mABA inserted supramolecular triple helix formation in the solid state in synthetic tripeptides containing β-cyanoalanine and Aib as corner residues
Konar, Anita Dutt; CrystEngComm 14 (2012) 6689–; doi:10.1039/c2ce25527h

data_7208680
_publ_section_title
;
 mABA inserted supramolecular triple helix formation in the solid state in
 synthetic tripeptides containing \b-cyanoalanine and Aib as corner
 residues
;
_journal_issue                   20
_journal_name_full               CrystEngComm
_journal_page_first              6689
_journal_paper_doi               10.1039/c2ce25527h
_journal_volume                  14
_journal_year                    2012
_chemical_absolute_configuration unk
_chemical_formula_moiety         'C21 H28 N4 O6'
_chemical_formula_sum            'C21 H28 N4 O6'
_chemical_formula_weight         432.47
_space_group_IT_number           19
_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                   6.0152(11)
_cell_length_b                   12.442(2)
_cell_length_c                   29.838(6)
_cell_measurement_temperature    120(2)
_cell_volume                     2233.1(7)
_computing_cell_refinement       'Bruker SMART'
_computing_data_collection       'Bruker SMART'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      120(2)
_diffrn_measured_fraction_theta_full 0.614
_diffrn_measured_fraction_theta_max 0.614
_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     0.71073
_diffrn_reflns_av_R_equivalents  0.0765
_diffrn_reflns_av_sigmaI/netI    0.1484
_diffrn_reflns_limit_h_max       6
_diffrn_reflns_limit_h_min       -4
_diffrn_reflns_limit_k_max       16
_diffrn_reflns_limit_k_min       -13
_diffrn_reflns_limit_l_max       36
_diffrn_reflns_limit_l_min       -30
_diffrn_reflns_number            4001
_diffrn_reflns_theta_full        28.70
_diffrn_reflns_theta_max         28.70
_diffrn_reflns_theta_min         1.36
_exptl_absorpt_coefficient_mu    0.095
_exptl_absorpt_correction_T_max  0.986
_exptl_absorpt_correction_T_min  0.980
_exptl_absorpt_correction_type   'Empirical''Bruker SADABS V2.10'
_exptl_absorpt_process_details   'Bruker SADABS V2.10'
_exptl_crystal_colour            Colourless
_exptl_crystal_density_diffrn    1.286
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       Needle
_exptl_crystal_F_000             920
_exptl_crystal_size_max          0.40
_exptl_crystal_size_mid          0.18
_exptl_crystal_size_min          0.15
_refine_diff_density_max         0.226
_refine_diff_density_min         -0.226
_refine_diff_density_rms         0.054
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -1(2)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.799
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     294
_refine_ls_number_reflns         3136
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.799
_refine_ls_R_factor_all          0.1045
_refine_ls_R_factor_gt           0.0559
_refine_ls_shift/su_max          0.002
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0487P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1145
_refine_ls_wR_factor_ref         0.1322
_reflns_number_gt                1628
_reflns_number_total             3136
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c2ce25527h.txt
_cod_data_source_block           as1f
_cod_original_sg_symbol_H-M      P212121
_cod_database_code               7208680