Structural and theoretical study of four novel norcantharidine derivatives: two new cases of conditional isomorphism
Tan, Xue-Jie; Liu, Shuai; Hei, Xiao-Ming; Yang, Feng-Cun; He, Peng-Bing; Guo, Feng; Xing, Dian-Xiang; Acta Crystallographica Section C 76 (2020) 75–86; doi:10.1107/S2053229619016164

data_2021935
_publ_section_title
;
 Structural and theoretical study of four novel norcantharidine
 derivatives: two new cases of conditional isomorphism
;
_journal_coeditor_code           YO3069
_journal_issue                   1
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              75
_journal_page_last               86
_journal_paper_doi               10.1107/S2053229619016164
_journal_volume                  76
_journal_year                    2020
_chemical_absolute_configuration syn
_chemical_formula_iupac          'C14 H12 N2 O5'
_chemical_formula_moiety         'C14 H12 N2 O5'
_chemical_formula_sum            'C14 H12 N2 O5'
_chemical_formula_weight         288.26
_chemical_name_common
;
norcantharidine - 4-nitraaniline
;
_chemical_name_systematic
(3a<i>R</i>,4<i>S</i>,7<i>R</i>,7a<i>S</i>)-2-(4-nitrophenyl)-3a,4,5,6,7,7a-hexahydro-1<i>H</i>-4,7-epoxyisoindole-1,3(2<i>H</i>)-dione
_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   difmap
_audit_creation_method           SHELXL-2016/6
_cell_angle_alpha                90
_cell_angle_beta                 98.918(7)
_cell_angle_gamma                90
_cell_formula_units_Z            2
_cell_length_a                   5.3661(4)
_cell_length_b                   18.6171(16)
_cell_length_c                   6.6116(5)
_cell_measurement_reflns_used    380
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      26.00
_cell_measurement_theta_min      2.45
_cell_volume                     652.52(9)
_computing_cell_refinement
;
SMART (Bruker, 2000)
;
_computing_data_collection
;
SMART (Bruker, 2000)
;
_computing_data_reduction
;
SAINT (Bruker, 2000)
;
_computing_molecular_graphics
;
SHELXTL (Bruker, 2000), PLATON (Spek, 2009), WinGX2014
(Farrugia, 2012),
DIAMOND (Brandenburg & Putz, 1999) and Mercury (Macrae <i>et al.</i>,
2008)
;
_computing_publication_material
;
SHELXL2016 (Sheldrick, 2015b)
;
_computing_structure_refinement
;
SHELXL2016 (Sheldrick, 2015b)
;
_computing_structure_solution
;
SHELXT (Sheldrick, 2015a)
;
_diffrn_ambient_temperature      293(2)
_diffrn_detector_area_resol_mean 10.12
_diffrn_measured_fraction_theta_full 0.995
_diffrn_measured_fraction_theta_max 0.963
_diffrn_measurement_device_type  'Bruker SMART CCD area detector'
_diffrn_measurement_method       'phi and omega scans'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54184
_diffrn_reflns_av_R_equivalents  0.0217
_diffrn_reflns_av_unetI/netI     0.0355
_diffrn_reflns_limit_h_max       5
_diffrn_reflns_limit_h_min       -6
_diffrn_reflns_limit_k_max       22
_diffrn_reflns_limit_k_min       -22
_diffrn_reflns_limit_l_max       8
_diffrn_reflns_limit_l_min       -7
_diffrn_reflns_number            2121
_diffrn_reflns_theta_full        67.684
_diffrn_reflns_theta_max         71.350
_diffrn_reflns_theta_min         4.751
_diffrn_source                   'fine-focus sealed tube'
_exptl_absorpt_coefficient_mu    0.960
_exptl_absorpt_correction_T_max  0.080
_exptl_absorpt_correction_T_min  0.070
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
(SADABS; Bruker, 2000)
;
_exptl_crystal_colour            'light yellow'
_exptl_crystal_density_diffrn    1.467
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plate
_exptl_crystal_F_000             300
_exptl_crystal_size_max          0.33
_exptl_crystal_size_mid          0.30
_exptl_crystal_size_min          0.12
_refine_diff_density_max         0.177
_refine_diff_density_min         -0.157
_refine_ls_abs_structure_details
;
Flack <i>x</i> determined using 354 quotients [(I+)-(I-)]/[(I+)+(I-)]
(Parsons <i>et al.</i>,  2013)
;
_refine_ls_abs_structure_Flack   0.5(3)
_refine_ls_extinction_coef       0.0126(19)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method
;
SHELXL2016 (Sheldrick, 2015b)
;
_refine_ls_goodness_of_fit_ref   1.059
_refine_ls_hydrogen_treatment    refall
_refine_ls_matrix_type           full
_refine_ls_number_parameters     239
_refine_ls_number_reflns         1717
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.058
_refine_ls_R_factor_all          0.0447
_refine_ls_R_factor_gt           0.0403
_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^)+(0.0546P)^2^+0.0162P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1022
_refine_ls_wR_factor_ref         0.1091
_reflns_number_gt                1549
_reflns_number_total             1717
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            yo3069sup1.cif
_cod_data_source_block           NCA-NA
_cod_original_sg_symbol_H-M      'P 21'
_cod_database_code               2021935
_cod_database_fobs_code          2021935
_shelx_estimated_absorpt_t_min   0.521
_shelx_estimated_absorpt_t_max   0.824
_shelx_hkl_checksum              9947
_shelx_res_checksum              50695