Nature of Urea-Fluoride Interaction: Incipient and Definitive Proton Transfer
Massimo Boiocchi; Laura Del Boca; David Esteban Gómez; Luigi Fabbrizzi; Maurizio Licchelli; Enrico Monzani; Journal of the American Chemical Society 126 (2004) 16507–16514; doi:10.1021/ja045936c

data_4113282
_publ_contact_author
;
  Prof Luigi Fabbrizzi
  Dipartimento di Chimica Generale
  University of Pavia
  via Taramelli 12, I-27100 Pavia, ITALY
;
_publ_contact_author_email
;
 luigi.fabbrizzi@unipv.it
;
_publ_section_title
;
 Nature of Urea-Fluoride Interaction: Incipient and Definitive Proton
 Transfer
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              16507
_journal_page_last               16514
_journal_paper_doi               10.1021/ja045936c
_journal_volume                  126
_journal_year                    2004
_chemical_formula_moiety         'C16 H36 N, C13 H10 N4 O5, C2 H3 O2'
_chemical_formula_sum            'C31 H49 N5 O7'
_chemical_formula_weight         603.75
_chemical_name_common
;
 Tetra-n-butylammonium 1,3-bis-(4-nitro-phenyl)-urea
 acetate 
;
_chemical_name_systematic
;
 ?
;
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_Int_Tables_number      14
_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                 106.07(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   10.0827(17)
_cell_length_b                   20.434(2)
_cell_length_c                   17.282(5)
_cell_measurement_reflns_used    25
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      13
_cell_measurement_theta_min      6
_cell_volume                     3421.5(12)
_computing_cell_refinement       'CAD4 Express (Enraf Nonius, 1994)'
_computing_data_collection       'CAD4 Express (Enraf Nonius, 1994)'
_computing_data_reduction        'XCAD4 (Harms & Wocadlo, 1995)'
_computing_molecular_graphics    'Ortep-3 for Windows (Farrugia, 1997)'
_computing_publication_material  'WinGX publication routines (Farrugia, 1999)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SIR-97 (Altomare et al., 1999)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_diffrn_measurement_device_type  'Enraf Nonius CAD4'
_diffrn_measurement_method       'omega/2theta 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  0.0331
_diffrn_reflns_av_sigmaI/netI    0.1319
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       25
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       20
_diffrn_reflns_limit_l_min       -21
_diffrn_reflns_number            7094
_diffrn_reflns_theta_full        25.97
_diffrn_reflns_theta_max         25.97
_diffrn_reflns_theta_min         1.58
_diffrn_standards_decay_%        0
_diffrn_standards_interval_time  250
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    0.083
_exptl_absorpt_correction_T_max  0.9706
_exptl_absorpt_correction_T_min  0.9099
_exptl_absorpt_correction_type   psi-scan
_exptl_absorpt_process_details
;
North A.C.T., Phillips D.C. & Mathews F.S. (1968) Acta. Cryst. A24, 351
Number of psi-scan sets used was   4
Theta correction was applied.
Averaged transmission function was used.
No Fourier smoothing was applied.
;
_exptl_crystal_colour            'deep yellow'
_exptl_crystal_density_diffrn    1.172
_exptl_crystal_description       prism
_exptl_crystal_F_000             1304
_exptl_crystal_size_max          0.7
_exptl_crystal_size_mid          0.5
_exptl_crystal_size_min          0.35
_refine_diff_density_max         0.145
_refine_diff_density_min         -0.135
_refine_diff_density_rms         0.035
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.980
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     395
_refine_ls_number_reflns         6700
_refine_ls_number_restraints     2
_refine_ls_restrained_S_all      0.980
_refine_ls_R_factor_all          0.2425
_refine_ls_R_factor_gt           0.0757
_refine_ls_shift/su_max          0.009
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0519P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1254
_refine_ls_wR_factor_ref         0.1794
_reflns_number_gt                2198
_reflns_number_total             6700
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja045936csi20040707_042528_2.cif
_cod_data_source_block           da36
_cod_original_sg_symbol_H-M      'P 21/c'
_cod_database_code               4113282