Inversion symmetry and local vs. dispersive interactions in the nucleation of hydrogen bonded cyclic n-mer and tape of imidazolecarboxamidines.
Long, Sihui; Muthusamy, Venkatraj; Willis, Peter G.; Parkin, Sean; Cammers, Arthur; Beilstein journal of organic chemistry 4 (2008) 23–; doi:10.3762/bjoc.4.23

data_4029803
_publ_section_title
;
 Inversion symmetry and local vs. dispersive interactions in the
 nucleation of hydrogen bonded cyclic n-mer and tape of
 imidazolecarboxamidines.
;
_journal_name_full               'Beilstein journal of organic chemistry'
_journal_page_first              23
_journal_paper_doi               10.3762/bjoc.4.23
_journal_volume                  4
_journal_year                    2008
_chemical_formula_sum            'C18 H29 N5 O2'
_chemical_formula_weight         347.46
_space_group_IT_number           33
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2c -2n'
_symmetry_space_group_name_H-M   'P n a 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            8
_cell_length_a                   18.066(4)
_cell_length_b                   10.234(2)
_cell_length_c                   22.275(5)
_cell_measurement_reflns_used    154979
_cell_measurement_temperature    173(2)
_cell_measurement_theta_max      25.35
_cell_measurement_theta_min      1.00
_cell_volume                     4118.4(15)
_computing_cell_refinement       'SCALEPACK (Otwinowski & Minor, 1997)'
_computing_data_collection       'COLLECT (Nonius, 1998)'
_computing_data_reduction        'DENZO-SMN (Otwinowski & Minor, 1997)'
_computing_molecular_graphics    'XP in Siemens SHELXTL (Sheldrick, 1994)'
_computing_publication_material
'SHELX97-2 (Sheldrick, 1997) and local procedures'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      173(1)
_diffrn_detector_area_resol_mean 18
_diffrn_measured_fraction_theta_full .999
_diffrn_measured_fraction_theta_max .999
_diffrn_measurement_device_type  'Nonius KappaCCD diffractometer'
_diffrn_measurement_method       '\w scans at fixed \c = 55\%'
_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  0.0762
_diffrn_reflns_av_sigmaI/netI    0.0633
_diffrn_reflns_limit_h_max       19
_diffrn_reflns_limit_h_min       -19
_diffrn_reflns_limit_k_max       11
_diffrn_reflns_limit_k_min       -11
_diffrn_reflns_limit_l_max       23
_diffrn_reflns_limit_l_min       -23
_diffrn_reflns_number            19888
_diffrn_reflns_theta_full        22.50
_diffrn_reflns_theta_max         22.50
_diffrn_reflns_theta_min         1.83
_diffrn_standards_decay_%        <1
_exptl_absorpt_coefficient_mu    0.075
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.121
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       'irregular block'
_exptl_crystal_F_000             1504
_exptl_crystal_size_max          0.44
_exptl_crystal_size_mid          0.30
_exptl_crystal_size_min          0.30
_refine_diff_density_max         .228
_refine_diff_density_min         -.239
_refine_diff_density_rms         .044
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.00
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.116
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     451
_refine_ls_number_reflns         5371
_refine_ls_number_restraints     417
_refine_ls_restrained_S_all      1.105
_refine_ls_R_factor_all          0.0908
_refine_ls_R_factor_gt           0.0737
_refine_ls_shift/su_max          0.096
_refine_ls_shift/su_mean         0.016
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0632P)^2^+2.7613P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1638
_refine_ls_wR_factor_ref         0.1728
_reflns_number_gt                4459
_reflns_number_total             5371
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            12a.cif
_cod_data_source_block           k01131x
_cod_original_cell_volume        4118.4(14)
_cod_original_sg_symbol_H-M      'P na21'
_cod_database_code               4029803