# Electronic Supplementary Material (ESI) for Organic & Biomolecular Chemistry.
# This journal is © The Royal Society of Chemistry 2015

####################################################################### 
# 
# This file contains crystal structure data downloaded from the 
# Cambridge Structural Database (CSD) hosted by the Cambridge 
# Crystallographic Data Centre (CCDC).
# 
# Full information about CCDC data access policies and citation 
# guidelines are available at http://www.ccdc.cam.ac.uk/access/V1 
# 
# Audit and citation data items may have been added by the CCDC. 
# Please retain this information to preserve the provenance of 
# this file and to allow appropriate attribution of the data. 
# 
#######################################################################

data_15023
_database_code_depnum_ccdc_archive 'CCDC 1421862'
_audit_update_record             
;
2015-09-01 deposited with the CCDC.
2015-09-22 downloaded from the CCDC.
;
_audit_creation_date             2015-02-27
_audit_creation_method           CRYSTALS_ver_14.61

_oxford_structure_analysis_title 'mo_15023_0ma in Pca2(1)'
_chemical_name_systematic        ?
_chemical_melting_point          ?
_cell_length_a                   11.2256(13)
_cell_length_b                   19.596(3)
_cell_length_c                   7.9601(12)
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_volume                     1751.1(3)

_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_H-M   'P c a 21 '
_symmetry_space_group_name_Hall  ?
loop_
_symmetry_equiv_pos_as_xyz
x,y,z
-x,-y,z+1/2
-x+1/2,y,z+1/2
x+1/2,-y,z

loop_
_atom_type_symbol
_atom_type_scat_dispersion_real
_atom_type_scat_dispersion_imag
_atom_type_scat_Cromer_Mann_a1
_atom_type_scat_Cromer_Mann_b1
_atom_type_scat_Cromer_Mann_a2
_atom_type_scat_Cromer_Mann_b2
_atom_type_scat_Cromer_Mann_a3
_atom_type_scat_Cromer_Mann_b3
_atom_type_scat_Cromer_Mann_a4
_atom_type_scat_Cromer_Mann_b4
_atom_type_scat_Cromer_Mann_c
_atom_type_scat_source
C 0.0033 0.0016 2.3100 20.8439 1.0200 10.2075 1.5886 0.5687 0.8650 51.6512
0.2156 'International Tables Vol C 4.2.6.8 and 6.1.1.4'
H 0.0000 0.0000 0.4930 10.5109 0.3229 26.1257 0.1402 3.1424 0.0408 57.7998
0.0030 'International Tables Vol C 4.2.6.8 and 6.1.1.4'
O 0.0106 0.0060 3.0485 13.2771 2.2868 5.7011 1.5463 0.3239 0.8670 32.9089
0.2508 'International Tables Vol C 4.2.6.8 and 6.1.1.4'
Si 0.0817 0.0704 6.2915 2.4386 3.0353 32.3337 1.9891 0.6785 1.5410 81.6937
1.1407 'International Tables Vol C 4.2.6.8 and 6.1.1.4'


_cell_formula_units_Z            4

# Given Formula = C20 H24 O1 Si1 
# Dc =      1.17 Fooo =    664.00 Mu =      1.34 M =    308.50
# Found Formula = C20 H24 O1 Si1 
# Dc =      1.17 FOOO =    664.00 Mu =      1.34 M =    308.50

_chemical_formula_sum            'C20 H24 O1 Si1'
_chemical_formula_moiety         'C20 H24 O1 Si1'
_chemical_compound_source        ?
_chemical_formula_weight         308.50


_cell_measurement_reflns_used    4997
_cell_measurement_theta_min      3
_cell_measurement_theta_max      30
_cell_measurement_temperature    150

_exptl_crystal_description       plate
_exptl_crystal_colour            colorless
_exptl_crystal_size_min          0.050
_exptl_crystal_size_mid          0.150
_exptl_crystal_size_max          0.300

_exptl_crystal_density_diffrn    1.170
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    'not measured'
# Non-dispersive F(000): 
_exptl_crystal_F_000             664
_exptl_absorpt_coefficient_mu    0.134

