Syntheses and Crystal Structures of Fused Thiophenes: [7]Helicene and Double Helicene, a D2-Symmetric Dimer of 3,3'-Bis(dithieno[2,3-b:3',2'-d]thiophene)
Chunli Li; Jianwu Shi; Li Xu; Yangguang Wang; Yanxiang Cheng; Hua Wang; Journal of Organic Chemistry 74 (2009) 408–411; doi:10.1021/jo802080g

data_4024239
_publ_section_title
;
Syntheses and Crystal Structures of Fused Thiophenes: [7]Helicene and
Double Helicene, a D2-Symmetric Dimer of
3,3'-Bis(dithieno[2,3-b:3',2'-d]thiophene)
;
_journal_name_full               'Journal of Organic Chemistry'
_journal_page_first              408
_journal_page_last               411
_journal_paper_doi               10.1021/jo802080g
_journal_volume                  74
_journal_year                    2009
_chemical_formula_sum            'C22 H20 S7 Si2'
_chemical_formula_weight         564.98
_space_group_IT_number           2
_symmetry_cell_setting           triclinic
_symmetry_space_group_name_Hall  '-P 1'
_symmetry_space_group_name_H-M   'P -1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                73.108(8)
_cell_angle_beta                 81.205(9)
_cell_angle_gamma                72.258(8)
_cell_formula_units_Z            2
_cell_length_a                   7.964(4)
_cell_length_b                   11.560(5)
_cell_length_c                   16.232(7)
_cell_measurement_temperature    296(2)
_cell_volume                     1358.5(11)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      296(2)
_diffrn_measured_fraction_theta_full 0.911
_diffrn_measured_fraction_theta_max 0.911
_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  0.0257
_diffrn_reflns_av_sigmaI/netI    0.0649
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -15
_diffrn_reflns_limit_l_max       21
_diffrn_reflns_limit_l_min       -14
_diffrn_reflns_number            8637
_diffrn_reflns_theta_full        28.36
_diffrn_reflns_theta_max         28.36
_diffrn_reflns_theta_min         1.92
_exptl_absorpt_coefficient_mu    0.679
_exptl_absorpt_correction_T_max  0.9352
_exptl_absorpt_correction_T_min  0.8992
_exptl_crystal_density_diffrn    1.381
_exptl_crystal_density_method    'not measured'
_exptl_crystal_F_000             584
_exptl_crystal_size_max          0.16
_exptl_crystal_size_mid          0.12
_exptl_crystal_size_min          0.10
_refine_diff_density_max         0.262
_refine_diff_density_min         -0.291
_refine_diff_density_rms         0.062
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.010
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     280
_refine_ls_number_reflns         6200
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.010
_refine_ls_R_factor_all          0.0949
_refine_ls_R_factor_gt           0.0485
_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^)+(0.0450P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0988
_refine_ls_wR_factor_ref         0.1175
_reflns_number_gt                3642
_reflns_number_total             6200
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            jo802080g_si_001.cif
_cod_data_source_block           w001
_cod_depositor_comments
;
The following automatic conversions were performed:
'_symmetry_cell_setting' value 'Triclinic' changed to 'triclinic'
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 
;
_cod_original_sg_symbol_H-M      P-1
_cod_database_code               4024239