Role of the <i>gauche</i> effect and local 1,3-dipole–dipole interactions in stabilizing an unusual conformation of tartarodinitriles
Rychlewska, Urszula; Waścinska, Natalia; Warżajtis, Beata; Gawroński, Jacek; Acta Crystallographica Section B 64 (2008) 497–503; doi:10.1107/S0108768108018272

data_2104166
_publ_contact_author
;
Urszula Rychlewska
Faculty of Chemistry
Adam Mickiewicz University
Grunwaldzka 6
60-780 Pozna\'n
Poland
;
_publ_section_title
;
 Role of the <i>gauche</i> effect and local 1,3-dipole--dipole
 interactions in stabilizing an unusual conformation of
 tartarodinitriles
;
_journal_coeditor_code           BS5062
_journal_issue                   4
_journal_name_full               'Acta Crystallographica Section B'
_journal_page_first              497
_journal_page_last               503
_journal_paper_doi               10.1107/S0108768108018272
_journal_volume                  64
_journal_year                    2008
_chemical_formula_sum            'C4 H4 N2 O2'
_chemical_formula_weight         112.09
_space_group_IT_number           61
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_symmetry_space_group_name_Hall  '-P 2ac 2ab'
_symmetry_space_group_name_H-M   'P b c a'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
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_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   7.2155(15)
_cell_length_b                   6.2725(12)
_cell_length_c                   10.828(2)
_cell_measurement_reflns_used    478
_cell_measurement_temperature    130(2)
_cell_measurement_theta_max      26.09
_cell_measurement_theta_min      3.76
_cell_volume                     490.07(17)
_computing_cell_refinement       'CrysAlisPRO v.1.171 (Oxford Diffraction,2007)'
_computing_data_collection
'CrysAlis CCD v.1.171 (Oxford Diffraction,2007)'
_computing_data_reduction        'CrysAlisPRO v.1.171 (Oxford Diffraction,2007)'
_computing_molecular_graphics
;
Simens Analytical X-Ray Instruments (1989),
Mercury (Bruno, et al. 2002)
;
_computing_publication_material  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-86 (Sheldrick, 1990)'
_diffrn_ambient_temperature      130(2)
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_diffrn_measurement_device_type  'Kuma KM4CCD \k-geometry diffractometer'
_diffrn_measurement_method       '\w scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
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_diffrn_reflns_av_R_equivalents  0.0390
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_diffrn_reflns_limit_h_max       5
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_diffrn_reflns_limit_k_min       -7
_diffrn_reflns_limit_l_max       13
_diffrn_reflns_limit_l_min       -13
_diffrn_reflns_number            2811
_diffrn_reflns_theta_full        26.09
_diffrn_reflns_theta_max         26.09
_diffrn_reflns_theta_min         3.76
_diffrn_standards_interval_count 'every 50 dc frames'
_diffrn_standards_number         '3 reference frames'
_exptl_absorpt_coefficient_mu    0.125
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.519
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prismatic
_exptl_crystal_F_000             232
_exptl_crystal_size_max          0.50
_exptl_crystal_size_mid          0.35
_exptl_crystal_size_min          0.20
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_refine_diff_density_min         -0.261
_refine_ls_extinction_method     none
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_refine_ls_number_parameters     41
_refine_ls_number_reflns         478
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.133
_refine_ls_R_factor_all          0.0582
_refine_ls_R_factor_gt           0.0416
_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^)+(0.0645P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0995
_refine_ls_wR_factor_ref         0.1178
_reflns_number_gt                352
_reflns_number_total             478
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            bs5062.cif
_cod_data_source_block           1a
_cod_original_cell_volume        490.04(17)
_cod_original_sg_symbol_H-M      Pbca
_cod_database_code               2104166
_cod_database_fobs_code          2104166