A step toward polytwistane: synthesis and characterization of C2-symmetric tritwistane.
Olbrich, Martin; Mayer, Peter; Trauner, Dirk; Organic & biomolecular chemistry 12 (2014) 108–112; doi:10.1039/c3ob42152j

data_7153660
_publ_section_title
;
 A step toward polytwistane: synthesis and characterization of
 C2-symmetric tritwistane.
;
_journal_issue                   1
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              108
_journal_page_last               112
_journal_paper_doi               10.1039/c3ob42152j
_journal_volume                  12
_journal_year                    2014
_chemical_formula_moiety         'C20 H20 Cl4'
_chemical_formula_sum            'C20 H20 Cl4'
_chemical_formula_weight         402.184
_space_group_IT_number           2
_symmetry_cell_setting           triclinic
_symmetry_Int_Tables_number      2
_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_block_code                C20H20Cl4_rv254_trauner
_audit_creation_method           'form98_non/compatible with shelxl97-2'
_audit_update_record             12-Jul-13
_cell_angle_alpha                83.186(2)
_cell_angle_beta                 87.4669(19)
_cell_angle_gamma                66.2540(16)
_cell_formula_units_Z            2
_cell_length_a                   7.0286(4)
_cell_length_b                   8.7167(5)
_cell_length_c                   15.6853(9)
_cell_measurement_reflns_used    122
_cell_measurement_temperature    123(2)
_cell_measurement_theta_max      31.6774
_cell_measurement_theta_min      3.5380
_cell_volume                     873.40(9)
_computing_cell_refinement       'APEX2 v2012.4-3 (Bruker AXS)'
_computing_data_collection       'Bruker Instrument Service v3.0.21'
_computing_data_reduction        'SAINT V8.18C (Bruker AXS Inc., 2011)'
_computing_structure_refinement
;
Sheldrick, G. M. (2008).
<i>Acta Cryst.</i> A<b>64</b>, 112--122.
;
_computing_structure_solution
;
A. Altomare, M. C. Burla, M. Camalli, G. L. Cascarano, C. Giacovazzo, A.
Guagliardi, A. G. G. Moliterni, G. Polidori, R. Spagna: SIR97: a new tool for
crystal structure determination and refinement; J. Appl. Crystallogr. 1999,
32, 115-119.
;
_diffrn_ambient_temperature      123(2)
_diffrn_detector_area_resol_mean 10.4167
_diffrn_measured_fraction_theta_full 0.991
_diffrn_measured_fraction_theta_max 0.991
_diffrn_measurement_device       'fixed-chi three-circle diffractometer'
_diffrn_measurement_device_type  'Bruker D8Venture'
_diffrn_measurement_method       'mix of phi and omega scans'
_diffrn_radiation_collimation    0.8_mm
_diffrn_radiation_monochromator  'focusing mirrors'
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0244
_diffrn_reflns_av_sigmaI/netI    0.0296
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       -8
_diffrn_reflns_limit_k_max       10
_diffrn_reflns_limit_k_min       -10
_diffrn_reflns_limit_l_max       18
_diffrn_reflns_limit_l_min       -18
_diffrn_reflns_number            8310
_diffrn_reflns_theta_full        25.01
_diffrn_reflns_theta_max         25.03
_diffrn_reflns_theta_min         3.17
_diffrn_source_current           50
_diffrn_source_power             2.5
_diffrn_source_type              'Bruker TXS'
_diffrn_source_voltage           50
_exptl_absorpt_coefficient_mu    0.677
_exptl_absorpt_correction_T_max  0.9582
_exptl_absorpt_correction_T_min  0.9197
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS V2012/1 (Bruker AXS Inc.)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.52931(16)
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             416
_exptl_crystal_size_max          0.151
_exptl_crystal_size_mid          0.089
_exptl_crystal_size_min          0.081
_refine_diff_density_max         0.364
_refine_diff_density_min         -0.227
_refine_diff_density_rms         0.059
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.116
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     217
_refine_ls_number_reflns         3057
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.116
_refine_ls_R_factor_all          0.0354
_refine_ls_R_factor_gt           0.0299
_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^)+(0.0276P)^2^+0.7769P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0744
_refine_ls_wR_factor_ref         0.0766
_reflns_number_gt                2728
_reflns_number_total             3057
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c3ob42152j.txt
_cod_data_source_block           rv254
_cod_database_code               7153660