6,6-Dicyanopentafulvenes: Electronic Structure and Regioselectivity in [2 + 2] Cycloaddition-Retroelectrocyclization Reactions
Aaron D. Finke; Oliver Dumele; Michal Zalibera; Daria Confortin; Pawel Cias; Govindasamy Jayamurugan; Jean-Paul Gisselbrecht; Corinne Boudon; W. Bernd Schweizer; Georg Gescheidt; François Diederich; Journal of the American Chemical Society 134 (2012) 18139–18146; doi:10.1021/ja309141r

data_4118860
_publ_contact_author_email       schweizer@org.chem.ethz.ch
_publ_contact_author_name        'B. Schweizer'
_publ_section_title
;
 6,6-Dicyanopentafulvenes: Electronic Structure and Regioselectivity in [2
 + 2] Cycloaddition-Retroelectrocyclization Reactions
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              18139
_journal_page_last               18146
_journal_paper_doi               10.1021/ja309141r
_journal_volume                  134
_journal_year                    2012
_chemical_formula_moiety         'C52 H84 N2 Si4'
_chemical_formula_sum            'C52 H84 N2 Si4'
_chemical_formula_weight         849.58
_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'
_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                 106.826(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   13.2013(7)
_cell_length_b                   14.5468(7)
_cell_length_c                   14.6172(7)
_cell_measurement_reflns_used    9939
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      26.01
_cell_measurement_theta_min      2.31
_cell_volume                     2686.9(2)
_computing_cell_refinement       'Bruker SAINT'
_computing_data_collection       'Bruker APEX2'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Platon, Ortep'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement
'OLEX2 (Dolomanov, 2009), SHELXL-97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 0.996
_diffrn_measured_fraction_theta_max 0.996
_diffrn_measurement_device_type  'Bruker APEX-II CCD'
_diffrn_measurement_method       '\f and \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  0.0354
_diffrn_reflns_av_sigmaI/netI    0.0540
_diffrn_reflns_limit_h_max       17
_diffrn_reflns_limit_h_min       -17
_diffrn_reflns_limit_k_max       18
_diffrn_reflns_limit_k_min       -18
_diffrn_reflns_limit_l_max       19
_diffrn_reflns_limit_l_min       -18
_diffrn_reflns_number            33046
_diffrn_reflns_theta_full        27.61
_diffrn_reflns_theta_max         27.61
_diffrn_reflns_theta_min         1.46
_exptl_absorpt_coefficient_mu    0.143
_exptl_absorpt_correction_T_max  0.9971
_exptl_absorpt_correction_T_min  0.9449
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   SADABS
_exptl_crystal_colour            green
_exptl_crystal_density_diffrn    1.050
_exptl_crystal_description       plate
_exptl_crystal_F_000             932
_exptl_crystal_size_max          0.40
_exptl_crystal_size_mid          0.24
_exptl_crystal_size_min          0.02
_refine_diff_density_max         0.433
_refine_diff_density_min         -0.339
_refine_diff_density_rms         0.047
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -0.01(7)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.127
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     554
_refine_ls_number_reflns         11813
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.127
_refine_ls_R_factor_all          0.0593
_refine_ls_R_factor_gt           0.0444
_refine_ls_shift/su_max          0.008
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0500P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0965
_refine_ls_wR_factor_ref         0.1031
_reflns_number_gt                9904
_reflns_number_total             11813
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja309141r_si_001_1.cif
_cod_data_source_block           d090911_0m
_cod_database_code               4118860