Constructing a photoferroelectric semiconductor by regulating non-covalent interactions through halogen substitution.
He, Yueyue; Wu, Shufang; Li, Xiaofei; Wang, Qi; Zhao, Ruifang; Pan, Lin; Qin, Chengbing; Zhang, Xian-Ming; Fu, Dongying; Chemical science 16 (2025) 20948–20958; doi:10.1039/d5sc05946a

data_1575922
_publ_section_title
;
 Constructing a photoferroelectric semiconductor by regulating
 non-covalent interactions through halogen substitution.
;
_journal_issue                   44
_journal_name_full               'Chemical science'
_journal_page_first              20948
_journal_page_last               20958
_journal_paper_doi               10.1039/d5sc05946a
_journal_volume                  16
_journal_year                    2025
_chemical_formula_moiety         'Br4 Pb, 2(C3 H9 Cl N)'
_chemical_formula_sum            'C6 H18 Br4 Cl2 N2 Pb'
_chemical_formula_weight         715.92
_space_group_crystal_system      orthorhombic
_space_group_IT_number           36
_space_group_name_Hall           'C 2c -2'
_space_group_name_H-M_alt        'C m c 21'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_audit_creation_date             2024-11-10
_audit_creation_method
;
Olex2 1.5
(compiled 2024.02.16 svn.r378c4104 for OlexSys, GUI svn.r6928)
;
_audit_update_record
;
2024-11-27 deposited with the CCDC.	2025-09-30 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   27.1369(14)
_cell_length_b                   8.3450(3)
_cell_length_c                   8.1438(3)
_cell_measurement_reflns_used    5141
_cell_measurement_temperature    300.15
_cell_measurement_theta_max      30.6950
_cell_measurement_theta_min      2.5140
_cell_volume                     1844.22(13)
_computing_molecular_graphics    'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_structure_refinement  'SHELXL 2018/3 (Sheldrick, 2015)'
_computing_structure_solution    'SHELXS  (Sheldrick, 2008)'
_diffrn_ambient_temperature      300.15
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.917
_diffrn_measurement_device_type  'CCD area detector'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0767
_diffrn_reflns_av_unetI/netI     0.0581
_diffrn_reflns_Laue_measured_fraction_full 0.999
_diffrn_reflns_Laue_measured_fraction_max 0.917
_diffrn_reflns_limit_h_max       37
_diffrn_reflns_limit_h_min       -38
_diffrn_reflns_limit_k_max       11
_diffrn_reflns_limit_k_min       -11
_diffrn_reflns_limit_l_max       11
_diffrn_reflns_limit_l_min       -11
_diffrn_reflns_number            12754
_diffrn_reflns_point_group_measured_fraction_full 0.999
_diffrn_reflns_point_group_measured_fraction_max 0.860
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         30.719
_diffrn_reflns_theta_min         2.553
_exptl_absorpt_coefficient_mu    18.084
_exptl_crystal_colour            colourless
_exptl_crystal_colour_primary    colourless
_exptl_crystal_density_diffrn    2.579
_exptl_crystal_description       plate
_exptl_crystal_F_000             1296
_refine_diff_density_max         2.164
_refine_diff_density_min         -1.777
_refine_diff_density_rms         0.293
_refine_ls_abs_structure_details
;
 Refined as an inversion twin.
;
_refine_ls_abs_structure_Flack   0.492(14)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.008
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     75
_refine_ls_number_reflns         2509
_refine_ls_number_restraints     24
_refine_ls_restrained_S_all      1.012
_refine_ls_R_factor_all          0.0803
_refine_ls_R_factor_gt           0.0577
_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^)+(0.1078P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1512
_refine_ls_wR_factor_ref         0.1597
_reflns_Friedel_coverage         0.758
_reflns_Friedel_fraction_full    0.999
_reflns_Friedel_fraction_max     0.794
_reflns_number_gt                1920
_reflns_number_total             2509
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d5sc05946a2.cif
_cod_data_source_block           exp_300K
_cod_depositor_comments
'Adding full bibliography for 1575922--1575924.cif.'
_cod_original_cell_volume        1844.22(14)
_cod_database_code               1575922
_shelx_shelxl_version_number     2018/3
_olex2_refinement_description
;
1. Twinned data refinement
 Scales: 0.508(14)
 0.492(14)
2. Fixed Uiso
 At 1.2 times of:
  All C(H,H) groups, All N(H,H,H) groups
3. Restrained distances
 C2-C3
 1.5 with sigma of 0.02
 C2-C1
 1.5 with sigma of 0.02
 N1-C1
 1.47 with sigma of 0.02
 Pb1-Br1
 3.04 with sigma of 0.001
4. Rigid bond restraints
 N1
 with sigma for 1-2 distances of 0.01 and sigma for 1-3 distances of 0.01
 C3
 with sigma for 1-2 distances of 0.01 and sigma for 1-3 distances of 0.01
 C2, C3
 with sigma for 1-2 distances of 0.01 and sigma for 1-3 distances of 0.01
5. Uiso/Uaniso restraints and constraints
Uanis(C3) \\sim Ueq: with sigma of 0.01 and sigma for terminal atoms of 0.02
Uanis(C2) \\sim Ueq, Uanis(C1) \\sim Ueq: with sigma of 0.01 and sigma for
terminal atoms of 0.02
6.a Secondary CH2 refined with riding coordinates:
 C3(H3A,H3B), C2(H2A,H2B), C1(H1D,H1E)
6.b Idealised Me refined as rotating group:
 N1(H1A,H1B,H1C)
;
_olex2_submission_special_instructions 'No special instructions were received'