Polymorphic gabapentin: thermal behaviour, reactivity and interconversion of forms in solution and solid-state
Braga, Dario; Grepioni, Fabrizia; Maini, Lucia; Rubini, Katia; Polito, Marco; Brescello, Roberto; Cotarca, Livius; Duarte, M. Teresa; André, Vânia; Piedade, M. Fátima M.; New Journal of Chemistry 32 (2008) 1788–; doi:10.1039/b809662g

data_7053757
_publ_section_title
;
 Polymorphic gabapentin: thermal behaviour, reactivity and interconversion
 of forms in solution and solid-state
;
_journal_issue                   10
_journal_name_full               'New Journal of Chemistry'
_journal_page_first              1788
_journal_paper_doi               10.1039/b809662g
_journal_volume                  32
_journal_year                    2008
_chemical_formula_sum            'C9 H17 N O2'
_chemical_formula_weight         171.24
_chemical_name_common            Gabapentin
_space_group_IT_number           15
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-C 2yc'
_symmetry_space_group_name_H-M   'C 1 2/c 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                 108.31(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            8
_cell_length_a                   30.582(9)
_cell_length_b                   5.932(3)
_cell_length_c                   10.915(3)
_cell_measurement_temperature    293(2)
_cell_volume                     1879.9(12)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_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  0.0177
_diffrn_reflns_av_sigmaI/netI    0.0203
_diffrn_reflns_limit_h_max       34
_diffrn_reflns_limit_h_min       -36
_diffrn_reflns_limit_k_max       7
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       12
_diffrn_reflns_limit_l_min       0
_diffrn_reflns_number            1740
_diffrn_reflns_theta_full        24.95
_diffrn_reflns_theta_max         24.95
_diffrn_reflns_theta_min         3.51
_exptl_absorpt_coefficient_mu    0.085
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.210
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plate
_exptl_crystal_F_000             752
_exptl_crystal_size_max          0.22
_exptl_crystal_size_mid          0.17
_exptl_crystal_size_min          0.12
_refine_diff_density_max         0.279
_refine_diff_density_min         -0.194
_refine_diff_density_rms         0.062
_refine_ls_extinction_coef       0.017(2)
_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   1.083
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     122
_refine_ls_number_reflns         1642
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.083
_refine_ls_R_factor_all          0.0640
_refine_ls_R_factor_gt           0.0476
_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^)+(0.0849P)^2^+0.6689P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1248
_refine_ls_wR_factor_ref         0.1362
_reflns_number_gt                1285
_reflns_number_total             1642
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b809662gsup1.cif
_cod_data_source_block           gabapentin_Form_III_RT
_cod_depositor_comments
;
The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Monoclinic' changed to 'monoclinic'
according to /home/saulius/struct/CIF-dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.2 from 2011-04-26.

Automatic conversion script
Id: cif_fix_values 1891 2012-01-12 08:04:46Z andrius 
;
_cod_original_sg_symbol_H-M      C2/c
_cod_database_code               7053757