The 3,3,6,6-Tetramethyl <i>cis</i>-<i>transoid</i>-<i>cis</i>-Photocyclodimer of <i>tert</i>-Butyl 2,5-Dihydro-5,5-dimethyl-2-oxo-1<i>H</i>-pyrrole-1-carboxylate
Kopf, Jürgen; Wrobel, Matthias Nils; Margaretha, Paul; Acta Crystallographica Section C 54 (1998) 1499–1501; doi:10.1107/S0108270198005344

data_2007729
_publ_section_title
;
 The 3,3,6,6-Tetramethyl
 <i>cis</i>-<i>transoid</i>-<i>cis</i>-Photocyclodimer of
 <i>tert</i>-Butyl
 2,5-Dihydro-5,5-dimethyl-2-oxo-1<i>H</i>-pyrrole-1-carboxylate
;
_journal_issue                   10
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              1499
_journal_page_last               1501
_journal_paper_doi               10.1107/S0108270198005344
_journal_volume                  54
_journal_year                    1998
_chemical_formula_sum            'C22 H34 N2 O6'
_chemical_formula_weight         422.51
_chemical_melting_point          466
_chemical_name_systematic
;
Di-t-butyl cis-transoid-cis-perhydro-3,3,6,6-tetramethyl-1,4-
dioxocyclobuta[1,2-c:3,4-c']-dipyrrole-2,5-dicarboxylate
;
_space_group_IT_number           15
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-C 2yc'
_symmetry_space_group_name_H-M   'C 1 2/c 1'
_audit_creation_method           SHELXL97
_cell_angle_alpha                90.00
_cell_angle_beta                 95.430(10)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   17.2980(10)
_cell_length_b                   10.7380(10)
_cell_length_c                   12.4530(10)
_cell_measurement_reflns_used    25
_cell_measurement_temperature    173.0(10)
_cell_measurement_theta_max      45.7
_cell_measurement_theta_min      41.3
_cell_volume                     2302.7(3)
_computing_cell_refinement       'CAD-4 EXPRESS'
_computing_data_collection       'CAD-4 EXPRESS (Enraf-Nonius, 1994)'
_computing_data_reduction        'CADSHEL (Kopf, 1987)'
_computing_molecular_graphics    'SHELXTL-Plus (Sheldrick, 1992)'
_computing_publication_material  'PLATON95 (Spek, 1990)'
_computing_structure_refinement  SHELXL97
_computing_structure_solution    'SHELXS97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      173.0(10)
_diffrn_measured_fraction_theta_full 0.474
_diffrn_measured_fraction_theta_max 0.474
_diffrn_measurement_device_type  'Enraf-Nonius CAD-4 diffractometer'
_diffrn_measurement_method       '2\q/\w scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.012
_diffrn_reflns_av_sigmaI/netI    0.008
_diffrn_reflns_limit_h_max       21
_diffrn_reflns_limit_h_min       -21
_diffrn_reflns_limit_k_max       3
_diffrn_reflns_limit_k_min       -13
_diffrn_reflns_limit_l_max       15
_diffrn_reflns_limit_l_min       0
_diffrn_reflns_number            2555
_diffrn_reflns_theta_full        76.26
_diffrn_reflns_theta_max         76.26
_diffrn_reflns_theta_min         4.85
_diffrn_standards_decay_%        1
_diffrn_standards_interval_time  '120 min'
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    0.724
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.219
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             912
_exptl_crystal_size_max          0.8
_exptl_crystal_size_mid          0.7
_exptl_crystal_size_min          0.7
_refine_diff_density_max         0.366
_refine_diff_density_min         -0.223
_refine_ls_extinction_coef       0.0105(5)
_refine_ls_extinction_method     SHELXL97
_refine_ls_goodness_of_fit_ref   1.078
_refine_ls_hydrogen_treatment    'H-atom treatment: mixed'
_refine_ls_matrix_type           full
_refine_ls_number_parameters     159
_refine_ls_number_reflns         2417
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.078
_refine_ls_R_factor_all          0.045
_refine_ls_R_factor_gt           0.045
_refine_ls_shift/su_max          0.002
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w = 1/[\s^2^(Fo^2^)+(0.0522P)^2^+2.4367P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_ref         0.114
_reflns_number_gt                2368
_reflns_number_total             2417
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            jz1280.cif
_cod_data_source_block           ntb
_cod_depositor_comments
;
The following automatic conversions were performed:

'_exptl_crystal_density_meas' value 'not measured' was changed to '?'
- the value is perceived as not measured.

Automatic conversion script
Id: cif_fix_values 3008 2015-01-20 13:52:24Z robertas 

The following automatic conversions were performed:

'_refine_ls_weighting_scheme' value 'calc w =
1/[\s^2^(Fo^2^)+(0.0522P)^2^+2.4367P] where P=(Fo^2^+2Fc^2^)/3' was
changed to 'calc'. New tag '_refine_ls_weighting_details' was
created. The value of the new tag was set to 'w =
1/[\s^2^(Fo^2^)+(0.0522P)^2^+2.4367P] where P=(Fo^2^+2Fc^2^)/3'.

Automatic conversion script
Id: cif_fix_values 3143 2015-03-26 13:38:13Z robertas 
;
_cod_original_sg_symbol_H-M      'C 2/c'
_cod_database_code               2007729