# Sheldrick geometric approximatio 0.98 0.99 
# No experimental values of Tmin/max available 
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS (Siemens, 1996)'
_exptl_absorpt_correction_T_min  0.98
_exptl_absorpt_correction_T_max  0.99
_diffrn_measurement_device_type  'Bruker Kappa Apex2'
_diffrn_measurement_device       Area
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.71073
_diffrn_measurement_method       'φ & ω scans'

# If a reference occurs more than once, delete the author 
# and date from subsequent references. 
_computing_data_collection       'Apex2 (Bruker AXS, 2006)'
_computing_cell_refinement       'Apex2 (Bruker AXS, 2006)'
_computing_data_reduction        'Apex2 (Bruker AXS, 2006)'
_computing_structure_solution    'Superflip (Palatinus & Chapuis, 2007)'
_computing_structure_refinement  'CRYSTALS (Betteridge et al., 2003)'
_computing_publication_material  'CRYSTALS (Betteridge et al., 2003)'
_computing_molecular_graphics    'CAMERON (Watkin et al., 1996)'

_diffrn_standards_interval_time  .
_diffrn_standards_interval_count .
_diffrn_standards_number         0
_diffrn_standards_decay_%        ?

_diffrn_ambient_temperature      150
_diffrn_reflns_number            7404
_reflns_number_total             2711
_diffrn_reflns_av_R_equivalents  0.028
# Number of reflections without Friedels Law is 0 
# Number of reflections with Friedels Law is 2711 
# Theoretical number of reflections is about 5175 


_diffrn_reflns_theta_min         2.091
_diffrn_reflns_theta_max         30.146
_diffrn_measured_fraction_theta_max 0.979

_diffrn_reflns_theta_full        28.036
_diffrn_measured_fraction_theta_full 0.985


_diffrn_reflns_limit_h_min       -15
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_k_min       -25
_diffrn_reflns_limit_k_max       27
_diffrn_reflns_limit_l_min       -11
_diffrn_reflns_limit_l_max       6
_reflns_limit_h_min              0
_reflns_limit_h_max              15
_reflns_limit_k_min              0
_reflns_limit_k_max              27
_reflns_limit_l_min              0
_reflns_limit_l_max              11

_oxford_diffrn_Wilson_B_factor   0.00
_oxford_diffrn_Wilson_scale      0.00

_atom_sites_solution_primary     Other #heavy,direct,difmap,geom,iterative
# _atom_sites_solution_secondary  difmap
_atom_sites_solution_hydrogens   difmap

_refine_diff_density_min         -0.22
_refine_diff_density_max         0.38


# The current dictionary definitions do not cover the 
# situation where the reflections used for refinement were 
# selected by a user-defined sigma threshold 


# The values actually used during refinement 
_oxford_reflns_threshold_expression_ref I>-3.0\s(I)
_refine_ls_number_reflns         2704
_refine_ls_number_restraints     1
_refine_ls_number_parameters     271
_oxford_refine_ls_R_factor_ref   0.0418
_refine_ls_wR_factor_ref         0.0944
_refine_ls_goodness_of_fit_ref   1.0075
_refine_ls_shift/su_max          0.0009545
_refine_ls_shift/su_mean         0.0000422


# The values computed with all filters except I/sigma 
_oxford_reflns_number_all        2704
_refine_ls_R_factor_all          0.0418
_refine_ls_wR_factor_all         0.0944

# The values computed with a 2 sigma cutoff - a la SHELX 
_reflns_threshold_expression     I>2.0σ(I)
_reflns_number_gt                2357
_refine_ls_R_factor_gt           0.0354
_refine_ls_wR_factor_gt          0.0871

# choose from: rm (reference molecule of known chirality), 
# ad (anomolous dispersion - Flack), rmad (rm and ad), 
# syn (from synthesis), unk (unknown) or . (not applicable). 
_chemical_absolute_configuration unk


_refine_ls_structure_factor_coef Fsqd
_refine_ls_matrix_type           full
_refine_ls_hydrogen_treatment    refxyz #undef, noref, refall,
# refxyz, refU, constr or mixed
_refine_ls_weighting_scheme      calc
_refine_ls_weighting_details     
;
 Method= Modified Sheldrick 
 w=1/[σ²(F²) + ( 0.05P)² + 0.28P] 
 ,where P=(max(Fo²,0) + 2Fc²)/3 
;

