The observed and energetically feasible crystal structures of 5-substituted uracils
Barnett, Sarah A.; Hulme, Ashley T.; Issa, Nizar; Lewis, Thomas C.; Price, Louise S.; Tocher, Derek A.; Price, Sarah L.; New Journal of Chemistry 32 (2008) 1761–; doi:10.1039/b806763e

data_7052009
_publ_section_title
;
 The observed and energetically feasible crystal structures of
 5-substituted uracils
;
_journal_issue                   10
_journal_name_full               'New Journal of Chemistry'
_journal_page_first              1761
_journal_paper_doi               10.1039/b806763e
_journal_volume                  32
_journal_year                    2008
_chemical_formula_moiety         'C6 H8 N2 O2'
_chemical_formula_sum            'C6 H8 N2 O2'
_chemical_formula_weight         140.14
_chemical_name_systematic
;
5-Ethyluracil
;
_space_group_IT_number           2
_symmetry_cell_setting           triclinic
_symmetry_space_group_name_Hall  '-P 1'
_symmetry_space_group_name_H-M   'P -1'
_atom_sites_solution_hydrogens   difmap
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                100.027(7)
_cell_angle_beta                 96.109(7)
_cell_angle_gamma                92.374(8)
_cell_formula_units_Z            2
_cell_length_a                   3.9193(18)
_cell_length_b                   5.754(3)
_cell_length_c                   14.366(7)
_cell_measurement_reflns_used    1243
_cell_measurement_temperature    150(2)
_cell_measurement_theta_max      28.178
_cell_measurement_theta_min      2.899
_cell_volume                     316.6(3)
_computing_cell_refinement       'Bruker SAINT (Bruker 2003)'
_computing_data_collection       'Bruker SMART (Bruker 2001)'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Bruker SHELXTL (Bruker 2001)'
_computing_publication_material  'Bruker SHELXTL and local programs'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      150(2)
_diffrn_measured_fraction_theta_full 0.938
_diffrn_measured_fraction_theta_max 0.856
_diffrn_measurement_device_type  'Bruker SMART APEX diffractometer'
_diffrn_measurement_method       '\w rotation with narrow frames'
_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  0.0000
_diffrn_reflns_av_sigmaI/netI    0.1026
_diffrn_reflns_limit_h_max       5
_diffrn_reflns_limit_h_min       -5
_diffrn_reflns_limit_k_max       7
_diffrn_reflns_limit_k_min       -7
_diffrn_reflns_limit_l_max       18
_diffrn_reflns_limit_l_min       -18
_diffrn_reflns_number            4168
_diffrn_reflns_theta_full        26.00
_diffrn_reflns_theta_max         28.26
_diffrn_reflns_theta_min         2.90
_diffrn_standards_decay_%        0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.113
_exptl_absorpt_correction_T_max  1.0000
_exptl_absorpt_correction_T_min  0.4518
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'TWINABS v1.02 (Bruker, 2003)'
_exptl_crystal_colour            Colourless
_exptl_crystal_density_diffrn    1.470
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       Lath
_exptl_crystal_F_000             148
_exptl_crystal_size_max          0.70
_exptl_crystal_size_mid          0.22
_exptl_crystal_size_min          0.08
_refine_diff_density_max         0.423
_refine_diff_density_min         -0.313
_refine_diff_density_rms         0.077
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.931
_refine_ls_hydrogen_treatment    refall
_refine_ls_matrix_type           full
_refine_ls_number_parameters     123
_refine_ls_number_reflns         1346
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.931
_refine_ls_R_factor_all          0.0915
_refine_ls_R_factor_gt           0.0609
_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^)+(0.0676P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1342
_refine_ls_wR_factor_ref         0.1453
_reflns_number_gt                864
_reflns_number_total             1346
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b806763e.txt
_cod_data_source_block           STR0526
_cod_original_sg_symbol_H-M      P-1
_cod_database_code               7052009