Synthesis and reactivity of electron poor allenes: formation of completely organic frustrated Lewis pairs.
Palomas, David; Holle, Sigrid; Inés, Blanca; Bruns, Hans; Goddard, Richard; Alcarazo, Manuel; Dalton transactions (Cambridge, England : 2003) 41 (2012) 9073–9082; doi:10.1039/c2dt30195d

data_7019701
_publ_section_title
;
 Synthesis and reactivity of electron poor allenes: formation of
 completely organic frustrated Lewis pairs.
;
_journal_issue                   30
_journal_name_full
'Dalton transactions (Cambridge, England : 2003)'
_journal_page_first              9073
_journal_page_last               9082
_journal_paper_doi               10.1039/c2dt30195d
_journal_volume                  41
_journal_year                    2012
_chemical_compound_source        hexane
_chemical_formula_moiety         'C21 H16 F2 O4'
_chemical_formula_sum            'C21 H16 F2 O4'
_chemical_formula_weight         370.34
_chemical_name_systematic
;
1,1-di(ethoxycarbonyl)-2-(9H-3,6-difluoro-fluoren-9-ylidene)-ethene
;
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_Int_Tables_number      14
_symmetry_space_group_name_Hall  '-P 2yn'
_symmetry_space_group_name_H-M   'P 1 21/n 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_block_code                HOS-HG-120-02
_audit_creation_date             2012-01-18
_cell_angle_alpha                90.00
_cell_angle_beta                 101.410(3)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   4.5285(2)
_cell_length_b                   45.944(2)
_cell_length_c                   8.2961(4)
_cell_measurement_reflns_used    4296
_cell_measurement_temperature    100
_cell_measurement_theta_max      55.1395
_cell_measurement_theta_min      3.8485
_cell_volume                     1691.95(13)
_computing_cell_refinement       'SAINT software (Bruker AXS, 2004)'
_computing_data_collection       'PROTEUM2 (Bruker AXS, 2008)'
_computing_data_reduction        'SAINT software (Bruker AXS, 2004)'
_computing_molecular_graphics    'DIAMOND (Crystal Impact GbR, 2005)'
_computing_structure_refinement  'SHELXL-97 (G. M. Sheldrick, 2008)'
_computing_structure_solution    'SHELXS-97 (G. M. Sheldrick, 2008)'
_diffrn_ambient_temperature      100
_diffrn_detector_area_resol_mean 66.67
_diffrn_measured_fraction_theta_full 0.981
_diffrn_measured_fraction_theta_max 0.981
_diffrn_measurement_device_type  'Bruker AXS X8 Proteum'
_diffrn_measurement_method       'CCD \f- and \w-scans'
_diffrn_radiation_monochromator  'focusing multilayer optic'
_diffrn_radiation_source         '0.2 x 2mm^2^ focus rotating anode'
_diffrn_radiation_type           Cu-K\a
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.0651
_diffrn_reflns_av_sigmaI/netI    0.0672
_diffrn_reflns_limit_h_max       4
_diffrn_reflns_limit_h_min       -4
_diffrn_reflns_limit_k_max       48
_diffrn_reflns_limit_k_min       -48
_diffrn_reflns_limit_l_max       8
_diffrn_reflns_limit_l_min       -8
_diffrn_reflns_number            18616
_diffrn_reflns_theta_full        54.79
_diffrn_reflns_theta_max         54.79
_diffrn_reflns_theta_min         1.92
_diffrn_standards_decay_%        0
_diffrn_standards_interval_count 0
_diffrn_standards_interval_time  0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.972
_exptl_absorpt_correction_T_max  0.96683
_exptl_absorpt_correction_T_min  0.83181
_exptl_absorpt_correction_type   gaussian
_exptl_absorpt_process_details   'SADABS (Bruker AXS, 2008)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.454
_exptl_crystal_description       needle
_exptl_crystal_F_000             768
_exptl_crystal_size_max          0.35
_exptl_crystal_size_mid          0.04
_exptl_crystal_size_min          0.04
_refine_diff_density_max         0.376
_refine_diff_density_min         -0.317
_refine_diff_density_rms         0.064
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.056
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     246
_refine_ls_number_reflns         2071
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.056
_refine_ls_R_factor_all          0.0671
_refine_ls_R_factor_gt           0.0544
_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^)+(0.0518P)^2^+2.6833P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1368
_refine_ls_wR_factor_ref         0.1465
_reflns_number_gt                1705
_reflns_number_total             2071
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c2dt30195d.txt
_cod_data_source_block           6979_8
_cod_original_cell_volume        1691.96(14)
_cod_original_sg_symbol_Hall     '-p 2yn'
_cod_original_sg_symbol_H-M      'p 21/n'
_cod_database_code               7019701