Pyromellitic dihydrazides as hydrolytically stable analogs of pyromellitic diimide.
Amundson, Journey M.; Brush, Ryan B.; Jensen, Kara M.; Funk, Baela R.; Jung, Healeam; Mamicha, Sam K.; Young, Jr, Victor G; Garcia L, Eryck; Klivansky, Liana M.; Cao, Dennis D.; Organic & biomolecular chemistry 24 (2026) 2650–2654; doi:10.1039/d6ob00281a

data_7161076
_publ_section_title
;
 Pyromellitic dihydrazides as hydrolytically stable analogs of
 pyromellitic diimide.
;
_journal_issue                   13
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              2650
_journal_page_last               2654
_journal_paper_doi               10.1039/d6ob00281a
_journal_volume                  24
_journal_year                    2026
_chemical_absolute_configuration unk
_chemical_formula_moiety         'C18 H18 N4 O4'
_chemical_formula_sum            'C18 H18 N4 O4'
_chemical_formula_weight         354.36
_chemical_name_common            22124Z
_space_group_crystal_system      orthorhombic
_space_group_IT_number           18
_space_group_name_Hall           'P 2 2ab'
_space_group_name_H-M_alt        'P 21 21 2'
_atom_sites_solution_hydrogens   geom
_audit_creation_method           SHELXL-2018/3
_audit_update_record
;
2023-10-26 deposited with the CCDC.	2026-03-12 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            16
_cell_length_a                   20.9907(7)
_cell_length_b                   42.5286(15)
_cell_length_c                   6.9390(2)
_cell_measurement_reflns_used    2976
_cell_measurement_temperature    150(2)
_cell_measurement_theta_max      28.22
_cell_measurement_theta_min      2.97
_cell_volume                     6194.5(3)
_computing_cell_refinement       'Bruker SAINT'
_computing_data_collection       'Bruker APEX3'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-2018/3 (Sheldrick 2015)'
_computing_structure_solution    'SHELXT-2018/2 (Sheldrick 2015)'
_diffrn_ambient_temperature      150(2)
_diffrn_measured_fraction_theta_full 0.997
_diffrn_measured_fraction_theta_max 0.997
_diffrn_measurement_device_type  'Bruker PHOTON-III CPAD'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0450
_diffrn_reflns_av_unetI/netI     0.0610
_diffrn_reflns_Laue_measured_fraction_full 0.997
_diffrn_reflns_Laue_measured_fraction_max 0.997
_diffrn_reflns_limit_h_max       28
_diffrn_reflns_limit_h_min       -28
_diffrn_reflns_limit_k_max       56
_diffrn_reflns_limit_k_min       -56
_diffrn_reflns_limit_l_max       8
_diffrn_reflns_limit_l_min       -9
_diffrn_reflns_number            41725
_diffrn_reflns_point_group_measured_fraction_full 0.997
_diffrn_reflns_point_group_measured_fraction_max 0.994
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         28.314
_diffrn_reflns_theta_min         1.999
_diffrn_source                   micro-focus
_exptl_absorpt_coefficient_mu    0.110
_exptl_absorpt_correction_T_max  0.7457
_exptl_absorpt_correction_T_min  0.6621
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS-2016/2, (Sheldrick, 2016)'
_exptl_crystal_colour            yellow
_exptl_crystal_density_diffrn    1.520
_exptl_crystal_description       Needle
_exptl_crystal_F_000             2976
_exptl_crystal_size_max          0.200
_exptl_crystal_size_mid          0.035
_exptl_crystal_size_min          0.015
_exptl_transmission_factor_max   0.7457
_exptl_transmission_factor_min   0.6621
_refine_diff_density_max         0.361
_refine_diff_density_min         -0.235
_refine_diff_density_rms         0.055
_refine_ls_abs_structure_details
;
 Flack x determined using 3721 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   -0.1(7)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.018
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     937
_refine_ls_number_reflns         15366
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.018
_refine_ls_R_factor_all          0.0880
_refine_ls_R_factor_gt           0.0552
_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^)+(0.0631P)^2^+2.6852P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1319
_refine_ls_wR_factor_ref         0.1477
_reflns_Friedel_coverage         0.783
_reflns_Friedel_fraction_full    0.997
_reflns_Friedel_fraction_max     0.991
_reflns_number_gt                10783
_reflns_number_total             15366
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d6ob00281a2.cif
_cod_data_source_block           22124z
_cod_depositor_comments
'Adding full bibliography for 7161076--7161078.cif.'
_cod_database_code               7161076
_shelx_shelxl_version_number     2018/3
_shelx_estimated_absorpt_t_min   0.978
_shelx_estimated_absorpt_t_max   0.998
_shelx_res_checksum              37473