# Electronic Supplementary Material (ESI) for ChemComm.
# This journal is © The Royal Society of Chemistry 2018

####################################################################### 
# 
# 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_180403a
_database_code_depnum_ccdc_archive 'CCDC 1845058'
_audit_update_record             
;
2018-05-24 deposited with the CCDC.
2018-08-27 downloaded from the CCDC.
;

_audit_creation_method           SHELXL-2018/1
_shelx_SHELXL_version_number     2018/1
_chemical_name_systematic        ?
_chemical_name_common            ?
_chemical_melting_point          ?
_chemical_formula_moiety         ?
_chemical_formula_sum            'C27 H34 O Si2'
_chemical_formula_weight         430.72

loop_
_atom_type_symbol
_atom_type_description
_atom_type_scat_dispersion_real
_atom_type_scat_dispersion_imag
_atom_type_scat_source
C C 0.0033 0.0016 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
H H 0.0000 0.0000 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
O O 0.0106 0.0060 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
Si Si 0.0817 0.0704 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'

_space_group_crystal_system      triclinic
_space_group_IT_number           2
_space_group_name_H-M_alt        'P -1'
_space_group_name_Hall           '-P 1'

_shelx_space_group_comment       
; 
The symmetry employed for this shelxl refinement is uniquely defined 
by the following loop, which should always be used as a source of 
symmetry information in preference to the above space-group names. 
They are only intended as comments. 
;

loop_
_space_group_symop_operation_xyz
'x, y, z'
'-x, -y, -z'

_cell_length_a                   9.2327(8)
_cell_length_b                   9.5206(9)
_cell_length_c                   17.1628(19)
_cell_angle_alpha                94.671(4)
_cell_angle_beta                 104.862(4)
_cell_angle_gamma                112.646(3)
_cell_volume                     1318.0(2)
_cell_formula_units_Z            2
_cell_measurement_temperature    291(2)
_cell_measurement_reflns_used    8960
_cell_measurement_theta_min      2.89
_cell_measurement_theta_max      26.25

_exptl_crystal_description       block
_exptl_crystal_colour            colourless
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    ?
_exptl_crystal_density_diffrn    1.085
_exptl_crystal_F_000             464
_exptl_transmission_factor_min   0.7124
_exptl_transmission_factor_max   0.7454
_exptl_crystal_size_max          0.350
_exptl_crystal_size_mid          0.130
_exptl_crystal_size_min          0.120
_exptl_absorpt_coefficient_mu    0.149
_shelx_estimated_absorpt_T_min   0.950
_shelx_estimated_absorpt_T_max   0.982
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_correction_T_min  ?
_exptl_absorpt_correction_T_max  ?
_exptl_absorpt_process_details   sadabs
_exptl_absorpt_special_details   ?
_diffrn_ambient_temperature      291(2)
_diffrn_radiation_wavelength     0.71073
_diffrn_radiation_type           MoK\a
_diffrn_source                   ?
_diffrn_measurement_device_type  'Bruker APEX-III CMOS'
_diffrn_measurement_method       'φ and ω scans'
_diffrn_detector_area_resol_mean ?
_diffrn_reflns_number            23001
_diffrn_reflns_av_unetI/netI     0.0296
_diffrn_reflns_av_R_equivalents  0.0352
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_k_min       -11
_diffrn_reflns_limit_k_max       11
_diffrn_reflns_limit_l_min       -21
_diffrn_reflns_limit_l_max       21
_diffrn_reflns_theta_min         2.894
_diffrn_reflns_theta_max         26.493
_diffrn_reflns_theta_full        25.242
_diffrn_measured_fraction_theta_max 0.995
_diffrn_measured_fraction_theta_full 0.997
_diffrn_reflns_Laue_measured_fraction_max 0.995
_diffrn_reflns_Laue_measured_fraction_full 0.997
_diffrn_reflns_point_group_measured_fraction_max 0.995
_diffrn_reflns_point_group_measured_fraction_full 0.997
_reflns_number_total             5436
_reflns_number_gt                3968
_reflns_threshold_expression     'I > 2σ(I)'
_reflns_Friedel_coverage         0.000
_reflns_Friedel_fraction_max     .
_reflns_Friedel_fraction_full    .

_reflns_special_details          
; 
 Reflections were merged by SHELXL according to the crystal 
 class for the calculation of statistics and refinement. 
  
