Molecular folding screen: folding and unfolding of 1,8-anthrylene-ethynylene oligomers by photochemical cycloaddition and thermal cycloreversion.
Toyota, Shinji; Kuga, Makoto; Takatsu, Akiko; Goichi, Michio; Iwanaga, Tetsuo; Chemical communications (Cambridge, England)  (2008) 1323–1325; doi:10.1039/b717496a

data_7102959
_publ_section_title
;
 Molecular folding screen: folding and unfolding of
 1,8-anthrylene-ethynylene oligomers by photochemical cycloaddition and
 thermal cycloreversion.
;
_journal_issue                   11
_journal_name_full               'Chemical communications (Cambridge, England)'
_journal_page_first              1323
_journal_page_last               1325
_journal_paper_doi               10.1039/b717496a
_journal_year                    2008
_chemical_formula_moiety         'C68 H66 Si2'
_chemical_formula_sum            'C68 H66 Si2'
_chemical_formula_weight         939.39
_chemical_melting_point          281.0(10)
_space_group_IT_number           4
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  'P 2yb'
_symmetry_space_group_name_H-M   'P 1 21 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                 99.565(6)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   22.625(3)
_cell_length_b                   9.6582(11)
_cell_length_c                   24.852(4)
_cell_measurement_temperature    123(2)
_cell_volume                     5355.2(12)
_computing_cell_refinement       PROCESS-AUTO
_computing_data_collection       PROCESS-AUTO
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      123(2)
_diffrn_measured_fraction_theta_full 0.995
_diffrn_measured_fraction_theta_max 0.995
_diffrn_measurement_device_type  'Rigaku HR-RAXIS'
_diffrn_measurement_method       \w
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71075
_diffrn_reflns_av_R_equivalents  0.0732
_diffrn_reflns_av_sigmaI/netI    0.0740
_diffrn_reflns_limit_h_max       29
_diffrn_reflns_limit_h_min       -29
_diffrn_reflns_limit_k_max       12
_diffrn_reflns_limit_k_min       -12
_diffrn_reflns_limit_l_max       32
_diffrn_reflns_limit_l_min       -32
_diffrn_reflns_number            88674
_diffrn_reflns_theta_full        27.48
_diffrn_reflns_theta_max         27.48
_diffrn_reflns_theta_min         2.99
_exptl_absorpt_coefficient_mu    0.108
_exptl_absorpt_correction_T_max  0.9946
_exptl_absorpt_correction_T_min  0.9521
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   '(Higashi, 1995)'
_exptl_crystal_colour            yellow
_exptl_crystal_density_diffrn    1.165
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       needle
_exptl_crystal_F_000             2008
_exptl_crystal_size_max          0.46
_exptl_crystal_size_mid          0.05
_exptl_crystal_size_min          0.05
_refine_diff_density_max         0.429
_refine_diff_density_min         -0.403
_refine_diff_density_rms         0.067
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.26(10)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.077
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     1285
_refine_ls_number_reflns         23529
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.077
_refine_ls_R_factor_all          0.0773
_refine_ls_R_factor_gt           0.0618
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0725P)^2^+3.9016P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1612
_refine_ls_wR_factor_ref         0.1710
_reflns_number_gt                18230
_reflns_number_total             23529
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b717496a.txt
_cod_data_source_block           anti3mer
_cod_depositor_comments
;
The following automatic conversions were performed:

'_chemical_melting_point' value '280-282' was changed to '281.0(10)'
- the average value was taken and precision was estimated.

Automatic conversion script
Id: cif_fix_values 1646 2011-03-28 12:23:43Z adriana 
;
_cod_original_sg_symbol_H-M      'P 21'
_cod_database_code               7102959