The observation of a large gauche preference when 2-fluoroethylamine and 2-fluoroethanol become protonated.
Briggs, Caroline R. S.; Allen, Mark J.; O'Hagan, David; Tozer, David J.; Slawin, Alexandra M. Z.; Goeta, Andrés E; Howard, Judith A. K.; Organic & biomolecular chemistry 2 (2004) 732–740; doi:10.1039/b312188g

data_7151590
_publ_section_title
;
 The observation of a large gauche preference when 2-fluoroethylamine
 and 2-fluoroethanol become protonated.
;
_journal_issue                   5
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              732
_journal_page_last               740
_journal_paper_doi               10.1039/b312188g
_journal_volume                  2
_journal_year                    2004
_chemical_formula_moiety         'C16 H19 Cl F N'
_chemical_formula_sum            'C16 H19 Cl F N'
_chemical_formula_weight         279.77
_chemical_melting_point          ?
_space_group_IT_number           2
_symmetry_cell_setting           triclinic
_symmetry_space_group_name_Hall  '-P 1'
_symmetry_space_group_name_H-M   'P -1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                110.74(13)
_cell_angle_beta                 90.8(2)
_cell_angle_gamma                103.32(9)
_cell_formula_units_Z            2
_cell_length_a                   6.821(7)
_cell_length_b                   10.177(9)
_cell_length_c                   12.07(2)
_cell_measurement_reflns_used    12
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      168
_cell_measurement_theta_min      12
_cell_volume                     758.3(18)
_computing_cell_refinement       'Bruker SMART'
_computing_data_collection       'Bruker SMART'
_computing_data_reduction        'Bruker SHELXTL'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      293(2)
_diffrn_detector_area_resol_mean 0.9
_diffrn_measured_fraction_theta_full 0.735
_diffrn_measured_fraction_theta_max 0.735
_diffrn_measurement_device_type  'CCD area detector'
_diffrn_measurement_method       'phi and omega scans'
_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  0.2652
_diffrn_reflns_av_sigmaI/netI    0.1257
_diffrn_reflns_limit_h_max       7
_diffrn_reflns_limit_h_min       -7
_diffrn_reflns_limit_k_max       8
_diffrn_reflns_limit_k_min       -8
_diffrn_reflns_limit_l_max       5
_diffrn_reflns_limit_l_min       -13
_diffrn_reflns_number            1605
_diffrn_reflns_theta_full        23.25
_diffrn_reflns_theta_max         23.25
_diffrn_reflns_theta_min         1.81
_diffrn_standards_decay_%        -
_diffrn_standards_interval_count -
_diffrn_standards_interval_time  -
_diffrn_standards_number         -
_exptl_absorpt_coefficient_mu    0.249
_exptl_absorpt_correction_T_max  -
_exptl_absorpt_correction_T_min  -
_exptl_absorpt_correction_type   none
_exptl_absorpt_process_details   -
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.226
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       needle
_exptl_crystal_F_000             296
_exptl_crystal_size_max          .03
_exptl_crystal_size_mid          .03
_exptl_crystal_size_min          .12
_refine_diff_density_max         0.221
_refine_diff_density_min         -0.245
_refine_diff_density_rms         0.056
_refine_ls_extinction_coef       0.024(10)
_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   0.935
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     177
_refine_ls_number_reflns         1602
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      0.935
_refine_ls_R_factor_all          0.1876
_refine_ls_R_factor_gt           0.0887
_refine_ls_shift/su_max          0.074
_refine_ls_shift/su_mean         0.015
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.1102P)^2^+3.2791P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.2026
_refine_ls_wR_factor_ref         0.2708
_reflns_number_gt                801
_reflns_number_total             1602
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b312188g.txt
_cod_data_source_block           8
_cod_depositor_comments
;
The following automatic conversions were performed:
'_symmetry_cell_setting' value 'Triclinic' changed to 'triclinic'
according to '/home/adriana/struct/CIF-dictionaries/cif_core.dic'
dictionary named 'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_enum 1555 2011-01-17 13:19:09Z saulius 

The following automatic conversions were performed:

'_chemical_melting_point' value '-' was changed to '?' - the value is
undefined or not given.

Automatic conversion script
Id: cif_fix_values 1569 2011-02-09 13:29:24Z adriana 

The following automatic conversions were performed:

'_exptl_crystal_density_meas' value '-' was changed to '?' - the
value is perceived as not measured.

Automatic conversion script
Id: cif_fix_values 3008 2015-01-20 13:52:24Z robertas 
;
_cod_original_cell_volume        758.0(17)
_cod_original_sg_symbol_H-M      P-1
_cod_database_code               7151590