Discovery of three polymorphs of 7-fluoroisatin reveals challenges in using computational crystal structure prediction as a complement to experimental screening
Mohamed, Sharmarke; Barnett, Sarah A.; Tocher, Derek A.; Price, Sarah L.; Shankland, Kenneth; Leech, Charlotte K.; CrystEngComm  (2008) –; doi:10.1039/b714566g

data_7201755
_publ_section_title
;
 Discovery of three polymorphs of 7-fluoroisatin reveals challenges in
 using computational crystal structure prediction as a complement to
 experimental screening
;
_journal_name_full               CrystEngComm
_journal_paper_doi               10.1039/b714566g
_journal_year                    2008
_chemical_formula_moiety         'C8 H4 F N O2'
_chemical_formula_sum            'C8 H4 F N O2'
_chemical_formula_weight         165.12
_chemical_name_common            '7-Fluoroisatin Form II'
_chemical_name_systematic
;
7-Fluoroisatin Form II
;
_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                70.87(2)
_cell_angle_beta                 85.834(17)
_cell_angle_gamma                61.023(17)
_cell_formula_units_Z            4
_cell_length_a                   8.1207(13)
_cell_length_b                   8.2351(15)
_cell_length_c                   12.394(4)
_cell_measurement_reflns_used    3331
_cell_measurement_temperature    123(2)
_cell_measurement_theta_max      28.5950
_cell_measurement_theta_min      2.8772
_cell_volume                     681.3(3)
_computing_cell_refinement
;
CrysAlis RED, Oxford Diffraction Ltd., Version 1.171.31.5
;
_computing_data_collection
;
CrysAlis CCD, Oxford Diffraction Ltd., Version 1.171.31.5
;
_computing_data_reduction
;
CrysAlis RED, Oxford Diffraction Ltd., Version 1.171.31.5
;
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL and local programs'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      123(2)
_diffrn_detector_area_resol_mean 15.9745
_diffrn_measured_fraction_theta_full 0.991
_diffrn_measured_fraction_theta_max 0.881
_diffrn_measurement_device_type  'Oxford Diffraction Gemini'
_diffrn_measurement_method       '/w and /p scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'Enhance (Mu) X-ray Source'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0244
_diffrn_reflns_av_sigmaI/netI    0.0406
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       10
_diffrn_reflns_limit_k_min       -10
_diffrn_reflns_limit_l_max       15
_diffrn_reflns_limit_l_min       -15
_diffrn_reflns_number            6569
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         28.58
_diffrn_reflns_theta_min         2.88
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.135
_exptl_absorpt_correction_T_max  0.9946
_exptl_absorpt_correction_T_min  0.9774
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
CrysAlis RED, Oxford Diffraction Ltd., Version 1.171.31.5
Empirical absorption correction using spherical harmonics,
implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_crystal_colour            Yellow
_exptl_crystal_density_diffrn    1.610
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       Block
_exptl_crystal_F_000             336
_exptl_crystal_size_max          0.17
_exptl_crystal_size_mid          0.17
_exptl_crystal_size_min          0.04
_refine_diff_density_max         0.292
_refine_diff_density_min         -0.188
_refine_diff_density_rms         0.042
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.040
_refine_ls_hydrogen_treatment    refall
_refine_ls_matrix_type           full
_refine_ls_number_parameters     249
_refine_ls_number_reflns         3059
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.040
_refine_ls_R_factor_all          0.0554
_refine_ls_R_factor_gt           0.0340
_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^)+(0.0393P)^2^+0.0478P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0746
_refine_ls_wR_factor_ref         0.0815
_reflns_number_gt                2258
_reflns_number_total             3059
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b714566g.txt
_cod_data_source_block           06isis050_a
_cod_depositor_comments
;
The following automatic conversions were performed:
'_symmetry_cell_setting' value 'Triclinic' changed to 'triclinic'
according to '/home/saulius/struct/CIF-dictionaries/cif_core.dic'
dictionary named 'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_enum 1527 2010-12-29 10:47:43Z saulius 
;
_cod_original_sg_symbol_H-M      P-1
_cod_database_code               7201755