Do Halogen and Methyl Substituents Have Electronic Effects on the Structures of Simple

Do halogen and methyl substituents have electronic effects on the structures of simple disilanes? An experimental and theoretical study of the molecular structures of the series X3SiSiMe3 (X = H, F, Cl and Br)

Sandra J. Atkinson,aHeather E. Robertson,b Margit Hölbling,c Wolf-Walther du Mont,dCristina Mitrofan,dKarl Hasslerc and Sarah L. Mastersa*

a Department of Chemistry, University of Canterbury, Private Bag 4800, Christchurch, New Zealand, 8140. E-mail:

bSchool of Chemistry, University of Edinburgh, West Mains Road, Edinburgh, EH9 3JJ, UK

cInstitut für Anorganische Chemie, Technische Universität Graz, Stremayrgasse 16, A-8010 Graz, Austria. Email:

dInstitut für Anorganische und Analytische Chemie der Technische Universität Braunschweig, Hagenring 30, D-38106 Braunschweig, Germany. Email:

Supporting Information

Table S1 Geometric structures of X3SiSiMe3 (X = H, F, Cl, Br; 1 – 4) at the HF level using the 3-21G* and 6-31G* basis sets, and at the MP2 level using the 6-31G* and 6-311G* basis sets.a

Parameter / HF/3-21G* / HF/6-31G* / MP2/6-31G* / MP2/6-311G*
H3SiSiMe3
rSi-Si / 234.9 / 236.3 / 234.9 / 234.9
rSi-C / 189.2 / 189.8 / 189.2 / 188.5
rSi-H / 148.2 / 148.2 / 149.1 / 148.8
rC-Hav / 108.8 / 108.7 / 109.4 / 109.4
Si-Si-H / 111.3 / 111.3 / 111.3 / 111.1
Si-Si-C / 109.3 / 109.6 / 109.6 / 109.6
Si-C-Hav / 111.2 / 111.3 / 111.2 / 111.3
H(15)-Si-Si-C(11) / 180.0 / 180.0 / 180.0 / 180.0
Energy (Hartrees) / -694.9408 / -698.4430 / -699.0009 / -699.0983
F3SiSiMe3
rSi-Si / 230.4 / 233.9 / 232.4 / 233.3
rSi-C / 188.4 / 189.2 / 188.5 / 187.8
rSi-F / 158.1 / 158.4 / 161.0 / 160.6
rC-Hav / 108.8 / 108.7 / 109.4 / 109.4
Si-Si-F / 113.1 / 112.7 / 112.4 / 112.6
Si-Si-C / 108.2 / 108.4 / 108.4 / 108.3
Si-C-Hav / 111.2 / 111.3 / 111.1 / 111.2
F(15)-Si-Si-C(11) / 180.0 / 180.0 / 180.0 / 180.0
Energy (Hartrees) / -990.2005 / -995.2391 / -996.3123 / -996.5815
Cl3SiSiMe3
rSi-Si / 233.8 / 236.1 / 233.6 / 233.4
rSi-C / 188.3 / 188.9 / 188.4 / 187.6
rSi-Cl / 205.2 / 206.4 / 206.1 / 205.5
rC-Hav / 108.8 / 108.7 / 109.4 / 109.4
Si-Si-Cl / 111.6 / 111.8 / 111.4 / 111.5
Si-Si-C / 107.3 / 107.7 / 107.7 / 107.6
Si-C-Hav / 111.2 / 111.2 / 111.0 / 111.1
Cl(15)-Si-Si-C(11) / 180.0 / 180.0 / 180.0 / 180.0
Energy (Hartrees) / -2065.6038 / -2075.3198 / -2076.2620 / -2076.4543
Br3SiSiMe3
rSi-Si / 231.8 / 234.9 / 232.7 / 233.9
rSi-C / 188.3 / 188.9 / 188.3 / 187.6
rSi-Br / 219.8 / 222.0 / 222.5 / 223.3
rC-Hav / 108.8 / 108.6 / 109.4 / 109.4
Si-Si-Br / 110.4 / 111.2 / 110.9 / 110.8
Si-Si-C / 107.0 / 107.1 / 106.5 / 107.5
Si-C-Hav / 111.1 / 111.2 / 110.9 / 111.1
Br(15)-Si-Si-C(11) / 180.0 / 180.0 / 180.0 / 180.0
Energy (Hartrees) / -8374.2192 / -8406.5636 / -8407.4586 / -8415.0008
aAll distances in pm and all angles in degrees. See Figure 1 in the main text for atom numbering.

