Perchlorophenalenyl radical, C~13~Cl~9~: a modulated structure with nine threefold-symmetric molecules in the asymmetric unit
Koutentis, P. A.; Haddon, R. C.; Oakley, R. T.; Cordes, A. W.; Brock, C. P.; Acta Crystallographica Section B 57 (2001) 680–691; doi:10.1107/S0108768101011193

data_2103728
_publ_section_title
;
 Perchlorophenalenyl radical, C~13~Cl~9~: a modulated structure with
 nine threefold-symmetric molecules in the asymmetric unit
;
_journal_issue                   5
_journal_name_full               'Acta Crystallographica Section B'
_journal_page_first              680
_journal_page_last               691
_journal_paper_doi               10.1107/S0108768101011193
_journal_volume                  57
_journal_year                    2001
_chemical_formula_moiety         'C13 Cl9'
_chemical_formula_sum            'C13 Cl9'
_chemical_formula_weight         475.18
_chemical_melting_point
;
160_C(dec) in air;  248_C under Ar.
;
_chemical_name_systematic
;
perchlorophenalenyl radical
;
_space_group_IT_number           160
_symmetry_cell_setting           trigonal
_symmetry_space_group_name_Hall  'R 3 -2"'
_symmetry_space_group_name_H-M   'R 3 m :H'
_audit_creation_method
;
SHELXL-97, macros written locally, and C. P. Brock
;
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                120
_cell_formula_units_Z            3
_cell_length_a                   18.704(3)
_cell_length_b                   18.704(3)
_cell_length_c                   3.7792(7)
_cell_measurement_reflns_used    63143
_cell_measurement_temperature    299.0(10)
_cell_measurement_theta_max      27.5
_cell_measurement_theta_min      1.3
_cell_volume                     1145.0(3)
_computing_cell_refinement       'DENZO-SMN (Otwinowski & Minor, 1997)'
_computing_data_collection       'COLLECT software (Nonius, 1998)'
_computing_data_reduction        'SCALEPACK (Otwinowski & Minor, 1997)'
_computing_molecular_graphics    'SHELXTL PC (Sheldrick, 1990)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution
;
SIR92 (Altomare, Cascarano, Giacovazzo, Guagliardi, Burla,
Polidori & Camalli, 1994) in maXus (Mackay, Gilmore,
Edwards, Tremayne, Stewart & Shankland, 1998)
;
_diffrn_ambient_temperature      299.0(10)
_diffrn_detector_area_resol_mean 18
_diffrn_measured_fraction_theta_full .997
_diffrn_measured_fraction_theta_max .997
_diffrn_measurement_device_type  'Nonius Kappa-CCD diffractometer'
_diffrn_measurement_method       '\f and \w scans with 1.0\% steps'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     .71073
_diffrn_reflns_av_R_equivalents  .034
_diffrn_reflns_av_sigmaI/netI    .016
_diffrn_reflns_limit_h_max       24
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       0
_diffrn_reflns_limit_k_min       -21
_diffrn_reflns_limit_l_max       4
_diffrn_reflns_limit_l_min       -4
_diffrn_reflns_number            2409
_diffrn_reflns_theta_full        27.46
_diffrn_reflns_theta_max         27.5
_diffrn_reflns_theta_min         2.2
_diffrn_standards_decay_%        <1.
_exptl_absorpt_coefficient_mu    1.64
_exptl_absorpt_correction_T_max  .85
_exptl_absorpt_correction_T_min  .79
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'DENZO-SMN (Otwinowski & Minor, 1997)'
_exptl_crystal_colour            black
_exptl_crystal_density_diffrn    2.067
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description
;
Prisms.  The a prism axis is c. The six major faces belong
to the form {1 1 -2 0}.
;
_exptl_crystal_F_000             693
_exptl_crystal_size_max          .40
_exptl_crystal_size_mid          .10
_exptl_crystal_size_min          .10
_refine_diff_density_max         .36
_refine_diff_density_min         -.33
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   4.08
_refine_ls_matrix_type           full
_refine_ls_number_parameters     64
_refine_ls_number_reflns         323
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      4.08
_refine_ls_R_factor_all          .046
_refine_ls_R_factor_gt           .045
_refine_ls_shift/su_max          .000
_refine_ls_shift/su_mean         .000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.030P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_ref         .140
_reflns_number_gt                318
_reflns_number_total             323
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            bs0014.cif
_cod_data_source_block           pseudor3
_cod_original_sg_symbol_H-M      R3m
_cod_database_code               2103728