Unusually short ethylene bond and large amplitude torsional motion of (<i>E</i>)-stilbenes in crystals. X-ray crystallographic study of `stiff' stilbenes
Ogawa, K.; Harada, J.; Tomoda, S.; Acta Crystallographica Section B 51 (1995) 240–248; doi:10.1107/S010876819400950X

data_2101275
_publ_section_title
;
 Unusually short ethylene bond and large amplitude torsional motion of
 (<i>E</i>)-stilbenes in crystals. X-ray crystallographic study of
 `stiff' stilbenes
;
_journal_issue                   2
_journal_name_full               'Acta Crystallographica Section B'
_journal_page_first              240
_journal_page_last               248
_journal_paper_doi               10.1107/S010876819400950X
_journal_volume                  51
_journal_year                    1995
_chemical_formula_moiety         'C20 H20'
_chemical_formula_sum            'C20 H20'
_chemical_formula_weight         260.38
_chemical_melting_point          425.0
_chemical_name_systematic        '      (E)-7,7'-dimethyl-1,1'-biindanylidene'
_space_group_IT_number           2
_symmetry_cell_setting           triclinic
_symmetry_space_group_name_Hall  '-P 1'
_symmetry_space_group_name_H-M   'P -1'
_cell_angle_alpha                97.750(10)
_cell_angle_beta                 98.94(2)
_cell_angle_gamma                90.53(2)
_cell_formula_units_Z            4
_cell_length_a                   13.302(3)
_cell_length_b                   14.763(2)
_cell_length_c                   7.7570(10)
_cell_measurement_reflns_used    25
_cell_measurement_temperature    296
_cell_measurement_theta_max      78.7
_cell_measurement_theta_min      53.1
_cell_volume                     1490.3(4)
_computing_cell_refinement       MSC/AFC
_computing_data_collection
;
Rigaku AFC6A, MSC/AFC Diffractometer Control Software
;
_computing_data_reduction        xtal_DIFDAT_ADDREF_SORTRF
_computing_molecular_graphics    xtal_ORTEP
_computing_publication_material  xtal_BONDLA_CIFIO
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_computing_structure_solution    'SHELXS86 (Sheldrick)'
_diffrn_ambient_temperature      296
_diffrn_measurement_device       'Rigaku AFC6A'
_diffrn_measurement_method       \q/2\q
_diffrn_radiation_monochromator  graphite
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_diffrn_reflns_av_sigmaI/netI    .014
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_diffrn_reflns_limit_k_min       -16
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_diffrn_reflns_limit_l_min       -8
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_diffrn_reflns_reduction_process perpendicular_monochr_Lp
_diffrn_reflns_theta_max         60.
_diffrn_reflns_theta_min         3.02
_diffrn_standards_decay_%        0
_diffrn_standards_interval_count 150
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    0.46
_exptl_absorpt_correction_type   none
_exptl_absorpt_process_details   'Absorption correction not applied'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.16
_exptl_crystal_description       rectangular
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_refine_diff_density_min         -.287
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_refine_ls_R_factor_obs          .043
_refine_ls_shift/esd_max         .771
_refine_ls_shift/esd_mean        .046
_refine_ls_structure_factor_coef F
_refine_ls_weighting_details     'w = 1/(\s^2^(F)+0.0002F^2^)'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_all         .05
_refine_ls_wR_factor_obs         .048
_reflns_number_observed          3398
_reflns_number_total             4426
_reflns_observed_criterion       refl_observed_if_Inet_>2.000_sigma(Inet)
_cod_data_source_file            as0668.cif
_cod_data_source_block           7inrt
_cod_depositor_comments
;
The following automatic conversions were performed:

'_refine_ls_weighting_scheme' value '1/(\s^2^(F)+0.0002F^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)+0.0002F^2^)'.

Automatic conversion script
Id: cif_fix_values 3143 2015-03-26 13:38:13Z robertas 
;
_cod_original_cell_volume        1490.5(5)
_cod_original_sg_symbol_Hall     -P_1
_cod_database_code               2101275