Dimethyl dispiro[tricyclo[3.3.1.1^3,7^]decane-1,2'-bicyclo[1.1.0]butane-4',1''-tricyclo[3.3.1.1^3,7^]decane]-1',3'-dicarboxylate, a strain-enhanced bicyclo[1.1.0]butane with a very short intramolecular C—H···H—C contact
Bats, Jan W.; Bolte, Michael; Grundl, Marc A.; Hashmi, A. Stephen K.; Acta Crystallographica Section C 57 (2001) 441–443; doi:10.1107/S010827010100004X

data_2011904
_publ_section_title
;Dimethyl
 dispiro[tricyclo[3.3.1.1^3,7^]decane-1,2'-bicyclo[1.1.0]butane-4',1''-tricyclo[3.3.1.1^3,7^]decane]-1',3'-dicarboxylate,
 a strain-enhanced bicyclo[1.1.0]butane with a very short intramolecular
 C---H&#x00B7;&#x00B7;&#x00B7;H---C contact
;
_journal_issue                   4
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              441
_journal_page_last               443
_journal_paper_doi               10.1107/S010827010100004X
_journal_volume                  57
_journal_year                    2001
_chemical_formula_iupac          'C26 H34 O4'
_chemical_formula_moiety         'C26 H34 O4'
_chemical_formula_sum            'C26 H34 O4'
_chemical_formula_weight         410.53
_chemical_name_systematic
;
Dimethyl dispiro[tricyclo[3.3.1.1^3,7^]decan-1,2'-bicyclo[1.1.0]butan-4',1"-
tricyclo[3.3.1.1^3,7^]decane]-1',3'-dicarboxylate
;
_space_group_IT_number           2
_symmetry_cell_setting           triclinic
_symmetry_space_group_name_Hall  '-P 1'
_symmetry_space_group_name_H-M   'P -1'
_audit_creation_method           SHELXL-97
_cell_angle_alpha                89.442(11)
_cell_angle_beta                 82.317(14)
_cell_angle_gamma                70.628(8)
_cell_formula_units_Z            2
_cell_length_a                   9.710(2)
_cell_length_b                   10.3412(12)
_cell_length_c                   11.051(2)
_cell_measurement_reflns_used    154
_cell_measurement_temperature    143(2)
_cell_measurement_theta_max      23
_cell_measurement_theta_min      3
_cell_volume                     1036.7(3)
_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'
_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 .904
_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  .039
_diffrn_reflns_av_sigmaI/netI    .0313
_diffrn_reflns_limit_h_max       13
_diffrn_reflns_limit_h_min       -13
_diffrn_reflns_limit_k_max       14
_diffrn_reflns_limit_k_min       -15
_diffrn_reflns_limit_l_max       15
_diffrn_reflns_limit_l_min       -14
_diffrn_reflns_number            18851
_diffrn_reflns_theta_full        28.00
_diffrn_reflns_theta_max         31.00
_diffrn_reflns_theta_min         1.86
_diffrn_standards_decay_%        .0
_diffrn_standards_interval_time  600
_diffrn_standards_number         299
_exptl_absorpt_coefficient_mu    .087
_exptl_absorpt_correction_T_max  .979
_exptl_absorpt_correction_T_min  .952
_exptl_absorpt_correction_type   numerical
_exptl_absorpt_process_details
'using 7 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             444
_exptl_crystal_size_max          .48
_exptl_crystal_size_mid          .40
_exptl_crystal_size_min          .28
_refine_diff_density_max         .37
_refine_diff_density_min         -.22
_refine_ls_extinction_coef       .010(2)
_refine_ls_extinction_method     SHELXL97
_refine_ls_goodness_of_fit_ref   1.060
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     274
_refine_ls_number_reflns         5993
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.060
_refine_ls_R_factor_all          .051
_refine_ls_R_factor_gt           .040
_refine_ls_shift/su_max          <0.001
_refine_ls_shift/su_mean         <0.001
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w = 1/[\s^2^(Fo^2^)+(0.05P)^2^+0.3P] where P = (Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_ref         .108
_reflns_number_gt                5005
_reflns_number_total             5993
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            sk1443.cif
_cod_data_source_block           I
_cod_database_code               2011904