Engineering short, strong hydrogen bonds in urea di-carboxylic acid complexes
Jones, Andrew O. F.; Leech, Charlotte K.; McIntyre, Garry J.; Wilson, Chick C.; Thomas, Lynne H.; CrystEngComm 16 (2014) 8177–; doi:10.1039/C4CE00587B

data_7217954
_publ_section_title
;
 Engineering short, strong hydrogen bonds in urea di-carboxylic acid
 complexes
;
_journal_issue                   35
_journal_name_full               CrystEngComm
_journal_page_first              8177
_journal_paper_doi               10.1039/C4CE00587B
_journal_volume                  16
_journal_year                    2014
_chemical_formula_sum            'C8 H16 N4 O6'
_chemical_formula_weight         264.25
_chemical_name_common
;
 bis(methylurea) fumaric acid
;
_chemical_name_systematic
;
 bis(N-methylurea) trans-butenedioic acid
;
_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   difmap
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 100.730(6)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   8.7741(14)
_cell_length_b                   5.4413(7)
_cell_length_c                   13.9303(19)
_cell_measurement_reflns_used    3951
_cell_measurement_temperature    300
_cell_measurement_theta_max      54.95
_cell_measurement_theta_min      6.04
_cell_volume                     653.44(16)
_computing_cell_refinement       'CrystalClear 1.4.0 (Rigaku, 2008)'
_computing_data_collection       'CrystalClear 1.4.0 (Rigaku, 2008)'
_computing_data_reduction        'CrystalClear 1.4.0 (Rigaku, 2008)'
_computing_molecular_graphics    'Mercury (McRae, 2006)'
_computing_publication_material  'WINGX (Farrugia, 1999)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      300
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.999
_diffrn_measurement_device_type  'Rigaku R-AXIS RAPID IP Image Plate'
_diffrn_measurement_method       'Image plate'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71075
_diffrn_reflns_av_R_equivalents  0.0466
_diffrn_reflns_av_sigmaI/netI    0.0308
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       7
_diffrn_reflns_limit_k_min       -7
_diffrn_reflns_limit_l_max       18
_diffrn_reflns_limit_l_min       -18
_diffrn_reflns_number            8681
_diffrn_reflns_theta_full        27.48
_diffrn_reflns_theta_max         27.48
_diffrn_reflns_theta_min         3.02
_exptl_absorpt_coefficient_mu    0.115
_exptl_absorpt_correction_T_max  1.0000
_exptl_absorpt_correction_T_min  0.8368
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'ABSCOR, Rigaku 1995'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.343
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             280
_exptl_crystal_size_max          0.3
_exptl_crystal_size_mid          0.3
_exptl_crystal_size_min          0.2
_refine_diff_density_max         0.143
_refine_diff_density_min         -0.116
_refine_diff_density_rms         0.030
_refine_ls_extinction_coef       0.004(4)
_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    refall
_refine_ls_matrix_type           full
_refine_ls_number_parameters     115
_refine_ls_number_reflns         1494
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.031
_refine_ls_R_factor_all          0.0949
_refine_ls_R_factor_gt           0.0487
_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^)+(0.0437P)^2^+0.1277P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0962
_refine_ls_wR_factor_ref         0.1168
_reflns_number_gt                865
_reflns_number_total             1494
_reflns_threshold_expression     >2\s(I)
_cod_duplicate_entry             7214489
_cod_data_source_file            c4ce00587b2.cif
_cod_data_source_block           mu_fum_300k
_cod_original_sg_symbol_H-M      P21/n
_cod_database_code               7217954