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_7019698
_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 H18 O4'
_chemical_formula_sum            'C21 H18 O4'
_chemical_formula_weight         334.35
_chemical_name_systematic
;
1,1-di(ethoxycarbonyl)-2-(9H-fluoren-9-ylidene)-ethene
;
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_Int_Tables_number      14
_symmetry_space_group_name_Hall  '-P 2ybc'
_symmetry_space_group_name_H-M   'P 1 21/c 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_block_code                HOS-HG-013-01
_audit_creation_date             2012-01-18
_cell_angle_alpha                90.00
_cell_angle_beta                 115.659(6)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   9.5811(7)
_cell_length_b                   20.9360(19)
_cell_length_c                   9.7491(7)
_cell_measurement_reflns_used    41585
_cell_measurement_temperature    100
_cell_measurement_theta_max      33.0992
_cell_measurement_theta_min      2.6698
_cell_volume                     1762.7(3)
_computing_cell_refinement       'DENZO (Bruker AXS, 2006)'
_computing_data_collection       'DATCOL (Bruker AXS, 2006)'
_computing_data_reduction        'DENZO (Bruker AXS, 2006)'
_computing_molecular_graphics    'DIAMOND (Crystal Impact GbR, 2005)'
_computing_publication_material
;
OLEX2: a complete structure solution, refinement and analysis program.
Dolomanov et al., J. Appl. Cryst. (2009). 42, 339-341
;
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      100
_diffrn_detector_area_resol_mean 18.02
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.999
_diffrn_measurement_device_type  'Bruker AXS Enraf-Nonius KappaCCD'
_diffrn_measurement_method       'CCD \f- and \w-scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         '0.2 x 2mm^2^ focus rotating anode'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0835
_diffrn_reflns_av_sigmaI/netI    0.0607
_diffrn_reflns_limit_h_max       14
_diffrn_reflns_limit_h_min       -14
_diffrn_reflns_limit_k_max       32
_diffrn_reflns_limit_k_min       -28
_diffrn_reflns_limit_l_max       14
_diffrn_reflns_limit_l_min       -14
_diffrn_reflns_number            36463
_diffrn_reflns_theta_full        27.50
_diffrn_reflns_theta_max         33.17
_diffrn_reflns_theta_min         2.67
_diffrn_standards_decay_%        0
_diffrn_standards_interval_count 0
_diffrn_standards_interval_time  0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.087
_exptl_absorpt_correction_T_max  0.99409
_exptl_absorpt_correction_T_min  0.97111
_exptl_absorpt_correction_type   gaussian
_exptl_absorpt_process_details   'SADABS (Bruker AXS, 2008)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.260
_exptl_crystal_description       plate
_exptl_crystal_F_000             704
_exptl_crystal_size_max          0.30
_exptl_crystal_size_mid          0.12
_exptl_crystal_size_min          0.07
_refine_diff_density_max         0.440
_refine_diff_density_min         -0.470
_refine_diff_density_rms         0.101
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.194
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     228
_refine_ls_number_reflns         6720
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.194
_refine_ls_R_factor_all          0.1006
_refine_ls_R_factor_gt           0.0656
_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^)+(0.1000P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3
;
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1703
_refine_ls_wR_factor_ref         0.1922
_reflns_number_gt                4666
_reflns_number_total             6720
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c2dt30195d.txt
_cod_data_source_block           6971_6
_cod_original_cell_volume        1762.7(2)
_cod_original_sg_symbol_Hall     '-p 2ybc'
_cod_original_sg_symbol_H-M      'P 21/c'
_cod_database_code               7019698