The smallest alpha,gamma-peptide nanotubulet segments: cyclic alpha,gamma-tetrapeptide dimers.
Amorín, Manuel; Brea, Roberto J.; Castedo, Luis; Granja, Juan R.; Organic letters 7 (2005) 4681–4684; doi:10.1021/ol0518885

data_1506718
_publ_section_title
;
 The smallest alpha,gamma-peptide nanotubulet segments: cyclic
 alpha,gamma-tetrapeptide dimers.
;
_journal_issue                   21
_journal_name_full               'Organic letters'
_journal_page_first              4681
_journal_page_last               4684
_journal_paper_doi               10.1021/ol0518885
_journal_volume                  7
_journal_year                    2005
_chemical_compound_source        'synthesis as described'
_chemical_formula_moiety         'C36 H38 N4 O4'
_chemical_formula_sum            'C36 H38 N4 O4'
_chemical_formula_weight         641.79
_chemical_name_systematic
;
 ?
;
_space_group_IT_number           4
_symmetry_cell_setting           monoclinic
_symmetry_Int_Tables_number      4
_symmetry_space_group_name_Hall  'P 2yb'
_symmetry_space_group_name_H-M   'P 1 21 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_conform_dict_location     ftp://ftp.iucr.org/pub/cif_core.dic
_audit_conform_dict_name         cif_core.dic
_audit_conform_dict_version      2.2
_audit_creation_date             2002-06-25T17:56:18-00:00
_audit_creation_method           'WinGX routine CIF_UPDATE'
_cell_angle_alpha                90
_cell_angle_beta                 107.321(2)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   12.9029(17)
_cell_length_b                   14.6931(19)
_cell_length_c                   19.457(3)
_cell_measurement_reflns_used    1904
_cell_measurement_temperature    110(2)
_cell_measurement_theta_max      28.21
_cell_measurement_theta_min      2.63
_cell_measurement_wavelength     0.71073
_cell_volume                     3521.5(8)
_computing_cell_refinement       'SAINT (Bruker AXS)'
_computing_data_collection       'SMART (Bruker AXS)'
_computing_data_reduction        'SAINT (Bruker AXS)'
_computing_molecular_graphics    'Ortep-3 for Windows (Farrugia, 1997)'
_computing_publication_material  'WinGX publication routines (Farrugia, 1999)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      110(2)
_diffrn_measured_fraction_theta_full 0.949
_diffrn_measured_fraction_theta_max 0.949
_diffrn_measurement_device_type  'Bruker P4'
_diffrn_measurement_method       '\w scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0231
_diffrn_reflns_av_unetI/netI     0.0534
_diffrn_reflns_limit_h_max       16
_diffrn_reflns_limit_h_min       -17
_diffrn_reflns_limit_k_max       19
_diffrn_reflns_limit_k_min       -17
_diffrn_reflns_limit_l_max       25
_diffrn_reflns_limit_l_min       0
_diffrn_reflns_number            23385
_diffrn_reflns_theta_full        28.29
_diffrn_reflns_theta_max         28.29
_diffrn_reflns_theta_min         1.1
_exptl_absorpt_coefficient_mu    0.085
_exptl_absorpt_correction_T_max  1
_exptl_absorpt_correction_T_min  0.8705
_exptl_absorpt_correction_type   SADABS
_exptl_crystal_colour            colourless
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             1384
_exptl_crystal_size_max          0.54
_exptl_crystal_size_mid          0.39
_exptl_crystal_size_min          0.15
_refine_diff_density_max         1.241
_refine_diff_density_min         -0.43
_refine_diff_density_rms         0.064
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.0(11)
_refine_ls_extinction_coef       0.0018(6)
_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   1.029
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     867
_refine_ls_number_reflns         15139
_refine_ls_number_restraints     14
_refine_ls_restrained_S_all      1.052
_refine_ls_R_factor_all          0.097
_refine_ls_R_factor_gt           0.0631
_refine_ls_shift/su_max          1.642
_refine_ls_shift/su_mean         0.034
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0949P)^2^+2.3521P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1652
_refine_ls_wR_factor_ref         0.1899
_reflns_number_gt                11048
_reflns_number_total             15139
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ol0518885si20050805_074557.cif
_cod_data_source_block           jg07ma1n
_cod_database_code               1506718