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_7151589
_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         'C2 H7 Cl F N'
_chemical_formula_sum            'C2 H7 Cl F N'
_chemical_formula_weight         99.54
_chemical_melting_point          ?
_space_group_IT_number           61
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  '-P 2ac 2ab'
_symmetry_space_group_name_H-M   'P b c a'
_atom_sites_solution_hydrogens   difmap
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            8
_cell_length_a                   7.621(1)
_cell_length_b                   8.543(1)
_cell_length_c                   14.830(2)
_cell_measurement_reflns_used    924
_cell_measurement_temperature    150(2)
_cell_measurement_theta_max      25.86
_cell_measurement_theta_min      12.06
_cell_volume                     965.5(2)
_computing_cell_refinement       'SMART-NT V5.0 (Bruker, 1998a)'
_computing_data_collection       'SMART-NT V5.0 (Bruker, 1998a)'
_computing_data_reduction        'SAINT-NT V5.0 (Bruker, 1998b)'
_computing_molecular_graphics    'SHELXTL-NT V5.1 (Bruker, 1998c)'
_computing_publication_material  -
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      150(2)
_diffrn_measured_fraction_theta_full 0.947
_diffrn_measured_fraction_theta_max 0.947
_diffrn_measurement_device_type  'Bruker SMART-1K CCD Diffractometer'
_diffrn_measurement_method       '\w 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  0.0290
_diffrn_reflns_av_sigmaI/netI    0.0158
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       11
_diffrn_reflns_limit_k_min       -11
_diffrn_reflns_limit_l_max       20
_diffrn_reflns_limit_l_min       -20
_diffrn_reflns_number            10312
_diffrn_reflns_theta_full        30.29
_diffrn_reflns_theta_max         30.29
_diffrn_reflns_theta_min         2.75
_diffrn_standards_decay_%        0
_diffrn_standards_interval_count -
_diffrn_standards_interval_time  -
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.643
_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    1.370
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       'thin plate'
_exptl_crystal_F_000             416
_exptl_crystal_size_max          0.40
_exptl_crystal_size_mid          0.30
_exptl_crystal_size_min          0.06
_refine_diff_density_max         0.454
_refine_diff_density_min         -0.174
_refine_diff_density_rms         0.048
_refine_ls_extinction_coef       -
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.078
_refine_ls_hydrogen_treatment    refall
_refine_ls_matrix_type           full
_refine_ls_number_parameters     74
_refine_ls_number_reflns         1371
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.078
_refine_ls_R_factor_all          0.0344
_refine_ls_R_factor_gt           0.0265
_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^)+(0.0361P)^2^+0.1706P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0651
_refine_ls_wR_factor_ref         0.0688
_reflns_number_gt                1154
_reflns_number_total             1371
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b312188g.txt
_cod_data_source_block           6
_cod_depositor_comments
;
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        965.4(2)
_cod_original_sg_symbol_H-M      Pbca
_cod_database_code               7151589