An anomalous ferroelastic phase transition arising from an unusual <i>cis</i>-/<i>anti</i>-conformational reversal of polar organic cations.
Zhao, Bing-Qing; Chen, Xiao-Xian; Ye, Hui; Gong, Ya-Ping; Wang, Jun; Ye, Le; Zhang, Wei-Xiong; Chemical science 14 (2023) 5965–5973; doi:10.1039/d3sc01101a

data_1568992
_publ_section_title
;
 An anomalous ferroelastic phase transition arising from an unusual
 <i>cis</i>-/<i>anti</i>-conformational reversal of polar organic cations.
;
_journal_issue                   22
_journal_name_full               'Chemical science'
_journal_page_first              5965
_journal_page_last               5973
_journal_paper_doi               10.1039/d3sc01101a
_journal_volume                  14
_journal_year                    2023
_chemical_formula_moiety         'Br6 Te, 2(C4 H11 Br N)'
_chemical_formula_sum            'C8 H22 Br8 N2 Te'
_chemical_formula_weight         913.15
_space_group_crystal_system      monoclinic
_space_group_IT_number           4
_space_group_name_Hall           'P 2yb'
_space_group_name_H-M_alt        'P 1 21 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     iterative
_audit_creation_date             2022-11-06
_audit_creation_method
;
Olex2 1.5-beta
(compiled 2021.10.07 svn.r9718050b for OlexSys, GUI svn.r5381)
;
_audit_update_record
;
2022-11-27 deposited with the CCDC.	2023-05-01 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 84.748(3)
_cell_angle_gamma                90
_cell_formula_units_Z            2
_cell_length_a                   8.5323(5)
_cell_length_b                   9.6457(6)
_cell_length_c                   13.8826(8)
_cell_measurement_reflns_used    9914
_cell_measurement_temperature    150.00
_cell_measurement_theta_max      59.02
_cell_measurement_theta_min      2.78
_cell_volume                     1137.74(12)
_computing_molecular_graphics    'Olex2 1.5-beta (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 1.5-beta (Dolomanov et al., 2009)'
_computing_structure_refinement  'SHELXL 2014/7 (Sheldrick, 2015)'
_computing_structure_solution    'olex2.solve 1.5-beta (Bourhis et al., 2015)'
_diffrn_ambient_temperature      150.00
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 0.997
_diffrn_measurement_device_type  'CCD area detector'
_diffrn_measurement_method       'phi and omega scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0546
_diffrn_reflns_av_unetI/netI     0.0394
_diffrn_reflns_Laue_measured_fraction_full 1.000
_diffrn_reflns_Laue_measured_fraction_max 0.997
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       12
_diffrn_reflns_limit_k_min       -12
_diffrn_reflns_limit_l_max       17
_diffrn_reflns_limit_l_min       -17
_diffrn_reflns_number            19369
_diffrn_reflns_point_group_measured_fraction_full 0.987
_diffrn_reflns_point_group_measured_fraction_max 0.978
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         27.105
_diffrn_reflns_theta_min         1.473
_exptl_absorpt_coefficient_mu    15.347
_exptl_absorpt_correction_T_max  0.0828
_exptl_absorpt_correction_T_min  0.0141
_exptl_absorpt_correction_type   none
_exptl_crystal_density_diffrn    2.666
_exptl_crystal_description       block
_exptl_crystal_F_000             832
_refine_diff_density_max         1.627
_refine_diff_density_min         -0.681
_refine_diff_density_rms         0.186
_refine_ls_abs_structure_details
;
 Flack x determined using 1909 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   -0.17(3)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.065
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     176
_refine_ls_number_reflns         4906
_refine_ls_number_restraints     9
_refine_ls_restrained_S_all      1.064
_refine_ls_R_factor_all          0.0633
_refine_ls_R_factor_gt           0.0604
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.1041P)^2^+5.8486P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1728
_refine_ls_wR_factor_ref         0.1754
_reflns_Friedel_coverage         0.851
_reflns_Friedel_fraction_full    0.973
_reflns_Friedel_fraction_max     0.957
_reflns_number_gt                4571
_reflns_number_total             4906
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d3sc01101a4.cif
_cod_data_source_block           new1
_cod_depositor_comments
'Adding full bibliography for 1568992--1568995.cif.'
_cod_database_code               1568992
_shelx_shelxl_version_number     2014/7
_olex2_refinement_description
;
1. Fixed Uiso
 At 1.2 times of:
  All C(H,H) groups, All N(H) groups
 At 1.5 times of:
  All C(H,H,H) groups
2. Restrained distances
 C2-C1 = C5-C6
 1.51 with sigma of 0.0001
3. Uiso/Uaniso restraints and constraints
Uanis(C4) \\sim Ueq: with sigma of 0.02 and sigma for terminal atoms of 0.04
4.a Ternary CH refined with riding coordinates:
 N1(H1), N2(H2)
4.b Secondary CH2 refined with riding coordinates:
 C1(H1A,H1B), C2(H2A,H2B), C5(H5A,H5B), C6(H6A,H6B)
4.c Idealised Me refined as rotating group:
 C3(H3A,H3B,H3C), C4(H4A,H4B,H4C), C7(H7A,H7B,H7C), C8(H8A,H8B,H8C)
;
_shelx_res_checksum              9531
_olex2_submission_special_instructions 'No special instructions were received'