Molecular structure and conformation of triphenylsilane from gas-phase electron diffraction and theoretical calculations, and structural variations in H4nSiPhn molecules (n = 14)

Anna Rita Campanelli · Aldo Domenicano · Fabio Ramondo · István Hargittai

SUPPLEMENTARY MATERIAL

Table S1 Equilibrium molecular geometrya,b of phenylsilane from MO calculations
Parameterc / Basis set 6-31G* / Basis set 6-311++G**
HF / B3LYP / HF / B3LYP
r(SiC) / 1.8817 / 1.8798 / 1.8824 / 1.8826
r(SiHA) / 1.4783 / 1.4903 / 1.4803 / 1.4881
r(SiHB) / 1.4766 / 1.4884 / 1.4789 / 1.4862
r(C1C2) / 1.3957 / 1.4063 / 1.3952 / 1.4041
r(C2C3) / 1.3853 / 1.3956 / 1.3856 / 1.3938
r(C3C4) / 1.3855 / 1.3960 / 1.3853 / 1.3939
r(C2H2) / 1.0768 / 1.0881 / 1.0770 / 1.0858
r(C3H3) / 1.0756 / 1.0870 / 1.0757 / 1.0846
r(C4H4) / 1.0756 / 1.0870 / 1.0757 / 1.0844
C1SiHA / 111.78 / 112.02 / 111.35 / 111.39
C1SiHB / 109.78 / 109.96 / 109.65 / 109.76
HASiHB / 107.99 / 107.76 / 108.20 / 108.11
HBSiHC / 109.47 / 109.30 / 109.75 / 109.68
SiC1C2 / 121.08 / 121.03 / 121.08 / 121.02
C2C1C6 / 117.85 / 117.94 / 117.84 / 117.96
C1C2C3 / 121.22 / 121.13 / 121.23 / 121.11
C2C3C4 / 119.94 / 120.00 / 119.96 / 120.03
C3C4C5 / 119.83 / 119.78 / 119.79 / 119.74
C1C2H2 / 119.95 / 119.91 / 119.98 / 119.96
Table S1, continued
C3C2H2 / 118.83 / 118.96 / 118.79 / 118.93
C2C3H3 / 119.95 / 119.91 / 119.94 / 119.89
C4C3H3 / 120.11 / 120.09 / 120.10 / 120.07
C3C4H4 / 120.08 / 120.11 / 120.10 / 120.13
a The molecule has Cs symmetry in its equilibrium conformation, with the symmetry plane perpendicular to the plane of the benzene ring. b Bond distances are given in Å, angles in degrees. c The ring atoms are numbered as in Fig. 4 of Ref. [4]. Atom HA lies in the symmetry plane, while HB and HC are mirror images of each other.
Table S2 Equilibrium molecular geometry of diphenylsilane from MO calculationsa,b
Parameterc / Basis set 6-31G* / Basis set 6-311++G**
HF / B3LYP / HF / B3LYP
r(SiC) / 1.8841 / 1.8822 / 1.8843 / 1.8851
r(SiH) / 1.4788 / 1.4918 / 1.4811 / 1.4890
r(C1C2) / 1.3951 / 1.4063 / 1.3942 / 1.4037
r(C2C3) / 1.3867 / 1.3962 / 1.3875 / 1.3949
r(C3C4) / 1.3843 / 1.3955 / 1.3837 / 1.3931
r(C4C5) / 1.3868 / 1.3967 / 1.3872 / 1. 3949
r(C5C6) / 1.3842 / 1.3951 / 1.3838 / 1. 3930
r(C1C6) / 1.3973 / 1.4074 / 1.3971 / 1.4050
r(C2H2) / 1.0764 / 1.0879 / 1.0767 / 1.0856
r(C3H3) / 1.0756 / 1.0871 / 1.0757 / 1.0846
r(C4H4) / 1.0757 / 1.0870 / 1.0758 / 1.0845
r(C5H5) / 1.0756 / 1.0871 / 1.0757 / 1.0846
r(C6H6) / 1.0765 / 1.0880 / 1.0770 / 1.0858
C1ASiC1B / 111.99 / 112.15 / 112.19 / 112.20
C1ASiHC / 107.24 / 107.10 / 107.18 / 107.15
C1ASiHD / 111.33 / 111.58 / 110.98 / 111.05
HCSiHD / 107.65 / 107.27 / 108.31 / 108.21
SiC1C2 / 120.72 / 120.68 / 120.75 / 120.76
SiC1C6 / 121.50 / 121.46 / 121.46 / 121.31
Table S2, continued
C2C1C6 / 117.78 / 117.85 / 117.77 / 117.92
C1C2C3 / 121.28 / 121.21 / 121.28 / 121.16
C2C3C4 / 119.91 / 119.97 / 119.92 / 119.99
C3C4C5 / 119.84 / 119.79 / 119.80 / 119.76
C4C5C6 / 119.96 / 120.01 / 119.97 / 120.04
C1C6C5 / 121.24 / 121.17 / 121.25 / 121.13
C1C2H2 / 119.85 / 119.73 / 119.89 / 119.79
C3C2H2 / 118.87 / 119.07 / 118.83 / 119.06
C2C3H3 / 119.96 / 119.93 / 119.94 / 119.92