 _reflns_Friedel_fraction is defined as the number of unique 
 Friedel pairs measured divided by the number that would be 
 possible theoretically, ignoring centric projections and 
 systematic absences. 
;

_computing_data_collection       'Bruker APEX3'
_computing_cell_refinement       'Bruker SAINT'
_computing_data_reduction        'Bruker SAINT'
_computing_structure_solution    'SHELXS-97 (Sheldrick 2008)'
_computing_structure_refinement  'SHELXL-2018/1 (Sheldrick, 2018)'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_refine_special_details          ?
_refine_ls_structure_factor_coef Fsqd
_refine_ls_matrix_type           full
_refine_ls_weighting_scheme      calc
_refine_ls_weighting_details     
'w=1/[σ²(Fo²)+(0.0524P)²+0.3096P] where P=(Fo²+2Fc²)/3'
_atom_sites_solution_primary     ?
_atom_sites_solution_secondary   ?
_atom_sites_solution_hydrogens   geom
_refine_ls_hydrogen_treatment    constr
_refine_ls_extinction_method     'SHELXL-2018/1 (Sheldrick 2018)'
_refine_ls_extinction_coef       0.054(4)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4^
_refine_ls_number_reflns         5436
_refine_ls_number_parameters     279
_refine_ls_number_restraints     0
_refine_ls_R_factor_all          0.0669
_refine_ls_R_factor_gt           0.0439
_refine_ls_wR_factor_ref         0.1207
_refine_ls_wR_factor_gt          0.1072
_refine_ls_goodness_of_fit_ref   1.029
_refine_ls_restrained_S_all      1.029
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000