# Uequiv = arithmetic mean of Ui i.e. Ueqiv = (U1+U2+U3)/3

# Replace last . with number of unfound hydrogen atoms attached to an atom.

# ..._refinement_flags_... 
# . no refinement constraints           S special position constraint on site
# G rigid group refinement of site      R riding atom
# D distance or angle restraint on site T thermal displacement constraints
# U Uiso or Uij restraint (rigid bond)  P partial occupancy constraint


loop_
_atom_site_label
_atom_site_type_symbol
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_U_iso_or_equiv
_atom_site_occupancy
_atom_site_adp_type
_atom_site_refinement_flags_posn
_atom_site_refinement_flags_adp
_atom_site_refinement_flags_occupancy
_atom_site_disorder_assembly
_atom_site_disorder_group
_atom_site_attached_hydrogens
Si1 Si 0.53370(4) 0.68754(3) 0.83132(18) 0.0206 1.0000 Uani . . . . . .
O1 O 0.33303(15) 0.83109(9) 0.2349(3) 0.0355 1.0000 Uani . . . . . .
C1 C 0.36715(17) 0.81703(11) 0.3732(3) 0.0241 1.0000 Uani . . . . . .
C2 C 0.43663(16) 0.85674(9) 0.5071(3) 0.0208 1.0000 Uani . . . . . .
C3 C 0.47527(17) 0.78469(10) 0.5775(3) 0.0203 1.0000 Uani . . . . . .
C4 C 0.37437(19) 0.75070(11) 0.4717(3) 0.0256 1.0000 Uani . . . . . .
C5 C 0.52896(15) 0.90803(9) 0.4525(3) 0.0194 1.0000 Uani . . . . . .
C6 C 0.61159(16) 0.89075(9) 0.3291(4) 0.0234 1.0000 Uani . . . . . .
C7 C 0.69887(18) 0.93701(11) 0.2796(3) 0.0275 1.0000 Uani . . . . . .
C8 C 0.70477(18) 1.00080(11) 0.3542(3) 0.0288 1.0000 Uani . . . . . .
C9 C 0.62277(19) 1.01909(10) 0.4757(3) 0.0280 1.0000 Uani . . . . . .
C10 C 0.53439(18) 0.97303(10) 0.5242(3) 0.0234 1.0000 Uani . . . . . .
C11 C 0.47493(17) 0.77419(10) 0.7673(3) 0.0211 1.0000 Uani . . . . . .
C12 C 0.5474(3) 0.83013(12) 0.8565(4) 0.0373 1.0000 Uani . . . . . .
C13 C 0.4942(2) 0.67139(13) 1.0564(3) 0.0313 1.0000 Uani . . . . . .
C14 C 0.69948(19) 0.68629(14) 0.8039(4) 0.0333 1.0000 Uani . . . . . .
C15 C 0.46751(17) 0.61851(9) 0.6973(3) 0.0225 1.0000 Uani . . . . . .
C16 C 0.34797(19) 0.59985(11) 0.7148(3) 0.0275 1.0000 Uani . . . . . .
C17 C 0.2971(2) 0.54953(13) 0.6149(4) 0.0369 1.0000 Uani . . . . . .
C18 C 0.3649(3) 0.51672(13) 0.4946(4) 0.0431 1.0000 Uani . . . . . .
C19 C 0.4830(3) 0.53418(13) 0.4739(4) 0.0430 1.0000 Uani . . . . . .
C20 C 0.5332(2) 0.58456(12) 0.5731(4) 0.0325 1.0000 Uani . . . . . .
H21 H 0.384(2) 0.8737(13) 0.580(4) 0.0242 1.0000 Uiso . . . . . .
H31 H 0.550(2) 0.7739(13) 0.532(4) 0.0236 1.0000 Uiso . . . . . .
H41 H 0.301(2) 0.7466(14) 0.534(4) 0.0295 1.0000 Uiso . . . . . .
H42 H 0.389(2) 0.7125(15) 0.416(4) 0.0295 1.0000 Uiso . . . . . .
H61 H 0.610(2) 0.8446(14) 0.279(4) 0.0271 1.0000 Uiso . . . . . .
H71 H 0.757(3) 0.9237(12) 0.196(4) 0.0323 1.0000 Uiso . . . . . .
H81 H 0.760(2) 1.0334(12) 0.319(4) 0.0333 1.0000 Uiso . . . . . .
H91 H 0.632(2) 1.0629(15) 0.534(4) 0.0317 1.0000 Uiso . . . . . .
H101 H 0.481(2) 0.9855(14) 0.600(4) 0.0276 1.0000 Uiso . . . . . .
H111 H 0.392(2) 0.7796(13) 0.812(4) 0.0249 1.0000 Uiso . . . . . .
H121 H 0.515(2) 0.8764(16) 0.838(5) 0.0428 1.0000 Uiso . . . . . .
H122 H 0.533(3) 0.8263(16) 0.984(5) 0.0428 1.0000 Uiso . . . . . .
H123 H 0.631(3) 0.8263(15) 0.828(5) 0.0428 1.0000 Uiso . . . . . .
H131 H 0.526(2) 0.6307(17) 1.100(4) 0.0386 1.0000 Uiso . . . . . .
H132 H 0.518(2) 0.7114(17) 1.139(5) 0.0386 1.0000 Uiso . . . . . .
H133 H 0.410(3) 0.6779(15) 1.074(5) 0.0386 1.0000 Uiso . . . . . .
H141 H 0.733(2) 0.6442(14) 0.825(4) 0.0398 1.0000 Uiso . . . . . .
H142 H 0.741(3) 0.7191(14) 0.881(4) 0.0398 1.0000 Uiso . . . . . .
H143 H 0.725(3) 0.7006(15) 0.684(5) 0.0398 1.0000 Uiso . . . . . .
H161 H 0.299(2) 0.6233(14) 0.796(4) 0.0328 1.0000 Uiso . . . . . .
H171 H 0.212(3) 0.5409(16) 0.632(5) 0.0423 1.0000 Uiso . . . . . .
H181 H 0.333(3) 0.486(2) 0.429(5) 0.0512 1.0000 Uiso . . . . . .
H191 H 0.529(3) 0.5145(18) 0.384(5) 0.0501 1.0000 Uiso . . . . . .
H201 H 0.617(2) 0.5987(16) 0.563(4) 0.0386 1.0000 Uiso . . . . . .

