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_7053755
_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            'C16 H21 N O3'
_chemical_formula_weight         275.34
_chemical_name_common            GBPL_BenzoicAcid_cocrystal
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2yn'
_symmetry_space_group_name_H-M   'P 1 21/n 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                 97.601(7)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   6.5410(4)
_cell_length_b                   19.2190(5)
_cell_length_c                   12.0700(6)
_cell_measurement_temperature    150(2)
_cell_measurement_theta_max      26.40
_cell_measurement_theta_min      3.37
_cell_volume                     1504.01(13)
_computing_cell_refinement       'BRUKER SMART'
_computing_data_collection       'BRUKER SMART'
_computing_data_reduction        'BRUKER SAINT'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    SIR97
_diffrn_ambient_temperature      150(2)
_diffrn_measured_fraction_theta_full 0.983
_diffrn_measured_fraction_theta_max 0.983
_diffrn_measurement_device_type  'CCD area detector'
_diffrn_measurement_method       'phi and omega scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71069
_diffrn_reflns_av_R_equivalents  0.0505
_diffrn_reflns_av_sigmaI/netI    0.0624
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       -6
_diffrn_reflns_limit_k_max       24
_diffrn_reflns_limit_k_min       -21
_diffrn_reflns_limit_l_max       15
_diffrn_reflns_limit_l_min       -15
_diffrn_reflns_number            11010
_diffrn_reflns_theta_full        26.40
_diffrn_reflns_theta_max         26.40
_diffrn_reflns_theta_min         3.37
_exptl_absorpt_coefficient_mu    0.084
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.216
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             592
_exptl_crystal_size_max          0.24
_exptl_crystal_size_mid          0.04
_exptl_crystal_size_min          0.03
_refine_diff_density_max         0.170
_refine_diff_density_min         -0.181
_refine_diff_density_rms         0.036
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.954
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     265
_refine_ls_number_reflns         3026
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.954
_refine_ls_R_factor_all          0.0977
_refine_ls_R_factor_gt           0.0449
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0471P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0915
_refine_ls_wR_factor_ref         0.1031
_reflns_number_gt                1772
_reflns_number_total             3026
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b809662gsup1.cif
_cod_data_source_block           GabapentinLactam_Benzoic_Acid_cocrystal
_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 

The following automatic conversions were performed:

'_exptl_crystal_density_meas' value 'not measured' was changed to '?'
- the value is perceived as not measured.

Automatic conversion script
Id: cif_fix_values 3008 2015-01-20 13:52:24Z robertas 
;
_cod_original_cell_volume        1504.01(12)
_cod_original_sg_symbol_H-M      P21/n
_cod_database_code               7053755