A high-pressure polymorph of <small>L</small>-α-leucine
Yamashita, Motoi; Inomata, Shinsuke; Ishikawa, Kouki; Kashiwagi, Tatsuki; Matsuo, Hiroshi; Sawamura, Seiji; Kato, Minoru; Acta Crystallographica Section E 63 (2007) o2762–o2764; doi:10.1107/S1600536807018764

data_2213115
_publ_section_title
;
 A high-pressure polymorph of <small>L</small>-\a-leucine
;
_journal_coeditor_code           BG2041
_journal_issue                   5
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              o2762
_journal_page_last               o2764
_journal_paper_doi               10.1107/S1600536807018764
_journal_volume                  63
_journal_year                    2007
_chemical_formula_iupac          'C6 H13 N O2'
_chemical_formula_moiety         'C6 H13 N O2'
_chemical_formula_structural     '(C H3 )2 C H C H2 C H (N H2) C O O H'
_chemical_formula_sum            'C6 H13 N O2'
_chemical_formula_weight         131.17
_chemical_name_common            L-\a-leucine
_chemical_name_systematic
;
2-ammonio-4-methylpentanoate
;
_space_group_IT_number           5
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  'C 2y'
_symmetry_space_group_name_H-M   'C 1 2 1'
_cell_angle_alpha                90
_cell_angle_beta                 96.17(2)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   8.807(3)
_cell_length_b                   5.9750(10)
_cell_length_c                   14.193(3)
_cell_measurement_reflns_used    25
_cell_measurement_temperature    296(2)
_cell_measurement_theta_max      29.6
_cell_measurement_theta_min      28.4
_cell_volume                     742.5(3)
_computing_cell_refinement       'MSC/AFC Diffractometer Control Software'
_computing_data_collection
;
MSC/AFC Diffractometer Control Software
(Molecular Structure Corporation, 1988)
;
_computing_data_reduction
;
TEXSAN (Molecular Structure Corporation, 2004)
;
_computing_molecular_graphics    'ORTEPII (Johnson, 1976)'
_computing_publication_material  TEXSAN
_computing_structure_refinement  TEXSAN
_computing_structure_solution    'SIR92 (Altomare <i>et al.</i>,  1994)'
_diffrn_ambient_temperature      296(2)
_diffrn_measured_fraction_theta_full 0.953
_diffrn_measured_fraction_theta_max 0.93
_diffrn_measurement_device_type  'Rigaku AFC-5S'
_diffrn_measurement_method       \w--2\q
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'sealed X-ray tube'
_diffrn_radiation_type           'Cu K\a'
_diffrn_radiation_wavelength     1.5418
_diffrn_reflns_av_R_equivalents  0.024
_diffrn_reflns_limit_h_max       0
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       7
_diffrn_reflns_limit_k_min       -7
_diffrn_reflns_limit_l_max       18
_diffrn_reflns_limit_l_min       -17
_diffrn_reflns_number            1570
_diffrn_reflns_theta_full        67.00
_diffrn_reflns_theta_max         79.47
_diffrn_standards_decay_%        2.89
_diffrn_standards_interval_count 150
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    0.718
_exptl_absorpt_correction_T_max  0.868
_exptl_absorpt_correction_T_min  0.738
_exptl_absorpt_correction_type   psi-scan
_exptl_absorpt_process_details   '(North <i>et al.</i>,  1968)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.173
_exptl_crystal_density_meas      1.1675
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             288.00
_exptl_crystal_size_max          0.400
_exptl_crystal_size_mid          0.400
_exptl_crystal_size_min          0.200
_refine_diff_density_max         0.17
_refine_diff_density_min         -0.15
_refine_ls_extinction_coef       0.11(2)
_refine_ls_extinction_method     'Zachariasen (1967) type 2, Gaussian isotropic'
_refine_ls_goodness_of_fit_all   1.502
_refine_ls_goodness_of_fit_ref   1.502
_refine_ls_hydrogen_treatment    noref
_refine_ls_matrix_type           full
_refine_ls_number_constraints    0
_refine_ls_number_parameters     83
_refine_ls_number_reflns         834
_refine_ls_number_restraints     0
_refine_ls_R_factor_all          0.0388
_refine_ls_R_factor_gt           0.0331
_refine_ls_shift/su_max          0.0168
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w = 1/[\s^2^(Fo^2^) + (0.05(Max(Fo^2^,0) + 2Fc^2^)/3)^2^]'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_all         0.1039
_refine_ls_wR_factor_ref         0.1039
_reflns_number_gt                756
_reflns_number_total             834
_reflns_threshold_expression     F^2^>2\s(F^2^)
_cod_data_source_file            bg2041.cif
_cod_data_source_block           III
_cod_original_sg_symbol_H-M      'C 2'
_cod_database_code               2213115
_cod_database_fobs_code          2213115