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_2104856
_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         'C15 H18 N2 O2'
_chemical_formula_sum            'C15 H18 N2 O2'
_chemical_formula_weight         258.31
_chemical_name_systematic
;
 ?
;
_space_group_IT_number           19
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2ac 2ab'
_symmetry_space_group_name_H-M   'P 21 21 21'
_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                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   10.1490(5)
_cell_length_b                   10.9390(10)
_cell_length_c                   12.3100(10)
_cell_measurement_reflns_used    25
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      14
_cell_measurement_theta_min      13
_cell_volume                     1366.66(18)
_computing_cell_refinement       'Enraf-Nonius CAD4 Version 5.0'
_computing_data_collection       'Enraf-Nonius CAD4 Version 5.0'
_computing_data_reduction        'JANA2006, (Petricek,2006)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution
'SIR97(Cascarano al.,Acta Cryst.,1996,A52,C-79)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_device_type  CAD4-MACHIII
_diffrn_measurement_method       'theta-2theta scan'
_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  0.0000
_diffrn_reflns_av_sigmaI/netI    0.0194
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       12
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       14
_diffrn_reflns_limit_l_min       0
_diffrn_reflns_number            1386
_diffrn_reflns_theta_full        24.96
_diffrn_reflns_theta_max         24.96
_diffrn_reflns_theta_min         2.49
_diffrn_standards_decay_%        9
_diffrn_standards_interval_time  3600
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    0.084
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.255
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             552
_exptl_crystal_size_max          0.5
_exptl_crystal_size_mid          0.4
_exptl_crystal_size_min          0.3
_refine_diff_density_max         0.131
_refine_diff_density_min         -0.174
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -3(2)
_refine_ls_extinction_coef       0.028(4)
_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   1.069
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     174
_refine_ls_number_reflns         1386
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.069
_refine_ls_R_factor_all          0.0470
_refine_ls_R_factor_gt           0.0346
_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^)+(0.0678P)^2^+0.0829P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0946
_refine_ls_wR_factor_ref         0.1011
_reflns_number_gt                1179
_reflns_number_total             1386
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            so5040.cif
_cod_data_source_block           10b-room
_cod_database_code               2104856
_cod_database_fobs_code          2104856