Table S2 Refined and calculated (HF/6-31G*) amplitudes of vibration (u), associated ra distances and corresponding correction values (k) for the rh1 refinement of 1,1,1-trimethyldisilane.a,b

Atom pair / ra / uGED / k / ucalc. / Restraint
u1 / C(3)-H(4) / 108.4(2) / 6.0(2) / 0.4 / 7.5 / 7.5(7)
u2 / C(3)-H(5) / 108.3(2) / 6.0(tied to u1) / 0.4 / 7.5
u3 / Si(1)-H(17) / 150.4(4) / 6.4(4) / 0.3 / 8.6 / 8.6(8)
u4 / H(4)...H(5) / 174.4(5) / 12.1(fixed) / -0.2 / 12.1
u5 / H(4)...H(6) / 174.4(5) / 12.0(fixed) / -0.2 / 12.0
u6 / Si(2)-C(3) / 188.1(1) / 4.8(1) / 0.1 / 5.1
u7 / Si(1)-Si(2) / 233.4(2) / 5.8(2) / 0.1 / 5.3
u8 / H(17)...H(16) / 241.5(10) / 14.4(fixed) / -0.3 / 14.4
u9 / Si(2)...H(5) / 247.5(4) / 10.6(5) / -0.3 / 11.7
u10 / Si(2)...H(4) / 247.5(4) / 10.5(tied to u9) / -0.3 / 11.6
u11 / C(3)...C(7) / 306.5(3) / 10.3(4) / -0.2 / 9.6
u12 / H(5)...H(9) / 305.3(12) / 30.9(fixed) / -3.1 / 30.9
u13 / H(4)...H(10) / 305.4(9) / 31.6(fixed) / -3.0 / 31.6
u14 / H(17)...Si(2) / 319.5(9) / 14.3(fixed) / -0.3 / 14.3
u15 / C(3)...H(9) / 326.6(7) / 21.2(18) / 0.3 / 21.2 / 21.2(20)
u16 / C(3)...H(10) / 326.6(4) / 21.7(tied to u15) / 0.2 / 21.7
u17 / Si(1)...C(3) / 344.5(4) / 12.3(2) / -0.4 / 11.3
u18 / H(4)...H(9) / 353.5(7) / 33.7(fixed) / -0.9 / 33.7
u19 / H(17)...H(8) / 345.8(14) / 40.3(fixed) / -5.8 / 40.3
u20 / Si(1)...H(4) / 358.2(7) / 23.4(fixed) / 0.3 / 23.4
u21 / H(17)...C(7) / 385.2(12) / 29.8(fixed) / 0.9 / 29.8
u22 / C(3)...H(8) / 398.7(3) / 11.5(fixed) / -2.6 / 11.5
u23 / H(17)...H(10) / 405.8(11) / 43.9(fixed) / -1.1 / 43.9
u24 / H(4)...H(13) / 423.3(8) / 21.6(fixed) / -2.7 / 21.6
u25 / H(4)...H(8) / 423.3(6) / 21.9(fixed) / -2.8 / 21.9
u26 / Si(1)...H(5) / 439.4(4) / 12.4(fixed) / -3.0 / 12.4
u27 / H(17)...C(3) / 468.3(7) / 13.3(fixed) / -4.5 / 13.3
u28 / H(17)...H(9) / 483.3(12) / 29.1(fixed) / -2.6 / 29.1
u29 / H(4)...H(14) / 482.1(6) / 14.3(fixed) / -4.5 / 14.3
u30 / H(17)...H(4) / 488.7(8) / 24.3(fixed) / -5.1 / 24.3
u31 / H(17)...H(5) / 552.8(8) / 16.2(fixed) / -6.4 / 16.2
a Distances are in pm. Estimated standard deviations, obtained in the least-squares refinement, are given in parentheses.
bUnrefined amplitudes of vibration were fixed at the values obtained using the HF/6-31G* force field.

