Synthesis of highly hindered oxepins and an azepine from bis-trityl carbenium ions: structural characterisation by NMR and X-ray crystallography
Carey, Kieran A.; Clegg, William; Elsegood, Mark R. J.; Golding, Bernard T.; Stuart Hill, M. N.; Maskill, Howard; Journal of the Chemical Society, Perkin Transactions 1  (2002) 2673–; doi:10.1039/b207108h

data_7204497
_publ_section_title
;
 Synthesis of highly hindered oxepins and an azepine from bis-trityl
 carbenium ions: structural characterisation by NMR and X-ray
 crystallography
;
_journal_issue                   23
_journal_name_full
'Journal of the Chemical Society, Perkin Transactions 1'
_journal_page_first              2673
_journal_paper_doi               10.1039/b207108h
_journal_year                    2002
_chemical_formula_sum            'C42 H37 N O4'
_chemical_formula_weight         619.73
_chemical_name_systematic
;
?
;
_space_group_IT_number           5
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  'I 2y'
_symmetry_space_group_name_H-M   'I 1 2 1'
_atom_sites_solution_hydrogens   'geom except H1 coords freely refined'
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   'all non-H atoms found by direct methods'
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 91.406(4)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   9.8515(11)
_cell_length_b                   8.9880(10)
_cell_length_c                   17.9926(19)
_cell_measurement_reflns_used    3769
_cell_measurement_temperature    160(2)
_cell_measurement_theta_max      27.5
_cell_measurement_theta_min      2.0
_cell_volume                     1592.7(3)
_computing_cell_refinement       'local programs'
_computing_data_collection       'Stoe DIF4'
_computing_data_reduction        'local programs'
_computing_molecular_graphics    'Siemens SHELXTL'
_computing_publication_material  'SHELXTL and local programs'
_computing_structure_refinement  'Siemens SHELXTL'
_computing_structure_solution    'Siemens SHELXTL'
_diffrn_ambient_temperature      160(2)
_diffrn_measured_fraction_theta_full 0.986
_diffrn_measured_fraction_theta_max 0.986
_diffrn_measurement_device_type  'Stoe-Siemens diffractometer'
_diffrn_measurement_method       '\w/\q scans with on-line profile fitting'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54184
_diffrn_reflns_av_R_equivalents  0.0228
_diffrn_reflns_av_sigmaI/netI    0.0190
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       10
_diffrn_reflns_limit_k_min       -10
_diffrn_reflns_limit_l_max       21
_diffrn_reflns_limit_l_min       -21
_diffrn_reflns_number            3900
_diffrn_reflns_theta_full        67.61
_diffrn_reflns_theta_max         67.61
_diffrn_reflns_theta_min         4.92
_diffrn_standards_decay_%        2
_diffrn_standards_interval_time  60
_diffrn_standards_number         5
_exptl_absorpt_coefficient_mu    0.652
_exptl_absorpt_correction_T_max  0.918
_exptl_absorpt_correction_T_min  0.534
_exptl_absorpt_correction_type   empirical
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.292
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             656
_exptl_crystal_size_max          0.56
_exptl_crystal_size_mid          0.50
_exptl_crystal_size_min          0.25
_refine_diff_density_max         0.207
_refine_diff_density_min         -0.168
_refine_diff_density_rms         0.039
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.2(2)
_refine_ls_extinction_coef       0.0037(4)
_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   1.067
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     220
_refine_ls_number_reflns         2785
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.067
_refine_ls_R_factor_all          0.0390
_refine_ls_R_factor_gt           0.0388
_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^)+(0.0736P)^2^+0.5813P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1050
_refine_ls_wR_factor_ref         0.1051
_reflns_number_gt                2769
_reflns_number_total             2785
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b207108h.txt
_cod_data_source_block           hm15
_cod_original_sg_symbol_H-M      I2
_cod_database_code               7204497