<small>L</small>-Methioninamide ester amide of squaric acid diethyl ester
Tsonko Kolev; Emiliya Cherneva; Michael Spiteller; William S. Sheldrick; Heike Mayer-Figge; Acta Crystallographica Section E 62 (2006) o1390–o1392; doi:10.1107/S1600536806008440

data_2208514
_publ_section_title
;
 <small>L</small>-Methioninamide ester amide of squaric acid diethyl
 ester
;
_journal_coeditor_code           BT2021
_journal_issue                   4
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              o1390
_journal_page_last               o1392
_journal_paper_doi               10.1107/S1600536806008440
_journal_volume                  62
_journal_year                    2006
_chemical_formula_iupac          'C11 H16 N2 O4 S'
_chemical_formula_moiety         'C11 H16 N2 O4 S'
_chemical_formula_sum            'C11 H16 N2 O4 S'
_chemical_formula_weight         272.32
_chemical_name_systematic
;
2-(2-ethoxy-3,4-dioxocyclobutenylamino)-2-[2-(methylsulfanyl)ethyl]acetamide
;
_space_group_IT_number           4
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  'P 2yb'
_symmetry_space_group_name_H-M   'P 1 21 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 103.355(7)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   9.5810(11)
_cell_length_b                   7.3961(12)
_cell_length_c                   9.9354(13)
_cell_measurement_reflns_used    25
_cell_measurement_temperature    294(2)
_cell_measurement_theta_max      15.05
_cell_measurement_theta_min      7.25
_cell_volume                     685.00(16)
_computing_cell_refinement       'R3m/V User's Guide'
_computing_data_collection       'R3m/V User's Guide (Siemens, 1989)'
_computing_data_reduction        'XDISK (Siemens, 1989)'
_computing_molecular_graphics    'SHELXTL-Plus (Sheldrick, 1995)'
_computing_publication_material  SHELXL97
_computing_structure_refinement  'SHELXL97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      294(2)
_diffrn_measured_fraction_theta_full 0.986
_diffrn_measured_fraction_theta_max 0.986
_diffrn_measurement_device_type  'Siemens P4 four-circle'
_diffrn_measurement_method       \w
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0262
_diffrn_reflns_av_sigmaI/netI    0.0343
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -1
_diffrn_reflns_limit_k_max       8
_diffrn_reflns_limit_k_min       -1
_diffrn_reflns_limit_l_max       11
_diffrn_reflns_limit_l_min       -11
_diffrn_reflns_number            1754
_diffrn_reflns_theta_full        25.0
_diffrn_reflns_theta_max         25.0
_diffrn_reflns_theta_min         2.11
_diffrn_standards_decay_%        1
_diffrn_standards_interval_count 100
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    0.245
_exptl_absorpt_correction_T_max  0.948325
_exptl_absorpt_correction_T_min  0.873015
_exptl_absorpt_correction_type   psi-scan
_exptl_absorpt_process_details   '(XPREP in SHELXTL-Plus; Sheldrick, 1995)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.320
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             288
_exptl_crystal_size_max          0.55
_exptl_crystal_size_mid          0.48
_exptl_crystal_size_min          0.22
_refine_diff_density_max         0.221
_refine_diff_density_min         -0.170
_refine_ls_abs_structure_details 'Flack (1983), 204 Friedel pairs'
_refine_ls_abs_structure_Flack   0.05(19)
_refine_ls_extinction_coef       0.09(2)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL97
_refine_ls_goodness_of_fit_ref   1.052
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     166
_refine_ls_number_reflns         1487
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.052
_refine_ls_R_factor_all          0.0563
_refine_ls_R_factor_gt           0.0473
_refine_ls_shift/su_max          0.009
_refine_ls_shift/su_mean         0.001
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0523P)^2^+0.2827P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1154
_refine_ls_wR_factor_ref         0.1223
_reflns_number_gt                1294
_reflns_number_total             1487
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            bt2021.cif
_cod_data_source_block           I
_cod_depositor_comments
;
The following automatic conversions were performed:
'_symmetry_cell_setting' value 'Monoclinic' changed to 'monoclinic'
according to '/home/saulius/struct/CIF-dictionaries/cif_core.dic'
dictionary named 'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_enum 1527 2010-12-29 10:47:43Z saulius 

The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Monoclinic' changed to 'monoclinic'
according to /home/saulius/struct/CIF-dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_values 1715 2011-07-08 13:25:40Z adriana 
;
_cod_original_sg_symbol_H-M      'P 21'
_cod_database_code               2208514
_cod_database_fobs_code          2208514