Shape-persistent V-shaped mesogens—formation of nematic phases with biaxial order
Matthias Lehmann; Shin-Woong Kang; Christiane Köhn; Sönke Haseloh; Ute Kolb; Dieter Schollmeyer; QingBing Wang; Satyendra Kumar; Journal of Materials Chemistry 16 (2006) 4326–; doi:10.1039/b605718g

data_7203431
_publ_section_title
;
 Shape-persistent V-shaped mesogens---formation of nematic phases with
 biaxial order
;
_journal_issue                   44
_journal_name_full               'Journal of Materials Chemistry'
_journal_page_first              4326
_journal_paper_doi               10.1039/b605718g
_journal_volume                  16
_journal_year                    2006
_chemical_formula_sum            'C69 H72 O5'
_chemical_formula_weight         981.27
_chemical_name_common
;3,6-Bis-(2,5-bis-hexyloxy-4-phenylethynyl-phenylethynyl)-
fluoren-9-one
;
_space_group_IT_number           15
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-C 2yc'
_symmetry_space_group_name_H-M   'C 1 2/c 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                 97.142(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   16.0034(9)
_cell_length_b                   33.0383(7)
_cell_length_c                   10.6224(5)
_cell_measurement_reflns_used    24
_cell_measurement_temperature    193(2)
_cell_measurement_theta_max      73
_cell_measurement_theta_min      65
_cell_volume                     5572.8(4)
_computing_cell_refinement       'Enraf Nonius Software V5'
_computing_data_collection       'Enraf Nonius Software V5'
_computing_data_reduction        'Corinc (Dr\"ager, 1971)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SIR-92 (Altomare, 1994)'
_diffrn_ambient_temperature      193(2)
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.999
_diffrn_measurement_device       '\k-geometry diffractometer'
_diffrn_measurement_device_type  'CAD4 Enraf Nonius'
_diffrn_measurement_method       \q/2\w
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.0269
_diffrn_reflns_av_sigmaI/netI    0.0314
_diffrn_reflns_limit_h_max       19
_diffrn_reflns_limit_h_min       -19
_diffrn_reflns_limit_k_max       41
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       13
_diffrn_reflns_limit_l_min       0
_diffrn_reflns_number            5950
_diffrn_reflns_theta_full        73.86
_diffrn_reflns_theta_max         73.86
_diffrn_reflns_theta_min         2.67
_diffrn_source                   'rotating anode'
_diffrn_standards_decay_%        5
_diffrn_standards_interval_time  60
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    0.558
_exptl_absorpt_correction_T_max  0.9463
_exptl_absorpt_correction_T_min  0.6055
_exptl_absorpt_correction_type   none
_exptl_absorpt_process_details   'Corinc (Dr\"ager, 1971)'
_exptl_crystal_colour            green
_exptl_crystal_density_diffrn    1.170
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       needle
_exptl_crystal_F_000             2104
_exptl_crystal_size_max          1.00
_exptl_crystal_size_mid          0.20
_exptl_crystal_size_min          0.10
_refine_diff_density_max         0.268
_refine_diff_density_min         -0.184
_refine_diff_density_rms         0.037
_refine_ls_extinction_coef       0.00026(3)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_ref   1.026
_refine_ls_hydrogen_treatment    refU
_refine_ls_matrix_type           full
_refine_ls_number_parameters     358
_refine_ls_number_reflns         5636
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.026
_refine_ls_R_factor_all          0.0590
_refine_ls_R_factor_gt           0.0453
_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^)+(0.0527P)^2^+3.3413P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_obs         0.1119
_refine_ls_wR_factor_ref         0.1207
_reflns_number_gt                4561
_reflns_number_total             5636
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b605718g.txt
_cod_data_source_block           ml2
_cod_original_sg_symbol_H-M      'C 2/c'
_cod_database_code               7203431