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_2104878
_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_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         'C16 H20 N2 O2'
_chemical_formula_sum            'C16 H20 N2 O2'
_chemical_formula_weight         272.34
_space_group_IT_number           1
_symmetry_cell_setting           triclinic
_symmetry_space_group_name_Hall  'P 1'
_symmetry_space_group_name_H-M   'P 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.176(2)
_cell_angle_beta                 79.737(2)
_cell_angle_gamma                70.800(2)
_cell_formula_units_Z            2
_cell_length_a                   7.4277(2)
_cell_length_b                   7.4388(3)
_cell_length_c                   13.5369(5)
_cell_measurement_reflns_used    10488
_cell_measurement_temperature    150(2)
_cell_measurement_theta_max      27
_cell_measurement_theta_min      1
_cell_volume                     693.52(4)
_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 0.980
_diffrn_measured_fraction_theta_max 0.980
_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  0.0700
_diffrn_reflns_av_sigmaI/netI    0.0418
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_k_max       9
_diffrn_reflns_limit_k_min       -9
_diffrn_reflns_limit_l_max       15
_diffrn_reflns_limit_l_min       -17
_diffrn_reflns_number            11078
_diffrn_reflns_theta_full        27.18
_diffrn_reflns_theta_max         27.18
_diffrn_reflns_theta_min         2.91
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.087
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.304
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       irregular
_exptl_crystal_F_000             292
_exptl_crystal_size_max          0.5
_exptl_crystal_size_mid          0.35
_exptl_crystal_size_min          0.25
_refine_diff_density_max         0.285
_refine_diff_density_min         -0.243
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.2(9)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.077
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     363
_refine_ls_number_reflns         5078
_refine_ls_number_restraints     3
_refine_ls_restrained_S_all      1.077
_refine_ls_R_factor_all          0.0410
_refine_ls_R_factor_gt           0.0394
_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^)+(0.0539P)^2^+0.1346P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0994
_refine_ls_wR_factor_ref         0.1008
_reflns_number_gt                4906
_reflns_number_total             5078
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            so5040.cif
_cod_data_source_block           2a
_cod_database_code               2104878
_cod_database_fobs_code          2104878