Treating octasilanol [Si<sub>8</sub>O<sub>12</sub>][OH]<sub>8</sub> with tetramethoxysilane and trimethoxyvinylsilane: a halogen-free synthetic route to alkoxysilyl-substituted double-four-ring siloxanes.
Nozawa, Takeshi; Kobayashi, Toshiaki; Matsumoto, Tomohiro; Yagihashi, Fujio; Sato, Kazuhiko; Igarashi, Masayasu; Dalton transactions (Cambridge, England : 2003) 50 (2021) 1594–1598; doi:10.1039/d0dt04265j

data_7706375
_publ_section_title
;
 Treating octasilanol [Si<sub>8</sub>O<sub>12</sub>][OH]<sub>8</sub> with
 tetramethoxysilane and trimethoxyvinylsilane: a halogen-free synthetic
 route to alkoxysilyl-substituted double-four-ring siloxanes.
;
_journal_issue                   5
_journal_name_full
'Dalton transactions (Cambridge, England : 2003)'
_journal_page_first              1594
_journal_page_last               1598
_journal_paper_doi               10.1039/d0dt04265j
_journal_volume                  50
_journal_year                    2021
_chemical_formula_moiety         'C24 H72 O44 Si16'
_chemical_formula_sum            'C24 H72 O44 Si16'
_chemical_formula_weight         1514.25
_chemical_name_systematic        '[Si8O12][OSi(OMe)3]8'
_space_group_crystal_system      monoclinic
_space_group_IT_number           9
_space_group_name_Hall           'C -2yc'
_space_group_name_H-M_alt        'C 1 c 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     dual
_audit_creation_date             2020-04-07
_audit_creation_method
;
Olex2 1.2
(compiled 2018.05.29 svn.r3508 for OlexSys, GUI svn.r5506)
;
_audit_update_record
;
2020-05-07 deposited with the CCDC.	2020-12-29 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 90.201(5)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   14.713(3)
_cell_length_b                   16.575(4)
_cell_length_c                   26.663(6)
_cell_measurement_reflns_used    5169
_cell_measurement_temperature    93
_cell_measurement_theta_max      27.5
_cell_measurement_theta_min      3.2
_cell_volume                     6502(3)
_computing_cell_refinement       'CrystalClear-SM Expert 2.1 b29 (Rigaku, 2013)'
_computing_data_collection       'CrystalClear-SM Expert 2.1 b29 (Rigaku, 2013)'
_computing_data_reduction        'CrystalClear-SM Expert 2.1 b29 (Rigaku, 2013)'
_computing_molecular_graphics    'Olex2 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 (Dolomanov et al., 2009)'
_computing_structure_refinement  'ShelXL (Sheldrick, 2015)'
_computing_structure_solution    'ShelXT (Sheldrick, 2015)'
_diffrn_ambient_temperature      93
_diffrn_measured_fraction_theta_full 0.997
_diffrn_measured_fraction_theta_max 0.995
_diffrn_measurement_device_type  'Rigaku Pilatus 200K'
_diffrn_measurement_method       '\w scans'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71075
_diffrn_reflns_av_R_equivalents  0.1161
_diffrn_reflns_av_unetI/netI     0.1137
_diffrn_reflns_Laue_measured_fraction_full 0.997
_diffrn_reflns_Laue_measured_fraction_max 0.995
_diffrn_reflns_limit_h_max       18
_diffrn_reflns_limit_h_min       -19
_diffrn_reflns_limit_k_max       21
_diffrn_reflns_limit_k_min       -21
_diffrn_reflns_limit_l_max       34
_diffrn_reflns_limit_l_min       -34
_diffrn_reflns_number            40200
_diffrn_reflns_point_group_measured_fraction_full 0.985
_diffrn_reflns_point_group_measured_fraction_max 0.974
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         27.478
_diffrn_reflns_theta_min         3.056
_diffrn_source                   'Rotating Anode'
_exptl_absorpt_coefficient_mu    0.413
_exptl_absorpt_correction_T_max  1.000
_exptl_absorpt_correction_T_min  0.674
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   '(REQAB; Jacobson, 1998)'
_exptl_crystal_colour            Colorless
_exptl_crystal_density_diffrn    1.547
_exptl_crystal_description       Plate
_exptl_crystal_F_000             3168
_exptl_crystal_recrystallization_method
'Re-crystallisation from solvent: toluene and hexane'
_exptl_crystal_size_max          0.23
_exptl_crystal_size_mid          0.14
_exptl_crystal_size_min          0.04
_refine_diff_density_max         0.903
_refine_diff_density_min         -0.514
_refine_diff_density_rms         0.113
_refine_ls_abs_structure_details
;
 Flack x determined using 3916 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   0.56(13)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.967
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     808
_refine_ls_number_reflns         14534
_refine_ls_number_restraints     2
_refine_ls_restrained_S_all      0.967
_refine_ls_R_factor_all          0.0965
_refine_ls_R_factor_gt           0.0659
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0930P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1520
_refine_ls_wR_factor_ref         0.1664
_reflns_Friedel_coverage         0.956
_reflns_Friedel_fraction_full    0.972
_reflns_Friedel_fraction_max     0.953
_reflns_number_gt                10389
_reflns_number_total             14534
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d0dt04265j2.cif
_cod_data_source_block           shelx_trans
_cod_depositor_comments
;
The following automatic conversions were performed:

