A new molecular scaffold for the formation of supramolecular peptide double helices: the crystallographic insight.
Guha, Samit; Drew, Michael G. B.; Banerjee, Arindam; Organic letters 9 (2007) 1347–1350; doi:10.1021/ol0701870

data_1505341
_publ_section_title
;
 A new molecular scaffold for the formation of supramolecular peptide
 double helices: the crystallographic insight.
;
_journal_issue                   7
_journal_name_full               'Organic letters'
_journal_page_first              1347
_journal_page_last               1350
_journal_paper_doi               10.1021/ol0701870
_journal_volume                  9
_journal_year                    2007
_chemical_formula_sum            'C9 H18 N2 O3'
_chemical_formula_weight         202.25
_chemical_name_systematic
; 
 ? 
;
_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                89.816(9)
_cell_angle_beta                 87.074(10)
_cell_angle_gamma                89.234(8)
_cell_formula_units_Z            4
_cell_length_a                   12.5522(14)
_cell_length_b                   5.5160(5)
_cell_length_c                   15.9248(19)
_cell_measurement_temperature    150(2)
_cell_volume                     1101.1(2)
_computing_cell_refinement       'Crysalis, Oxford Diffraction'
_computing_data_collection       'Crysalis, Oxford Diffraction'
_computing_data_reduction        'Crysalis, Oxford Diffraction'
_computing_molecular_graphics    PLATON(Spek,2004)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      150(2)
_diffrn_measured_fraction_theta_full 0.893
_diffrn_measured_fraction_theta_max 0.893
_diffrn_measurement_device       'Oxford Diffaction X-Calibur System'
_diffrn_measurement_method       '321 frames, counting time 10 s.'
_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  0.1036
_diffrn_reflns_av_sigmaI/netI    0.0521
_diffrn_reflns_limit_h_max       17
_diffrn_reflns_limit_h_min       -17
_diffrn_reflns_limit_k_max       7
_diffrn_reflns_limit_k_min       -6
_diffrn_reflns_limit_l_max       21
_diffrn_reflns_limit_l_min       -22
_diffrn_reflns_number            15873
_diffrn_reflns_theta_full        30.16
_diffrn_reflns_theta_max         30.16
_diffrn_reflns_theta_min         1.62
_exptl_absorpt_coefficient_mu    0.091
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            white
_exptl_crystal_density_diffrn    1.220
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       needle
_exptl_crystal_F_000             440
_exptl_crystal_size_max          0.30
_exptl_crystal_size_mid          0.05
_exptl_crystal_size_min          0.05
_refine_diff_density_max         0.645
_refine_diff_density_min         -0.441
_refine_diff_density_rms         0.123
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   4.8(19)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.019
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     517
_refine_ls_number_reflns         7951
_refine_ls_number_restraints     3
_refine_ls_restrained_S_all      1.019
_refine_ls_R_factor_all          0.1079
_refine_ls_R_factor_gt           0.1028
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
;
_refine_ls_weighting_details 
  w=1/[\s^2^(Fo^2^)+(0.1786P)^2^+2.7105P] where P=(Fo^2^+2Fc^2^)/3 
;
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.2926
_refine_ls_wR_factor_ref         0.2992
_reflns_number_gt                7405
_reflns_number_total             7951
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ol0701870si20070124_104726.cif
_cod_data_source_block           y
_cod_original_sg_symbol_H-M      P1
_cod_database_code               1505341