Extreme oxatriquinanes and a record C-O bond length.
Gunbas, Gorkem; Hafezi, Nema; Sheppard, William L; Olmstead, Marilyn M; Stoyanova, Irini V; Tham, Fook S; Meyer, Matthew P; Mascal, Mark; Nature chemistry 4 (2012) 1018–1023; doi:10.1038/nchem.1502

data_1509131
_publ_section_title
;
 Extreme oxatriquinanes and a record C-O bond length.
;
_journal_issue                   12
_journal_name_full               'Nature chemistry'
_journal_page_first              1018
_journal_page_last               1023
_journal_paper_doi               10.1038/nchem.1502
_journal_volume                  4
_journal_year                    2012
_chemical_formula_moiety         'C12 H21 O, F6 P'
_chemical_formula_sum            'C12 H21 F6 O P'
_chemical_formula_weight         326.26
_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                 97.677(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   8.4923(3)
_cell_length_b                   14.1476(5)
_cell_length_c                   12.0094(4)
_cell_measurement_reflns_used    9997
_cell_measurement_temperature    90(2)
_cell_measurement_theta_max      31.6
_cell_measurement_theta_min      2.72
_cell_volume                     1429.94(9)
_computing_cell_refinement       'SAINT (Bruker, 2011)'
_computing_data_collection       'Apex2 (Bruker, 2011)'
_computing_data_reduction        'SAINT (Bruker, 2011)'
_computing_publication_material  'SHELXL-97 (Sheldrick, 2008)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      90(2)
_diffrn_detector_area_resol_mean 8.3
_diffrn_measured_fraction_theta_full 0.997
_diffrn_measured_fraction_theta_max 0.997
_diffrn_measurement_device_type  'Bruker SMART ApexII'
_diffrn_measurement_method       \w
_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  0.0655
_diffrn_reflns_av_sigmaI/netI    0.0330
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       20
_diffrn_reflns_limit_k_min       -20
_diffrn_reflns_limit_l_max       17
_diffrn_reflns_limit_l_min       -17
_diffrn_reflns_number            23684
_diffrn_reflns_theta_full        31.62
_diffrn_reflns_theta_max         31.62
_diffrn_reflns_theta_min         2.42
_exptl_absorpt_coefficient_mu    0.252
_exptl_absorpt_correction_T_max  0.958
_exptl_absorpt_correction_T_min  0.891
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS (Sheldrick, 2003)'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.515
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       needle
_exptl_crystal_F_000             680
_exptl_crystal_size_max          0.47
_exptl_crystal_size_mid          0.21
_exptl_crystal_size_min          0.17
_refine_diff_density_max         0.386
_refine_diff_density_min         -0.498
_refine_diff_density_rms         0.057
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.058
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     239
_refine_ls_number_reflns         4806
_refine_ls_number_restraints     6
_refine_ls_restrained_S_all      1.061
_refine_ls_R_factor_all          0.0474
_refine_ls_R_factor_gt           0.0424
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0697P)^2^+0.4869P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1272
_refine_ls_wR_factor_ref         0.1311
_reflns_number_gt                4195
_reflns_number_total             4806
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            nchem.1502-s2.cif
_cod_data_source_block           a4
_cod_original_sg_symbol_H-M      'P 21/c'
_cod_database_code               1509131