Table S3 Refined and calculated (HF/6-31G*)amplitudes of vibration (u), associated ra distances and corresponding correction values (k) for the rh1 refinement of 1,1,1-trifluoro-2,2,2-trimethyldisilane.a,b

Atom pair / ra / uGED / k / ucalc. / Restraint
u1 / C(3)-H(4) / 110.6(2) / 5.3(2) / 0.4 / 7.5
u2 / C(3)-H(5) / 110.6(2) / 5.3(tied to u1) / 0.4 / 7.5
u3 / Si(1)-F(15) / 158.1(1) / 3.4(1) / 0.1 / 3.9 / 3.9(3)
u4 / H(4)...H(5) / 176.8(6) / 12.1(fixed) / -0.1 / 12.1
u5 / H(4)...H(6) / 176.8(6) / 12.0(fixed) / -0.1 / 12.0
u6 / Si(2)-C(3) / 187.9(1) / 4.6(1) / 0.1 / 5.1
u7 / Si(1)-Si(2) / 233.4(2) / 6.5(2) / 0.1 / 5.2
u8 / Si(2)...H(5) / 250.0(6) / 11.7(fixed) / -0.3 / 11.7
u9 / Si(2)...H(4) / 250.0(6) / 11.6(fixed) / -0.3 / 11.6
u10 / F(15)...F(16) / 253.5(2) / 7.4(2) / -0.2 / 7.1
u11 / C(3)...C(7) / 307.4(5) / 11.6(7) / -0.2 / 10.0 / 10.0(9)
u12 / H(4)...H(10) / 308.0(14) / 32.9(fixed) / -3.6 / 32.9
u13 / H(5)...H(9) / 311.2(20) / 32.3(fixed) / -3.2 / 32.3
u14 / Si(2)...F(15) / 326.7(2) / 10.5(4) / -0.3 / 10.4
u15 / C(3)...H(10) / 329.4(8) / 22.5(fixed) / 0.4 / 22.5
u16 / C(3)...H(9) / 330.6(11) / 22.1(fixed) / 0.3 / 22.1
u17 / Si(1)...C(3) / 343.1(5) / 10.7(5) / -0.4 / 11.7
u18 / Si(1)...H(4) / 358.4(8) / 24.6(fixed) / 0.4 / 24.6
u19 / H(4)...F(15) / 346.7(11) / 41.9(fixed) / -6.6 / 41.9
u20 / H(4)...H(9) / 358.5(12) / 35.5(fixed) / -0.9 / 35.5
u21 / C(3)...F(15) / 388.0(6) / 33.8(14) / 1.0 / 29.2
u22 / C(3)...H(8) / 401.8(5) / 11.7(fixed) / -2.8 / 11.7
u23 / H(4)...F(16) / 410.8(8) / 43.7(fixed) / -1.1 / 43.7
u24 / H(4)...H(8) / 428.1(9) / 22.5(fixed) / -3.0 / 22.5
u25 / H(4)...H(13) / 429.6(13) / 22.3(fixed) / -3.0 / 22.3
u26 / Si(1)...H(5) / 440.5(5) / 12.7(fixed) / -3.3 / 12.7
u27 / C(3)...F(17) / 474.5(4) / 14.0(5) / -4.9 / 10.3 / 10.3(10)
u28 / H(4)...H(14) / 487.5(9) / 14.3(fixed) / -4.9 / 14.3
u29 / H(5)...F(15) / 488.9(6) / 29.0(fixed) / -2.7 / 29.0
u30 / H(4)...F(17) / 496.9(8) / 24.2(fixed) / -5.3 / 24.2
u31 / H(5)...F(17) / 561.6(5) / 13.7(fixed) / -7.3 / 13.7
a Distances are in pm. Estimated standard deviations, obtained in the least-squares refinement, are given in parentheses.
bUnrefined amplitudes of vibration were fixed at the values obtained using the HF/6-31G* force field.

