Comprehensive Structural Studies of 2',3'-Difluorinated Nucleosides: Comparison of Theory, Solution, and Solid State
Joseph J. Barchi; Rajeshri G. Karki; Marc C. Nicklaus; Maqbool A. Siddiqui; Clifford George; Igor A. Mikhailopulo; Victor E. Marquez; Journal of the American Chemical Society 130 (2008) 9048–9057; doi:10.1021/ja800964g

data_4108019
_publ_section_title
;
 Comprehensive Structural Studies of 2',3'-Difluorinated Nucleosides:
 Comparison of Theory, Solution, and Solid State
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              9048
_journal_page_last               9057
_journal_paper_doi               10.1021/ja800964g
_journal_volume                  130
_journal_year                    2008
_chemical_absolute_configuration syn
_chemical_formula_moiety         'C8 H9 F2 N3 O4'
_chemical_formula_sum            'C8 H9 F2 N3 O4'
_chemical_formula_weight         249.18
_space_group_IT_number           4
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  'P 2yb'
_symmetry_space_group_name_H-M   'P 1 21 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                 103.214(3)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   9.015(1)
_cell_length_b                   5.568(1)
_cell_length_c                   10.058(1)
_cell_measurement_reflns_used    2292
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      66.952
_cell_measurement_theta_min      4.515
_cell_volume                     491.50(11)
_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_measured_fraction_theta_full 0.935
_diffrn_measured_fraction_theta_max 0.935
_diffrn_measurement_device_type  'CCD area detector'
_diffrn_measurement_method       'omega scans'
_diffrn_radiation_monochromator  'Gobel mirrors'
_diffrn_radiation_source         'rotating anode'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.0245
_diffrn_reflns_av_sigmaI/netI    0.0308
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       5
_diffrn_reflns_limit_k_min       -6
_diffrn_reflns_limit_l_max       10
_diffrn_reflns_limit_l_min       -11
_diffrn_reflns_number            2515
_diffrn_reflns_theta_full        67.07
_diffrn_reflns_theta_max         67.07
_diffrn_reflns_theta_min         4.52
_diffrn_standards_decay_%        0.0
_exptl_absorpt_coefficient_mu    1.406
_exptl_absorpt_correction_T_max  0.972
_exptl_absorpt_correction_T_min  0.638
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   sadabs
_exptl_crystal_colour            clear
_exptl_crystal_density_diffrn    1.684
_exptl_crystal_description       plate
_exptl_crystal_F_000             256
_exptl_crystal_size_max          0.32
_exptl_crystal_size_mid          0.07
_exptl_crystal_size_min          0.02
_refine_diff_density_max         0.149
_refine_diff_density_min         -0.194
_refine_diff_density_rms         0.047
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.06(18)
_refine_ls_extinction_coef       0.069(4)
_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   1.074
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     161
_refine_ls_number_reflns         1357
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.073
_refine_ls_R_factor_all          0.0307
_refine_ls_R_factor_gt           0.0302
_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^)+(0.0525P)^2^+0.0263P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0770
_refine_ls_wR_factor_ref         0.0776
_reflns_number_gt                1322
_reflns_number_total             1357
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja800964g-file005.cif
_cod_data_source_block           6NxylFF
_cod_database_code               4108019