A helical, aromatic, peptide nanotube.
Crisma, Marco; Toniolo, Claudio; Royo, Soledad; Jiménez, Ana I; Cativiela, Carlos; Organic letters 8 (2006) 6091–6094; doi:10.1021/ol062600u

data_1506320
_publ_section_title
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 A helical, aromatic, peptide nanotube.
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_journal_issue                   26
_journal_name_full               'Organic letters'
_journal_page_first              6091
_journal_page_last               6094
_journal_paper_doi               10.1021/ol062600u
_journal_volume                  8
_journal_year                    2006
_chemical_formula_sum            'C40 H43 N3 O4'
_chemical_formula_weight         629.77
_chemical_name_systematic
;
 Boc-(S,S)-c3diPhe-(R,R)-c3diPhe-NHiPr
;
_space_group_IT_number           170
_symmetry_cell_setting           hexagonal
_symmetry_space_group_name_Hall  'P 65'
_symmetry_space_group_name_H-M   'P 65'
_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                120.00
_cell_formula_units_Z            6
_cell_length_a                   23.721(3)
_cell_length_b                   23.721(3)
_cell_length_c                   12.930(3)
_cell_measurement_reflns_used    48
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      20
_cell_measurement_theta_min      12
_cell_volume                     6300.8(18)
_computing_molecular_graphics    'Ortep-3 for Windows (Farrugia, 1997)'
_computing_publication_material  'PARST 96 (Nardelli, 1995)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SIR 2002 (Burla et al., 2003)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_diffrn_measurement_device_type  'Philips PW1100 diffractometer'
_diffrn_measurement_method       '\q-2\q scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.1096
_diffrn_reflns_av_sigmaI/netI    0.0801
_diffrn_reflns_limit_h_max       23
_diffrn_reflns_limit_h_min       -26
_diffrn_reflns_limit_k_max       26
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       14
_diffrn_reflns_limit_l_min       0
_diffrn_reflns_number            10089
_diffrn_reflns_theta_full        60.01
_diffrn_reflns_theta_max         60.01
_diffrn_reflns_theta_min         5.50
_diffrn_standards_decay_%        none
_diffrn_standards_interval_count 100
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    0.510
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    0.996
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             2016
_exptl_crystal_size_max          0.40
_exptl_crystal_size_mid          0.25
_exptl_crystal_size_min          0.15
_refine_diff_density_max         0.328
_refine_diff_density_min         -0.174
_refine_diff_density_rms         0.045
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.3(5)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.026
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           fullcycle
_refine_ls_number_parameters     376
_refine_ls_number_reflns         3281
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.026
_refine_ls_R_factor_all          0.0744
_refine_ls_R_factor_gt           0.0605
_refine_ls_shift/su_max          0.063
_refine_ls_shift/su_mean         0.012
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.1029P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1594
_refine_ls_wR_factor_ref         0.1708
_reflns_number_gt                2467
_reflns_number_total             3281
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ol062600usi20061022_014039.cif
_cod_data_source_block           mc88
_cod_depositor_comments
;
The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Hexagonal' changed to 'hexagonal'
according to /home/saulius/struct/CIF-dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_values 1715 2011-07-08 13:25:40Z adriana 
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_cod_original_sg_symbol_H-M      P6(5)
_cod_database_code               1506320