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_1568994
_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      orthorhombic
_space_group_IT_number           31
_space_group_name_Hall           'P -2ab -2'
_space_group_name_H-M_alt        'P m 21 n'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     iterative
_audit_creation_date             2022-10-21
_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                 90
_cell_angle_gamma                90
_cell_formula_units_Z            2
_cell_length_a                   8.7336(8)
_cell_length_b                   9.8400(8)
_cell_length_c                   13.8013(10)
_cell_measurement_reflns_used    8396
_cell_measurement_temperature    325.00
_cell_measurement_theta_max      44.40
_cell_measurement_theta_min      2.78
_cell_volume                     1186.06(17)
_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      325.00
_diffrn_measured_fraction_theta_full 0.993
_diffrn_measured_fraction_theta_max 0.992
_diffrn_measurement_device_type  'Bruker APEX-II CCD'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_type           GaK\a
_diffrn_radiation_wavelength     1.34138
_diffrn_reflns_av_R_equivalents  0.0540
_diffrn_reflns_av_unetI/netI     0.0392
_diffrn_reflns_Laue_measured_fraction_full 0.993
_diffrn_reflns_Laue_measured_fraction_max 0.992
_diffrn_reflns_limit_h_max       11
_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       -13
_diffrn_reflns_number            16526
_diffrn_reflns_point_group_measured_fraction_full 0.990
_diffrn_reflns_point_group_measured_fraction_max 0.983
_diffrn_reflns_theta_full        53.594
_diffrn_reflns_theta_max         59.560
_diffrn_reflns_theta_min         2.785
_exptl_absorpt_coefficient_mu    17.625
_exptl_absorpt_correction_type   none
_exptl_crystal_density_diffrn    2.557
_exptl_crystal_description       block
_exptl_crystal_F_000             832
_refine_diff_density_max         1.281
_refine_diff_density_min         -0.899
_refine_diff_density_rms         0.171
_refine_ls_abs_structure_details
;
 Classical Flack method preferred over Parsons because s.u. lower.
;
_refine_ls_abs_structure_Flack   0.02(3)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.993
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     115
_refine_ls_number_reflns         2764
_refine_ls_number_restraints     107
_refine_ls_restrained_S_all      0.982
_refine_ls_R_factor_all          0.1150
_refine_ls_R_factor_gt           0.0823
_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^)+(0.2000P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.2450
_refine_ls_wR_factor_ref         0.2933
_reflns_Friedel_coverage         0.873
_reflns_Friedel_fraction_full    0.988
_reflns_Friedel_fraction_max     0.973
_reflns_number_gt                1459
_reflns_number_total             2764
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d3sc01101a4.cif
_cod_data_source_block           pm21n
_cod_depositor_comments
'Adding full bibliography for 1568992--1568995.cif.'
_cod_database_code               1568994
_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
 N2-C6 = N2-C8 = N2-C7
 1.5 with sigma of 0.02
 C1-N1
 2.52 with sigma of 0.02
 C4-C3 = C4-C2 = C3-C2
 2.52 with sigma of 0.02
 N1-C4 = N1-C3 = N1-C2
 1.5 with sigma of 0.02
3. Uiso/Uaniso restraints and constraints
Br2 \\sim N2 \\sim C5 \\sim C6 \\sim C7 \\sim C8: within 2A with sigma of 0.04
and sigma for terminal atoms of 0.08 within 2A
Uanis(C5) \\sim Ueq, Uanis(Br2) \\sim Ueq, Uanis(C6) \\sim Ueq, Uanis(N2) \\sim
Ueq, Uanis(C8) \\sim Ueq, Uanis(C7) \\sim Ueq: with sigma of 0.04 and sigma for
terminal atoms of 0.08
Uanis(Br1) \\sim Ueq, Uanis(C1) \\sim Ueq, Uanis(C2) \\sim Ueq, Uanis(N1) \\sim
Ueq, Uanis(C4) \\sim Ueq, Uanis(C3) \\sim Ueq: with sigma of 0.02 and sigma for
terminal atoms of 0.04
Uanis(N1) = Uanis(Br1) = Uanis(C1) = Uanis(C2) = Uanis(C4) = Uanis(C3)
4. Others
 Fixed Sof: Br1(0.5) N1(0.5) H1(0.5) C1(0.5) H1a(0.5) H1b(0.5) C2(0.5)
 H2a(0.5) H2b(0.5) C3(0.5) H3a(0.5) H3b(0.5) H3c(0.5) C4(0.5) H4a(0.5) H4b(0.5)
 H4c(0.5) Br2(0.5) N2(0.5) H2(0.5) C5(0.5) H5a(0.5) H5b(0.5) C6(0.5) H6a(0.5)
 H6b(0.5) C7(0.5) H7a(0.5) H7b(0.5) H7c(0.5) C8(0.5) H8a(0.5) H8b(0.5) H8c(0.5)
5.a Ternary CH refined with riding coordinates:
 N1(H1), N2(H2)
5.b Secondary CH2 refined with riding coordinates:
 C1(H1a,H1b), C2(H2a,H2b), C5(H5a,H5b), C6(H6a,H6b)
5.c Me refined with riding coordinates:
 C3(H3a,H3b,H3c), C4(H4a,H4b,H4c), C7(H7a,H7b,H7c), C8(H8a,H8b,H8c)
;
_shelx_res_checksum              23476
_olex2_submission_special_instructions 'No special instructions were received'