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_7116506
_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 H24 Br2 O2'
_chemical_formula_weight         564.30
_chemical_name_common            2,10BrNP
_chemical_name_systematic
2,10dibromo3(2isopropylphenyl)3(4methoxyphenyl)3Hbenzo[f]chromene
_chemical_properties_physical    Photo-sensitive
_space_group_crystal_system      triclinic
_space_group_IT_number           2
_space_group_name_Hall           '-P 1'
_space_group_name_H-M_alt        'P -1'
_symmetry_space_group_name_Hall  '-P 1'
_symmetry_space_group_name_H-M   'P -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                79.651(2)
_cell_angle_beta                 77.966(2)
_cell_angle_gamma                77.931(2)
_cell_formula_units_Z            2
_cell_length_a                   8.9872(17)
_cell_length_b                   9.0894(17)
_cell_length_c                   15.463(3)
_cell_measurement_reflns_used    4246
_cell_measurement_temperature    90.0
_cell_measurement_theta_max      26.3383
_cell_measurement_theta_min      2.3549
_cell_volume                     1195.8(4)
_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 0.951
_diffrn_measured_fraction_theta_max 0.951
_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  0.0159
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       11
_diffrn_reflns_limit_k_min       -11
_diffrn_reflns_limit_l_max       15
_diffrn_reflns_limit_l_min       -19
_diffrn_reflns_number            6211
_diffrn_reflns_theta_full        26.34
_diffrn_reflns_theta_max         26.34
_diffrn_reflns_theta_min         1.36
_diffrn_source                   'sealed tube'
_exptl_absorpt_coefficient_mu    3.414
_exptl_absorpt_correction_T_max  0.23
_exptl_absorpt_correction_T_min  0.17
_exptl_absorpt_correction_type   empirical
_exptl_absorpt_process_details   'SADABS Sheldrick 1996'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.567
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             568
_exptl_crystal_preparation       photochromic
_exptl_crystal_recrystallization_method
'Re-crystallisation from solvent: dichrolomethane/hexane/methanol mixed solvent'
_exptl_crystal_size_max          0.800
_exptl_crystal_size_mid          0.800
_exptl_crystal_size_min          0.600
_refine_diff_density_max         1.876
_refine_diff_density_min         -0.515
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.088
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     301
_refine_ls_number_reflns         4637
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.088
_refine_ls_R_factor_all          0.0477
_refine_ls_R_factor_gt           0.0440
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0731P)^2^+4.5419P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1332
_refine_ls_wR_factor_ref         0.1351
_reflns_number_gt                4197
_reflns_number_total             4637
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            c4cc10294k2.cif
_cod_data_source_block           I
_cod_database_code               7116506
_shelx_res_checksum              99373