Fluoride-Triggered Ring-Opening of Photochromic Diarylpyrans into Merocyanine Dyes: Naked-Eye Sensing in Subppm Levels.
Mukhopadhyay, Arindam; Maka, Vijay Kumar; Moorthy, Jarugu Narasimha; The Journal of organic chemistry 81 (2016) 7741–7750; doi:10.1021/acs.joc.6b01361

data_4037046
_publ_section_title
;
 Fluoride-Triggered Ring-Opening of Photochromic Diarylpyrans into
 Merocyanine Dyes: Naked-Eye Sensing in Subppm Levels.
;
_journal_issue                   17
_journal_name_full               'The Journal of organic chemistry'
_journal_page_first              7741
_journal_page_last               7750
_journal_paper_doi               10.1021/acs.joc.6b01361
_journal_volume                  81
_journal_year                    2016
_chemical_absolute_configuration unk
_chemical_formula_moiety         'C33 H44 O3 Si2'
_chemical_formula_sum            'C33 H44 O3 Si2'
_chemical_formula_weight         544.86
_chemical_melting_point          352.1(10)
_space_group_crystal_system      monoclinic
_space_group_IT_number           4
_space_group_name_Hall           'P 2yb'
_space_group_name_H-M_alt        'P 1 21 1'
_atom_sites_solution_hydrogens   geom
_audit_creation_method           SHELXL-2014/7
_cell_angle_alpha                90
_cell_angle_beta                 92.2340(10)
_cell_angle_gamma                90
_cell_formula_units_Z            2
_cell_length_a                   6.1609(3)
_cell_length_b                   13.3530(6)
_cell_length_c                   18.5067(8)
_cell_measurement_reflns_used    150
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      20
_cell_measurement_theta_min      3
_cell_volume                     1521.32(12)
_computing_cell_refinement       'Bruker SAINT'
_computing_data_collection       'Bruker APEX2'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Ortep for Windows (Farrugia, 2012)'
_computing_publication_material  'WinGX publication routines (Farrugia, 2012)'
_computing_structure_refinement  'SHELXL-2014/7 (Sheldrick, 2014)'
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.997
_diffrn_measurement_device_type  'Bruker APEX-II CCD'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0695
_diffrn_reflns_av_unetI/netI     0.1018
_diffrn_reflns_Laue_measured_fraction_full 0.999
_diffrn_reflns_Laue_measured_fraction_max 0.997
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       -8
_diffrn_reflns_limit_k_max       17
_diffrn_reflns_limit_k_min       -17
_diffrn_reflns_limit_l_max       24
_diffrn_reflns_limit_l_min       -24
_diffrn_reflns_number            23380
_diffrn_reflns_point_group_measured_fraction_full 0.999
_diffrn_reflns_point_group_measured_fraction_max 0.997
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         28.350
_diffrn_reflns_theta_min         3.051
_diffrn_source                   'sealed tube'
_exptl_absorpt_coefficient_mu    0.148
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.189
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       cuboidal
_exptl_crystal_F_000             588
_exptl_crystal_size_max          0.2
_exptl_crystal_size_mid          0.2
_exptl_crystal_size_min          0.2
_refine_diff_density_max         0.396
_refine_diff_density_min         -0.300
_refine_diff_density_rms         0.060
_refine_ls_abs_structure_details
;
 Refined as an inversion twin.
;
_refine_ls_abs_structure_Flack   -0.07(14)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.015
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     354
_refine_ls_number_reflns         7588
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.015
_refine_ls_R_factor_all          0.0955
_refine_ls_R_factor_gt           0.0539
_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^)+(0.0450P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0931
_refine_ls_wR_factor_ref         0.1052
_reflns_Friedel_coverage         0.919
_reflns_Friedel_fraction_full    0.999
_reflns_Friedel_fraction_max     0.997
_reflns_number_gt                5382
_reflns_number_total             7588
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            jo6b01361_si_002.cif
_cod_data_source_block           BP-P2
_cod_depositor_comments
;
The following automatic conversions were performed:

data item '_chemical_melting_point' value '78-80 deg C' was changed
to '352.1(10)' -- it was converted from degrees Celsius(C) to
Kelvins(K), the average value was taken and precision was estimated.

Automatic conversion script
Id: cif_fix_values 6909 2019-04-08 15:41:33Z antanas 
;
_cod_original_sg_symbol_H-M      'P 21'
_cod_database_code               4037046
_shelx_shelxl_version_number     2014/7
_shelx_res_checksum              5854
_shelx_hkl_checksum              55169