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_4029796
_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_moiety         'C19 H32 N4'
_chemical_formula_sum            'C19 H32 N4'
_chemical_formula_weight         316.49
_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                 100.910(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   9.3059(6)
_cell_length_b                   12.1138(8)
_cell_length_c                   16.5226(11)
_cell_measurement_reflns_used    9601
_cell_measurement_temperature    90.0(2)
_cell_measurement_theta_max      69.50
_cell_measurement_theta_min      3.65
_cell_volume                     1828.9(2)
_computing_cell_refinement       'APEX2 (Bruker-AXS, 2006)'
_computing_data_collection       'APEX2 (Bruker-AXS, 2006)'
_computing_data_reduction        'APEX2 (Bruker-AXS, 2006)'
_computing_molecular_graphics    'XP in SHELXTL (Sheldrick, 2008)'
_computing_publication_material
; 
SHELX97-2 (Sheldrick, 2008) and local procedures 
;
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      90.0(2)
_diffrn_detector_area_resol_mean 18
_diffrn_measured_fraction_theta_full 0.994
_diffrn_measured_fraction_theta_max 0.994
_diffrn_measurement_device_type  'Bruker X8 Proteum diffractometer'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_monochromator  'graded multilayer optics'
_diffrn_radiation_source         'fine-focus rotating anode'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.0394
_diffrn_reflns_av_sigmaI/netI    0.0220
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       11
_diffrn_reflns_limit_k_min       -14
_diffrn_reflns_limit_l_max       19
_diffrn_reflns_limit_l_min       -20
_diffrn_reflns_number            26867
_diffrn_reflns_theta_full        69.38
_diffrn_reflns_theta_max         69.38
_diffrn_reflns_theta_min         4.56
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.530
_exptl_absorpt_correction_T_max  0.959
_exptl_absorpt_correction_T_min  0.859
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'Sadabs in APEX2 (BrukerAXS, 2006)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.149
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             696
_exptl_crystal_size_max          0.12
_exptl_crystal_size_mid          0.10
_exptl_crystal_size_min          0.08
_refine_diff_density_max         0.215
_refine_diff_density_min         -0.175
_refine_diff_density_rms         0.035
_refine_ls_extinction_coef       0.0021(3)
_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   1.031
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     212
_refine_ls_number_reflns         3408
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.031
_refine_ls_R_factor_all          0.0379
_refine_ls_R_factor_gt           0.0357
_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^)+(0.0393P)^2^+0.7447P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0896
_refine_ls_wR_factor_ref         0.0919
_reflns_number_gt                3196
_reflns_number_total             3408
_reflns_threshold_expression     >2\s(I)
_cod_data_source_file            7c_Ci.cif
_cod_data_source_block           x07077
_cod_original_sg_symbol_H-M      'P 21/n'
_cod_database_code               4029796