Polymorphism in secondary squaramides: on the importance of π-interactions involving the four membered ring
Prohens, Rafel; Portell, Anna; Vallcorba, Oriol; Font-Bardia, Mercè; Bauzá, Antonio; Frontera, Antonio; CrystEngComm 20 (2018) 237–; doi:10.1039/C7CE01945A

data_7229637
_publ_section_title
;
 Polymorphism in secondary squaramides: on the importance of
 \p-interactions involving the four membered ring
;
_journal_issue                   2
_journal_name_full               CrystEngComm
_journal_page_first              237
_journal_paper_doi               10.1039/C7CE01945A
_journal_volume                  20
_journal_year                    2018
_chemical_formula_moiety         'C12 H22 N4 O2'
_chemical_formula_sum            'C12 H22 N4 O2'
_chemical_formula_weight         254.34
_space_group_IT_number           43
_space_group_name_Hall           'F 2 -2d'
_space_group_name_H-M_alt        'F d d 2'
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'F 2 -2d'
_symmetry_space_group_name_H-M   'F d d 2'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_block_doi                 10.5517/cc132vz0
_audit_creation_method           SHELXL-97
_audit_update_record
;
2014-07-23 deposited with the CCDC.
2017-12-01 downloaded from the CCDC.
;
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            8
_cell_length_a                   16.185(14)
_cell_length_b                   29.012(18)
_cell_length_c                   6.093(4)
_cell_measurement_reflns_used    613
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      31
_cell_measurement_theta_min      3
_cell_volume                     2861(4)
_computing_cell_refinement       AUTOMAR
_computing_data_collection       MARXDS
_computing_data_reduction        MARSCALE
_computing_molecular_graphics    'ORTEP (Brueggermann and Smith, 1990)'
_computing_publication_material  'PLATON (Spek, 1990)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.996
_diffrn_measured_fraction_theta_max 0.850
_diffrn_measurement_device_type  'MAR345 with an image plate detector'
_diffrn_measurement_method       'phi scan'
_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  0.0743
_diffrn_reflns_av_sigmaI/netI    0.0540
_diffrn_reflns_limit_h_max       24
_diffrn_reflns_limit_h_min       -22
_diffrn_reflns_limit_k_max       42
_diffrn_reflns_limit_k_min       -43
_diffrn_reflns_limit_l_max       8
_diffrn_reflns_limit_l_min       -8
_diffrn_reflns_number            5245
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         32.42
_diffrn_reflns_theta_min         2.81
_exptl_absorpt_coefficient_mu    0.083
_exptl_absorpt_correction_T_max  0.99
_exptl_absorpt_correction_T_min  0.98
_exptl_absorpt_correction_type   empirical
_exptl_absorpt_process_details   sadabs
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.181
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             1104
_exptl_crystal_size_max          0.2
_exptl_crystal_size_mid          0.1
_exptl_crystal_size_min          0.1
_refine_diff_density_max         0.299
_refine_diff_density_min         -0.163
_refine_diff_density_rms         0.041
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.137
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     85
_refine_ls_number_reflns         1961
_refine_ls_number_restraints     4
_refine_ls_restrained_S_all      1.139
_refine_ls_R_factor_all          0.0950
_refine_ls_R_factor_gt           0.0695
_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 w=1/[\s^2^(Fo^2^)+(0.0998P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1901
_refine_ls_wR_factor_ref         0.2027
_reflns_number_gt                1419
_reflns_number_total             1961
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c7ce01945a2.cif
_cod_data_source_block           anom71a
_cod_depositor_comments
'Adding full bibliography for 7229635--7229638.cif.'
_cod_original_sg_symbol_H-M      Fdd2
_cod_database_code               7229637