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_7005686
_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            'C26 H19 B F15 P'
_chemical_formula_weight         658.19
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_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_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 90.482(12)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   8.955(5)
_cell_length_b                   15.767(9)
_cell_length_c                   19.743(11)
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      25.0
_cell_measurement_theta_min      2.0
_cell_volume                     2787(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 0.988
_diffrn_measured_fraction_theta_max 0.988
_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  0.0691
_diffrn_reflns_av_sigmaI/netI    0.0870
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_k_max       16
_diffrn_reflns_limit_k_min       -17
_diffrn_reflns_limit_l_max       21
_diffrn_reflns_limit_l_min       -21
_diffrn_reflns_number            11750
_diffrn_reflns_theta_full        23.26
_diffrn_reflns_theta_max         23.26
_diffrn_reflns_theta_min         1.65
_exptl_absorpt_coefficient_mu    0.215
_exptl_absorpt_correction_T_max  0.800992
_exptl_absorpt_correction_T_min  0.520733
_exptl_absorpt_correction_type   empirical
_exptl_crystal_density_diffrn    1.568
_exptl_crystal_density_method    'not measured'
_exptl_crystal_F_000             1320
_exptl_crystal_size_max          0.28
_exptl_crystal_size_mid          0.23
_exptl_crystal_size_min          0.21
_refine_diff_density_max         0.184
_refine_diff_density_min         -0.266
_refine_diff_density_rms         0.043
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.862
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     392
_refine_ls_number_reflns         3951
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.862
_refine_ls_R_factor_all          0.0796
_refine_ls_R_factor_gt           0.0436
_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^)+(0.0532P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1008
_refine_ls_wR_factor_ref         0.1061
_reflns_number_gt                2152
_reflns_number_total             3951
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b704417h.txt
_cod_data_source_block           t-Bu2HP(C6F4)BF(C6F5)2
_cod_original_cell_volume        2788(3)
_cod_original_sg_symbol_H-M      P2(1)/n
_cod_database_code               7005686