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_1568995
_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      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   mixed
_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                 94.430(8)
_cell_angle_gamma                90
_cell_formula_units_Z            2
_cell_length_a                   8.7521(7)
_cell_length_b                   9.7104(6)
_cell_length_c                   14.0201(11)
_cell_measurement_reflns_used    6537
_cell_measurement_temperature    350(2)
_cell_measurement_theta_max      75.7060
_cell_measurement_theta_min      5.0590
_cell_volume                     1187.96(15)
_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      350
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_device_type  AtlasS2
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54184
_diffrn_reflns_av_unetI/netI     0.0487
_diffrn_reflns_Laue_measured_fraction_full 1.000
_diffrn_reflns_Laue_measured_fraction_max 1.000
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       11
_diffrn_reflns_limit_k_min       -11
_diffrn_reflns_limit_l_max       16
_diffrn_reflns_limit_l_min       -16
_diffrn_reflns_number            4055
_diffrn_reflns_point_group_measured_fraction_full 1.000
_diffrn_reflns_point_group_measured_fraction_max 1.000
_diffrn_reflns_theta_full        67.684
_diffrn_reflns_theta_max         68.922
_diffrn_reflns_theta_min         3.162
_exptl_absorpt_coefficient_mu    24.257
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.03947
_exptl_absorpt_correction_type   multi-scan
_exptl_crystal_colour            yellow
_exptl_crystal_density_diffrn    2.528
_exptl_crystal_description       plate
_exptl_crystal_F_000             828
_exptl_crystal_size_max          0.22
_exptl_crystal_size_mid          0.11
_exptl_crystal_size_min          0.03
_refine_diff_density_max         2.526
_refine_diff_density_min         -1.142
_refine_diff_density_rms         0.244
_refine_ls_abs_structure_details
;
 Flack x determined using 1066 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   0.002(14)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.066
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     232
_refine_ls_number_reflns         4055
_refine_ls_number_restraints     209
_refine_ls_restrained_S_all      1.044
_refine_ls_R_factor_all          0.0885
_refine_ls_R_factor_gt           0.0796
_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^)+(0.1613P)^2^+3.3367P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.2463
_refine_ls_wR_factor_ref         0.2553
_reflns_Friedel_coverage         0.880
_reflns_Friedel_fraction_full    1.000
_reflns_Friedel_fraction_max     1.000
_reflns_number_gt                3408
_reflns_number_total             4055
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d3sc01101a4.cif
_cod_data_source_block           a
_cod_depositor_comments
'Adding full bibliography for 1568992--1568995.cif.'
_cod_database_code               1568995
_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
 N1-C4 = N1-C2 = N1-C3
 1.5 with sigma of 0.01
 C2-C1
 1.53 with sigma of 0.02
 Br1-C1
 2.05 with sigma of 0.02
 C2A-C1A
 1.53 with sigma of 0.02
 Br1A-C1A
 2.05 with sigma of 0.02
 N2-C8 = N2-C7 = N2-C6
 1.5 with sigma of 0.02
 C6-C5
 1.53 with sigma of 0.02
 Br2-C5
 2.05 with sigma of 0.02
 C5-N2
 2.5 with sigma of 0.02
 N1A-C3A = N1A-C2A = N1A-C4A
 1.5 with sigma of 0.01
 C4-C2 \\sim C4-C3 \\sim C2-C3
 with sigma of 0.02
 C7-C8 \\sim C7-C6 \\sim C8-C6 \\sim N2-C5
 with sigma of 0.04
 C3A-C2A \\sim C3A-C4A \\sim C2A-C4A
 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 0.02
and sigma for terminal atoms of 0.04 within 2A
Br1 \\sim N1 \\sim C1 \\sim C2 \\sim C3 \\sim C4 \\sim Br1A \\sim N1A \\sim C1A
\\sim C2A \\sim C3A \\sim C4A: within 2A with sigma of 0.02 and sigma for
terminal atoms of 0.04 within 2A
4. Others
 Sof(Br1A)=Sof(N1A)=Sof(H1Aa)=Sof(C1A)=Sof(H1Ab)=Sof(H1Ac)=Sof(C2A)=Sof(H2Aa)=
 Sof(H2Ab)=Sof(C3A)=Sof(H3Aa)=Sof(H3Ab)=Sof(H3Ac)=Sof(C4A)=Sof(H4Aa)=Sof(H4Ab)=
 Sof(H4Ac)=1-FVAR(1)
 Sof(Br1)=Sof(N1)=Sof(H1)=Sof(C1)=Sof(H1a)=Sof(H1b)=Sof(C2)=Sof(H2a)=Sof(H2b)=
 Sof(C3)=Sof(H3a)=Sof(H3b)=Sof(H3c)=Sof(C4)=Sof(H4a)=Sof(H4b)=Sof(H4c)=FVAR(1)
5.a Riding coordinates:
 C3(H3a,H3b,H3c), C7(H7a,H7b,H7c), C8(H8a,H8b,H8c)
5.b Ternary CH refined with riding coordinates:
 N1(H1), N1A(H1Aa), N2(H2)
5.c Secondary CH2 refined with riding coordinates:
 C1(H1a,H1b), C2(H2a,H2b), C1A(H1Ab,H1Ac), C2A(H2Aa,H2Ab), C5(H5a,H5b), C6(H6a,
 H6b)
5.d Me refined with riding coordinates:
 C4A(H4Aa,H4Ab,H4Ac)
5.e Idealised Me refined as rotating group:
 C4(H4a,H4b,H4c), C3A(H3Aa,H3Ab,H3Ac)
;
_shelx_res_checksum              30230
_olex2_submission_special_instructions 'No special instructions were received'