Table S4 Refined and calculated (HF/6-31G*)amplitudes of vibration (u), associated ra distances and corresponding correction values (k) for the rh1 refinement of 1,1,1-trichloro-2,2,2-trimethyldisilane.a,b

Atom pair / ra / uGED / k / ucalc. / Restraint
u1 / C(3)-H(4) / 107.4(3) / 8.2(3) / 0.4 / 7.5
u2 / C(3)-H(5) / 107.4(3) / 8.2(tied to u1) / 0.4 / 7.5
u3 / H(4)...H(5) / 173.2(6) / 12.1(fixed) / -0.1 / 12.1
u4 / H(4)...H(6) / 173.2(6) / 12.0(fixed) / -0.2 / 12.0
u5 / Si(2)-C(3) / 187.1(2) / 6.1(2) / 0.1 / 5.1
u6 / Si(1)-Cl(15) / 204.7(1) / 5.3(1) / 0.1 / 4.7
u7 / Si(1)-Si(2) / 233.3(2) / 7.0(2) / 0.1 / 5.5
u8 / Si(2)...H(5) / 246.3(4) / 11.8(fixed) / -0.3 / 11.8
u9 / Si(2)...H(4) / 246.2(4) / 11.7(fixed) / -0.3 / 11.7
u10 / C(3)...C(7) / 309.5(5) / 10.1(fixed) / -0.2 / 10.1
u11 / H(4)...H(10) / 304.8(9) / 33.4(fixed) / -3.9 / 33.4
u12 / H(5)...H(9) / 316.2(13) / 33.1(fixed) / -3.4 / 33.1
u13 / Cl(15)...Cl(16) / 328.9(2) / 9.5(1) / -0.2 / 8.8
u14 / C(3)...H(10) / 328.1(5) / 22.9(fixed) / 0.5 / 22.9
u15 / C(3)...H(9) / 333.1(8) / 22.6(fixed) / 0.4 / 22.6
u16 / Si(1)...C(3) / 338.5(4) / 10.6(6) / -0.3 / 11.5 / 11.5(11)
u17 / Si(1)...H(4) / 350.8(6) / 24.8(fixed) / 0.5 / 24.8
u18 / H(4)...H(9) / 357.7(8) / 36.4(fixed) / -0.9 / 36.4
u19 / Si(2)...Cl(15) / 362.5(2) / 11.8(2) / -0.3 / 11.6
u20 / H(4)...Cl(15) / 351.1(8) / 41.7(fixed) / -6.8 / 41.7
u21 / C(3)...H(8) / 399.7(5) / 11.8(fixed) / -2.9 / 11.8
u22 / C(3)...Cl(15) / 405.9(5) / 35.5(10) / 0.6 / 29.7 / 29.7(30)
u23 / H(4)...H(8) / 422.6(7) / 22.9(fixed) / -3.1 / 22.9
u24 / H(4)...H(13) / 428.6(9) / 22.6(fixed) / -3.1 / 22.6
u25 / H(4)...Cl(16) / 428.0(6) / 46.6(fixed) / -1.6 / 46.6
u26 / Si(1)...H(5) / 433.5(4) / 12.7(fixed) / -3.4 / 12.7
u27 / H(4)...H(14) / 480.9(7) / 14.5(fixed) / -5.1 / 14.5
u28 / H(5)...Cl(15) / 502.5(6) / 30.3(fixed) / -3.5 / 30.3
u29 / C(3)...Cl(17) / 514.2(3) / 13.1(4) / -4.0 / 10.6
u30 / H(4)...Cl(17) / 534.7(6) / 23.3(fixed) / -4.4 / 23.3
u31 / H(5)...Cl(17) / 596.9(4) / 14.5(fixed) / -6.3 / 14.5

aDistances are in pm. Estimated standard deviations, obtained in the least-squares refinement, are given in parentheses.

bUnrefined amplitudes of vibration were fixed at the values obtained using the HF/6-31G* force field.