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_adp_type
_atom_site_occupancy
_atom_site_site_symmetry_order
_atom_site_calc_flag
_atom_site_refinement_flags_posn
_atom_site_refinement_flags_adp
_atom_site_refinement_flags_occupancy
_atom_site_disorder_assembly
_atom_site_disorder_group
Si1 Si 0.48649(6) 0.04517(6) 0.17932(3) 0.05759(17) Uani 1 1 d . . . . .
Si2 Si 0.26916(7) 0.14514(6) 0.41372(3) 0.05885(18) Uani 1 1 d . . . . .
O23 O 0.45428(18) 0.57930(15) 0.16361(9) 0.0730(4) Uani 1 1 d . . . . .
C1 C 0.15712(19) -0.00874(19) 0.24216(10) 0.0450(4) Uani 1 1 d . . . . .
C2 C 0.0585(2) -0.1396(2) 0.16900(10) 0.0482(4) Uani 1 1 d . . . . .
C3 C 0.0491(2) -0.2890(2) 0.16836(11) 0.0586(5) Uani 1 1 d . . . . .
H3 H 0.103903 -0.311516 0.215773 0.070 Uiso 1 1 calc R U . . .
C4 C -0.0405(3) -0.4049(2) 0.09830(13) 0.0688(5) Uani 1 1 d . . . . .
H4 H -0.044794 -0.503948 0.099118 0.083 Uiso 1 1 calc R U . . .
C5 C -0.1230(3) -0.3747(3) 0.02775(12) 0.0715(6) Uani 1 1 d . . . . .
H5 H -0.183158 -0.452957 -0.019118 0.086 Uiso 1 1 calc R U . . .
C6 C -0.1161(2) -0.2285(3) 0.02675(12) 0.0693(5) Uani 1 1 d . . . . .
H6 H -0.172147 -0.207567 -0.020907 0.083 Uiso 1 1 calc R U . . .
C7 C -0.0261(2) -0.1118(2) 0.09645(11) 0.0567(4) Uani 1 1 d . . . . .
H7 H -0.021972 -0.012921 0.094844 0.068 Uiso 1 1 calc R U . . .
C8 C 0.16090(19) -0.02077(19) 0.32070(10) 0.0463(4) Uani 1 1 d . . . . .
C9 C 0.0623(2) -0.1711(2) 0.34071(10) 0.0514(4) Uani 1 1 d . . . . .
C10 C 0.1375(3) -0.2606(2) 0.37716(13) 0.0725(6) Uani 1 1 d . . . . .
H10 H 0.251125 -0.227074 0.389047 0.087 Uiso 1 1 calc R U . . .
C11 C 0.0462(4) -0.3990(3) 0.39603(16) 0.0957(8) Uani 1 1 d . . . . .
H11 H 0.098459 -0.458098 0.420057 0.115 Uiso 1 1 calc R U . . .
C12 C -0.1203(5) -0.4494(3) 0.37966(17) 0.1020(10) Uani 1 1 d . . . . .
H12 H -0.181435 -0.543517 0.391728 0.122 Uiso 1 1 calc R U . . .
C13 C -0.1973(3) -0.3619(3) 0.34556(15) 0.0903(8) Uani 1 1 d . . . . .
H13 H -0.310627 -0.395596 0.335102 0.108 Uiso 1 1 calc R U . . .
C14 C -0.1062(2) -0.2224(2) 0.32653(11) 0.0646(5) Uani 1 1 d . . . . .
H14 H -0.159051 -0.162561 0.303967 0.078 Uiso 1 1 calc R U . . .
C15 C 0.24479(19) 0.14459(19) 0.22102(9) 0.0444(4) Uani 1 1 d . . . . .
C16 C 0.38464(19) 0.17943(19) 0.19413(9) 0.0463(4) Uani 1 1 d . . . . .
C17 C 0.4551(2) 0.3267(2) 0.17586(10) 0.0523(4) Uani 1 1 d . . . . .
H17 H 0.548608 0.352563 0.159036 0.063 Uiso 1 1 calc R U . . .
C18 C 0.3910(2) 0.4349(2) 0.18190(10) 0.0539(4) Uani 1 1 d . . . . .
C19 C 0.2537(2) 0.3988(2) 0.20750(11) 0.0568(4) Uani 1 1 d . . . . .
H19 H 0.209621 0.470911 0.212094 0.068 Uiso 1 1 calc R U . . .
C20 C 0.1820(2) 0.2553(2) 0.22622(11) 0.0532(4) Uani 1 1 d . . . . .
H20 H 0.088531 0.231493 0.242903 0.064 Uiso 1 1 calc R U . . .
C21 C 0.5801(3) 0.6130(3) 0.12513(15) 0.0815(6) Uani 1 1 d . . . . .
H21A H 0.607925 0.714571 0.112367 0.122 Uiso 1 1 calc R U . . .
H21B H 0.540785 0.537165 0.075348 0.122 Uiso 1 1 calc R U . . .
H21C H 0.676269 0.609885 0.161758 0.122 Uiso 1 1 calc R U . . .
C22 C 0.3714(3) -0.0905(3) 0.07783(13) 0.0745(6) Uani 1 1 d . . . . .
H22A H 0.433877 -0.145315 0.065985 0.112 Uiso 1 1 calc R U . . .
H22B H 0.354442 -0.032684 0.035778 0.112 Uiso 1 1 calc R U . . .
H22C H 0.266310 -0.163593 0.079348 0.112 Uiso 1 1 calc R U . . .
C23 C 0.5059(3) -0.0609(3) 0.26479(13) 0.0810(7) Uani 1 1 d . . . . .
H23A H 0.557928 -0.127525 0.254783 0.121 Uiso 1 1 calc R U . . .
H23B H 0.398129 -0.122345 0.268052 0.121 Uiso 1 1 calc R U . . .
H23C H 0.571780 0.012396 0.315707 0.121 Uiso 1 1 calc R U . . .
C24 C 0.7002(3) 0.1641(3) 0.17792(18) 0.0948(8) Uani 1 1 d . . . . .
H24A H 0.755588 0.097946 0.173788 0.142 Uiso 1 1 calc R U . . .
H24B H 0.760148 0.241527 0.227749 0.142 Uiso 1 1 calc R U . . .
H24C H 0.694918 0.213907 0.131499 0.142 Uiso 1 1 calc R U . . .
C25 C 0.1251(4) 0.2346(4) 0.42142(17) 0.1132(10) Uani 1 1 d . . . . .
H25A H 0.165807 0.301624 0.474443 0.170 Uiso 1 1 calc R U . . .
H25B H 0.017809 0.154379 0.414600 0.170 Uiso 1 1 calc R U . . .
H25C H 0.117275 0.294040 0.379210 0.170 Uiso 1 1 calc R U . . .
C26 C 0.3090(3) 0.0676(3) 0.50924(12) 0.0842(7) Uani 1 1 d . . . . .
H26A H 0.363155 0.151860 0.556169 0.126 Uiso 1 1 calc R U . . .
H26B H 0.378320 0.014770 0.506984 0.126 Uiso 1 1 calc R U . . .
H26C H 0.206036 -0.003841 0.513831 0.126 Uiso 1 1 calc R U . . .
C27 C 0.4718(3) 0.2909(3) 0.41341(15) 0.1064(10) Uani 1 1 d . . . . .
H27A H 0.528504 0.359501 0.466332 0.160 Uiso 1 1 calc R U . . .
H27B H 0.454990 0.349906 0.371940 0.160 Uiso 1 1 calc R U . . .
H27C H 0.536952 0.238889 0.401797 0.160 Uiso 1 1 calc R U . . .