C4C3H3 / 120.13 / 120.10 / 120.14 / 120.09
C3C4H4 / 120.10 / 120.12 / 120.13 / 120.13
C5C4H4 / 120.06 / 120.10 / 120.07 / 120.10
C4C5H5 / 120.07 / 120.07 / 120.07 / 120.04
C6C5H5 / 119.97 / 119.93 / 119.96 / 119.93
C5C6H6 / 118.88 / 119.00 / 118.81 / 118.95
C1C6H6 / 119.88 / 119.82 / 119.94 / 119.92
d / 44.2 / 43.2 / 47.9 / 47.7
a The molecule has C2 symmetry in its equilibrium conformation. b Bond distances are given in Å, angles in degrees. c Atoms are labeled as in tetraphenylsilane, see Fig. 1 of Ref. [1], with atoms HC and HD replacing rings C and D, respectively. dDefined as the dihedral angle between the least-squares plane through the carbon atoms of the benzene ring and the plane defined by the SiC bond and the C2 axis.
Table S3 Equilibrium molecular geometry of triphenylsilane from MO calculationsa,b
Parameterc / Basis set 6-31G* / Basis set 6-311++G**
HF / B3LYP / HF / B3LYP
r(SiC) / 1.8883 / 1.8865 / 1.8882 / 1.8892
r(SiH) / 1.4791 / 1.4920 / 1.4820 / 1.4901
r(C1C2) / 1.3951 / 1.4065 / 1.3943 / 1.4036
r(C2C3) / 1.3871 / 1.3965 / 1.3875 / 1.3951
r(C3C4) / 1.3843 / 1.3956 / 1.3840 / 1.3933
r(C4C5) / 1.3868 / 1.3966 / 1.3868 / 1. 3948
r(C5C6) / 1.3840 / 1.3951 / 1.3843 / 1. 3932
r(C1C6) / 1.3979 / 1.4075 / 1.3973 / 1.4053
r(C2H2) / 1.0757 / 1.0877 / 1.0760 / 1.0852
r(C3H3) / 1.0757 / 1.0872 / 1.0758 / 1.0847
r(C4H4) / 1.0757 / 1.0871 / 1.0758 / 1.0845
r(C5H5) / 1.0757 / 1.0872 / 1.0758 / 1.0847
r(C6H6) / 1.0771 / 1.0884 / 1.0774 / 1.0861
C1ASiC1B / 110.98 / 110.79 / 110.90 / 110.67
C1ASiH / 107.91 / 108.12 / 108.00 / 108.24
SiC1C2 / 122.33 / 121.92 / 122.40 / 121.95
SiC1C6 / 119.97 / 120.28 / 119.90 / 120.18
C2C1C6 / 117.70 / 117.78 / 117.70 / 117.86
C1C2C3 / 121.23 / 121.20 / 121.24 / 121.14
Table S3, continued
C2C3C4 / 120.01 / 120.02 / 120.02 / 120.06
C3C4C5 / 119.81 / 119.76 / 119.77 / 119.73
C4C5C6 / 119.89 / 119.97 / 119.89 / 119.98
C1C6C5 / 121.37 / 121.26 / 121.38 / 121.22
C1C2H2 / 119.86 / 119.71 / 119.91 / 119.78
C3C2H2 / 118.91 / 119.09 / 118.85 / 119.08
C2C3H3 / 119.89 / 119.90 / 119.87 / 119.88
C4C3H3 / 120.10 / 120.08 / 120.11 / 120.06
C3C4H4 / 120.12 / 120.14 / 120.14 / 120.16
C5C4H4 / 120.07 / 120.10 / 120.09 / 120.11
C4C5H5 / 120.10 / 120.08 / 120.12 / 120.07
C6C5H5 / 120.01 / 119.95 / 119.99 / 119.95
C5C6H6 / 118.79 / 118.94 / 118.73 / 118.90
C1C6H6 / 119.84 / 119.80 / 119.89 / 119.88
d / 41.6 / 35.9 / 41.9 / 40.7
a The molecule has C3 symmetry in its equilibrium conformation. b Bond distances are given in Å, angles in degrees. c Atoms are labeled according to Fig. 1. dDefined as the dihedral angle between the least-squares plane through the carbon atoms of the benzene ring and the plane defined by the SiC bond and the C3 axis.
Table S4 Equilibrium molecular geometry of tetraphenylsilane from MO calculationsa,b
Parameterc / Basis set 6-31G* / Basis set 6-311++G**
HF / B3LYP / HF / B3LYP
r(SiC) / 1.8966 / 1.8941 / 1.8963 / 1.8961
r(C1C2) / 1.3960 / 1.4069 / 1.3949 / 1.4041
r(C2C3) / 1.3867 / 1.3962 / 1.3875 / 1.3949
r(C3C4) / 1.3843 / 1.3956 / 1.3836 / 1.3932
r(C4C5) / 1.3861 / 1.3961 / 1.3865 / 1. 3943
r(C5C6) / 1.3849 / 1.3960 / 1.3844 / 1. 3938
r(C1C6) / 1.3989 / 1.4088 / 1.3984 / 1.4062
