2)°]. In addition, the sum of the C–Sb–C bond angles in the title compound [297.3 (1)°] is bigger than that in the corresponding adduct tBu3Ga-SbEt3 (292.8°). The influence of bulky organic substituents on the Ga—Sb distance becomes obvious when comparing the title compound, which shows a Ga—Sb bond length of 2.9243 (5) Å, with the Ga—Sb distances reported for tBu3Ga-SbMe3 [2.8435 (3) Å], tBu3Ga-SbEt3 [2.8479 (5) Å] and tBu3Ga—Sb(iPr)3 [2.9618 (2) Å]. Sb(iPr)3 is sterically more demanding than tBuSbEt2, leading to a larger sum of the C–Sb–C bond angles, whereas SbMe3 and SbEt3 are sterically less hindered.