Table S5 Refined and calculated (HF/6-31G*)amplitudes of vibration (u), associated ra distances and corresponding correction values (k) for the rh1 refinement of 1,1,1-tribromo-2,2,2-trimethyldisilane.a,b

Atom pair / ra / uGED / k / ucalc. / Restraint
u1 / C(3)-H(4) / 108.6(3) / 7.6(4) / 0.4 / 7.5
u2 / C(3)-H(5) / 108.6(3) / 7.6(tied to u1) / 0.4 / 7.5
u3 / H(4)...H(5) / 174.9(7) / 12.1(fixed) / -0.1 / 12.1
u4 / H(4)...H(6) / 174.8(7) / 12.0(fixed) / -0.2 / 12.0
u5 / Si(2)-C(3) / 189.2(1) / 4.7(2) / 0.1 / 5.2
u6 / Si(1)-Br(15) / 221.1(1) / 6.0(1) / 0.1 / 4.9
u7 / Si(1)-Si(2) / 234.8(2) / 5.9(4) / 0.1 / 5.5 / 5.5(5)
u8 / Si(2)...H(5) / 249.1(5) / 11.8(fixed) / -0.2 / 11.8
u9 / Si(2)...H(4) / 249.0(5) / 11.8(fixed) / -0.3 / 11.8
u10 / C(3)...C(7) / 309.7(5) / 10.5(fixed) / -0.2 / 10.5
u11 / H(4)...H(10) / 307.0(12) / 33.3(fixed) / -4.3 / 33.3
u12 / H(5)...H(9) / 311.1(16) / 34.2(fixed) / -3.1 / 34.2
u13 / C(3)...H(10) / 329.9(7) / 22.9(fixed) / 0.6 / 22.9
u14 / C(3)...H(9) / 331.1(9) / 23.3(fixed) / 0.3 / 23.3
u15 / Si(1)...C(3) / 344.9(4) / 12.4(fixed) / -0.3 / 12.4
u16 / Si(1)...H(4) / 358.5(8) / 26.4(fixed) / 0.5 / 26.4
u17 / Br(15)...Br(16) / 356.4(1) / 11.9(2) / -0.3 / 10.0
u18 / H(4)...H(9) / 357.2(10) / 37.1(fixed) / -0.9 / 37.1
u19 / H(4)...Br(15) / 363.4(9) / 46.8(fixed) / -6.0 / 46.8
u20 / Si(2)...Br(15) / 375.6(2) / 12.5(4) / -0.5 / 13.0
u21 / C(3)...H(8) / 401.6(5) / 12.0(fixed) / -3.1 / 12.0
u22 / C(3)...Br(15) / 420.1(5) / 36.5(13) / 0.3 / 31.6 / 31.6(30)
u23 / H(4)...H(8) / 426.3(9) / 22.9(fixed) / -3.1 / 22.9
u24 / H(4)...H(13) / 427.7(11) / 23.0(fixed) / -3.4 / 23.0
u25 / Si(1)...H(5) / 440.1(5) / 13.1(fixed) / -3.6 / 13.1
u26 / H(4)...Br(16) / 445.3(6) / 43.9(fixed) / -1.6 / 43.9
u27 / H(4)...H(14) / 485.1(9) / 14.7(fixed) / -5.2 / 14.7
u28 / H(5)...Br(15) / 516.5(6) / 34.7(fixed) / -3.8 / 34.7
u29 / C(3)...Br(17) / 533.9(3) / 12.8(5) / -4.0 / 11.2
u30 / H(4)...Br(17) / 557.0(7) / 25.3(fixed) / -4.0 / 25.3
u31 / H(5)...Br(17) / 614.2(5) / 15.5(fixed) / -7.2 / 15.5

aDistances are in pm. Estimated standard deviations, obtained in the least-squares refinement, are given in parentheses.

bUnrefined amplitudes of vibration were fixed at the values obtained using the HF/6-31G* force field.

