Anion-π interactions influence pK(a) values.
Cadman, Christopher J.; Croft, Anna K.; Beilstein journal of organic chemistry 7 (2011) 320–328; doi:10.3762/bjoc.7.42

data_4029777
_publ_section_title
;
 Anion-\p interactions influence pK(a) values.
;
_journal_name_full               'Beilstein journal of organic chemistry'
_journal_page_first              320
_journal_page_last               328
_journal_paper_doi               10.3762/bjoc.7.42
_journal_volume                  7
_journal_year                    2011
_chemical_formula_moiety         'C17 H14 O'
_chemical_formula_sum            'C17 H14 O'
_chemical_formula_weight         234.28
_chemical_name_systematic
;
 ?
;
_space_group_IT_number           15
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-C 2yc'
_symmetry_space_group_name_H-M   'C 1 2/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                 96.356(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            8
_cell_length_a                   13.3991(5)
_cell_length_b                   8.2341(3)
_cell_length_c                   22.8014(8)
_cell_measurement_reflns_used    24100
_cell_measurement_temperature    120(2)
_cell_measurement_theta_max      27.48
_cell_measurement_theta_min      2.91
_cell_volume                     2500.20(16)
_computing_cell_refinement
'DENZO (Otwinowski & Minor, 1997) & COLLECT (Hooft, R.W.W., 1998)'
_computing_data_collection       'COLLECT (Hooft, R.W.W., 1998)'
_computing_data_reduction
'DENZO (Otwinowski & Minor, 1997) & COLLECT (Hooft, R.W.W., 1998)'
_computing_molecular_graphics    'CAMERON (Watkin, et al., 1993)'
_computing_publication_material  'WINGX (Farrugia, 1998)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      120(2)
_diffrn_detector_area_resol_mean 9.091
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.999
_diffrn_measurement_device_type
'Bruker-Nonius Roper CCD camera on \k-goniostat'
_diffrn_measurement_method       '\f & \w scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'Bruker-Nonius FR591 rotating anode'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0602
_diffrn_reflns_av_sigmaI/netI    0.0440
_diffrn_reflns_limit_h_max       17
_diffrn_reflns_limit_h_min       -17
_diffrn_reflns_limit_k_max       10
_diffrn_reflns_limit_k_min       -10
_diffrn_reflns_limit_l_max       29
_diffrn_reflns_limit_l_min       -29
_diffrn_reflns_number            17562
_diffrn_reflns_theta_full        27.47
_diffrn_reflns_theta_max         27.47
_diffrn_reflns_theta_min         2.99
_exptl_absorpt_coefficient_mu    0.076
_exptl_absorpt_correction_T_max  0.9925
_exptl_absorpt_correction_T_min  0.9776
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS 2007/2 (Sheldrick, G.M., 2007)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.245
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             992
_exptl_crystal_size_max          0.30
_exptl_crystal_size_mid          0.30
_exptl_crystal_size_min          0.10
_refine_diff_density_max         0.270
_refine_diff_density_min         -0.284
_refine_diff_density_rms         0.059
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.046
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     165
_refine_ls_number_reflns         2874
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.046
_refine_ls_R_factor_all          0.0821
_refine_ls_R_factor_gt           0.0553
_refine_ls_shift/su_max          0.002
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0925P)^2^+1.0572P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1463
_refine_ls_wR_factor_ref         0.1638
_reflns_number_gt                2077
_reflns_number_total             2874
_reflns_threshold_expression     >2\s(I)
_cod_data_source_file            1860-5397-7-42-S4.cif
_cod_data_source_block           2009src0664
_cod_original_sg_symbol_H-M      'C 2/c'
_cod_database_code               4029777