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_4108018
_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         'C9 H10 F2 N2 O4 . 1/6(C2 H6 O)'
_chemical_formula_sum            'C9.33 H11 F2 N2 O4.17'
_chemical_formula_weight         255.87
_chemical_name_systematic
; 
 ? 
;
_space_group_IT_number           170
_symmetry_cell_setting           hexagonal
_symmetry_space_group_name_Hall  'P 65'
_symmetry_space_group_name_H-M   'P 65'
_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                 90.00
_cell_angle_gamma                120.00
_cell_formula_units_Z            12
_cell_length_a                   23.159(1)
_cell_length_b                   23.159(1)
_cell_length_c                   7.016(1)
_cell_measurement_reflns_used    7029
_cell_measurement_temperature    198(2)
_cell_measurement_theta_max      64.708
_cell_measurement_theta_min      2.203
_cell_volume                     3258.8(5)
_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      198(2)
_diffrn_measured_fraction_theta_full 0.990
_diffrn_measured_fraction_theta_max 0.990
_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  0.0753
_diffrn_reflns_av_sigmaI/netI    0.0603
_diffrn_reflns_limit_h_max       22
_diffrn_reflns_limit_h_min       -26
_diffrn_reflns_limit_k_max       24
_diffrn_reflns_limit_k_min       -27
_diffrn_reflns_limit_l_max       8
_diffrn_reflns_limit_l_min       -8
_diffrn_reflns_number            14903
_diffrn_reflns_theta_full        64.78
_diffrn_reflns_theta_max         64.78
_diffrn_reflns_theta_min         2.20
_diffrn_standards_decay_%        0.0
_exptl_absorpt_coefficient_mu    1.272
_exptl_absorpt_correction_T_max  0.962
_exptl_absorpt_correction_T_min  0.700
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   sadabs
_exptl_crystal_colour            clear
_exptl_crystal_density_diffrn    1.565
_exptl_crystal_description       rod
_exptl_crystal_F_000             1588
_exptl_crystal_size_max          0.28
_exptl_crystal_size_mid          0.03
_exptl_crystal_size_min          0.03
_refine_diff_density_max         0.287
_refine_diff_density_min         -0.211
_refine_diff_density_rms         0.045
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.0(2)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.995
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     410
_refine_ls_number_reflns         3500
_refine_ls_number_restraints     16
_refine_ls_restrained_S_all      0.993
_refine_ls_R_factor_all          0.0586
_refine_ls_R_factor_gt           0.0440
_refine_ls_shift/su_max          0.020
_refine_ls_shift/su_mean         0.001
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0423P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0925
_refine_ls_wR_factor_ref         0.0977
_reflns_number_gt                2703
_reflns_number_total             3500
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja800964g-file004.cif
_cod_data_source_block           xylFF
_cod_database_code               4108018