Tuning Lewis acidity using the reactivity of "frustrated Lewis pairs": facile formation of phosphine-boranes and cationic phosphonium-boranes.
Welch, Gregory C.; Cabrera, Lourdes; Chase, Preston A.; Hollink, Emily; Masuda, Jason D.; Wei, Pingrong; Stephan, Douglas W.; Dalton transactions (Cambridge, England : 2003)  (2007) 3407–3414; doi:10.1039/b704417h

data_7005684
_publ_section_title
;
 Tuning Lewis acidity using the reactivity of "frustrated Lewis pairs":
 facile formation of phosphine-boranes and cationic
 phosphonium-boranes.
;
_journal_issue                   31
_journal_name_full
'Dalton transactions (Cambridge, England : 2003)'
_journal_page_first              3407
_journal_page_last               3414
_journal_paper_doi               10.1039/b704417h
_journal_year                    2007
_chemical_formula_sum            'C27 H21 B F15 P'
_chemical_formula_weight         672.22
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_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_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 105.156(12)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   9.544(6)
_cell_length_b                   18.426(11)
_cell_length_c                   17.134(10)
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      25.0
_cell_measurement_theta_min      2.0
_cell_volume                     2908(3)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.994
_diffrn_measured_fraction_theta_max 0.994
_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  0.0189
_diffrn_reflns_av_sigmaI/netI    0.0290
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       19
_diffrn_reflns_limit_k_min       -20
_diffrn_reflns_limit_l_max       13
_diffrn_reflns_limit_l_min       -18
_diffrn_reflns_number            12247
_diffrn_reflns_theta_full        23.20
_diffrn_reflns_theta_max         23.20
_diffrn_reflns_theta_min         2.21
_exptl_absorpt_coefficient_mu    0.208
_exptl_absorpt_correction_T_max  0.488936
_exptl_absorpt_correction_T_min  0.345020
_exptl_absorpt_correction_type   empirical
_exptl_crystal_density_diffrn    1.535
_exptl_crystal_density_method    'not measured'
_exptl_crystal_F_000             1352
_exptl_crystal_size_max          0.25
_exptl_crystal_size_mid          0.23
_exptl_crystal_size_min          0.18
_refine_diff_density_max         0.229
_refine_diff_density_min         -0.218
_refine_diff_density_rms         0.033
_refine_ls_extinction_coef       0.0039(8)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_ref   0.945
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     398
_refine_ls_number_reflns         4120
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.945
_refine_ls_R_factor_all          0.0634
_refine_ls_R_factor_gt           0.0385
_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^)+(0.0757P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1065
_refine_ls_wR_factor_ref         0.1143
_reflns_number_gt                2650
_reflns_number_total             4120
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b704417h.txt
_cod_data_source_block           i-Pr3P(C6F4)BF(C6F5)2
_cod_original_sg_symbol_H-M      P2(1)/c
_cod_database_code               7005684