r(C2H2) / 1.0749 / 1.0871 / 1.0751 / 1.0847
r(C3H3) / 1.0757 / 1.0872 / 1.0758 / 1.0847
r(C4H4) / 1.0757 / 1.0871 / 1.0758 / 1.0846
r(C5H5) / 1.0758 / 1.0872 / 1.0758 / 1.0848
r(C6H6) / 1.0762 / 1.0878 / 1.0767 / 1.0857
C1ASiC1B / 108.16 / 108.64 / 107.90 / 108.20
C1ASiC1C / 110.13 / 109.89 / 110.26 / 110.11
SiC1C2 / 121.90 / 121.53 / 122.16 / 121.90
SiC1C6 / 120.71 / 120.91 / 120.46 / 120.47
C2C1C6 / 117.38 / 117.54 / 117.38 / 117.62
C1C2C3 / 121.42 / 121.34 / 121.43 / 121.28
C2C3C4 / 120.07 / 120.08 / 120.07 / 120.10
Table S4, continued
C3C4C5 / 119.67 / 119.67 / 119.64 / 119.64
C4C5C6 / 119.96 / 120.01 / 119.96 / 120.03
C1C6C5 / 121.50 / 121.36 / 121.53 / 121.33
C1C2H2 / 119.89 / 119.65 / 119.99 / 119.79
C3C2H2 / 118.69 / 119.01 / 118.59 / 118.92
C2C3H3 / 119.84 / 119.85 / 119.81 / 119.83
C4C3H3 / 120.09 / 120.07 / 120.12 / 120.07
C3C4H4 / 120.18 / 120.18 / 120.21 / 120.20
C5C4H4 / 120.14 / 120.15 / 120.16 / 120.16
C4C5H5 / 120.13 / 120.10 / 120.13 / 120.07
C6C5H5 / 119.92 / 119.89 / 119.92 / 119.90
C5C6H6 / 118.66 / 118.85 / 118.57 / 118.81
C1C6H6 / 119.84 / 119.78 / 119.89 / 119.86
d / 40.4 / 38.9 / 42.5 / 41.8
a The molecule has S4 symmetry in its equilibrium conformation. b Bond distances are given in Å, angles in degrees. c Atoms are labeled according to Fig. 1 of Ref. [1]. dDefined as the dihedral angle between the least-squares plane through the carbon atoms of the benzene ring and the plane defined by the SiC bond and the S4 axis.
Table S5 Distances and mean amplitudes of vibration for conformation-dependent CC pairs in triphenylsilane, from electron diffraction
Atom paira / ra (Å)b / l (Å)
Experimentalc / Calculatedd
C1AC1B / 3.073 / 0.112(5)e / 0.110
C1AC2B / 3.341 / 0.225 / 0.223
C1AC3B / 4.710 / 0.218 / 0.216
C1AC4B / 5.628 / 0.166 / 0.164
C1AC5B / 5.481 / 0.141 / 0.139
C1AC6B / 4.360 / 0.141 / 0.139
C2AC1B / 3.977 / 0.308 / 0.306
C2AC2B / 3.968 / 0.489 / 0.487
C2AC3B / 5.293 / 0.533 / 0.531
C2AC4B / 6.370 / 0.465 / 0.463
C2AC5B / 6.384 / 0.354 / 0.352
C2AC6B / 5.335 / 0.269 / 0.267
C3AC1B / 5.181 / 0.288 / 0.286
C3AC2B / 4.955 / 0.488 / 0.486
C3AC3B / 6.178 / 0.564 / 0.562
C3AC4B / 7.372 / 0.489 / 0.487
C3AC5B / 7.535 / 0.358 / 0.356
C3AC6B / 6.567 / 0.260 / 0.258
Table S5, continued
C4AC1B / 5.628 / 0.210 / 0.208
C4AC2B / 5.376 / 0.404 / 0.402
C4AC3B / 6.531 / 0.460 / 0.458
C4AC4B / 7.710 / 0.381 / 0.379
C4AC5B / 7.897 / 0.309 / 0.307
C4AC6B / 6.970 / 0.256 / 0.254
C5AC1B / 5.038 / 0.294 / 0.292
C5AC2B / 4.936 / 0.535 / 0.533
C5AC3B / 6.074 / 0.594 / 0.592
C5AC4B / 7.119 / 0.512 / 0.510
C5AC5B / 7.198 / 0.462 / 0.460
C5AC6B / 6.266 / 0.400 / 0.398
C6AC1B / 3.789 / 0.331 / 0.329
C6AC2B / 3.944 / 0.552 / 0.550
C6AC3B / 5.171 / 0.582 / 0.580
C6AC4B / 6.075 / 0.508 / 0.506
C6AC5B / 5.983 / 0.465 / 0.463
C6AC6B / 4.960 / 0.415 / 0.413
a The multiplicity is 3 for all CC pairs. b All distances are dependent parameters. c The amplitudes have been refined in a single group, including also conformation-dependent CH pairs, with constant differences between them. d From spectroscopic calculations based on the B3LYP/6-31G* force field. e The least-squares standard deviation is in parentheses in units of the last digit.

