Substituted 2,4,4,6-tetraphenyl-4H-selenopyrans: preparation, photocolouration and 4H-selenopyran ring geometry; an X-ray and DFT calculation study
Jiří Kroulík; Jan Čejka; Stanislav Böhm; Pavel Šebek; Stanislav Nešp°urek; Igor Koshets; Petr Sedmera; Petr Halada; Vladimír Havlíček; Bohumil Kratochvíl; Josef Kuthan; J. Chem. Soc., Perkin Trans. 2  (2002) 1909–1916; doi:10.1039/b204976g

data_7204463
_publ_section_title
;
 Substituted 2,4,4,6-tetraphenyl-4H-selenopyrans: preparation,
 photocolouration and 4H-selenopyran ring geometry; an X-ray and DFT
 calculation study
;
_journal_issue                   11
_journal_name_full               'J. Chem. Soc., Perkin Trans. 2'
_journal_page_first              1909
_journal_page_last               1916
_journal_paper_doi               10.1039/b204976g
_journal_year                    2002
_chemical_formula_moiety         'C29 H22 Se1'
_chemical_formula_sum            'C29 H22 Se'
_chemical_formula_weight         449.45
_chemical_melting_point          139.0(10)
_chemical_name_systematic        2,4,4,6-tetraphenyl-4H-selenopyran
_space_group_IT_number           33
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2c -2n'
_symmetry_space_group_name_H-M   'P n a 21'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_audit_creation_date             02-22-08
_audit_creation_method           CRYSTALS_ver_12-03-99
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            8
_cell_length_a                   18.117(3)
_cell_length_b                   7.088(1)
_cell_length_c                   34.009(7)
_cell_measurement_reflns_used    23
_cell_measurement_temperature    293
_cell_measurement_theta_max      40
_cell_measurement_theta_min      38
_cell_volume                     4367.2(13)
_computing_cell_refinement       'CAD-4 software (Enraf-Nonius, 1989)'
_computing_data_collection       'CAD-4 software (Enraf-Nonius, 1989)'
_computing_data_reduction
;
RC93 (Watkin, D.J., Prout, C.K., Lilley, P.M.deQ. 1994)
;
_computing_molecular_graphics
;
CAMERON (Watkin, Prout & Pearce,  1996)
;
_computing_publication_material
;
CRYSTALS Issue 10 (Watkin, Prout, Carruthers & Betteridge, 1996)
;
_computing_structure_refinement
;
CRYSTALS Issue 10 (Watkin, Prout, Carruthers & Betteridge, 1996)
;
_computing_structure_solution    'SIR92 (Giacovazzo et al, 1992)'
_diffrn_ambient_temperature      293
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_device_type  'Enraf-nonius CAD4'
_diffrn_measurement_method       \w/2\q
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_type           'Cu K\a'
_diffrn_radiation_wavelength     1.54180
_diffrn_reflns_av_R_equivalents  0.01
_diffrn_reflns_limit_h_max       22
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       0
_diffrn_reflns_limit_k_min       -8
_diffrn_reflns_limit_l_max       41
_diffrn_reflns_limit_l_min       -42
_diffrn_reflns_number            9314
_diffrn_reflns_theta_max         78.00
_diffrn_reflns_theta_min         0.00
_diffrn_standards_decay_%        2.76
_diffrn_standards_interval_count 0
_diffrn_standards_interval_time  0
_diffrn_standards_number         2
_exptl_absorpt_coefficient_mu    2.40
_exptl_absorpt_correction_T_max  0.71
_exptl_absorpt_correction_T_min  0.51
_exptl_absorpt_correction_type   psi-scan
_exptl_absorpt_process_details   '\y scan,(North et al, 1968)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.37
_exptl_crystal_density_meas      ?
_exptl_crystal_description       block
_exptl_crystal_F_000             1836.66
_exptl_crystal_size_max          0.53
_exptl_crystal_size_mid          0.28
_exptl_crystal_size_min          0.14
_refine_diff_density_max         0.88
_refine_diff_density_min         -3.29
_refine_ls_abs_structure_details 'Flack, 0 Friedel-pairs'
_refine_ls_abs_structure_Flack   0.288(15)
_refine_ls_extinction_method     None
_refine_ls_goodness_of_fit_ref   1.0400
_refine_ls_hydrogen_treatment    refall
_refine_ls_matrix_type           full
_refine_ls_number_parameters     718
_refine_ls_number_reflns         7769
_refine_ls_R_factor_gt           0.0621
_refine_ls_shift/su_max          0.002258
_refine_ls_structure_factor_coef F
_refine_ls_weighting_details
;
Chebychev polynomial with 5 parameters, Carruthers & Watkin , 1979,
6.64     7.61     6.81     2.15    0.963
;
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_ref         0.0529
_reflns_limit_h_max              22
_reflns_limit_h_min              0
_reflns_limit_k_max              8
_reflns_limit_k_min              0
_reflns_limit_l_max              41
_reflns_limit_l_min              -42
_reflns_number_gt                7769
_reflns_number_total             8281
_reflns_threshold_expression     >1.96\s(I)
_cod_data_source_file            b204976g.txt
_cod_data_source_block           CRYSTALS_cif2
_cod_depositor_comments
;
The following automatic conversions were performed:
'_symmetry_cell_setting' value 'Orthorhombic ' changed to 'orthorhombic'
according to '/home/adriana/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 1555 2011-01-17 13:19:09Z saulius 

The following automatic conversions were performed:

'_chemical_melting_point' value '138-140' was changed to '139.0(10)'
- the average value was taken and precision was estimated.

Automatic conversion script
Id: cif_fix_values 1569 2011-02-09 13:29:24Z adriana 
;
_cod_original_cell_volume        4367.0
_cod_original_sg_symbol_H-M      'P n a 21 '
_cod_original_formula_sum        ' C29 H22 Se1 '
_cod_database_code               7204463