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_1568993
_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 Sn, 2(C4 H11 Br N)'
_chemical_formula_sum            'C8 H22 Br8 N2 Sn'
_chemical_formula_weight         904.24
_space_group_crystal_system      orthorhombic
_space_group_IT_number           19
_space_group_name_Hall           'P 2ac 2ab'
_space_group_name_H-M_alt        'P 21 21 21'
_atom_sites_solution_hydrogens   geom
_audit_creation_date             2022-10-25
_audit_creation_method
;
Olex2 1.2
(compiled 2018.05.29 svn.r3508 for OlexSys, GUI svn.r5506)
;
_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            4
_cell_length_a                   17.2270(2)
_cell_length_b                   9.68680(10)
_cell_length_c                   14.0647(2)
_cell_measurement_reflns_used    8447
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      76.0010
_cell_measurement_theta_min      4.0200
_cell_volume                     2347.04(5)
_computing_molecular_graphics    'Olex2 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 (Dolomanov et al., 2009)'
_computing_structure_refinement  'ShelXL (Sheldrick, 2015)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 0.989
_diffrn_measurement_device_type  AtlasS2
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54184
_diffrn_reflns_av_R_equivalents  0.0462
_diffrn_reflns_av_unetI/netI     0.0446
_diffrn_reflns_Laue_measured_fraction_full 1.000
_diffrn_reflns_Laue_measured_fraction_max 0.989
_diffrn_reflns_limit_h_max       18
_diffrn_reflns_limit_h_min       -21
_diffrn_reflns_limit_k_max       9
_diffrn_reflns_limit_k_min       -11
_diffrn_reflns_limit_l_max       13
_diffrn_reflns_limit_l_min       -17
_diffrn_reflns_number            10439
_diffrn_reflns_point_group_measured_fraction_full 0.983
_diffrn_reflns_point_group_measured_fraction_max 0.967
_diffrn_reflns_theta_full        67.684
_diffrn_reflns_theta_max         76.163
_diffrn_reflns_theta_min         4.058
_exptl_absorpt_coefficient_mu    24.555
_exptl_crystal_density_diffrn    2.559
_exptl_crystal_description       plate
_exptl_crystal_F_000             1656
_refine_diff_density_max         1.328
_refine_diff_density_min         -0.669
_refine_diff_density_rms         0.156
_refine_ls_abs_structure_details
;
 Flack x determined using 1833 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   -0.001(6)
_refine_ls_extinction_coef       0.00085(8)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     'SHELXL-2014/7 (Sheldrick 2014'
_refine_ls_goodness_of_fit_ref   1.054
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     194
_refine_ls_number_reflns         4747
_refine_ls_number_restraints     70
_refine_ls_restrained_S_all      1.055
_refine_ls_R_factor_all          0.0417
_refine_ls_R_factor_gt           0.0406
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0728P)^2^+1.3291P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1103
_refine_ls_wR_factor_ref         0.1121
_reflns_Friedel_coverage         0.726
_reflns_Friedel_fraction_full    0.960
_reflns_Friedel_fraction_max     0.938
_reflns_number_gt                4608
_reflns_number_total             4747
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d3sc01101a4.cif
_cod_data_source_block           293k
_cod_depositor_comments
'Adding full bibliography for 1568992--1568995.cif.'
_cod_database_code               1568993
_shelx_shelxl_version_number     2014/7
_olex2_refinement_description
;
1. Fixed Uiso
 At 1.2 times of:
  All C(H,H) groups, All C(H,H,H,H) groups, All N(H) groups
 At 1.5 times of:
  All C(H,H,H) groups
2. Restrained distances
 C1A-C2 = C1-C2
 1.53 with sigma of 0.01
 Br1-C1 = Br1A-C1A
 1.95 with sigma of 0.01
 N1-C3 = N1-C4 = N1-C2
 1.5 with sigma of 0.01
 C4-C2 \\sim C3-C2 \\sim C4-C3
 with sigma of 0.01
3. Uiso/Uaniso restraints and constraints
Br1 \\sim Br1A \\sim N1 \\sim C1 \\sim C1A \\sim C2 \\sim C3 \\sim C4: within
2A with sigma of 0.02 and sigma for terminal atoms of 0.04
4. Others
 Fixed Sof: Br1(0.52038) Br1A(0.47962) C1(0.52038) H1A(0.52038) H1B(0.52038)
 C1A(0.47962) H1AA(0.47962) H1AB(0.47962) H2AA(0.52038) H2AB(0.52038)
 H2BC(0.47962) H2BD(0.47962)
5.a Ternary CH refined with riding coordinates:
 N1(H1), N2(H2)
5.b Secondary CH2 refined with riding coordinates:
 C1(H1A,H1B), C1A(H1AA,H1AB), C2(H2AA,H2AB), C2(H2BC,H2BD), C5(H5A,H5B),
 C6(H6A,H6B)
5.c Me refined with riding coordinates:
 C4(H4A,H4B,H4C)
5.d Idealised Me refined as rotating group:
 C3(H3A,H3B,H3C), C7(H7A,H7B,H7C), C8(H8A,H8B,H8C)
;
_shelx_res_checksum              77219
_olex2_submission_special_instructions 'No special instructions were received'