Hydrogen Bonding in Crystal Structures ofN,N‘-Bis(3-pyridyl)urea. Why Is the N−H···O Tape Synthon Absent in Diaryl Ureas with Electron-Withdrawing Groups?
Reddy, L. Sreenivas; Basavoju, Srinivas; Vangala, Venu R.; Nangia, Ashwini; Crystal Growth & Design 6 (2006) 161–; doi:10.1021/cg0580152

data_4504802
_publ_section_title
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 Hydrogen Bonding in Crystal Structures ofN,N&#x2018;-Bis(3-pyridyl)urea.
 Why Is the N&#x2212;H&#x00B7;&#x00B7;&#x00B7;O Tape Synthon Absent in
 Diaryl Ureas with Electron-Withdrawing Groups?
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_journal_issue                   1
_journal_name_full               'Crystal Growth &amp; Design'
_journal_page_first              161
_journal_paper_doi               10.1021/cg0580152
_journal_volume                  6
_journal_year                    2006
_chemical_formula_moiety         'C11 H10 N4 O, 2 (H2 O)'
_chemical_formula_sum            'C11 H14 N4 O3'
_chemical_formula_weight         250.26
_chemical_melting_point          499
_chemical_name_common            1,3-bis(3-pyridyl)ureadihydrate
_chemical_name_systematic
; 
 1,3-bis(3-pyridyl)ureadihydrate 
;
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2ybc'
_symmetry_space_group_name_H-M   'P 1 21/c 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                 101.260(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   6.7932(8)
_cell_length_b                   19.560(2)
_cell_length_c                   9.2746(11)
_cell_measurement_reflns_used    920
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      24.93
_cell_measurement_theta_min      2.47
_cell_volume                     1208.6(2)
_computing_cell_refinement       'Bruker SMART'
_computing_data_collection       'Bruker SMART'
_computing_data_reduction        'Bruker SAINT'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 0.997
_diffrn_measured_fraction_theta_max 0.997
_diffrn_measurement_device_type  'CCD area detector'
_diffrn_measurement_method       'phi and omega scans'
_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  0.0388
_diffrn_reflns_av_sigmaI/netI    0.0510
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       -8
_diffrn_reflns_limit_k_max       21
_diffrn_reflns_limit_k_min       -24
_diffrn_reflns_limit_l_max       10
_diffrn_reflns_limit_l_min       -11
_diffrn_reflns_number            5789
_diffrn_reflns_theta_full        26.01
_diffrn_reflns_theta_max         26.01
_diffrn_reflns_theta_min         2.08
_exptl_absorpt_coefficient_mu    0.103
_exptl_absorpt_correction_T_max  0.9918
_exptl_absorpt_correction_T_min  0.9777
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'Bruker AXS SADABS program'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.375
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       needle
_exptl_crystal_F_000             528
_exptl_crystal_size_max          0.22
_exptl_crystal_size_mid          0.10
_exptl_crystal_size_min          0.08
_refine_diff_density_max         0.239
_refine_diff_density_min         -0.193
_refine_diff_density_rms         0.044
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.031
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     198
_refine_ls_number_reflns         2386
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.031
_refine_ls_R_factor_all          0.0801
_refine_ls_R_factor_gt           0.0499
_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^)+(0.0463P)^2^+0.0531P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0984
_refine_ls_wR_factor_ref         0.1097
_reflns_number_gt                1651
_reflns_number_total             2386
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            cg0580152_dipyurea_3_dihydrare100k.cif
_cod_data_source_block           1,3-bis(3-pyridyl)ureadihydrate
_cod_depositor_comments
;
The following automatic conversions were performed:

'_chemical_melting_point' value '499K' was changed to '499' - the
value should be numeric and without a unit
designator.

'_symmetry_cell_setting' value 'Monoclinic' changed to
'monoclinic' according to
/home/saulius/struct/CIF-dictionaries/cif_core.dic dictionary named
'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_values 1715 2011-07-08 13:25:40Z adriana 
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_cod_original_cell_volume        1208.7(2)
_cod_original_sg_symbol_Hall     '-P 2ybc '
_cod_original_sg_symbol_H-M      'P 2 1 / c'
_cod_database_code               4504802