Twisting the arm: structural constraints in bicyclic expanded-ring N-heterocyclic carbenes.
Sampford, Katharine R.; Carden, Jamie L.; Kidner, Edward B.; Berry, Abigail; Cavell, Kingsley J.; Murphy, Damien M.; Kariuki, Benson M.; Newman, Paul D.; Dalton transactions (Cambridge, England : 2003) 48 (2019) 1850–1858; doi:10.1039/c8dt04462g

data_7048666
_publ_section_title
;
 Twisting the arm: structural constraints in bicyclic expanded-ring
 N-heterocyclic carbenes.
;
_journal_issue                   5
_journal_name_full
'Dalton transactions (Cambridge, England : 2003)'
_journal_page_first              1850
_journal_page_last               1858
_journal_paper_doi               10.1039/c8dt04462g
_journal_volume                  48
_journal_year                    2019
_chemical_absolute_configuration ad
_chemical_formula_moiety         'C21 H25 Au Cl N3'
_chemical_formula_sum            'C21 H25 Au Cl N3'
_chemical_formula_weight         551.86
_space_group_crystal_system      orthorhombic
_space_group_IT_number           19
_space_group_name_Hall           'P 2ac 2ab'
_space_group_name_H-M_alt        'P 21 21 21'
_symmetry_space_group_name_Hall  'P 2ac 2ab'
_symmetry_space_group_name_H-M   'P 21 21 21'
_atom_sites_solution_hydrogens   geom
_audit_creation_method           SHELXL-2018/1
_audit_update_record
;
2018-12-10 deposited with the CCDC.
2018-12-11 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            8
_cell_length_a                   20.5559(5)
_cell_length_b                   13.8353(4)
_cell_length_c                   14.0400(4)
_cell_measurement_reflns_used    11589
_cell_measurement_temperature    298(2)
_cell_measurement_theta_max      29.3430
_cell_measurement_theta_min      3.5910
_cell_volume                     3992.93(19)
_computing_cell_refinement       'CrysAlisPro 1.171.39.45b (Rigaku OD, 2018)'
_computing_data_collection       'CrysAlisPro 1.171.39.45b (Rigaku OD, 2018)'
_computing_data_reduction        'CrysAlisPro 1.171.39.45b (Rigaku OD, 2018)'
_computing_molecular_graphics    ORTEP-3
_computing_publication_material  WinGX
_computing_structure_refinement  SHELXL
_computing_structure_solution    SHELXS
_diffrn_ambient_temperature      298(2)
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 0.905
_diffrn_measurement_device_type  'SuperNova, Dual, Cu at home/near, Atlas'
_diffrn_measurement_method       '\w scans'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0313
_diffrn_reflns_av_unetI/netI     0.0500
_diffrn_reflns_Laue_measured_fraction_full 1.000
_diffrn_reflns_Laue_measured_fraction_max 0.905
_diffrn_reflns_limit_h_max       28
_diffrn_reflns_limit_h_min       -27
_diffrn_reflns_limit_k_max       19
_diffrn_reflns_limit_k_min       -17
_diffrn_reflns_limit_l_max       18
_diffrn_reflns_limit_l_min       -17
_diffrn_reflns_number            24636
_diffrn_reflns_point_group_measured_fraction_full 0.998
_diffrn_reflns_point_group_measured_fraction_max 0.849
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         29.677
_diffrn_reflns_theta_min         1.756
_exptl_absorpt_coefficient_mu    7.512
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.54916
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
CrysAlisPro 1.171.39.45b (Rigaku Oxford Diffraction, 2018)
Empirical absorption correction using spherical harmonics,
 implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.836
_exptl_crystal_description       plate
_exptl_crystal_F_000             2144
_exptl_crystal_size_max          0.347
_exptl_crystal_size_mid          0.204
_exptl_crystal_size_min          0.080
_refine_diff_density_max         1.017
_refine_diff_density_min         -0.977
_refine_diff_density_rms         0.157
_refine_ls_abs_structure_details
;
 Flack x determined using 3077 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   -0.026(5)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.017
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     475
_refine_ls_number_reflns         9615
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.017
_refine_ls_R_factor_all          0.0384
_refine_ls_R_factor_gt           0.0285
_refine_ls_shift/su_max          0.004
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0114P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0456
_refine_ls_wR_factor_ref         0.0498
_reflns_Friedel_coverage         0.704
_reflns_Friedel_fraction_full    0.995
_reflns_Friedel_fraction_max     0.779
_reflns_number_gt                8196
_reflns_number_total             9615
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            c8dt04462g2.cif
_cod_data_source_block           pdn1806b
_cod_depositor_comments
'Adding full bibliography for 7048655--7048669.cif.'
_cod_database_code               7048666
_shelx_shelxl_version_number     2018/1
_shelx_estimated_absorpt_t_min   0.180
_shelx_estimated_absorpt_t_max   0.585
_shelx_res_checksum              74626