Table S6Experimental gas electron diffraction coordinates from the refinement of 1,1,1-trimethyldisilane.

Atom / x / y / z
Si(1) / 0.0 / 0.0 / 0.0
Si(2) / 233.5 / 0.0 / 0.0
C(3) / 296.3 / -88.7 / -153.6
H(4) / 261.5 / -39.3 / -243.5
H(5) / 404.6 / -89.9 / -155.7
H(6) / 261.5 / -191.2 / -155.8
C(7) / 296.3 / 177.3 / 0.0
H(8) / 261.5 / 230.5 / 87.7
H(9) / 404.6 / 179.8 / 0.0
H(10) / 261.5 / 230.5 / -87.7
C(11) / 296.3 / -88.7 / 153.6
H(12) / 261.5 / -191.2 / 155.8
H(13) / 404.6 / -89.9 / 155.7
H(14) / 261.5 / -39.3 / 243.5
H(15) / -54.7 / 70.1 / -121.3
H(16) / -54.7 / -140.1 / 0.0
H(17) / -54.7 / 70.1 / 121.3

aCoordinates are given in pm.

Table S7 Experimentalgas electron diffraction coordinates from the refinement of 1,1,1-trifluoro-2,2,2-trimethyldisilane.

Atom / x / y / z
Si(1) / 0.0 / 0.0 / 0.0
Si(2) / 233.5 / 0.0 / 0.0
C(3) / 294.3 / 177.9 / 0.0
H(4) / 259.0 / 233.2 / 88.9
H(5) / 404.6 / 183.4 / 0.0
H(6) / 259.0 / 233.2 / -88.9
C(7) / 294.3 / -88.9 / 154.0
H(8) / 259.0 / -193.6 / 157.5
H(9) / 404.6 / -91.7 / 158.9
H(10) / 259.0 / -39.6 / 246.4
C(11) / 294.3 / -88.9 / -154.0
H(12) / 259.0 / -39.6 / -246.4
H(13) / 404.6 / -91.7 / -158.9
H(14) / 259.0 / -193.6 / -157.5
F(15) / -59.3 / 73.3 / 126.9
F(16) / -59.3 / 73.3 / -126.9
F(17) / -59.3 / -146.6 / 0.0

aCoordinates are given in pm.

Table S8 Experimental gas electron diffraction coordinates from the refinement of 1,1,1-trichloro-2,2,2-trimethyldisilane.

Atom / x / y / z
Si(1) / 0.0 / 0.0 / 0.0
Si(2) / 233.4 / 0.0 / 0.0
C(3) / 288.1 / 179.0 / 0.0
H(4) / 251.3 / 230.6 / 87.1
H(5) / 395.5 / 186.5 / 0.0
H(6) / 251.3 / 230.6 / -87.1
C(7) / 288.1 / -89.5 / 155.0
H(8) / 251.3 / -190.7 / 156.1
H(9) / 395.5 / -93.2 / 161.5
H(10) / 251.3 / -39.9 / 243.2
C(11) / 288.1 / -89.5 / -155.0
H(12) / 251.3 / -39.9 / -243.2
H(13) / 395.5 / -93.2 / -161.5
H(14) / 251.3 / -190.7 / -156.1
Cl(15) / -76.1 / 95.1 / 164.7
Cl(16) / -76.1 / 95.1 / -164.7
Cl(17) / -76.1 / -190.1 / -0.0

aCoordinates are given in pm.

