Supramolecular synthons based on N–H⋯N and C–H⋯O hydrogen bonds. Crystal engineering of a helical structure with 5,5-diethylbarbituric acid
Vishweshwar, Peddy; Thaimattam, Ram; Jaskólski, Mariusz; Desiraju, Gautam R.; Chemical Communications  (2002) 1830–1831; doi:10.1039/b204388b

data_7114482
_publ_section_title
;
 Supramolecular synthons based on N--H&#x22ef;N and C--H&#x22ef;O hydrogen 
 bonds. Crystal engineering of a helical structure with 5,5-diethylbarbituric
 acid
;
_journal_issue                   17
_journal_name_full               'Chemical Communications'
_journal_page_first              1830
_journal_page_last               1831
_journal_paper_doi               10.1039/b204388b
_journal_year                    2002
_chemical_formula_sum            'C14 H24 N6 O3'
_chemical_formula_weight         324.39
_chemical_melting_point          443
_chemical_name_common
;
1:1 molecular complex of 5,5-diethylbarbituric acid and 1,3,5,7-
hexamethylenetetramine
;
_chemical_name_systematic
; 
1:1 molecular complex of 5,5-diethylbarbituric acid and 1,3,5,7-
hexamethylenetetramine 
;
_space_group_IT_number           61
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  '-P 2ac 2ab'
_symmetry_space_group_name_H-M   'P b c a'
_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                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            8
_cell_length_a                   10.866(2)
_cell_length_b                   13.263(3)
_cell_length_c                   22.634(5)
_cell_measurement_reflns_used    1200
_cell_measurement_temperature    100
_cell_volume                     3261.9(12)
_computing_data_collection       KUMA-1
_computing_data_reduction        'KM4-RED [KUMA-2]'
_computing_molecular_graphics    'PLUTON (Spek, 1992)'
_computing_publication_material  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      100
_diffrn_measured_fraction_theta_full 0.997
_diffrn_measured_fraction_theta_max 0.997
_diffrn_measurement_device_type  'KUMA CCD detector [KUMA-1]'
_diffrn_measurement_method       '\w scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0442
_diffrn_reflns_av_sigmaI/netI    0.0438
_diffrn_reflns_limit_h_max       14
_diffrn_reflns_limit_h_min       -14
_diffrn_reflns_limit_k_max       17
_diffrn_reflns_limit_k_min       -17
_diffrn_reflns_limit_l_max       29
_diffrn_reflns_limit_l_min       -14
_diffrn_reflns_number            19108
_diffrn_reflns_theta_full        27.50
_diffrn_reflns_theta_max         27.50
_diffrn_reflns_theta_min         3.56
_exptl_absorpt_coefficient_mu    0.096
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            Colorless
_exptl_crystal_density_diffrn    1.321
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       Cubic
_exptl_crystal_F_000             1392
_exptl_crystal_size_max          0.30
_exptl_crystal_size_mid          0.30
_exptl_crystal_size_min          0.20
_refine_diff_density_max         0.225
_refine_diff_density_min         -0.223
_refine_diff_density_rms         0.041
_refine_ls_extinction_coef       0.0037(8)
_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   1.257
_refine_ls_hydrogen_treatment    refall
_refine_ls_matrix_type           full
_refine_ls_number_parameters     305
_refine_ls_number_reflns         3736
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.257
_refine_ls_R_factor_all          0.0861
_refine_ls_R_factor_gt           0.0649
_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^)+(0.0471P)^2^+0.1173P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1120
_refine_ls_wR_factor_ref         0.1194
_reflns_number_gt                3127
_reflns_number_total             3736
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b204388b.txt
_cod_data_source_block           uro
_cod_depositor_comments
;
The following automatic conversions were performed:
'_atom_site_symetry_multiplicity' tag replaced with
'_atom_site_symmetry_multiplicity'.

Automatic conversion script
Id: cif_correct_tags 1440 2010-10-19 06:21:57Z saulius 

The following automatic conversions were performed:

'_cell_measurement_temperature' value '100K' was changed to '100' -
the value should be numeric and without a unit
designator.

'_diffrn_ambient_temperature' value '100K' was changed
to '100' - the value should be numeric and without a unit
designator.

'_chemical_melting_point' value '443 K' was changed to
'443' - the value should be numeric and without a unit
designator.

'_symmetry_cell_setting' value 'Orthorhombic' changed to
'orthorhombic' according to
/usr/data/users/saulius/automatic-downloads/retrospective/RSC/lib/dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.2 from 2011-04-26.

Automatic conversion script
Id: cif_fix_values 2281 2013-09-26 08:29:07Z andrius 
;
_cod_original_cell_volume        3262.0(11)
_cod_original_sg_symbol_H-M      Pbca
_cod_database_code               7114482