Rational molecular designs for drastic acceleration of the color-fading speed of photochromic naphthopyrans
Katsutoshi Arai; Yoichi Kobayashi; Jiro Abe; Chem.Commun. 51 (2015) 3057–; doi:10.1039/C4cc10294K

data_7116508
_publ_section_title
;
 Rational molecular designs for drastic acceleration of the color-fading
 speed of photochromic naphthopyrans
;
_journal_name_full               Chem.Commun.
_journal_page_first              3057
_journal_paper_doi               10.1039/C4cc10294K
_journal_volume                  51
_journal_year                    2015
_chemical_formula_sum            'C29 H25 Br O2'
_chemical_formula_weight         485.40
_chemical_name_systematic
2bromo3(2isopropylphenyl)3(4methoxyphenyl)3Hbenzo[f]chromene
_chemical_properties_physical    Photo-sensitive
_space_group_crystal_system      monoclinic
_space_group_IT_number           14
_space_group_name_Hall           '-P 2yn'
_space_group_name_H-M_alt        'P 1 21/n 1'
_symmetry_space_group_name_Hall  '-P 2yn'
_symmetry_space_group_name_H-M   'P 1 21/n 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_update_record
;
2014-10-28 deposited with the CCDC.
2015-01-15 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 101.4400(5)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   8.4379(3)
_cell_length_b                   16.1157(6)
_cell_length_c                   16.8070(6)
_cell_measurement_reflns_used    7268
_cell_measurement_temperature    90.0
_cell_measurement_theta_max      26.0262
_cell_measurement_theta_min      2.4728
_cell_volume                     2240.06(14)
_computing_cell_refinement       'SAINT V8.32B (Bruker AXS Inc., 2013)'
_computing_data_collection       'Bruker SMART APEXII'
_computing_data_reduction        'SAINT V8.32B (Bruker AXS Inc., 2013)'
_computing_molecular_graphics    'XSHELL V6.3.1 (Bruker AXS)'
_computing_publication_material  'Generate Report (Bruker AXS)'
_computing_structure_refinement  'SHELXL-2013 (Sheldrick, 2013)'
_diffrn_ambient_temperature      90.0
_diffrn_detector_area_resol_mean 8.3333
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_diffrn_measurement_device_type  'Bruker D8 goniometer'
_diffrn_measurement_method       'omega scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0134
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       19
_diffrn_reflns_limit_k_min       -19
_diffrn_reflns_limit_l_max       17
_diffrn_reflns_limit_l_min       -20
_diffrn_reflns_number            11385
_diffrn_reflns_theta_full        26.04
_diffrn_reflns_theta_max         26.04
_diffrn_reflns_theta_min         1.77
_diffrn_source                   'sealed tube'
_exptl_absorpt_coefficient_mu    1.860
_exptl_absorpt_correction_T_max  0.52
_exptl_absorpt_correction_T_min  0.44
_exptl_absorpt_correction_type   empirical
_exptl_absorpt_process_details   'SADABS Sheldrick 1996'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.439
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             1000
_exptl_crystal_preparation       photochromic
_exptl_crystal_recrystallization_method
'Re-crystallisation from solvent: dichrolomethane/hexane mixed solvent'
_exptl_crystal_size_max          0.600
_exptl_crystal_size_mid          0.500
_exptl_crystal_size_min          0.400
_refine_diff_density_max         0.366
_refine_diff_density_min         -0.316
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.047
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     292
_refine_ls_number_reflns         4403
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.047
_refine_ls_R_factor_all          0.0258
_refine_ls_R_factor_gt           0.0227
_refine_ls_shift/su_max          0.002
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0314P)^2^+1.1707P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0589
_refine_ls_wR_factor_ref         0.0601
_reflns_number_gt                4044
_reflns_number_total             4403
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            c4cc10294k2.cif
_cod_data_source_block           Ib
_cod_database_code               7116508
_shelx_res_checksum              10434