(±)-7,7,9,9-Tetramethyl-2,3:4,5-dinaphtho-1,6,8-trioxa-7,9-disilacyclonona-2,4-diene
Qiancai Liu; Mengxian Ding; Yonghua Lin; Yan Xing; Acta Crystallographica Section C 54 (1998) 145–146; doi:10.1107/S0108270197010317

data_2006980
_publ_contact_author
;  Prof. Mengxian Ding
   Changchun Institute of Applied Chemistry
   Chinese Academy of Sciences,
   159 Renmin Street, Changchun 130022
   People's Republic of China
;
_publ_section_title
(+-)-7,7,9,9-Tetramethyl-2,3:4,5-dinaphtho-1,6,8-trioxa-7,9-disilacyclonona-2,4-diene
_journal_issue                   1
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              145
_journal_page_last               146
_journal_paper_doi               10.1107/S0108270197010317
_journal_volume                  54
_journal_year                    1998
_chemical_formula_moiety         'C24 H24 O3 Si2'
_chemical_formula_sum            'C24 H24 O3 Si2'
_chemical_formula_weight         416.61
_chemical_melting_point          446.1(10)
_chemical_name_systematic
;
(+-)- 7,7,9,9-tetramethyl-2,3:4,5-di(naphtho)-1,6,8-trioxa-
7,9-disila-cyclonona-2,4-diene
;
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2yn'
_symmetry_space_group_name_H-M   'P 1 21/n 1'
_atom_type_scat_source           IntTabC
_audit_creation_method           SHELXL
_cell_angle_alpha                90.00
_cell_angle_beta                 94.320(10)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   10.6940(10)
_cell_length_b                   13.4810(10)
_cell_length_c                   15.307(2)
_cell_measurement_reflns_used    30
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      9.96
_cell_measurement_theta_min      4.83
_cell_volume                     2200.5(4)
_computing_cell_refinement       DIF4
_computing_data_collection       'DIF4 (Stoe & Cie, 1991a)'
_computing_data_reduction        'REDU4 (Stoe & Cie, 1991b)'
_computing_molecular_graphics    'SHELXTL-Plus (Sheldrick, 1991)'
_computing_publication_material  'XL SHELXTL-Plus'
_computing_structure_refinement  'SHELXL93 (Sheldrick, 1993)'
_computing_structure_solution    'SHELXS86 (Sheldrick, 1990)'
_diffrn_ambient_temperature      293(2)
_diffrn_measurement_device       'Siemens P4 4-circle-diffractometer'
_diffrn_measurement_method       \w/2\q
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0182
_diffrn_reflns_av_sigmaI/netI    0.0595
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       17
_diffrn_reflns_limit_l_min       0
_diffrn_reflns_number            4615
_diffrn_reflns_theta_max         24
_diffrn_reflns_theta_min         2.02
_diffrn_standards_decay_%        0
_diffrn_standards_interval_time  100
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    0.183
_exptl_absorpt_correction_T_max  0.26632
_exptl_absorpt_correction_T_min  0.24335
_exptl_absorpt_correction_type
'empirical \y scans (North, Phillips & Mathews, 1968)'
_exptl_crystal_colour            yellow
_exptl_crystal_density_diffrn    1.258
_exptl_crystal_density_meas      ?
_exptl_crystal_description       prism
_exptl_crystal_F_000             880
_exptl_crystal_size_max          0.42
_exptl_crystal_size_mid          0.38
_exptl_crystal_size_min          0.32
_refine_diff_density_max         0.182
_refine_diff_density_min         -0.205
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_all   0.489
_refine_ls_goodness_of_fit_obs   0.479
_refine_ls_matrix_type           full
_refine_ls_number_parameters     306
_refine_ls_number_reflns         3434
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.505
_refine_ls_restrained_S_obs      0.479
_refine_ls_R_factor_all          0.0713
_refine_ls_R_factor_obs          .0404
_refine_ls_shift/esd_max         0.179
_refine_ls_shift/esd_mean        0.023
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w = 1/[\s^2^(Fo^2^)+(0.2186P)^2^+2.3095P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_all         0.1637
_refine_ls_wR_factor_obs         .1217
_reflns_number_observed          2170
_reflns_number_total             3451
_reflns_observed_criterion       >2sigma(I)
_cod_data_source_file            vj1062.cif
_cod_data_source_block           e041
_cod_depositor_comments
;
The following automatic conversions were performed:
'_symmetry_cell_setting' value 'Monoclinic' changed to 'monoclinic'
according to '/home/saulius/struct/CIF-dictionaries/cif_core.dic'
dictionary named 'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_enum 1527 2010-12-29 10:47:43Z saulius 

The following automatic conversions were performed:

'_chemical_melting_point' value '172-174\%C' was changed to
'446.1(10)' - it was converted from degrees Celsius(C) to Kelvins(K),
the average value was taken and precision was estimated.

Automatic conversion script
Id: cif_fix_values 1646 2011-03-28 12:23:43Z adriana 

The following automatic conversions were performed:

'_chemical_melting_point' value '172-174\%C' was changed to
'446.1(10)' - it was converted from degrees Celsius(C) to Kelvins(K),
the average value was taken and precision was
estimated.

'_symmetry_cell_setting' value 'Monoclinic' changed to
'monoclinic' according to
/home/saulius/struct/CIF-dictionaries/cif_core.dic dictionary named
'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_values 1715 2011-07-08 13:25:40Z adriana 

The following automatic conversions were performed:

'_exptl_crystal_density_meas' value 'not measured' was changed to '?'
- the value is perceived as not measured.

Automatic conversion script
Id: cif_fix_values 3008 2015-01-20 13:52:24Z robertas 

The following automatic conversions were performed:

'_refine_ls_weighting_scheme' value 'calc w =
1/[\s^2^(Fo^2^)+(0.2186P)^2^+2.3095P] where P=(Fo^2^+2Fc^2^)/3' was
changed to 'calc'. New tag '_refine_ls_weighting_details' was
created. The value of the new tag was set to 'w =
1/[\s^2^(Fo^2^)+(0.2186P)^2^+2.3095P] where P=(Fo^2^+2Fc^2^)/3'.

Automatic conversion script
Id: cif_fix_values 3143 2015-03-26 13:38:13Z robertas 
;
_cod_original_sg_symbol_H-M      'P 21/n'
_cod_database_code               2006980