Two Organic Diselenides: Dimesityl Diselenide and Bis(2,4,6-triisopropylphenyl) Diselenide
Jeske, Jörg; Salzen, Andreas Martens-von; du Mont, Wolf-Walther; Jones, Peter G.; Acta Crystallographica Section C 54 (1998) 1873–1875; doi:10.1107/S0108270198010579

data_2007888
_publ_section_title
;
 Two Organic Diselenides: Dimesityl Diselenide and
 Bis(2,4,6-triisopropylphenyl) Diselenide
;
_journal_issue                   12
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              1873
_journal_page_last               1875
_journal_paper_doi               10.1107/S0108270198010579
_journal_volume                  54
_journal_year                    1998
_chemical_formula_moiety         'C18 H22 Se2'
_chemical_formula_sum            'C18 H22 Se2'
_chemical_formula_weight         396.28
_chemical_name_systematic
;
 dimesityl diselenide
;
_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'
_audit_creation_method           SHELXL
_cell_angle_alpha                90.00
_cell_angle_beta                 96.18(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   6.2064(15)
_cell_length_b                   18.379(4)
_cell_length_c                   14.943(4)
_cell_measurement_reflns_used    50
_cell_measurement_temperature    178(2)
_cell_measurement_theta_max      11.5
_cell_measurement_theta_min      10
_cell_volume                     1694.6(7)
_computing_cell_refinement       P3
_computing_data_collection       'P3 (Nicolet, 1987)'
_computing_data_reduction        'XDISK (Nicolet, 1987)'
_computing_molecular_graphics    'XP (Siemens, 1994b)'
_computing_publication_material  SHELXL-93
_computing_structure_refinement  'SHELXL-93 (Sheldrick, 1993)'
_computing_structure_solution    'SHELXS-86 (Sheldrick, 1990)'
_diffrn_ambient_temperature      178(2)
_diffrn_measurement_device       'Nicolet R3'
_diffrn_measurement_method       \w-scans
_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  0.0170
_diffrn_reflns_av_sigmaI/netI    0.0235
_diffrn_reflns_limit_h_max       2
_diffrn_reflns_limit_h_min       -7
_diffrn_reflns_limit_k_max       21
_diffrn_reflns_limit_k_min       -3
_diffrn_reflns_limit_l_max       17
_diffrn_reflns_limit_l_min       -17
_diffrn_reflns_number            4395
_diffrn_reflns_theta_max         25.05
_diffrn_reflns_theta_min         3.30
_diffrn_standards_decay_%        5
_diffrn_standards_interval_count 147
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    4.353
_exptl_absorpt_correction_T_max  0.647
_exptl_absorpt_correction_T_min  0.261
_exptl_absorpt_correction_type   'Psi scans (XEMP; Siemens, 1994a)'
_exptl_crystal_colour            yellow
_exptl_crystal_density_diffrn    1.553
_exptl_crystal_density_meas      ?
_exptl_crystal_description       tablet
_exptl_crystal_F_000             792
_exptl_crystal_size_max          0.7
_exptl_crystal_size_mid          0.4
_exptl_crystal_size_min          0.15
_refine_diff_density_max         0.475
_refine_diff_density_min         -0.571
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_all   1.042
_refine_ls_goodness_of_fit_obs   1.061
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     187
_refine_ls_number_reflns         2993
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.042
_refine_ls_restrained_S_obs      1.061
_refine_ls_R_factor_all          0.0380
_refine_ls_R_factor_obs          0.0304
_refine_ls_shift/esd_max         -0.128
_refine_ls_shift/esd_mean        0.002
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w = 1/[\s^2^(Fo^2^)+(0.0540P)^2^+0.5930P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_all         0.0835
_refine_ls_wR_factor_obs         0.0780
_reflns_number_observed          2546
_reflns_number_total             2993
_reflns_observed_criterion       >2sigma(I)
_cod_data_source_file            bm1242.cif
_cod_data_source_block           I
_cod_depositor_comments
;
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^)+(0.0540P)^2^+0.5930P] 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^)+(0.0540P)^2^+0.5930P] 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        1694.5(7)
_cod_original_sg_symbol_H-M      'P 21/c'
_cod_database_code               2007888