Helix-Forming Propensity of Aliphatic Urea Oligomers Incorporating Noncanonical Residue Substitution Patterns
Nagendar Pendem; Céline Douat; Paul Claudon; Michel Laguerre; Sabine Castano; Bernard Desbat; Dominique Cavagnat; Eric Ennifar; Brice Kauffmann; Gilles Guichard; Journal of the American Chemical Society 135 (2013) 4884–4892; doi:10.1021/ja401151v

data_4119513
_publ_section_title
;
 Helix-Forming Propensity of Aliphatic Urea Oligomers Incorporating
 Noncanonical Residue Substitution Patterns
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              4884
_journal_page_last               4892
_journal_paper_doi               10.1021/ja401151v
_journal_volume                  135
_journal_year                    2013
_chemical_absolute_configuration rmad
_chemical_formula_sum            'C52 H63 F3 N12 O6'
_chemical_formula_weight         1009.14
_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                   10.100(2)
_cell_length_b                   19.070(4)
_cell_length_c                   26.030(5)
_cell_measurement_temperature    100(2)
_cell_volume                     5013.6(17)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXD (Sheldrick, 2008)'
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 0.976
_diffrn_measured_fraction_theta_max 0.976
_diffrn_radiation_monochromator
'Bartels Monochromator with dual channel cut crystals (DCCM)'
_diffrn_radiation_source         'synchrotron radiation'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.75
_diffrn_reflns_av_R_equivalents  0.0633
_diffrn_reflns_av_sigmaI/netI    0.0280
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       23
_diffrn_reflns_limit_k_min       -23
_diffrn_reflns_limit_l_max       32
_diffrn_reflns_limit_l_min       -32
_diffrn_reflns_number            133471
_diffrn_reflns_theta_full        26.37
_diffrn_reflns_theta_max         26.37
_diffrn_reflns_theta_min         1.32
_exptl_absorpt_coefficient_mu    0.097
_exptl_absorpt_correction_T_max  0.9903
_exptl_absorpt_correction_T_min  0.9903
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.337
_exptl_crystal_description       parallelpiped
_exptl_crystal_F_000             2136
_exptl_crystal_size_max          0.10
_exptl_crystal_size_mid          0.10
_exptl_crystal_size_min          0.10
_refine_diff_density_max         0.287
_refine_diff_density_min         -0.298
_refine_diff_density_rms         0.046
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.0172(5)
_refine_ls_extinction_coef       0.008(2)
_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   1.048
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     659
_refine_ls_number_reflns         10027
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.048
_refine_ls_R_factor_all          0.0387
_refine_ls_R_factor_gt           0.0385
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0533P)^2^+2.4534P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0994
_refine_ls_wR_factor_ref         0.0996
_reflns_number_gt                9962
_reflns_number_total             10027
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja401151v_si_002.cif
_cod_data_source_block           PNala
_cod_database_code               4119513