Photoisomerization mechanism of iminoguanidinium receptors from spectroscopic methods and quantum chemical calculations.
Dang, Duy-Khoi; Einkauf, Jeffrey D.; Ma, Xinyou; Custelcean, Radu; Ma, Ying-Zhong; Zimmerman, Paul M.; Bryantsev, Vyacheslav S.; Physical chemistry chemical physics : PCCP 26 (2024) 24008–24020; doi:10.1039/d4cp02747g

data_7249271
_publ_section_title
;
 Photoisomerization mechanism of iminoguanidinium receptors from
 spectroscopic methods and quantum chemical calculations.
;
_journal_issue                   36
_journal_name_full               'Physical chemistry chemical physics : PCCP'
_journal_page_first              24008
_journal_page_last               24020
_journal_paper_doi               10.1039/d4cp02747g
_journal_volume                  26
_journal_year                    2024
_chemical_formula_sum            'C7 H10 Br N5'
_chemical_formula_weight         244.11
_chemical_name_common            2PyMIGHBr
_space_group_crystal_system      orthorhombic
_space_group_IT_number           33
_space_group_name_Hall           'P 2c -2n'
_space_group_name_H-M_alt        'P n a 21'
_atom_sites_solution_hydrogens   geom
_audit_creation_method           SHELXL-2017/1
_audit_update_record
;
2022-03-18 deposited with the CCDC.	2024-08-30 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   11.057
_cell_length_b                   10.978
_cell_length_c                   7.917
_cell_measurement_reflns_used    34281
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      30.556
_cell_measurement_theta_min      2.614
_cell_volume                     960.995
_computing_structure_refinement  'SHELXL-2017/1 (Sheldrick, 2017)'
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 0.993
_diffrn_measured_fraction_theta_max 0.996
_diffrn_measurement_device_type  Bruker
_diffrn_measurement_method       single
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0449
_diffrn_reflns_av_unetI/netI     0.0334
_diffrn_reflns_Laue_measured_fraction_full 0.993
_diffrn_reflns_Laue_measured_fraction_max 0.996
_diffrn_reflns_limit_h_max       15
_diffrn_reflns_limit_h_min       -15
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -15
_diffrn_reflns_limit_l_max       11
_diffrn_reflns_limit_l_min       -11
_diffrn_reflns_number            34281
_diffrn_reflns_point_group_measured_fraction_full 0.986
_diffrn_reflns_point_group_measured_fraction_max 0.992
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         30.556
_diffrn_reflns_theta_min         2.614
_exptl_absorpt_coefficient_mu    4.239
_exptl_absorpt_correction_T_max  0.816
_exptl_absorpt_correction_T_min  0.429
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   SADABS
_exptl_crystal_colour            yellow
_exptl_crystal_density_diffrn    1.687
_exptl_crystal_description       plate
_exptl_crystal_F_000             488
_exptl_crystal_size_max          0.240
_exptl_crystal_size_mid          0.130
_exptl_crystal_size_min          0.050
_exptl_transmission_factor_max   0.816
_exptl_transmission_factor_min   0.429
_refine_diff_density_max         0.399
_refine_diff_density_min         -0.288
_refine_diff_density_rms         0.075
_refine_ls_abs_structure_details
;
 Flack x determined using 1265 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   0.021(4)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.077
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     118
_refine_ls_number_reflns         2923
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.077
_refine_ls_R_factor_all          0.0193
_refine_ls_R_factor_gt           0.0183
_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^)+(0.0135P)^2^+0.2789P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0422
_refine_ls_wR_factor_ref         0.0427
_reflns_Friedel_coverage         0.870
_reflns_Friedel_fraction_full    0.979
_reflns_Friedel_fraction_max     0.988
_reflns_number_gt                2819
_reflns_number_total             2923
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d4cp02747g2.cif
_cod_data_source_block           2PyMIGHBr
_cod_depositor_comments          'Adding full bibliography for 7249271.cif.'
_cod_original_cell_volume        961.0
_cod_database_code               7249271
_shelx_shelxl_version_number     2017/1
_shelx_estimated_absorpt_t_min   0.429
_shelx_estimated_absorpt_t_max   0.816
_shelx_res_checksum              13645