_geom_special_details            
; 
 All esds (except the esd in the dihedral angle between two l.s. planes) 
 are estimated using the full covariance matrix.  The cell esds are taken 
 into account individually in the estimation of esds in distances, angles 
 and torsion angles; correlations between esds in cell parameters are only 
 used when they are defined by crystal symmetry.  An approximate (isotropic) 
 treatment of cell esds is used for estimating esds involving l.s. planes. 
;

loop_
_geom_bond_atom_site_label_1
_geom_bond_atom_site_label_2
_geom_bond_distance
_geom_bond_site_symmetry_2
_geom_bond_publ_flag
Si1 C23 1.857(2) . ?
Si1 C22 1.860(2) . ?
Si1 C24 1.867(2) . ?
Si1 C16 1.8916(17) . ?
Si2 C27 1.853(2) . ?
Si2 C25 1.859(3) . ?
Si2 C26 1.861(2) . ?
Si2 C8 1.8967(17) . ?
O23 C18 1.370(2) . ?
O23 C21 1.424(2) . ?
C1 C8 1.355(2) . ?
C1 C2 1.498(2) . ?
C1 C15 1.498(2) . ?
C2 C3 1.390(2) . ?
C2 C7 1.395(2) . ?
C3 C4 1.385(3) . ?
C4 C5 1.371(3) . ?
C5 C6 1.371(3) . ?
C6 C7 1.385(3) . ?
C8 C9 1.494(2) . ?
C9 C14 1.386(3) . ?
C9 C10 1.386(3) . ?
C10 C11 1.380(3) . ?
C11 C12 1.364(4) . ?
C12 C13 1.366(4) . ?
C13 C14 1.389(3) . ?
C15 C20 1.392(2) . ?
C15 C16 1.411(2) . ?
C16 C17 1.400(2) . ?
C17 C18 1.380(2) . ?
C18 C19 1.377(2) . ?
C19 C20 1.376(2) . ?

loop_
_geom_angle_atom_site_label_1
_geom_angle_atom_site_label_2
_geom_angle_atom_site_label_3
_geom_angle
_geom_angle_site_symmetry_1
_geom_angle_site_symmetry_3
_geom_angle_publ_flag
C23 Si1 C22 111.65(11) . . ?
C23 Si1 C24 107.00(12) . . ?
C22 Si1 C24 107.44(11) . . ?
C23 Si1 C16 112.25(9) . . ?
C22 Si1 C16 109.63(9) . . ?
C24 Si1 C16 108.69(10) . . ?
C27 Si2 C25 111.99(15) . . ?
C27 Si2 C26 106.54(12) . . ?
C25 Si2 C26 106.08(12) . . ?
C27 Si2 C8 114.14(10) . . ?
C25 Si2 C8 108.03(11) . . ?
C26 Si2 C8 109.75(9) . . ?
C18 O23 C21 117.93(16) . . ?
C8 C1 C2 124.66(15) . . ?
C8 C1 C15 121.22(14) . . ?
C2 C1 C15 113.98(13) . . ?
C3 C2 C7 117.28(16) . . ?
C3 C2 C1 123.45(15) . . ?
C7 C2 C1 119.25(15) . . ?
C4 C3 C2 121.12(17) . . ?
C5 C4 C3 120.52(19) . . ?
C6 C5 C4 119.57(18) . . ?
C5 C6 C7 120.25(18) . . ?
C6 C7 C2 121.27(18) . . ?
C1 C8 C9 121.12(15) . . ?
C1 C8 Si2 126.00(13) . . ?
C9 C8 Si2 112.65(11) . . ?
C14 C9 C10 117.81(18) . . ?
C14 C9 C8 121.09(17) . . ?
C10 C9 C8 121.05(17) . . ?
C11 C10 C9 120.9(2) . . ?
C12 C11 C10 120.4(3) . . ?
C11 C12 C13 120.1(2) . . ?
C12 C13 C14 119.9(2) . . ?
C9 C14 C13 120.9(2) . . ?
C20 C15 C16 118.96(15) . . ?
C20 C15 C1 118.12(14) . . ?
C16 C15 C1 122.90(14) . . ?
C17 C16 C15 117.48(15) . . ?
C17 C16 Si1 116.30(12) . . ?
C15 C16 Si1 126.22(13) . . ?
C18 C17 C16 122.47(16) . . ?
O23 C18 C19 116.05(16) . . ?
O23 C18 C17 124.53(17) . . ?
C19 C18 C17 119.42(16) . . ?
C20 C19 C18 119.47(16) . . ?
C19 C20 C15 122.18(16) . . ?

