Exploration of plastic-like phases in alkylurea systems. A thermal and X-ray study
Hashimoto, Masao; Tajima, Fukue; Eda, Kazuo; Yamamura, Kimiaki; Okazaki, Tadashi; Journal of Molecular Structure 734 (2005) 23–33; doi:10.1016/j.molstruc.2004.08.008

data_1100998
_publ_section_title
;
 Exploration of plastic-like phases in alkylurea systems.
 A thermal and X-ray study
;
_journal_issue                   1-3
_journal_name_full               'Journal of Molecular Structure'
_journal_page_first              23
_journal_page_last               33
_journal_paper_doi               10.1016/j.molstruc.2004.08.008
_journal_volume                  734
_journal_year                    2005
_chemical_formula_moiety         'C8 H18 N2 O'
_chemical_formula_sum            'C8 H18 N2 O'
_chemical_formula_weight         158.24
_chemical_melting_point          386.1
_chemical_name_common            n-heptylurea
_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
_cell_angle_alpha                90.00
_cell_angle_beta                 102.426(4)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   14.407(4)
_cell_length_b                   7.5290(18)
_cell_length_c                   9.318(2)
_cell_measurement_reflns_used    1193
_cell_measurement_temperature    296(2)
_cell_measurement_theta_max      22.997
_cell_measurement_theta_min      2.390
_cell_volume                     987.1(4)
_diffrn_ambient_temperature      296(2)
_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  0.0779
_diffrn_reflns_av_sigmaI/netI    0.0736
_diffrn_reflns_limit_h_max       13
_diffrn_reflns_limit_h_min       -18
_diffrn_reflns_limit_k_max       9
_diffrn_reflns_limit_k_min       -9
_diffrn_reflns_limit_l_max       11
_diffrn_reflns_limit_l_min       -11
_diffrn_reflns_number            5494
_diffrn_reflns_theta_max         27.43
_diffrn_reflns_theta_min         2.90
_exptl_absorpt_coefficient_mu    0.071
_exptl_absorpt_correction_T_max  1.000000
_exptl_absorpt_correction_T_min  -0.129001
_exptl_absorpt_correction_type   empirical
_exptl_absorpt_process_details   'program SADABS ver. 2.03(Sheldrick)'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.065
_exptl_crystal_density_method    'not measured'
_exptl_crystal_F_000             352
_exptl_crystal_size_max          0.67
_exptl_crystal_size_mid          0.54
_exptl_crystal_size_min          0.07
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.897
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     161
_refine_ls_number_reflns         2058
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.897
_refine_ls_R_factor_all          0.1446
_refine_ls_R_factor_gt           0.0786
_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^)+(0.1281P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1945
_refine_ls_wR_factor_ref         0.2253
_reflns_number_gt                971
_reflns_number_total             2058
_reflns_threshold_expression     >2sigma(I)
_cod_original_sg_symbol_H-M      'P 21/c'
_cod_database_code               1100998