Reactions of (tert-Butyldimethylsilyl)alkynes with IPy2BF4: Selective Synthesis of Novel Head-to-Head Dimers
José Barluenga; Isidro Llorente; Lorenzo J. Alvarez-García; José M. González; Pedro J. Campos; M. Rosario Díaz; Santiago García-Granda; Journal of the American Chemical Society 119 (1997) 6933–6934; doi:10.1021/ja970108n

data_4116995
_publ_section_title
;
 Reactions of (tert-Butyldimethylsilyl)alkynes with IPy2BF4: Selective
 Synthesis of Novel Head-to-Head Dimers
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              6933
_journal_page_last               6934
_journal_paper_doi               10.1021/ja970108n
_journal_volume                  119
_journal_year                    1997
_chemical_compound_source        syntesis
_chemical_formula_sum            'C24 H26 I2'
_chemical_formula_weight         568.25
_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'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL
_cell_angle_alpha                90.00
_cell_angle_beta                 95.66(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            8
_cell_length_a                   35.790(8)
_cell_length_b                   10.502(5)
_cell_length_c                   12.401(3)
_cell_measurement_reflns_used    25
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      24.97
_cell_measurement_theta_min      0.57
_cell_volume                     4638(3)
_computing_cell_refinement       'DIRDIF (Beurskens, 1992)'
_computing_data_collection
;
CAD-4 Diffractometer Control Software (Enraf-Nonius, 1994)
;
_computing_data_reduction        'REFLEX (Local Programs)'
_computing_molecular_graphics    'EUCLID package (Speck, 1982)'
_computing_publication_material  'SHELXL-93, PARST'
_computing_structure_refinement
; 
SHELXL93 (Sheldrick, 1993). Further geometrical calculations were
made with PARST (Nardelli, 1983).
;
_computing_structure_solution    'SHELXS-86 (Sheldrick, 1990)'
_diffrn_ambient_temperature      293(2)
_diffrn_measurement_device       'Enraf-Nonius CAD-4 diffractometer'
_diffrn_measurement_method       '\w-2\q scan technique'
_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  0.099
_diffrn_reflns_av_sigmaI/netI    0.3308
_diffrn_reflns_limit_h_max       42
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       12
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       14
_diffrn_reflns_limit_l_min       -14
_diffrn_reflns_number            9082
_diffrn_reflns_theta_max         24.97
_diffrn_reflns_theta_min         0.57
_diffrn_standards_decay_%        7
_diffrn_standards_interval_count 200
_diffrn_standards_interval_time  3600
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    2.717
_exptl_absorpt_correction_T_max  1.00
_exptl_absorpt_correction_T_min  0.35
_exptl_absorpt_correction_type   'DIFABS (Walker, Stuart, 1983)'
_exptl_crystal_colour            yellow
_exptl_crystal_density_diffrn    1.627
_exptl_crystal_density_meas      ?
_exptl_crystal_description       'prismatic plate'
_exptl_crystal_F_000             1104
_exptl_crystal_size_max          0.33
_exptl_crystal_size_mid          0.30
_exptl_crystal_size_min          0.13
_refine_diff_density_max         0.970
_refine_diff_density_min         -1.700
_refine_diff_density_rms         0.175
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_all   0.894
_refine_ls_goodness_of_fit_obs   1.222
_refine_ls_hydrogen_treatment    'isotropic common, riding'
_refine_ls_matrix_type           full
_refine_ls_number_parameters     470
_refine_ls_number_reflns         8158
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.894
_refine_ls_restrained_S_obs      1.222
_refine_ls_R_factor_all          0.1325
_refine_ls_R_factor_obs          0.0569
_refine_ls_shift/esd_max         -0.003
_refine_ls_shift/esd_mean        0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.1036P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_all         0.1634
_refine_ls_wR_factor_obs         0.1524
_reflns_number_observed          4034
_reflns_number_total             8158
_reflns_observed_criterion       >2sigma(I)
_cod_data_source_file            ja970108n.cif
_cod_data_source_block           4c
_cod_depositor_comments
;
The following automatic conversions were performed:

'_exptl_crystal_density_meas' value 'none' 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^)+(0.1036P)^2^+0.0000P] 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^)+(0.1036P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'.

Automatic conversion script
Id: cif_fix_values 3143 2015-03-26 13:38:13Z robertas 
;
_cod_original_cell_volume        4638.4(26)
_cod_database_code               4116995