Table S6 Total experimental electron diffraction intensities of triphenylsilane, IT(s)

Part 1: 50 cm camera distance (2.000 s 14.000 Å1, with s = 0.125 Å1; the Table develops horizontally)

.32768

/

.31669

/

.31860

/

.32965

/

.35080

/

.37492

.39159

/

.39893

/

.39925

/

.39476

/

.38545

/

.37547

.36426

/

.35344

/

.34395

/

.33747

/

.33711

/

.34315

.35788

/

.37887

/

.40542

/

.43581

/

.46448

/

.48907

.50490

/

.51123

/

.50956

/

.50503

/

.50076

/

.49762

.49345

/

.48765

/

.47765

/

.46580

/

.45349

/

.44185

.43020

/

.41934

/

.40768

/

.39569

/

.38358

/

.37228

.36296

/

.35552

/

.35069

/

.34858

/

.34684

/

.34634

.34553

/

.34372

/

.34137

/

.33909

/

.33741

/

.33835

.34116

/

.34671

/

.35301

/

.35919

/

.36434

/

.36724

.36741

/

.36497

/

.36142

/

.35599

/

.35099

/

.34668

.34499

/

.34503

/

.34698

/

.34885

/

.35139

/

.35323

.35315

/

.35093

/

.34688

/

.34085

/

.33401

/

.32695

.31880

/

.31267

/

.30723

/

.30272

/

.30049

/

.29835

. 29765

/

.29831

/

.29938

/

.30258

/

.30706

/

.31286

.31955

/

.32655

/

.33279

/

.33759

/

.34061

/

.34119

.33994

Table S6, continued

Part 2: 19 cm camera distance (8.50 s 35.00 Å1, with s = 0. 25 Å1; the Table develops horizontally)

.56840

/

.56387

/

.57225

/

.58103

.57641

/

.55791

/

.53409

/

.51750

/

.51278

/

.51380

.50945

/

.49426

/

.46908

/

.44158

/

.41881

/

.40317

.39465

/

.39393

/

.40140

/

.41596

/

.43138

/

.43937

.43459

/

.42204

/

.40678

/

.39512

/

.38833

/

.38419

.37903

/

.37356

/

.36755

/

.36205

/

.35598

/

.34924

.34274

/

.33994

/

.34093

/

.34497

/

.35049

/

.35606

.35770

/

.35554

/

.35036

/

.34319

/

.33639

/

.33041

.32758

/

.32492

/

.32256

/

.32065

/

.31902

/

.31692

.31508

/

.31257

/

.31064

/

.30994

/

.31063

/

.31197

.31360

/

.31465

/

. 31469

/

.31359

/

.31183

/

.30968

.30631

/

.30188

/

.29793

/

.29437

/

.29266

/

.29212

.29185

/

.29301

/

. 29380

/

.29480

/

.29584

/

.29591

.29564

/

.29509

/

.29415

/

.29346

/

.29319

/

.29215

. 29097

/

.28950

/

.28787

/

.28654

/

.28491

/

.28432

.28407

/

.28444

/

.28531

/

.28595

/

.28684

/

.28720

.28715

/

28703

/

.28606

/

.28509

/

.28443

/

.28392

.28396

/

.28373

/

.28334

/

.28331

/

.28283

/

.28277

.28269

1