Table S9 Experimentalgas electron diffraction coordinates from the refinement of 1,1,1-tribromo-2,2,2-trimethyldisilane.

Atom / x / y / z
Si(1) / 0.0 / 0.0 / 0.0
Si(2) / 234.8 / 0.0 / 0.0
C(3) / 295.7 / 179.1 / 0.0
H(4) / 260.2 / 232.5 / 87.9
H(5) / 404.4 / 183.6 / 0.0
H(6) / 260.2 / 232.5 / -87.9
C(7) / 295.7 / -89.6 / 155.1
H(8) / 260.2 / -192.4 / 157.4
H(9) / 404.4 / -91.8 / 159.0
H(10) / 260.2 / -40.1 / 245.3
C(11) / 295.7 / -89.6 / -155.1
H(12) / 260.2 / -40.1 / -245.3
H(13) / 404.4 / -91.8 / -159.0
H(14) / 260.2 / -192.4 / -157.4
Br(15) / -80.1 / 103.1 / 178.5
Br(16) / -80.1 / 103.1 / -178.5
Br(17) / -80.1 / -206.2 / 0.0

aCoordinates are given in pm.

Table S10 Calculated coordinates at the MP2/6-311+G* level for 1,1,1-trimethyldisilane.

Atom / x / y / z
Si(1) / 0.0 / 0.0 / 194.9
Si(2) / 0.0 / 0.0 / -40.0
C(3) / 0.0 / 177.5 / -103.2
H(4) / 88.3 / 232.6 / -69.5
H(5) / 0.0 / 179.4 / -212.7
H(6) / -88.3 / 232.6 / -69.5
C(7) / 153.7 / -88.8 / -103.2
H(8) / 157.3 / -192.7 / -69.5
H(9) / 155.4 / -89.7 / -212.7
H(10) / 245.6 / -39.9 / -69.5
C(11) / -153.7 / -88.8 / -103.2
H(12) / -245.6 / -39.9 / -69.5
H(13) / -155.4 / -89.7 / -212.7
H(14) / -157.3 / -192.7 / -69.5
H(15) / 120.3 / 69.5 / 248.2
H(16) / -120.3 / 69.5 / 248.2
H(17) / 0.0 / -138.9 / 248.2

aCoordinates are given in pm.

Table S11 Calculated coordinates at the MP2/6-311+G* level for 1,1,1-trifluoro-2,2,2-trimethyldisilane.

Atom / x / y / z
Si(1) / 0.0 / 0.0 / -116.7
Si(2) / 0.0 / 0.0 / 117.4
C(3) / 0.0 / 178.8 / 174.7
H(4) / -88.3 / 232.8 / 139.5
H(5) / 0.0 / 183.6 / 284.1
H(6) / 88.3 / 232.8 / 139.5
C(7) / -154.9 / -89.4 / 174.7
H(8) / -157.5 / -192.9 / 139.5
H(9) / -159.0 / -91.8 / 284.1
H(10) / -245.8 / -39.9 / 139.5
C(11) / 154.9 / -89.4 / 174.7
H(12) / 245.8 / -39.9 / 139.5
H(13) / 159.0 / -91.8 / 284.1
H(14) / 157.5 / -192.9 / 139.5
F(15) / -128.5 / 74.2 / -179.4
F(16) / 128.5 / 74.2 / -179.4
F(17) / 0.0 / -148.4 / -179.4

aCoordinates are given in pm.

Table S12 Calculated coordinates at the MP2/6-311+G* level for 1,1,1-trichloro-2,2,2-trimethyldisilane.

