Packing-dependent photochromism: the case of photoinduced intramolecular proton transfer in 6-(2',4'-dinitrobenzyl)-2,2'-bipyridine
Ohashi, Yuji; Acta Crystallographica Section B 60 (2004) 343–349; doi:10.1107/S0108768104005506

data_2102539
_publ_section_title
;
 Packing-dependent photochromism: the case of photoinduced
 intramolecular proton transfer in
 6-(2',4'-dinitrobenzyl)-2,2'-bipyridine
;
_journal_issue                   3
_journal_name_full               'Acta Crystallographica Section B'
_journal_page_first              343
_journal_page_last               349
_journal_paper_doi               10.1107/S0108768104005506
_journal_volume                  60
_journal_year                    2004
_chemical_formula_sum            'C17 H12 N4 O4'
_chemical_formula_weight         336.31
_chemical_name_systematic
;
 alpha form of 6-(2',4'-dinitrobenzyl)-2,2'-bipyridine
;
_space_group_IT_number           33
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2c -2n'
_symmetry_space_group_name_H-M   'P n a 21'
_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                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            8
_cell_length_a                   14.00590(10)
_cell_length_b                   5.13990(10)
_cell_length_c                   41.9853(6)
_cell_measurement_temperature    78(2)
_cell_volume                     3022.48(8)
_computing_cell_refinement       'SMART (Siemens, 1995)'
_computing_data_collection       'SMART (Siemens, 1995)'
_computing_data_reduction        'SAINT (Siemens, 1995)'
_computing_molecular_graphics    'ORTEP-II (Johnson, 1976)'
_computing_publication_material  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      78(2)
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.999
_diffrn_measurement_device_type  'Siemens CCD diffractometer'
_diffrn_measurement_method       omega-scan
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0797
_diffrn_reflns_av_sigmaI/netI    0.0824
_diffrn_reflns_limit_h_max       18
_diffrn_reflns_limit_h_min       -15
_diffrn_reflns_limit_k_max       6
_diffrn_reflns_limit_k_min       -6
_diffrn_reflns_limit_l_max       54
_diffrn_reflns_limit_l_min       -47
_diffrn_reflns_number            19857
_diffrn_reflns_theta_full        27.46
_diffrn_reflns_theta_max         27.46
_diffrn_reflns_theta_min         1.94
_exptl_absorpt_coefficient_mu    0.109
_exptl_absorpt_correction_T_max  1.000
_exptl_absorpt_correction_T_min  0.674
_exptl_absorpt_correction_type   empirical
_exptl_absorpt_process_details   'SADABS (Sheldrick, 1996)'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.478
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             1392
_exptl_crystal_size_max          0.35
_exptl_crystal_size_mid          0.10
_exptl_crystal_size_min          0.05
_refine_diff_density_max         1.133
_refine_diff_density_min         -0.269
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -1.0(19)
_refine_ls_extinction_coef       0.0104(11)
_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   1.033
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     452
_refine_ls_number_reflns         6678
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.033
_refine_ls_R_factor_all          0.1017
_refine_ls_R_factor_gt           0.0640
_refine_ls_shift/su_max          0.026
_refine_ls_shift/su_mean         0.002
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.1000P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1564
_refine_ls_wR_factor_ref         0.1794
_reflns_number_gt                4589
_reflns_number_total             6678
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            og0001.cif
_cod_data_source_block           alpha
_cod_depositor_comments
;
The following automatic conversions were performed:
'_symmetry_cell_setting' value 'Orthorhombic' changed to 'orthorhombic'
according to '/home/saulius/struct/CIF-dictionaries/cif_core.dic'
dictionary named 'cif_core.dic' version 2.4.1 from
2010-06-29.

'_exptl_absorpt_correction_type' value 'Empirical' changed to
'empirical' according to
'/home/saulius/struct/CIF-dictionaries/cif_core.dic' dictionary named
'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_enum 1527 2010-12-29 10:47:43Z saulius 

The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Orthorhombic' changed to
'orthorhombic' according to
/home/saulius/struct/CIF-dictionaries/cif_core.dic dictionary named
'cif_core.dic' version 2.4.1 from
2010-06-29.

'_exptl_absorpt_correction_type' value 'Empirical'
changed to 'empirical' according to
/home/saulius/struct/CIF-dictionaries/cif_core.dic dictionary named
'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_values 1715 2011-07-08 13:25:40Z adriana 
;
_cod_original_sg_symbol_H-M      Pna21
_cod_database_code               2102539
_cod_database_fobs_code          2102539