Squaric Acid N-Hydroxylamides: Synthesis, Structure, and Properties of Vinylogous Hydroxamic Acid Analogues
Nathaniel C. Lim; Martha D. Morton; Hilary A. Jenkins; Christian Brückner; Journal of Organic Chemistry 68 (2003) 9233–9241; doi:10.1021/jo035175g

data_4022566
_publ_section_title
;
 Squaric Acid N-Hydroxylamides: Synthesis, Structure,
 and Properties of Vinylogous Hydroxamic Acid Analogues
;
_journal_name_full               'Journal of Organic Chemistry'
_journal_page_first              9233
_journal_page_last               9241
_journal_paper_doi               10.1021/jo035175g
_journal_volume                  68
_journal_year                    2003
_chemical_formula_sum            'C14 H20 N2 O4'
_chemical_formula_weight         280.32
_chemical_melting_point          441.1(10)
_chemical_name_systematic
;
3-Morpholino-4-N-cyclohexylhydroxylaminocyclobut-3-ene-1,2-dione
;
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2ybc'
_symmetry_space_group_name_H-M   'P 1 21/c 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                 96.336(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   12.4038(12)
_cell_length_b                   8.6745(8)
_cell_length_c                   13.2282(12)
_cell_measurement_temperature    198(2)
_cell_volume                     1414.6(2)
_computing_cell_refinement       'Bruker XSCANS'
_computing_data_collection       'Bruker XSCANS'
_computing_data_reduction        'Bruker SHELXTL'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      198(2)
_diffrn_measured_fraction_theta_full 0.978
_diffrn_measured_fraction_theta_max 0.978
_diffrn_measurement_device_type  'Bruker P4'
_diffrn_measurement_method       '\w scans'
_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  0.0268
_diffrn_reflns_av_sigmaI/netI    0.0261
_diffrn_reflns_limit_h_max       15
_diffrn_reflns_limit_h_min       -16
_diffrn_reflns_limit_k_max       10
_diffrn_reflns_limit_k_min       -11
_diffrn_reflns_limit_l_max       17
_diffrn_reflns_limit_l_min       -16
_diffrn_reflns_number            9525
_diffrn_reflns_theta_full        27.50
_diffrn_reflns_theta_max         27.50
_diffrn_reflns_theta_min         1.65
_exptl_absorpt_coefficient_mu    0.097
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            Colourless
_exptl_crystal_density_diffrn    1.316
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       Plate
_exptl_crystal_F_000             600
_exptl_crystal_size_max          0.040
_exptl_crystal_size_mid          0.2
_exptl_crystal_size_min          0.25
_refine_diff_density_max         0.307
_refine_diff_density_min         -0.143
_refine_diff_density_rms         0.043
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.116
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     181
_refine_ls_number_reflns         3180
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.116
_refine_ls_R_factor_all          0.0648
_refine_ls_R_factor_gt           0.0460
_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^)+(0.0733P)^2^+0.0921P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1287
_refine_ls_wR_factor_ref         0.1355
_reflns_number_gt                2336
_reflns_number_total             3180
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            jo035175gsi20030814_084753.cif
_cod_data_source_block           Lim_et_al._compound_6c
_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:

'_chemical_melting_point' value '167-169 degC' was changed to
'441.1(10)' - it was converted from degrees Celsius(C) to Kelvins(K),
the average value was taken and precision was estimated.

Automatic conversion script
Id: cif_fix_values 1646 2011-03-28 12:23:43Z adriana 
;
_cod_original_sg_symbol_H-M      'P 21/c'
_cod_database_code               4022566