Cycloaddition reaction of tert-butyl isocyanate and a tellurium diimide dimer: extended helical structure of the ureato telluroxide {[OC(μ-NBut)2TeO]2(thf)}∞
Schatte, Gabriele; Chivers, Tristram; Jaska, Cory; Sandblom, Nicole; Chemical Communications  (2000) 1657–; doi:10.1039/b004137h

data_7111014
_publ_section_title
;
 Cycloaddition reaction of tert-butyl isocyanate and a tellurium diimide
 dimer: extended helical structure of the ureato telluroxide
 {[OC(\m-NBut)2TeO]2(thf)}\\infty
;
_journal_issue                   17
_journal_name_full               'Chemical Communications'
_journal_page_first              1657
_journal_paper_doi               10.1039/b004137h
_journal_year                    2000
_chemical_formula_moiety         'C18 H36 N4 O4 Te2, C4 H8 O'
_chemical_formula_sum            'C22 H44 N4 O5 Te2'
_chemical_formula_weight         699.81
_space_group_IT_number           92
_symmetry_cell_setting           tetragonal
_symmetry_space_group_name_Hall  'P 4abw 2nw'
_symmetry_space_group_name_H-M   'P 41 21 2'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           'manual editing of SHELXL template'
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   15.5941(7)
_cell_length_b                   15.5941(7)
_cell_length_c                   12.4867(8)
_cell_measurement_reflns_used    8192
_cell_measurement_temperature    193(2)
_cell_volume                     3036.5(3)
_computing_cell_refinement       'Bruker SAINT'
_computing_data_collection       'Bruker SMART'
_computing_data_reduction        'Bruker SHELXTL'
_computing_molecular_graphics    'ORTEP-3 (1.05) in WinGX-1.62'
_computing_publication_material  WinGX-1.62
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    SIR-97
_diffrn_ambient_temperature      193(2)
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_device_type  'CCD area detector'
_diffrn_measurement_method       'phi and omega scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus rotating anode'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0399
_diffrn_reflns_av_sigmaI/netI    0.0190
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       18
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       14
_diffrn_reflns_limit_l_min       0
_diffrn_reflns_number            13101
_diffrn_reflns_theta_full        24.71
_diffrn_reflns_theta_max         24.71
_diffrn_reflns_theta_min         1.85
_diffrn_standards_decay_%        'no decay'
_exptl_absorpt_coefficient_mu    1.955
_exptl_absorpt_correction_T_max  0.7580
_exptl_absorpt_correction_T_min  0.6304
_exptl_absorpt_correction_type   empirical
_exptl_absorpt_process_details
;SADABS, V 2.01, Software for Area-Detector Absorption
  Corrections; Bruker AXS Inc., Madison, WI, 2000. 
;
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.531
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             1392
_exptl_crystal_size_max          0.26
_exptl_crystal_size_mid          0.23
_exptl_crystal_size_min          0.15
_refine_diff_density_max         0.143
_refine_diff_density_min         -0.222
_refine_diff_density_rms         0.042
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.01(2)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.024
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     178
_refine_ls_number_reflns         2593
_refine_ls_number_restraints     44
_refine_ls_restrained_S_all      1.022
_refine_ls_R_factor_all          0.0188
_refine_ls_R_factor_gt           0.0164
_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^)+(0.0250P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0405
_refine_ls_wR_factor_ref         0.0413
_reflns_number_gt                2410
_reflns_number_total             2593
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b004137hsup1.cif
_cod_data_source_block           cal9972
_cod_database_code               7111014