(2<i>R</i>,3<i>R</i>)-Diacetyltartaric acid anhydride
Zhao-Bin Qi; Ming-Jie Zhang; Dong-Yan Yuan; Shan-Shan Ma; Xiang-Qian Wang; Acta Crystallographica Section E 61 (2005) o1085–o1086; doi:10.1107/S1600536805008469

data_2205485
_publ_section_title
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 (2<i>R</i>,3<i>R</i>)-Diacetyltartaric acid anhydride
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_journal_issue                   4
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              o1085
_journal_page_last               o1086
_journal_paper_doi               10.1107/S1600536805008469
_journal_volume                  61
_journal_year                    2005
_chemical_formula_iupac          'C8 H8 O7'
_chemical_formula_moiety         'C8 H8 O7'
_chemical_formula_sum            'C8 H8 O7'
_chemical_formula_weight         216.14
_chemical_melting_point          407
_chemical_name_systematic
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Diacetyltartaric acid anhydride
;
_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'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   5.4066(7)
_cell_length_b                   10.3363(14)
_cell_length_c                   17.434(2)
_cell_measurement_reflns_used    1835
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      21.89
_cell_measurement_theta_min      2.29
_cell_volume                     974.3(2)
_computing_cell_refinement       'SAINT (Bruker, 1997)'
_computing_data_collection       'SMART (Bruker, 1997)'
_computing_data_reduction        SAINT
_computing_molecular_graphics    'SHELXTL (Bruker, 1997)'
_computing_publication_material  SHELXTL
_computing_structure_refinement  'SHELXL97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_device_type  'Bruker SMART CCD area-detector'
_diffrn_measurement_method       '\f and \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  0.0231
_diffrn_reflns_av_sigmaI/netI    0.0187
_diffrn_reflns_limit_h_max       7
_diffrn_reflns_limit_h_min       -5
_diffrn_reflns_limit_k_max       13
_diffrn_reflns_limit_k_min       -13
_diffrn_reflns_limit_l_max       22
_diffrn_reflns_limit_l_min       -22
_diffrn_reflns_number            6584
_diffrn_reflns_theta_full        27.91
_diffrn_reflns_theta_max         27.91
_diffrn_reflns_theta_min         2.29
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.133
_exptl_absorpt_correction_T_max  0.976
_exptl_absorpt_correction_T_min  0.969
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   '(SADABS; Sheldrick, 1996)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.474
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             448
_exptl_crystal_size_max          0.24
_exptl_crystal_size_mid          0.20
_exptl_crystal_size_min          0.18
_refine_diff_density_max         0.128
_refine_diff_density_min         -0.173
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.071
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     138
_refine_ls_number_reflns         1381
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.071
_refine_ls_R_factor_all          0.0454
_refine_ls_R_factor_gt           0.0351
_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^)+(0.0644P)^2^] where P = (Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0950
_refine_ls_wR_factor_ref         0.0996
_reflns_number_gt                1093
_reflns_number_total             1381
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            gh6017.cif
_cod_data_source_block           I
_cod_depositor_comments
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The following automatic conversions were performed:
'_symmetry_cell_setting' value 'Orthorhombic' changed to 'orthorhombic'
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 'Orthorhombic' changed to
'orthorhombic' 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 
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_cod_database_code               2205485
_cod_database_fobs_code          2205485