_refine_ls_extinction_method     None
_oxford_refine_ls_scale          0.21385(19)
loop_
_geom_bond_atom_site_label_1
_geom_bond_site_symmetry_1
_geom_bond_atom_site_label_2
_geom_bond_site_symmetry_2
_geom_bond_distance
_geom_bond_publ_flag
Si1 . C11 . 1.892(2) yes
Si1 . C13 . 1.873(3) yes
Si1 . C14 . 1.874(2) yes
Si1 . C15 . 1.876(2) yes
O1 . C1 . 1.198(3) yes
C1 . C2 . 1.533(3) yes
C1 . C4 . 1.520(3) yes
C2 . C3 . 1.580(3) yes
C2 . C5 . 1.508(3) yes
C2 . H21 . 0.89(3) no
C3 . C4 . 1.560(3) yes
C3 . C11 . 1.525(3) yes
C3 . H31 . 0.94(2) no
C4 . H41 . 0.96(3) no
C4 . H42 . 0.89(3) no
C5 . C6 . 1.393(3) yes
C5 . C10 . 1.397(3) yes
C6 . C7 . 1.392(3) yes
C6 . H61 . 0.99(3) no
C7 . C8 . 1.386(3) yes
C7 . H71 . 0.96(3) no
C8 . C9 . 1.383(3) yes
C8 . H81 . 0.94(3) no
C9 . C10 . 1.396(3) yes
C9 . H91 . 0.98(3) no
C10 . H101 . 0.89(3) no
C11 . C12 . 1.539(3) yes
C11 . H111 . 1.01(2) no
C12 . H121 . 0.99(3) no
C12 . H122 . 1.03(4) no
C12 . H123 . 0.97(3) no
C13 . H131 . 0.94(3) no
C13 . H132 . 1.05(3) no
C13 . H133 . 0.96(3) no
C14 . H141 . 0.92(3) no
C14 . H142 . 1.00(3) no
C14 . H143 . 1.03(4) no
C15 . C16 . 1.398(3) yes
C15 . C20 . 1.401(3) yes
C16 . C17 . 1.390(3) yes
C16 . H161 . 0.96(3) no
C17 . C18 . 1.382(4) yes
C17 . H171 . 0.99(3) no
C18 . C19 . 1.378(4) yes
C18 . H181 . 0.88(4) no
C19 . C20 . 1.384(4) yes
C19 . H191 . 0.96(4) no
C20 . H201 . 0.98(3) no
loop_
_geom_angle_atom_site_label_1
_geom_angle_site_symmetry_1
_geom_angle_atom_site_label_2
_geom_angle_site_symmetry_2
_geom_angle_atom_site_label_3
_geom_angle_site_symmetry_3
_geom_angle
_geom_angle_publ_flag
C11 . Si1 . C13 . 109.07(11) yes
C11 . Si1 . C14 . 109.07(10) yes
C13 . Si1 . C14 . 110.15(11) yes
C11 . Si1 . C15 . 110.85(9) yes
C13 . Si1 . C15 . 109.17(10) yes
C14 . Si1 . C15 . 108.52(11) yes
O1 . C1 . C2 . 133.2(2) yes
O1 . C1 . C4 . 133.5(2) yes
C2 . C1 . C4 . 92.77(16) yes
C1 . C2 . C3 . 86.14(14) yes
C1 . C2 . C5 . 119.21(18) yes
C3 . C2 . C5 . 120.62(15) yes
C1 . C2 . H21 . 108.0(16) no
C3 . C2 . H21 . 106.4(17) no
C5 . C2 . H21 . 113.1(16) no
C2 . C3 . C4 . 89.48(15) yes
C2 . C3 . C11 . 118.13(17) yes
