Structure of three novel photochromic compounds; X-ray crystallographic and theoretical studies
Crano, J.; Knowles, D.; Kwiatkowski, P.; Flood, T.; Ross, R.; Chiang, L.; Lasch, J.; Chadha, R.; Siuzdak, G.; Acta Crystallographica Section B 50 (1994) 772–779; doi:10.1107/S0108768194005938

data_2101247
_publ_section_title
;
 Structure of three novel photochromic compounds; X-ray
 crystallographic and theoretical studies
;
_journal_issue                   6
_journal_name_full               'Acta Crystallographica Section B'
_journal_page_first              772
_journal_page_last               779
_journal_paper_doi               10.1107/S0108768194005938
_journal_volume                  50
_journal_year                    1994
_chemical_formula_sum            'C20 H21 F N2 O3'
_chemical_formula_weight         356.4
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2ybc'
_symmetry_space_group_name_H-M   'P 1 21/c 1'
_atom_type_scat_source           IntTabIV
_cell_angle_alpha                90
_cell_angle_beta                 98.900(10)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   11.484(3)
_cell_length_b                   13.832(2)
_cell_length_c                   11.5110(10)
_cell_measurement_reflns_used    25
_cell_measurement_temperature    173
_cell_measurement_theta_max      40
_cell_measurement_theta_min      30
_cell_volume                     1806.5(6)
_diffrn_measurement_device       'Rigaku AFC-6R four-circle'
_diffrn_measurement_method       2\q-\q
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.0426
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       12
_diffrn_reflns_limit_l_min       0
_diffrn_reflns_number            3403
_diffrn_reflns_theta_max         60.0
_diffrn_standards_decay_%        'not significant'
_diffrn_standards_interval_count 200
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    0.754
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.308
_exptl_crystal_description       parallelepiped
_exptl_crystal_size_max          0.50
_exptl_crystal_size_mid          0.40
_exptl_crystal_size_min          0.25
_refine_diff_density_max         0.33
_refine_diff_density_min         -0.26
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_obs   1.74
_refine_ls_hydrogen_treatment    noref
_refine_ls_number_parameters     319
_refine_ls_number_reflns         2229
_refine_ls_R_factor_obs          0.0468
_refine_ls_shift/esd_max         0.001
_refine_ls_structure_factor_coef F
_refine_ls_weighting_details     'w = 1/[\s^2^(F)+0.0015F^2^]'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_obs         0.0732
_reflns_number_observed          2229
_reflns_number_total             2691
_reflns_observed_criterion       F>6.0\s(F)
_cod_data_source_file            st1087.cif
_cod_data_source_block           st1087c
_cod_depositor_comments
;
The following automatic conversions were performed:

'_refine_ls_weighting_scheme' value '1/[\s^2^(F)+0.0015F^2^]' 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^(F)+0.0015F^2^]'.

Automatic conversion script
Id: cif_fix_values 3143 2015-03-26 13:38:13Z robertas 
;
_cod_original_cell_volume        1820.4(6)
_cod_original_formula_sum        'C20 H21 F1 N2 O3'
_cod_database_code               2101247