Unusual High-Temperature Reversible Phase-Transition Behavior, Structures, and Dielectric-Ferroelectric Properties of Two New Crown Ether Clathrates.
Tang, Yun-Zhi; Yu, Yin-Mei; Xiong, Jian-Bo; Tan, Yu-Hui; Wen, He-Rui; Journal of the American Chemical Society 137 (2015) 13345–13351; doi:10.1021/jacs.5b08061

data_4129550
_publ_section_title
;
 Unusual High-Temperature Reversible Phase-Transition Behavior,
 Structures, and Dielectric-Ferroelectric Properties of Two New Crown
 Ether Clathrates.
;
_journal_issue                   41
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              13345
_journal_page_last               13351
_journal_paper_doi               10.1021/jacs.5b08061
_journal_volume                  137
_journal_year                    2015
_chemical_formula_sum            'C18 H38 B F4 N O6'
_chemical_formula_weight         451.30
_space_group_IT_number           29
_space_group_name_Hall           'P 2c -2ac'
_space_group_name_H-M_alt        'P c a 21'
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_H-M   'P c a 21'
_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                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   13.381(3)
_cell_length_b                   12.051(2)
_cell_length_c                   14.234(3)
_cell_measurement_temperature    293(2)
_cell_volume                     2295.3(8)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_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  0.0768
_diffrn_reflns_av_sigmaI/netI    0.0730
_diffrn_reflns_limit_h_max       16
_diffrn_reflns_limit_h_min       -16
_diffrn_reflns_limit_k_max       14
_diffrn_reflns_limit_k_min       -14
_diffrn_reflns_limit_l_max       17
_diffrn_reflns_limit_l_min       -17
_diffrn_reflns_number            20323
_diffrn_reflns_theta_full        26.00
_diffrn_reflns_theta_max         26.00
_diffrn_reflns_theta_min         3.04
_exptl_absorpt_coefficient_mu    0.115
_exptl_absorpt_correction_T_max  0.9819
_exptl_absorpt_correction_T_min  0.9774
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   sadabs
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.306
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             968
_exptl_crystal_size_max          0.20
_exptl_crystal_size_mid          0.18
_exptl_crystal_size_min          0.16
_refine_diff_density_max         0.391
_refine_diff_density_min         -0.248
_refine_diff_density_rms         0.051
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.3(14)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.058
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     272
_refine_ls_number_reflns         4502
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.058
_refine_ls_R_factor_all          0.0909
_refine_ls_R_factor_gt           0.0706
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0810P)^2^+1.2185P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1778
_refine_ls_wR_factor_ref         0.1923
_reflns_number_gt                3381
_reflns_number_total             4502
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja5b08061_si_002.cif
_cod_data_source_block           bf4
_cod_original_sg_symbol_H-M      Pca2(1)
_cod_database_code               4129550