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_4029788
_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            'C20 H22 N4 O'
_chemical_formula_weight         334.42
_chemical_name_systematic
; 
 ? 
;
_space_group_IT_number           14
_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                 93.12(3)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   5.7170(11)
_cell_length_b                   13.990(3)
_cell_length_c                   22.318(5)
_cell_measurement_temperature    90(2)
_cell_volume                     1782.4(7)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      90(2)
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.999
_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  0.0483
_diffrn_reflns_av_sigmaI/netI    0.0408
_diffrn_reflns_limit_h_max       6
_diffrn_reflns_limit_h_min       -6
_diffrn_reflns_limit_k_max       16
_diffrn_reflns_limit_k_min       -16
_diffrn_reflns_limit_l_max       26
_diffrn_reflns_limit_l_min       -26
_diffrn_reflns_number            11760
_diffrn_reflns_theta_full        24.99
_diffrn_reflns_theta_max         24.99
_diffrn_reflns_theta_min         1.72
_exptl_absorpt_coefficient_mu    0.080
_exptl_absorpt_correction_T_max  0.9765
_exptl_absorpt_correction_T_min  0.9765
_exptl_crystal_density_diffrn    1.246
_exptl_crystal_density_method    'not measured'
_exptl_crystal_F_000             712
_exptl_crystal_size_max          0.30
_exptl_crystal_size_mid          0.30
_exptl_crystal_size_min          0.30
_refine_diff_density_max         0.634
_refine_diff_density_min         -0.296
_refine_diff_density_rms         0.059
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.038
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     259
_refine_ls_number_reflns         3138
_refine_ls_number_restraints     81
_refine_ls_restrained_S_all      1.039
_refine_ls_R_factor_all          0.0780
_refine_ls_R_factor_gt           0.0538
_refine_ls_shift/su_max          0.003
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0877P)^2^+1.1648P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1456
_refine_ls_wR_factor_ref         0.1613
_reflns_number_gt                2298
_reflns_number_total             3138
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            9b1_Ci.cif
_cod_data_source_block           k04123
_cod_original_cell_volume        1782.4(6)
_cod_database_code               4029788