Lone pair–πvsπ–π interactions in 5-fluoro-1-hexyluracil and 1-hexyluracil: a combined crystallographic and computational study
Barceló-Oliver, Miquel; Estarellas, Carolina; García-Raso, Angel; Terrón, Angel; Frontera, Antonio; Quiñonero, David; Molins, Elies; Deyà, Pere M.; CrystEngComm 12 (2010) 362–; doi:10.1039/b913111f

data_7211703
_publ_section_title
;
 Lone pair--\pvs\p--\p interactions in 5-fluoro-1-hexyluracil and
 1-hexyluracil: a combined crystallographic and computational study
;
_journal_issue                   2
_journal_name_full               CrystEngComm
_journal_page_first              362
_journal_paper_doi               10.1039/b913111f
_journal_volume                  12
_journal_year                    2010
_chemical_compound_source        'synthesis as described'
_chemical_formula_moiety         'C10 H16 N2 O2'
_chemical_formula_sum            'C10 H16 N2 O2'
_chemical_formula_weight         196.25
_space_group_IT_number           2
_symmetry_cell_setting           triclinic
_symmetry_Int_Tables_number      2
_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_conform_dict_location     ftp://ftp.iucr.org/pub/cif_core.dic
_audit_conform_dict_name         cif_core.dic
_audit_conform_dict_version      2.3
_audit_creation_date             2009-07-03T00:36:33-00:00
_audit_creation_method           'WinGX routine CIF_UPDATE'
_cell_angle_alpha                90.66(7)
_cell_angle_beta                 102.36(5)
_cell_angle_gamma                94.35(4)
_cell_formula_units_Z            8
_cell_length_a                   13.111(4)
_cell_length_b                   13.285(8)
_cell_length_c                   13.332(6)
_cell_measurement_reflns_used    17
_cell_measurement_temperature    294(2)
_cell_measurement_theta_max      8.5
_cell_measurement_theta_min      4.77
_cell_measurement_wavelength     0.71073
_cell_volume                     2260.9(19)
_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    'SHELXS-86 (Sheldrick, 1986)'
_diffrn_ambient_temperature      294(2)
_diffrn_detector                 'scintillation LiI'
_diffrn_detector_dtime           1.195
_diffrn_measured_fraction_theta_full 0.922
_diffrn_measured_fraction_theta_max 0.922
_diffrn_measurement_device       '\k-geometry diffractometer'
_diffrn_measurement_device_type  'Enraf Nonius CAD4'
_diffrn_measurement_method       'non-profiled omega scans'
_diffrn_orient_matrix_type
;
x-axis points to radiation source
the matrix is specified in reciprocal space
;
_diffrn_orient_matrix_UB_11      0.016774
_diffrn_orient_matrix_UB_12      -0.007181
_diffrn_orient_matrix_UB_13      0.076286
_diffrn_orient_matrix_UB_21      -0.071976
_diffrn_orient_matrix_UB_22      -0.032649
_diffrn_orient_matrix_UB_23      -0.003457
_diffrn_orient_matrix_UB_31      0.025895
_diffrn_orient_matrix_UB_32      -0.067765
_diffrn_orient_matrix_UB_33      -0.008891
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0
_diffrn_reflns_av_unetI/netI     0.2561
_diffrn_reflns_limit_h_max       15
_diffrn_reflns_limit_h_min       -15
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -15
_diffrn_reflns_limit_l_max       15
_diffrn_reflns_limit_l_min       0
_diffrn_reflns_number            7328
_diffrn_reflns_theta_full        24.97
_diffrn_reflns_theta_max         24.97
_diffrn_reflns_theta_min         1.54
_diffrn_source                   'Enraf Nonius FR590'
_diffrn_standards_decay_%        8
_diffrn_standards_interval_time  60
_diffrn_standards_number         2
_exptl_absorpt_coefficient_mu    0.081
_exptl_absorpt_correction_T_max  0.9952
_exptl_absorpt_correction_T_min  0.9678
_exptl_absorpt_correction_type   refdelf
_exptl_absorpt_process_details
;
Walker, N. & Stuart, D (1983) Acta. Cryst. A39, 158-166
;
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.153
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             848
_exptl_crystal_size_max          0.38
_exptl_crystal_size_mid          0.11
_exptl_crystal_size_min          0.04
_refine_diff_density_max         0.318
_refine_diff_density_min         -0.222
_refine_diff_density_rms         0.054
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.929
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     509
_refine_ls_number_reflns         7328
_refine_ls_number_restraints     36
_refine_ls_restrained_S_all      0.933
_refine_ls_R_factor_all          0.3291
_refine_ls_R_factor_gt           0.108
_refine_ls_shift/su_max          0
_refine_ls_shift/su_mean         0
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.1315P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.2664
_refine_ls_wR_factor_ref         0.3354
_reflns_number_gt                1950
_reflns_number_total             7328
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b913111f.txt
_cod_data_source_block           pm128
_cod_database_code               7211703