Structures of cyclic dipeptides: an X-ray and computational study of <i>cis</i>- and <i>trans</i>-<i>cyclo</i>(Pip-Phe), <i>cyclo</i>(Pro-Phe) and their <i>N</i>-methyl derivatives
Budesinsky, Milos; Cisarova, Ivana; Podlaha, Jaroslav; Borremans, Frans; Martins, José C.; Waroquier, Michel; Pauwels, Ewald; Acta Crystallographica Section B 66 (2010) 662–677; doi:10.1107/S0108768110040243

data_2104875
_publ_section_title
;
 Structures of cyclic dipeptides: an X-ray and computational study of
 <i>cis</i>- and <i>trans</i>-<i>cyclo</i>(Pip-Phe),
 <i>cyclo</i>(Pro-Phe) and their <i>N</i>-methyl derivatives
;
_journal_coeditor_code           SO5040
_journal_issue                   6
_journal_name_full               'Acta Crystallographica Section B'
_journal_page_first              662
_journal_page_last               677
_journal_paper_doi               10.1107/S0108768110040243
_journal_volume                  66
_journal_year                    2010
_chemical_formula_moiety         '2(C15 H18 N4 O4), H2 O'
_chemical_formula_sum            'C15 H19 N2 O2.5'
_chemical_formula_weight         267.32
_chemical_name_systematic
;
 ?
;
_space_group_IT_number           4
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  'P 2yb'
_symmetry_space_group_name_H-M   'P 1 21 1'
_atom_sites_solution_hydrogens   difmap
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 91.6730(11)
_cell_angle_gamma                90.00
_cell_formula_units_Z            8
_cell_length_a                   8.4202(2)
_cell_length_b                   24.7788(4)
_cell_length_c                   13.4204(3)
_cell_measurement_reflns_used    25066
_cell_measurement_temperature    150(2)
_cell_measurement_theta_max      25.0
_cell_measurement_theta_min      1
_cell_volume                     2798.87(10)
_computing_cell_refinement       'COLLECT and DENZO'
_computing_data_collection
'COLLECT (Hooft, 1998) and DENZO (Otwinowski & Minor, 1997)'
_computing_data_reduction        'COLLECT and DENZO'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SIR92 (Altomare et al., 1994)'
_diffrn_ambient_temperature      150(2)
_diffrn_detector_area_resol_mean 9.091
_diffrn_measured_fraction_theta_full 0.994
_diffrn_measured_fraction_theta_max 0.994
_diffrn_measurement_device_type  'Nonius KappaCCD area detector'
_diffrn_measurement_method       '\f and \w scans to fill the Ewald sphere'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71070
_diffrn_reflns_av_R_equivalents  0.0600
_diffrn_reflns_av_sigmaI/netI    0.0516
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       27
_diffrn_reflns_limit_k_min       -29
_diffrn_reflns_limit_l_max       15
_diffrn_reflns_limit_l_min       -15
_diffrn_reflns_number            31329
_diffrn_reflns_theta_full        25.04
_diffrn_reflns_theta_max         25.04
_diffrn_reflns_theta_min         1.52
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.087
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.269
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plate
_exptl_crystal_F_000             1144
_exptl_crystal_size_max          0.3
_exptl_crystal_size_mid          0.25
_exptl_crystal_size_min          0.25
_refine_diff_density_max         0.322
_refine_diff_density_min         -0.227
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -0.2(10)
_refine_ls_extinction_coef       0.0273(18)
_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   1.042
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     736
_refine_ls_number_reflns         9713
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.042
_refine_ls_R_factor_all          0.0712
_refine_ls_R_factor_gt           0.0535
_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^)+(0.0770P)^2^+0.7105P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1260
_refine_ls_wR_factor_ref         0.1370
_reflns_number_gt                8038
_reflns_number_total             9713
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            so5040.cif
_cod_data_source_block           1a
_cod_original_sg_symbol_H-M      'P 21'
_cod_database_code               2104875
_cod_database_fobs_code          2104875