Thermal-induced transformation of glutamic acid to pyroglutamic acid and self-cocrystallization: a charge–density analysis
Akram, Sehrish; Mehmood, Arshad; Noureen, Sajida; Ahmed, Maqsood; Acta Crystallographica Section C Structural Chemistry 78 (2022) –; doi:10.1107/S2053229621013607

data_2022513
_publ_section_title
;
 Thermal-induced transformation of glutamic acid to pyroglutamic acid and
 self-cocrystallization: a charge--density analysis
;
_journal_coeditor_code           EF3024
_journal_issue                   2
_journal_name_full
'Acta Crystallographica Section C Structural Chemistry'
_journal_paper_doi               10.1107/S2053229621013607
_journal_volume                  78
_journal_year                    2022
_chemical_absolute_configuration unk
_chemical_formula_iupac          'C5 H7 N O3, C5 H9 N O4, H2 O'
_chemical_formula_moiety         'C5 H7 N O3, C5 H9 N O4, H2 O'
_chemical_formula_sum            'C10 H18 N2 O8'
_chemical_formula_weight         294.248
_chemical_name_common
;
Glutamic acid--pyroglutamic acid--water (1/1/1)
;
_chemical_name_systematic
;
2-Aminopentanedioic acid--5-oxopyrrolidine-2-carboxylic acid--water (1/1/1)
;
_space_group_IT_number           4
_space_group_name_Hall           'P 2yb'
_space_group_name_H-M_alt        'P 1 21 1'
_symmetry_cell_setting           monoclinic
_atom_sites_solution_hydrogens   difmap
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           'MoPro v21.06             '
_cell_angle_alpha                90.
_cell_angle_beta                 96.817(2)
_cell_angle_gamma                90.
_cell_formula_units_Z            2
_cell_length_a                   5.1153(3)
_cell_length_b                   7.1849(4)
_cell_length_c                   18.4639(9)
_cell_measurement_reflns_used    3695
_cell_measurement_temperature    298(2)
_cell_measurement_theta_max      26.4
_cell_measurement_theta_min      2.22
_cell_volume                     673.80(6)
_computing_structure_refinement
;
MoPro (Jelsch <i>et al.</i>,  2005)
;
_diffrn_ambient_temperature      298(2)
_diffrn_measured_fraction_theta_full 0.926
_diffrn_measured_fraction_theta_max 0.99
_diffrn_measurement_device_type
;
Bruker D8 Venture
;
_diffrn_measurement_method       'Omega and phi scan'
_diffrn_radiation_monochromator  'helios Mirror Optics'
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.055
_diffrn_reflns_av_sigmaI/netI    0.07856
_diffrn_reflns_limit_h_max       6
_diffrn_reflns_limit_h_min       -6
_diffrn_reflns_limit_k_max       8
_diffrn_reflns_limit_k_min       -8
_diffrn_reflns_limit_l_max       22
_diffrn_reflns_limit_l_min       0
_diffrn_reflns_number            7139
_diffrn_reflns_theta_full        25.33
_diffrn_reflns_theta_max         25.33
_diffrn_reflns_theta_min         2.22
_exptl_absorpt_coefficient_mu    0.126
_exptl_absorpt_correction_T_max  0.7452
_exptl_absorpt_correction_T_min  0.4873
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
(SADABS; Bruker, 2016)
;
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.451
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plate-like
_exptl_crystal_F_000             312
_exptl_crystal_size_max          0.5
_exptl_crystal_size_mid          0.29
_exptl_crystal_size_min          0.07
_refine_diff_density_max         0.24
_refine_diff_density_min         -0.25
_refine_ls_abs_structure_details
;
Flack (1983)
;
_refine_ls_abs_structure_Flack   0.0(19)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.849
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     120
_refine_ls_number_reflns         2373
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.000
_refine_ls_R_factor_all          0.0684
_refine_ls_R_factor_gt           0.0455
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w =1/[\s^2^(Fo^2^)+(0.03314P)^2^+0.21229P] where P=(Fo^2^+2Fc^2'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0864
_refine_ls_wR_factor_ref         0.0959
_reflns_number_gt                1855
_reflns_number_total             2373
_reflns_threshold_expression     'I > 2 \s(I)'
_cod_data_source_file            ef3024sup1.cif
_cod_data_source_block           ELMAM2_MoPro
_cod_original_sg_symbol_Hall     ' P 2yb'
_cod_database_code               2022513
_cod_database_fobs_code 2022513