Two fluoradene derivatives: pseudosymmetry, eccentric ellipsoids and a phase transition
Xia, Aibing; Selegue, John P.; Carrillo, Alberto; Patrick, Brian O.; Parkin, Sean; Brock, Carolyn Pratt; Acta Crystallographica Section B 57 (2001) 507–516; doi:10.1107/S0108768101008631

data_2103700
_publ_section_title
;
 Two fluoradene derivatives: pseudosymmetry, eccentric ellipsoids and a
 phase transition
;
_journal_issue                   4
_journal_name_full               'Acta Crystallographica Section B'
_journal_page_first              507
_journal_page_last               516
_journal_paper_doi               10.1107/S0108768101008631
_journal_volume                  57
_journal_year                    2001
_chemical_formula_moiety         'C28 H32 Si'
_chemical_formula_sum            'C28 H32 Si'
_chemical_formula_weight         396.63
_chemical_melting_point          413.15
_chemical_name_systematic
;
7b-triisopropylsilylfluoradene
;
_space_group_IT_number           2
_symmetry_cell_setting           triclinic
_symmetry_space_group_name_Hall  '-P 1 (-1/2*x+1/2*z,-y,1/2*x+1/2*z)'
_symmetry_space_group_name_H-M   'B -1'
_audit_creation_method
;
SHELXL-97, macros written locally, and C. P. Brock
;
_cell_angle_alpha                80.780(10)
_cell_angle_beta                 83.450(10)
_cell_angle_gamma                84.070(10)
_cell_formula_units_Z            4
_cell_length_a                   8.0120(10)
_cell_length_b                   16.171(2)
_cell_length_c                   18.280(2)
_cell_measurement_reflns_used    27832
_cell_measurement_temperature    294.0(10)
_cell_measurement_theta_max      27.8
_cell_measurement_theta_min      2.6
_cell_volume                     2313.8(5)
_computing_cell_refinement       'DENZO-SMN (Otwinowski & Minor, 1997)'
_computing_data_collection       'COLLECT software (Nonius, 1998)'
_computing_data_reduction        'SCALEPACK (Otwinowski & Minor, 1997)'
_computing_molecular_graphics    'SHELXTL PC (Sheldrick, 1990)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution
;
Starting model from full structure (P1-bar rather than B1-bar;
two independent molecules in the asymmetric unit)
;
_diffrn_ambient_temperature      294.0(10)
_diffrn_detector_area_resol_mean 18
_diffrn_measured_fraction_theta_full .976
_diffrn_measured_fraction_theta_max .976
_diffrn_measurement_device_type  'Nonius KappaCCD diffractometer'
_diffrn_measurement_method       '\f and \w scans with 1.0\% steps'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     .71073
_diffrn_reflns_av_R_equivalents  .031
_diffrn_reflns_av_sigmaI/netI    .033
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       19
_diffrn_reflns_limit_k_min       -18
_diffrn_reflns_limit_l_max       21
_diffrn_reflns_limit_l_min       -21
_diffrn_reflns_number            3988
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         25.0
_diffrn_reflns_theta_min         3.2
_diffrn_standards_decay_%        <2.
_exptl_absorpt_coefficient_mu    .113
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            'pale yellow'
_exptl_crystal_density_diffrn    1.139
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       tablet
_exptl_crystal_F_000             856
_exptl_crystal_size_max          .58
_exptl_crystal_size_mid          .53
_exptl_crystal_size_min          .37
_refine_diff_density_max         .32
_refine_diff_density_min         -.54
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.03
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     271
_refine_ls_number_reflns         3988
_refine_ls_number_restraints     4
_refine_ls_restrained_S_all      1.03
_refine_ls_R_factor_all          .088
_refine_ls_R_factor_gt           .082
_refine_ls_shift/su_max          .000
_refine_ls_shift/su_mean         .000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.089P)^2^+3.9P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_ref         .206
_reflns_number_gt                3640
_reflns_number_total             3988
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            bs0015.cif
_cod_data_source_block           PseuTips
_cod_depositor_comments
;
The following automatic conversions were performed:

'_chemical_melting_point' value '140_C' was changed to '413.15' - it
was converted from degrees Celsius(C) to Kelvins(K).

Automatic conversion script
Id: cif_fix_values 1646 2011-03-28 12:23:43Z adriana 
;
_cod_original_sg_symbol_Hall     -b_1
_cod_original_sg_symbol_H-M      'P -1'
_cod_database_code               2103700
_cod_database_fobs_code          2103700