A novel photoreversible photochromic system involving a hydrogen transfer/cyclization sequence
Lokshin, Vladimir; Valès, Magali; Samat, André; Pèpe, Gérard; Metelitsa, Anatoly; Khodorkovsky, Vladimir; Chemical Communications (Cambridge, United Kingdom)  (2003) 2080–2081; doi:10.1039/b304861f

data_7113580
_publ_section_title
;
 A novel photoreversible photochromic system involving a hydrogen
 transfer/cyclization sequence
;
_journal_coden_ASTM              CHCOFS
_journal_issue                   16
_journal_name_full
;
 Chemical Communications (Cambridge, United Kingdom)
;
_journal_page_first              2080
_journal_page_last               2081
_journal_paper_doi               10.1039/b304861f
_journal_year                    2003
_chemical_formula_sum            'C25 H21 N O2'
_chemical_formula_weight         367.43
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_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_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 97.670(1)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   7.382(1)
_cell_length_b                   28.831(4)
_cell_length_c                   9.248(1)
_cell_measurement_temperature    293(2)
_cell_volume                     1950.6(4)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.165
_diffrn_measured_fraction_theta_max 0.165
_diffrn_measurement_device_type  'Nonius CAD4'
_diffrn_measurement_method       \w/2\q
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71069
_diffrn_reflns_av_R_equivalents  0.0000
_diffrn_reflns_av_sigmaI/netI    0.3291
_diffrn_reflns_limit_h_max       7
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       43
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       13
_diffrn_reflns_limit_l_min       -14
_diffrn_reflns_number            2253
_diffrn_reflns_theta_full        32.89
_diffrn_reflns_theta_max         32.89
_diffrn_reflns_theta_min         2.33
_exptl_absorpt_coefficient_mu    0.079
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            yellow
_exptl_crystal_density_diffrn    1.251
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       'pseudo hexagonal platelets'
_exptl_crystal_F_000             776
_exptl_crystal_size_max          0.3
_exptl_crystal_size_mid          0.3
_exptl_crystal_size_min          0.2
_refine_diff_density_max         0.200
_refine_diff_density_min         -0.127
_refine_diff_density_rms         0.031
_refine_ls_extinction_coef       0.38(6)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_ref   0.996
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     338
_refine_ls_number_reflns         2253
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.996
_refine_ls_R_factor_all          0.0934
_refine_ls_R_factor_gt           0.0435
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc 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          0.1645
_refine_ls_wR_factor_ref         0.3623
_reflns_number_gt                952
_reflns_number_total             2253
_reflns_threshold_expression     >2sigma(I)
_cod_duplicate_entry             7103831
_cod_data_source_file            b304861k.txt
_cod_data_source_block           vla281
_cod_depositor_comments
;
The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Monoclinic' changed to 'monoclinic'
according to
/usr/data/users/saulius/automatic-downloads/retrospective/RSC/lib/dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.2 from 2011-04-26.

Automatic conversion script
Id: cif_fix_values 2281 2013-09-26 08:29:07Z andrius 
;
_cod_original_sg_symbol_H-M      P21/n
_cod_database_code               7113580