data_2100450
loop_
_publ_author_name
'Barnett, Sarah A.'
'Broder, Charlotte K.'
'Shankland, Kenneth'
'David, Bill I. F.'
'Ibberson, Richard'
'Tocher, Derek A.'
_publ_section_title
;
Single crystal X-ray and neutron powder diffraction investigation of the
 phase transition in tetrachlorobenzene
;
_journal_coeditor_code         SO5001
_journal_date_accepted         2005-12-15
_journal_date_recd_electronic  2005-10-19
_journal_issue                 2
_journal_name_full             'Acta Crystallographica, Section B'
_journal_page_first            287
_journal_page_last             295
_journal_paper_category        FA
_journal_volume                62
_journal_year                  2006
_chemical_formula_moiety       'C6 Cl4 D2'
_chemical_formula_structural   'C6 D2 Cl4'
_chemical_formula_sum          'C6 Cl4 D2'
_chemical_formula_weight       217.88
_chemical_melting_point        ?
_chemical_name_common          '1,2,4,5-tetrachlorobenzene - beta polymorph'
_chemical_name_systematic
;
1,2,4,5-tetrachlorobenzene
;
_symmetry_cell_setting         Monoclinic
_symmetry_space_group_name_Hall ?
_symmetry_space_group_name_H-M P21/n
_cell_angle_alpha              90
_cell_angle_beta               99.7184(6)
_cell_angle_gamma              90
_cell_formula_units_Z          2
_cell_length_a                 3.78988(4)
_cell_length_b                 10.50328(5)
_cell_length_c                 9.56244(3)
_cell_measurement_reflns_used  1003
_cell_measurement_temperature  150(2)
_cell_measurement_theta_max    ?
_cell_measurement_theta_min    ?
_cell_volume                   375.182(5)
_computing_data_collection     'custom ISIS software'
_computing_data_reduction      'custom ISIS software'
_computing_structure_refinement 'Topas v3.1 (Coehlo, 2003)'
_computing_structure_solution  ?
_diffrn_ambient_temperature    150(2)
_diffrn_measurement_device_type 'HRPD, ISIS'
_diffrn_radiation_monochromator ?
_diffrn_radiation_type         Neutron
_diffrn_radiation_wavelength   ?
_diffrn_reflns_limit_h_max     5
_diffrn_reflns_limit_h_min     0
_diffrn_reflns_limit_k_max     14
_diffrn_reflns_limit_k_min     -14
_diffrn_reflns_limit_l_max     12
_diffrn_reflns_limit_l_min     -13
_diffrn_reflns_number          1003
_exptl_absorpt_coefficient_mu  0.51
_exptl_absorpt_correction_T_max ?
_exptl_absorpt_correction_T_min ?
_exptl_absorpt_correction_type empirical
_exptl_absorpt_process_details
;
Mu = 0.51cm^-1^ at 1.8\A
calculated using custom ISIS software program Arial Mucalc
;
_exptl_crystal_density_diffrn  ?
_exptl_crystal_density_meas    ?
_exptl_crystal_density_method  'not measured'
_exptl_crystal_F_000           ?
_refine_diff_density_max       ?
_refine_diff_density_min       ?
_refine_ls_extinction_coef     ?
_refine_ls_extinction_method   none
_refine_ls_goodness_of_fit_all 1.324
_refine_ls_hydrogen_treatment  refxyz
_refine_ls_matrix_type         sparse
_refine_ls_number_constraints  2
_refine_ls_number_parameters   37
_refine_ls_number_restraints   11
_refine_ls_shift/su_max        0.001
_refine_ls_weighting_details   ?
