Why Are Silyl Ethers Conformationally Different from Alkyl Ethers? Chair-Chair Conformational Equilibria in Silyloxycyclohexanes and Their Dependence on the Substituents on Silicon. The Wider Roles of Eclipsing, of 1,3-Repulsive Steric Interactions, and of Attractive Steric Interactions
Cecilia H. Marzabadi; J. Edgar Anderson; Jorge Gonzalez-Outeirino; Piers R. J. Gaffney; Christopher G. H. White; Derek A. Tocher; Louis J. Todaro; Journal of the American Chemical Society 125 (2003) 15163–15173; doi:10.1021/ja035936x

data_4114438
_publ_section_title
;
 Why Are Silyl Ethers Conformationally Different from Alkyl Ethers?
 Chair-Chair Conformational Equilibria in Silyloxycyclohexanes and Their
 Dependence on the Substituents on Silicon. The Wider Roles of Eclipsing,
 of 1,3-Repulsive Steric Interactions, and of Attractive Steric
 Interactions
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              15163
_journal_page_last               15173
_journal_paper_doi               10.1021/ja035936x
_journal_volume                  125
_journal_year                    2003
_chemical_formula_moiety         'C42 H40 O2 Si2'
_chemical_formula_sum            'C42 H40 O2 Si2'
_chemical_formula_weight         632.96
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2ybc'
_symmetry_space_group_name_H-M   'P 1 21/c 1'
_cell_angle_alpha                90
_cell_angle_beta                 96.53(8)
_cell_angle_gamma                90
_cell_formula_units_Z            8
_cell_length_a                   24.837(2)
_cell_length_b                   9.829(2)
_cell_length_c                   29.206(3)
_cell_measurement_reflns_used    25
_cell_measurement_temperature    295
_cell_measurement_theta_max      7.7
_cell_measurement_theta_min      5.5
_cell_volume                     7084(2)
_computing_cell_refinement       CAD4_(Enraf-Nonius,_1994)
_computing_data_collection       CAD4_(Enraf-Nonius,_1994)
_computing_data_reduction        process_OpenMoleN_(_1997)
_computing_publication_material  CIFGEN_IN_OpenMoleN_(_1997)
_computing_structure_refinement  LSFM_OpenMoleN_(_1997)
_computing_structure_solution    direct_methods_(SIR,_Burla_et_al.,_1989)
_diffrn_ambient_temperature      295
_diffrn_measurement_device_type  Enraf_Nonius_CAD4
_diffrn_measurement_method       \q/2\q
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_type           Mo-K\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0
_diffrn_reflns_av_sigmaI/netI    0.333
_diffrn_reflns_limit_h_max       26
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       0
_diffrn_reflns_limit_k_min       -10
_diffrn_reflns_limit_l_max       30
_diffrn_reflns_limit_l_min       -30
_diffrn_reflns_number            9558
_diffrn_reflns_theta_max         21.98
_diffrn_reflns_theta_min         2.5
_diffrn_source                   xray_tube
_diffrn_standards_decay_%        0
_diffrn_standards_interval_time  120
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    0.135
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.19
_exptl_crystal_density_method    none
_exptl_crystal_description       plate
_exptl_crystal_F_000             2688
_exptl_crystal_size_max          0.64
_exptl_crystal_size_mid          0.40
_exptl_crystal_size_min          0.12
_refine_diff_density_max         0.355
_refine_diff_density_min         -0.099
_refine_ls_extinction_coef       3.6427E-09
_refine_ls_extinction_expression
;
      equ(22) p292 "Crystallographic Computing" (1970)
;
_refine_ls_extinction_method     isotropic_(Zachariasen,_1963)
_refine_ls_goodness_of_fit_all   8.907
_refine_ls_goodness_of_fit_ref   1.510
_refine_ls_hydrogen_treatment    noref
_refine_ls_matrix_type           full
_refine_ls_number_constraints    0
_refine_ls_number_parameters     830
_refine_ls_number_reflns         3669
_refine_ls_number_restraints     320
_refine_ls_R_factor_all          0.165
_refine_ls_R_factor_gt           0.049
_refine_ls_shift/esd_mean        0.000
_refine_ls_shift/su_max          0.001
_refine_ls_structure_factor_coef F
_refine_ls_weighting_details     'w = 4Fo^2^/(\s^2^(Fo^2^) + 0.0016 Fo^4^)'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_all         0.278
_refine_ls_wR_factor_ref         0.050
_reflns_number_gt                3669
_reflns_number_total             9300
_reflns_threshold_expression     >3.0\s(I)
_cod_data_source_file            ja035936xsi20030904_095650.cif
_cod_data_source_block           5e
_cod_depositor_comments
;
The following automatic conversions were performed:

'_refine_ls_weighting_scheme' value '4Fo^2^/(\s^2^(Fo^2^) + 0.0016
Fo^4^)' was changed to 'calc'. New tag '_refine_ls_weighting_details'
was created. The value of the new tag was set to 'w =
4Fo^2^/(\s^2^(Fo^2^) + 0.0016 Fo^4^)'.

Automatic conversion script
Id: cif_fix_values 3143 2015-03-26 13:38:13Z robertas 
;
_cod_original_cell_volume        7083(3)
_cod_database_code               4114438