data item '_exptl_absorpt_correction_type' value 'Multi-scan' was
changed to 'multi-scan' in accordance with the
/home/data/users/saulius/crontab/automatic-downloads/rss-feeds/RSC/lib/dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.2 last updated on
2011-04-26.

Automatic conversion script
Id: cif_fix_values 7556 2019-12-06 15:28:31Z antanas 

 Adding full bibliography for 7706375.cif.
;
_cod_original_cell_volume        6503(2)
_cod_database_code               7706375
_shelx_shelxl_version_number     2018/3
_olex2_refinement_description
;
1. Fixed Uiso
 At 1.5 times of:
  All C(H,H,H) groups, All C(H,H,H,H,H,H) groups
2. Others
 Fixed Sof: O44(0.65) O42(0.65) H24A(0.65) H24B(0.65) H24C(0.65) H24D(0.35)
 H24E(0.35) H24F(0.35) O43(0.65) H22A(0.65) H22B(0.65) H22C(0.65) H22D(0.35)
 H22E(0.35) H22F(0.35) H23A(0.65) H23B(0.65) H23C(0.65) H23D(0.35) H23E(0.35)
 H23F(0.35) O42A(0.35) O43A(0.35) O44A(0.35)
3.a Idealised Me refined as rotating group:
 C10(H10A,H10B,H10C), C3(H3A,H3B,H3C), C20(H20A,H20B,H20C), C17(H17A,H17B,
 H17C), C24(H24A,H24B,H24C), C24(H24D,H24E,H24F), C2(H2A,H2B,H2C), C5(H5A,H5B,
 H5C), C8(H8A,H8B,H8C), C21(H21A,H21B,H21C), C15(H15A,H15B,H15C), C19(H19A,H19B,
 H19C), C12(H12A,H12B,H12C), C22(H22A,H22B,H22C), C22(H22D,H22E,H22F), C23(H23A,
 H23B,H23C), C23(H23D,H23E,H23F), C9(H9A,H9B,H9C), C18(H18A,H18B,H18C), C1(H1A,
 H1B,H1C), C7(H7A,H7B,H7C), C6(H6A,H6B,H6C), C14(H14A,H14B,H14C), C11(H11A,H11B,
 H11C), C13(H13A,H13B,H13C), C4(H4A,H4B,H4C), C16(H16A,H16B,H16C)
;
_shelx_res_checksum              11890
_olex2_submission_special_instructions 'No special instructions were received'