C4 . C3 . C11 . 118.36(17) yes
C2 . C3 . H31 . 108.1(17) no
C4 . C3 . H31 . 110.1(16) no
C11 . C3 . H31 . 110.8(18) no
C1 . C4 . C3 . 87.25(15) yes
C1 . C4 . H41 . 107.0(16) no
C3 . C4 . H41 . 112.2(18) no
C1 . C4 . H42 . 118.1(20) no
C3 . C4 . H42 . 119.6(17) no
H41 . C4 . H42 . 110(2) no
C2 . C5 . C6 . 119.93(17) yes
C2 . C5 . C10 . 121.35(18) yes
C6 . C5 . C10 . 118.72(17) yes
C5 . C6 . C7 . 120.68(19) yes
C5 . C6 . H61 . 119.9(15) no
C7 . C6 . H61 . 119.3(15) no
C6 . C7 . C8 . 120.0(2) yes
C6 . C7 . H71 . 119.6(16) no
C8 . C7 . H71 . 120.4(16) no
C7 . C8 . C9 . 120.13(19) yes
C7 . C8 . H81 . 121.3(17) no
C9 . C8 . H81 . 118.5(17) no
C8 . C9 . C10 . 119.9(2) yes
C8 . C9 . H91 . 119.4(16) no
C10 . C9 . H91 . 120.5(16) no
C5 . C10 . C9 . 120.5(2) yes
C5 . C10 . H101 . 120.0(17) no
C9 . C10 . H101 . 119.5(17) no
C3 . C11 . Si1 . 112.78(14) yes
C3 . C11 . C12 . 111.09(18) yes
Si1 . C11 . C12 . 109.31(15) yes
C3 . C11 . H111 . 109.7(17) no
Si1 . C11 . H111 . 109.0(15) no
C12 . C11 . H111 . 104.7(15) no
C11 . C12 . H121 . 113.0(19) no
C11 . C12 . H122 . 108.8(17) no
H121 . C12 . H122 . 99(3) no
C11 . C12 . H123 . 110(2) no
H121 . C12 . H123 . 113(3) no
H122 . C12 . H123 . 112(3) no
Si1 . C13 . H131 . 114(2) no
Si1 . C13 . H132 . 114.1(19) no
H131 . C13 . H132 . 108(3) no
Si1 . C13 . H133 . 110(2) no
H131 . C13 . H133 . 116(3) no
H132 . C13 . H133 . 93(2) no
Si1 . C14 . H141 . 113.1(17) no
Si1 . C14 . H142 . 112.2(18) no
H141 . C14 . H142 . 106(3) no
Si1 . C14 . H143 . 112.3(17) no
H141 . C14 . H143 . 107(3) no
H142 . C14 . H143 . 105(2) no
Si1 . C15 . C16 . 120.81(16) yes
Si1 . C15 . C20 . 122.35(16) yes
C16 . C15 . C20 . 116.8(2) yes
C15 . C16 . C17 . 121.6(2) yes
C15 . C16 . H161 . 119.0(15) no
C17 . C16 . H161 . 119.4(15) no
C16 . C17 . C18 . 120.0(3) yes
C16 . C17 . H171 . 116.2(20) no
C18 . C17 . H171 . 123.8(20) no
C17 . C18 . C19 . 119.8(2) yes
C17 . C18 . H181 . 121(2) no
C19 . C18 . H181 . 119(2) no
C18 . C19 . C20 . 120.0(3) yes
C18 . C19 . H191 . 120.4(18) no
C20 . C19 . H191 . 119.3(18) no
C15 . C20 . C19 . 121.8(2) yes
C15 . C20 . H201 . 115.3(20) no
C19 . C20 . H201 . 122.9(20) no


