Self-assembly of a bis-urea macrocycle into a columnar nanotube
Shimizu, Linda S.; Smith, Mark D.; Hughes, Andrew D.; Shimizu, Linda S.; Chemical Communications  (2001) 1592–; doi:10.1039/b102159c

data_7115039
_publ_section_title
;
 Self-assembly of a bis-urea macrocycle into a columnar nanotube
;
_journal_issue                   17
_journal_name_full               'Chemical Communications'
_journal_page_first              1592
_journal_paper_doi               10.1039/b102159c
_journal_year                    2001
_chemical_formula_sum            'C18 H20 N4 O2'
_chemical_formula_weight         324.38
_chemical_name_systematic
; 
? 
;
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2yn'
_symmetry_space_group_name_H-M   'P 1 21/n 1'
_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                 103.193(4)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   12.808(3)
_cell_length_b                   4.6145(10)
_cell_length_c                   13.950(3)
_cell_measurement_reflns_used    929
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      23.198
_cell_measurement_theta_min      2.456
_cell_volume                     802.7(3)
_computing_cell_refinement       'SAINT+ NT V6.02a (Bruker, 1998)'
_computing_data_collection       'SMART NT V5.619 (Bruker, 2000)'
_computing_data_reduction        'SAINT+ NT V6.02a'
_computing_molecular_graphics    'SHELXTL V5.1 (Sheldrick, 1997)'
_computing_publication_material  'SHELXTL V5.1'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_device_type  'Bruker SMART APEX CCD diffractometer'
_diffrn_measurement_method       '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  0.0676
_diffrn_reflns_av_sigmaI/netI    0.0821
_diffrn_reflns_limit_h_max       13
_diffrn_reflns_limit_h_min       -14
_diffrn_reflns_limit_k_max       5
_diffrn_reflns_limit_k_min       -5
_diffrn_reflns_limit_l_max       14
_diffrn_reflns_limit_l_min       -15
_diffrn_reflns_number            4211
_diffrn_reflns_theta_full        23.29
_diffrn_reflns_theta_max         23.29
_diffrn_reflns_theta_min         1.95
_diffrn_standards_decay_%        none
_exptl_absorpt_coefficient_mu    0.090
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.342
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       needle
_exptl_crystal_F_000             344
_exptl_crystal_size_max          0.22
_exptl_crystal_size_mid          0.03
_exptl_crystal_size_min          0.02
_refine_diff_density_max         0.123
_refine_diff_density_min         -0.126
_refine_diff_density_rms         0.030
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.008
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     117
_refine_ls_number_reflns         1155
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.008
_refine_ls_R_factor_all          0.0833
_refine_ls_R_factor_gt           0.0386
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
; calc 
[0.00000+1.00000exp(3.35(sin\q/\l)^2^)]/ 
[\s^2^(Fo^2^)+0.0000+0.0000*P+(0.0235P)^2^+0.0000sin\q/\l] 
where P = 0.33333Fo^2^ + 0.66667Fc^2^ 
;
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0695
_refine_ls_wR_factor_ref         0.0826
_reflns_number_gt                618
_reflns_number_total             1155
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b102159c.txt
_cod_data_source_block           lss286at
_cod_original_sg_symbol_H-M      P21/n
_cod_database_code               7115039