Two polymorphs of 2-ethyl-3-hydroxy-6-methylpyridinium hydrogen <i>N</i>-acetyl-<small>L</small>-glutamate from powder diffraction data
Chernyshev, Vladimir V.; Efimov, Sergey Y.; Paseshnichenko, Ksenia A.; Shiryaev, Andrey A.; Acta Crystallographica Section C 69 (2013) 1549–1552; doi:10.1107/S0108270113031557

data_2019277
_publ_section_title
;
 Two polymorphs of 2-ethyl-3-hydroxy-6-methylpyridinium hydrogen
 <i>N</i>-acetyl-<small>L</small>-glutamate from powder diffraction data
;
_journal_coeditor_code           CU3043
_journal_issue                   12
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              1549
_journal_page_last               1552
_journal_paper_doi               10.1107/S0108270113031557
_journal_volume                  69
_journal_year                    2013
_chemical_formula_iupac          'C8 H12 N O +, C7 H10 N O5 -'
_chemical_formula_moiety         'C8 H12 N O +, C7 H10 N O5 -'
_chemical_formula_sum            'C15 H22 N2 O6'
_chemical_formula_weight         326.35
_chemical_melting_point_gt       396
_chemical_melting_point_lt       398
_chemical_name_systematic
;
2-Ethyl-3-hydroxy-6-methylpyridinium hydrogen
<i>N</i>-acetyl-<i>L</i>-glutamate
;
_space_group_IT_number           19
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2ac 2ab'
_symmetry_space_group_name_H-M   'P 21 21 21'
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   27.821(2)
_cell_length_b                   12.0939(15)
_cell_length_c                   4.9917(13)
_cell_measurement_reflns_used    646
_cell_measurement_temperature    298(2)
_cell_measurement_theta_max      39.994
_cell_measurement_theta_min      3.174
_cell_volume                     1679.5(5)
_computing_cell_refinement       '<i>MRIA</i> (Zlokazov & Chernyshev, 1992)'
_computing_data_collection       '<i>DataCollector</i> (PANalytical, 2010)'
_computing_data_reduction        '<i>DataCollector</i> (PANalytical, 2010)'
_computing_molecular_graphics
'PLATON (Spek, 2009) and Mercury (Macrae <i>et al.</i>, 2008)'
_computing_publication_material
'<i>MRIA</i> (Zlokazov & Chernyshev, 1992) and SHELXL97 (Sheldrick, 2008)'
_computing_structure_refinement  '<i>MRIA</i> (Zlokazov & Chernyshev, 1992)'
_computing_structure_solution
'simulated annealing (Zhukov <i>et al.</i>, 2001)'
_diffrn_ambient_temperature      298(2)
_diffrn_measurement_device       'PANanalytical EMPYREAN'
_diffrn_radiation_monochromator  Ni-filter
_diffrn_radiation_source         'line-focus sealed tube'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.5418
_exptl_absorpt_coefficient_mu    0.841
_exptl_crystal_density_diffrn    1.291
_exptl_crystal_density_method    'not measured'
_exptl_crystal_F_000             696
_pd_block_diffractogram_id       O
_pd_char_colour                  colourless
_pd_char_particle_morphology     plate
_pd_instr_location
;
A. N. Frumkin Institute of Physical Chemistry and Electrochemistry RAS,
Leninsky prospect, 31,
Moscow 119071,
Russian Federation
;
_pd_meas_2theta_range_inc        0.017
_pd_meas_2theta_range_max        79.993
_pd_meas_2theta_range_min        4.020
_pd_meas_number_of_points        4470
_pd_meas_scan_method             cont
_pd_prep_pressure                101
_pd_prep_temperature             298(2)
_pd_proc_2theta_range_inc        0.017
_pd_proc_2theta_range_max        79.993
_pd_proc_2theta_range_min        4.020
_pd_proc_info_excluded_regions   none
_pd_proc_ls_background_function  'Chebyshev polynomial up to the 5th order'
_pd_proc_ls_pref_orient_corr
;
March--Dollase (1986) texture correction;
direction of preferred orientation [001],
parameter <i>r</i> = 1.05(1).
;
_pd_proc_ls_profile_function     'split-type pseudo-Voigt (Toraya, 1986)'
_pd_proc_ls_prof_R_factor        0.0345
_pd_proc_ls_prof_wR_expected     0.0455
_pd_proc_ls_prof_wR_factor       0.0447
_pd_proc_wavelength              1.5418
_pd_spec_mounting
;
thin layer on the non-diffracting silicon plate
;
_pd_spec_mount_mode              reflection
_pd_spec_shape                   flat_sheet
_pd_spec_size_axial              15
_pd_spec_size_equat              1
_pd_spec_size_thick              1
_refine_diff_density_max         0.41
_refine_diff_density_min         -0.38
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_all   0.9824
_refine_ls_hydrogen_treatment    noref
_refine_ls_matrix_type           fullcycle
_refine_ls_number_constraints    0
_refine_ls_number_parameters     126
_refine_ls_number_restraints     57
_refine_ls_shift/su_max          .002
_refine_ls_shift/su_mean         .000
_refine_ls_structure_factor_coef Inet
_refine_ls_weighting_scheme      sigma
_cod_data_source_file            cu3043.cif
_cod_data_source_block           O
_cod_database_code               2019277