loop_
_geom_torsion_atom_site_label_1
_geom_torsion_atom_site_label_2
_geom_torsion_atom_site_label_3
_geom_torsion_atom_site_label_4
_geom_torsion
_geom_torsion_site_symmetry_1
_geom_torsion_site_symmetry_2
_geom_torsion_site_symmetry_3
_geom_torsion_site_symmetry_4
_geom_torsion_publ_flag
C13 Si1 C11 C3 -165.83(14) . . . . no
C13 Si1 C11 C12 70.07(19) . . . . no
C14 Si1 C11 C3 73.83(18) . . . . no
C14 Si1 C11 C12 -50.3(2) . . . . no
C15 Si1 C11 C3 -45.59(16) . . . . no
C15 Si1 C11 C12 -169.70(17) . . . . no
C11 Si1 C15 C16 -71.5(2) . . . . no
C11 Si1 C15 C20 106.9(2) . . . . no
C13 Si1 C15 C16 48.7(2) . . . . no
C13 Si1 C15 C20 -132.9(2) . . . . no
C14 Si1 C15 C16 168.80(19) . . . . no
C14 Si1 C15 C20 -12.9(2) . . . . no
O1 C1 C2 C3 -156.3(3) . . . . no
O1 C1 C2 C5 -33.1(3) . . . . no
C4 C1 C2 C3 15.88(15) . . . . no
C4 C1 C2 C5 139.04(17) . . . . no
O1 C1 C4 C3 156.1(3) . . . . no
C2 C1 C4 C3 -16.06(15) . . . . no
C1 C2 C3 C4 -15.44(15) . . . . no
C1 C2 C3 C11 -137.71(18) . . . . no
C5 C2 C3 C4 -137.3(2) . . . . no
C5 C2 C3 C11 100.4(2) . . . . no
C1 C2 C5 C6 -46.8(3) . . . . no
C1 C2 C5 C10 133.7(2) . . . . no
C3 C2 C5 C6 57.2(3) . . . . no
C3 C2 C5 C10 -122.3(2) . . . . no
C2 C3 C4 C1 15.55(16) . . . . no
C11 C3 C4 C1 137.61(18) . . . . no
C2 C3 C11 Si1 -175.93(13) . . . . no
C2 C3 C11 C12 -52.8(2) . . . . no
C4 C3 C11 Si1 78.00(19) . . . . no
C4 C3 C11 C12 -158.87(19) . . . . no
C2 C5 C6 C7 -178.7(2) . . . . no
C10 C5 C6 C7 0.8(3) . . . . no
C2 C5 C10 C9 178.0(2) . . . . no
C6 C5 C10 C9 -1.5(3) . . . . no
C5 C6 C7 C8 0.5(4) . . . . no
C6 C7 C8 C9 -1.2(3) . . . . no
C7 C8 C9 C10 0.5(3) . . . . no
C8 C9 C10 C5 0.9(3) . . . . no
Si1 C15 C16 C17 179.05(19) . . . . no
C20 C15 C16 C17 0.6(3) . . . . no
Si1 C15 C20 C19 -179.4(2) . . . . no
C16 C15 C20 C19 -1.0(4) . . . . no
C15 C16 C17 C18 -0.1(4) . . . . no
C16 C17 C18 C19 -0.1(4) . . . . no
C17 C18 C19 C20 -0.2(4) . . . . no
C18 C19 C20 C15 0.8(4) . . . . no

