Dimethyl (1<i>R</i>,8<i>R</i>)-1,11,11-trimethyl-2,3-diazatricyclo[6.2.1.0^2,6^]undeca-3,5-diene-4,5-dicarboxylate, a chiral molecule with an approximate centrosymmetric crystal structure
Bats, Jan W.; Grundl, Marc A.; Hashmi, A. Stephen K.; Acta Crystallographica Section C 57 (2001) 208–210; doi:10.1107/S0108270100017960

data_2011774
_publ_section_title
;Dimethyl
 (1<i>R</i>,8<i>R</i>)-1,11,11-trimethyl-2,3-diazatricyclo[6.2.1.0^2,6^]undeca-3,5-diene-4,5-dicarboxylate,
 a chiral molecule with an approximate centrosymmetric crystal structure
;
_journal_issue                   2
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              208
_journal_page_last               210
_journal_paper_doi               10.1107/S0108270100017960
_journal_volume                  57
_journal_year                    2001
_chemical_formula_moiety         'C16 H22 N2 O4'
_chemical_formula_sum            'C16 H22 N2 O4'
_chemical_formula_weight         306.36
_chemical_name_systematic
;dimethyl
 (1R,8R)-1,11,11-trimethyl-2,3-diazatricyclo[6.2.1.0^2,6^]undecan-3,5-
dien-4,5-dicarboxylate
;
_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'
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 90.513(12)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   7.3772(14)
_cell_length_b                   20.063(3)
_cell_length_c                   10.4576(12)
_cell_measurement_reflns_used    188
_cell_measurement_temperature    143(2)
_cell_measurement_theta_max      23
_cell_measurement_theta_min      3
_cell_volume                     1547.8(4)
_computing_cell_refinement       SMART
_computing_data_collection       'SMART (Siemens, 1995)'
_computing_data_reduction        'SAINT (Siemens, 1995)'
_computing_molecular_graphics    'XP in SHELXTL (Sheldrick, 1996)'
_computing_publication_material  'CIF in SHELXL97 (Sheldrick, 1997)'
_computing_structure_refinement  'SHELXL97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      143(2)
_diffrn_measured_fraction_theta_full .991
_diffrn_measured_fraction_theta_max .951
_diffrn_measurement_device_type  SIEMENS_SMART
_diffrn_measurement_method       \w
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'normal-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     .71073
_diffrn_reflns_av_R_equivalents  .0293
_diffrn_reflns_av_sigmaI/netI    .0167
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       29
_diffrn_reflns_limit_k_min       -28
_diffrn_reflns_limit_l_max       15
_diffrn_reflns_limit_l_min       -14
_diffrn_reflns_number            30858
_diffrn_reflns_theta_full        29.50
_diffrn_reflns_theta_max         31.00
_diffrn_reflns_theta_min         1.95
_diffrn_standards_decay_%        .0
_diffrn_standards_interval_time  600
_diffrn_standards_number         524
_exptl_absorpt_coefficient_mu    .095
_exptl_absorpt_correction_T_max  .969
_exptl_absorpt_correction_T_min  .943
_exptl_absorpt_correction_type   numerical
_exptl_absorpt_process_details   'six indexed faces (SHELXTL; Sheldrick, 1996)'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.315
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             656
_exptl_crystal_size_max          .70
_exptl_crystal_size_mid          .40
_exptl_crystal_size_min          .36
_refine_diff_density_max         .437
_refine_diff_density_min         -.296
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.079
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     407
_refine_ls_number_reflns         4858
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.078
_refine_ls_R_factor_all          .0393
_refine_ls_R_factor_gt           .0359
_refine_ls_shift/su_max          .001
_refine_ls_shift/su_mean         .000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w = 1/[\s^2^(Fo^2^)+(0.055P)^2^+0.28P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_ref         .0959
_reflns_number_gt                4589
_reflns_number_total             4858
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            sk1429.cif
_cod_data_source_block           I
_cod_original_cell_volume        1547.7(4)
_cod_original_sg_symbol_H-M      'P 21'
_cod_database_code               2011774
_cod_database_fobs_code          2011774