Atom / x / y / z
Si(1) / 0.0 / 0.0 / -69.7
Si(2) / 0.0 / 0.0 / 163.6
C(3) / 154.9 / 89.5 / 220.2
H(4) / 157.3 / 192.9 / 184.8
H(5) / 159.3 / 92.0 / 329.6
H(6) / 245.7 / 39.8 / 184.8
C(7) / -154.9 / 89.5 / 220.2
H(8) / -245.7 / 39.8 / 184.8
H(9) / -159.3 / 92.0 / 329.6
H(10) / -157.3 / 192.9 / 184.8
C(11) / 0.0 / -178.9 / 220.2
H(12) / 88.4 / -232.7 / 184.8
H(13) / 0.0 / -183.9 / 329.6
H(14) / -88.4 / -232.7 / 184.8
Cl(15) / 0.0 / 191.3 / -144.6
Cl(16) / 165.7 / -95.6 / -144.6
Cl(17) / -165.7 / -95.6 / -144.6

aCoordinates are given in pm.

Table S13 Calculated coordinates at the MP2/6-311+G* level for 1,1,1-tribromo-2,2,2-trimethyldisilane.

Atom / x / y / z
Si(1) / 0.0 / 0.0 / -18.0
Si(2) / 0.0 / 0.0 / 216.0
C(3) / 155.0 / 89.5 / 272.1
H(4) / 157.3 / 192.9 / 236.7
H(5) / 159.3 / 92.0 / 381.5
H(6) / 245.7 / 39.8 / 236.7
C(7) / -155.0 / 89.5 / 272.1
H(8) / -245.7 / 39.8 / 236.7
H(9) / -159.3 / 92.0 / 381.5
H(10) / -157.3 / 192.9 / 236.7
C(11) / 0.0 / -178.9 / 272.1
H(12) / 88.4 / -232.7 / 236.7
H(13) / 0.0 / -184.0 / 381.5
H(14) / -88.4 / -232.7 / 236.7
Br(15) / 0.0 / 208.7 / -97.5
Br(16) / 180.8 / -104.4 / -97.5
Br(17) / -180.8 / -104.4 / -97.5

aCoordinates are given in pm.

Table S14 Least-squares correlation matrix (x100) for 1,1,1-trimethyldisilane.a

u9 / u15 / k2
p1 / 74
p6 / -80
u6 / 76
u7 / 60 / 56
a Only elements with absolute values 50% are shown; k2 is a scale factor.

Table S15 Least-squares correlation matrix (x100) for 1,1,1-trifluoro-2,2,2-trimethyldisilane.a

p5 / p7 / u10 / u14 / u17 / k2
p1 / -58
p5 / 69
p6 / -86 / -69
u3 / 76
u7 / 52
u11 / 70 / 54
u14 / 81
a Only elements with absolute values 50% are shown; k2 is a scale factor.

Table S16 Least-squares correlation matrix (x100) for 1,1,1-trichloro-2,2,2-trimethyldisilane.a

p5 / p6 / u6 / u13 / u16 / u19 / k2
p1 / -54 / -55
p2 / -52 / -63
p5 / 55 / -69
u5 / 70
u6 / 55 / 89
u13 / 61
u16 / 67
a Only elements with absolute values 50% are shown; k2 is a scale factor.

Table S17 Least-squares correlation matrix (x100) for 1,1,1-tribromo-2,2,2-trimethyldisilane.a

p5 / u7 / u17 / u20 / k2
p3 / 51 / 60
p5 / -60 / -72
u6 / 69 / 73
u17 / 85 / 56
k1 / 53
a Only elements with absolute values 50% are shown; k1 and k2 are scale factors.

Figure S1 Experimental and final weighted difference (experimental minus theoretical) molecular scattering intensities for 1,1,1-trimethyldisilane.

Figure S2 Experimental and final weighted difference (experimental minus theoretical) molecular scattering intensities for 1,1,1-trifluoro-2,2,2-trimethyldisilane.

Figure S3 Experimental and final weighted difference (experimental minus theoretical) molecular scattering intensities for 1,1,1-trichloro-2,2,2-trimethyldisilane.

Figure S4 Experimental and final weighted difference (experimental minus theoretical) molecular scattering intensities for 1,1,1-tribromo-2,2,2-trimethyldisilane.