_refine_ls_weighting_scheme    sigma
loop_
_symmetry_equiv_pos_site_id
_symmetry_equiv_pos_as_xyz
1 x,y,z
2 1/2-x,1/2+y,1/2-z
3 -x,-y,-z
4 1/2+x,1/2-y,1/2+z
loop_
_atom_site_type_symbol
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_U_iso_or_equiv
_atom_site_adp_type
_atom_site_calc_flag
_atom_site_occupancy
_atom_site_disorder_assembly
_atom_site_disorder_group
C C1b 0.0694(4) 0.46706(9) 0.36565(8) 1.73(2) Biso d 1 . .
C C2b -0.0187(5) 0.37303(12) 0.45853(8) 1.73(2) Biso d 1 . .
C C3b 0.0952(5) 0.59312(13) 0.40974(8) 1.73(2) Biso d 1 . .
Cl Cl1b 0.1517(5) 0.42866(10) 0.19978(10) 2.33(2) Biso d 1 . .
Cl Cl2b -0.0446(5) 0.21599(11) 0.40673(10) 2.33(2) Biso d 1 . .
D H1b 0.1536(6) 0.66714(12) 0.33803(13) 2.83(5) Biso d 1 . .
loop_
_atom_type_symbol
_atom_type_description
_atom_type_scat_dispersion_real
_atom_type_scat_dispersion_imag
_atom_type_scat_source
C C 0.0000 0.0000 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
H H 0.0000 0.0000 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
Cl Cl 0.0000 0.0000 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
loop_
_geom_angle_atom_site_label_1
_geom_angle_atom_site_label_2
_geom_angle_atom_site_label_3
_geom_angle_site_symmetry_1
_geom_angle_site_symmetry_2
_geom_angle_site_symmetry_3
_geom_angle
_geom_angle_publ_flag
Cl1b C1b C2b . . . 121.24(8) ?
Cl1b C1b C3b . . . 119.38(9) ?
C2b C1b C3b . . . 119.37(9) ?
Cl2b C2b C1b . . . 119.99(8) ?
Cl2b C2b C3b . . 3_566 119.82(11) ?
C1b C2b C3b . . 3_566 120.17(11) ?
C1b C3b C2b . . 3_566 120.40(11) ?
C1b C3b H1b . . . 120.23(11) ?
H1b C3b C2b . . 3_566 119.17(14) ?
loop_
_geom_bond_atom_site_label_1
_geom_bond_atom_site_label_2
_geom_bond_site_symmetry_1
_geom_bond_site_symmetry_2
_geom_bond_distance
_geom_bond_publ_flag
Cl1b C1b . . 1.7154(14) ?
Cl2b C2b . . 1.7202(17) ?
C1b C2b . . 1.4056(15) ?
C1b C3b . . 1.3880(16) ?
C2b C3b . 3_566 1.3858(14) ?
C3b H1b . . 1.0839(19) ?
loop_
_geom_torsion_atom_site_label_1
_geom_torsion_atom_site_label_2
_geom_torsion_atom_site_label_3
_geom_torsion_atom_site_label_4
_geom_torsion_site_symmetry_1
_geom_torsion_site_symmetry_2
_geom_torsion_site_symmetry_3
_geom_torsion_site_symmetry_4
_geom_torsion
_geom_torsion_publ_flag
Cl1b C1b C2b Cl2b . . . . 0.2(2) ?
Cl1b C1b C2b C3b . . . 3_566 -177.94(15) ?
C3b C1b C2b Cl2b . . . . -178.93(15) ?
C3b C1b C2b C3b . . . 3_566 3.0(2) ?
Cl1b C1b C3b C2b . . . 3_566 177.91(15) ?
C2b C1b C3b C2b . . . 3_566 -3.0(2) ?
Cl2b C2b C3b C1b . . 3_566 3_566 178.90(14) ?
C1b C2b C3b C1b . . 3_566 3_566 -3.0(3) ?
Cl1b C1b C3b H1b . . . . 3.1(3) ?
C2b C1b C3b H1b . . . . -177.8(2) ?
Cl2b C2b C3b H1b . . 3_566 3_566 4.0(3) ?
C1b C2b C3b H1b . . 3_566 3_566 -177.9(2) ?