C–H⋯F–C hydrogen bonding in 1,2,3,5-tetrafluorobenzene and other fluoroaromatic compounds and the crystal structure of alloxan revisited
Thakur, Tejender S.; Kirchner, Michael T.; Bläser, Dieter; Boese, Roland; Desiraju, Gautam R.; CrystEngComm 12 (2010) 2079–; doi:10.1039/b925082d

data_7212333
_publ_section_title
;
 C--H&#x22EF;F--C hydrogen bonding in 1,2,3,5-tetrafluorobenzene and other
 fluoroaromatic compounds and the crystal structure of alloxan revisited
;
_journal_issue                   7
_journal_name_full               CrystEngComm
_journal_page_first              2079
_journal_paper_doi               10.1039/b925082d
_journal_volume                  12
_journal_year                    2010
_chemical_formula_sum            'C6 H2 F4'
_chemical_formula_weight         150.08
_chemical_name_common            1.2.3.5-Tetrafluorobenzene
_chemical_name_systematic
;
1.2.3.5-Tetrafluorobenzene
;
_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                 96.340(19)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   3.703(4)
_cell_length_b                   14.572(17)
_cell_length_c                   10.573(13)
_cell_measurement_reflns_used    715
_cell_measurement_temperature    173(2)
_cell_measurement_theta_max      25.19
_cell_measurement_theta_min      2.38
_cell_volume                     567.0(11)
_computing_cell_refinement       'BRUKER AXS SMART APEX 2 Vers. 3.0-2009'
_computing_data_collection       'BRUKER AXS SMART APEX 2 Vers. 3.0-2009'
_computing_data_reduction        'BRUKER AXS SMART APEX 2 Vers. 3.0-2009'
_computing_molecular_graphics    'BRUKER AXS SHELXTL (c) 2008 / Vers. 2008/4'
_computing_publication_material  'BRUKER AXS SHELXTL (c) 2008 / Vers. 2008/4'
_computing_structure_refinement  'BRUKER AXS SHELXTL (c) 2008 / Vers. 2008/4'
_computing_structure_solution    'BRUKER AXS SMART APEX 2 Vers. 3.0-2009'
_diffrn_ambient_temperature      173(2)
_diffrn_detector_area_resol_mean 512
_diffrn_measured_fraction_theta_full 0.900
_diffrn_measured_fraction_theta_max 0.900
_diffrn_measurement_device_type
;
Siemens SMART three axis goniometer with APEX II area detector system
Bruker D8 KAPPA series II with APEX II area detector system
;
_diffrn_measurement_method
;
Data collection strategy APEX 2 / COSMO
with chi = 0
;
_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  0.0873
_diffrn_reflns_av_sigmaI/netI    0.0804
_diffrn_reflns_limit_h_max       4
_diffrn_reflns_limit_h_min       -4
_diffrn_reflns_limit_k_max       19
_diffrn_reflns_limit_k_min       -18
_diffrn_reflns_limit_l_max       14
_diffrn_reflns_limit_l_min       -9
_diffrn_reflns_number            2280
_diffrn_reflns_theta_full        28.71
_diffrn_reflns_theta_max         28.71
_diffrn_reflns_theta_min         2.39
_exptl_absorpt_coefficient_mu    0.195
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.758
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       cylindric
_exptl_crystal_F_000             296
_exptl_crystal_size_max          0.3
_exptl_crystal_size_mid          0.3
_exptl_crystal_size_min          0.3
_refine_diff_density_max         0.359
_refine_diff_density_min         -0.277
_refine_diff_density_rms         0.077
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.976
_refine_ls_hydrogen_treatment
;
Riding model on idealized geometrics
with the 1.2 fold isotropic displacement
parameters of the equivalent Uij of the
corresponding carbon atom
;
_refine_ls_matrix_type           full
_refine_ls_number_parameters     91
_refine_ls_number_reflns         1309
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.976
_refine_ls_R_factor_all          0.1133
_refine_ls_R_factor_gt           0.0671
_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^)+(0.0979P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1502
_refine_ls_wR_factor_ref         0.1767
_reflns_number_gt                736
_reflns_number_total             1309
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b925082d.txt
_cod_data_source_block           tetrafluorbe
_cod_original_cell_volume        567.1(11)
_cod_original_sg_symbol_H-M      P2(1)/c
_cod_database_code               7212333