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
C8 C1 C2 C3 -43.5(2) . . . . ?
C15 C1 C2 C3 140.81(17) . . . . ?
C8 C1 C2 C7 138.04(17) . . . . ?
C15 C1 C2 C7 -37.6(2) . . . . ?
C7 C2 C3 C4 0.2(3) . . . . ?
C1 C2 C3 C4 -178.31(17) . . . . ?
C2 C3 C4 C5 -0.3(3) . . . . ?
C3 C4 C5 C6 0.1(3) . . . . ?
C4 C5 C6 C7 0.2(3) . . . . ?
C5 C6 C7 C2 -0.4(3) . . . . ?
C3 C2 C7 C6 0.2(3) . . . . ?
C1 C2 C7 C6 178.70(16) . . . . ?
C2 C1 C8 C9 -0.4(2) . . . . ?
C15 C1 C8 C9 174.95(14) . . . . ?
C2 C1 C8 Si2 -174.47(12) . . . . ?
C15 C1 C8 Si2 0.9(2) . . . . ?
C27 Si2 C8 C1 -39.03(19) . . . . ?
C25 Si2 C8 C1 86.23(18) . . . . ?
C26 Si2 C8 C1 -158.53(16) . . . . ?
C27 Si2 C8 C9 146.47(15) . . . . ?
C25 Si2 C8 C9 -88.27(16) . . . . ?
C26 Si2 C8 C9 26.97(15) . . . . ?
C1 C8 C9 C14 -77.5(2) . . . . ?
Si2 C8 C9 C14 97.30(16) . . . . ?
C1 C8 C9 C10 105.2(2) . . . . ?
Si2 C8 C9 C10 -80.04(19) . . . . ?
C14 C9 C10 C11 2.2(3) . . . . ?
C8 C9 C10 C11 179.58(19) . . . . ?
C9 C10 C11 C12 -0.5(4) . . . . ?
C10 C11 C12 C13 -1.0(4) . . . . ?
C11 C12 C13 C14 0.9(4) . . . . ?
C10 C9 C14 C13 -2.3(3) . . . . ?
C8 C9 C14 C13 -179.71(17) . . . . ?
C12 C13 C14 C9 0.8(3) . . . . ?
C8 C1 C15 C20 -70.1(2) . . . . ?
C2 C1 C15 C20 105.76(16) . . . . ?
C8 C1 C15 C16 111.70(18) . . . . ?
C2 C1 C15 C16 -72.47(19) . . . . ?
C20 C15 C16 C17 1.5(2) . . . . ?
C1 C15 C16 C17 179.69(14) . . . . ?
C20 C15 C16 Si1 -178.01(12) . . . . ?
C1 C15 C16 Si1 0.2(2) . . . . ?
C23 Si1 C16 C17 137.46(14) . . . . ?
C22 Si1 C16 C17 -97.86(14) . . . . ?
C24 Si1 C16 C17 19.30(16) . . . . ?
C23 Si1 C16 C15 -43.06(17) . . . . ?
C22 Si1 C16 C15 81.63(16) . . . . ?
C24 Si1 C16 C15 -161.21(15) . . . . ?
C15 C16 C17 C18 -1.2(2) . . . . ?
Si1 C16 C17 C18 178.34(13) . . . . ?
C21 O23 C18 C19 -170.62(17) . . . . ?
C21 O23 C18 C17 9.0(3) . . . . ?
C16 C17 C18 O23 -179.04(16) . . . . ?
C16 C17 C18 C19 0.6(3) . . . . ?
O23 C18 C19 C20 179.36(16) . . . . ?
C17 C18 C19 C20 -0.3(3) . . . . ?
C18 C19 C20 C15 0.7(3) . . . . ?
C16 C15 C20 C19 -1.3(3) . . . . ?
C1 C15 C20 C19 -179.57(16) . . . . ?

_refine_diff_density_max         0.179
_refine_diff_density_min         -0.201
_refine_diff_density_rms         0.033

