Onset of three-centre, four-electron bonding in peri-substituted acenaphthenes: A structural and computational investigation.
Aschenbach, Lara K.; Knight, Fergus R.; Randall, Rebecca A. M.; Cordes, David B.; Baggott, Alex; Bühl, Michael; Slawin, Alexandra M. Z.; Woollins, J. Derek; Dalton transactions (Cambridge, England : 2003) 41 (2012) 3141–3153; doi:10.1039/c1dt11697e

data_7018104
_publ_section_title
;
 Onset of three-centre, four-electron bonding in peri-substituted
 acenaphthenes: A structural and computational investigation.
;
_journal_issue                   11
_journal_name_full
'Dalton transactions (Cambridge, England : 2003)'
_journal_page_first              3141
_journal_page_last               3153
_journal_paper_doi               10.1039/c1dt11697e
_journal_volume                  41
_journal_year                    2012
_chemical_formula_moiety         'C24 H18 Se2'
_chemical_formula_sum            'C24 H18 Se2'
_chemical_formula_weight         464.33
_space_group_IT_number           29
_symmetry_cell_setting           orthorhombic
_symmetry_Int_Tables_number      29
_symmetry_space_group_name_Hall  'P 2c -2ac'
_symmetry_space_group_name_H-M   'P c a 21'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_cell_angle_alpha                90.0000
_cell_angle_beta                 90.0000
_cell_angle_gamma                90.0000
_cell_formula_units_Z            4
_cell_length_a                   22.1470(15)
_cell_length_b                   5.221(4)
_cell_length_c                   15.829(7)
_cell_measurement_reflns_used    5762
_cell_measurement_temperature    93
_cell_measurement_theta_max      25.35
_cell_measurement_theta_min      3.16
_cell_volume                     1830.3(16)
_computing_cell_refinement       'CrystalClear-SM Expert 2.0 rc13'
_computing_data_collection
'CrystalClear-SM Expert 2.0 rc13 (Rigaku, 2009)'
_computing_data_reduction        'CrystalClear-SM Expert 2.0 rc13'
_computing_molecular_graphics    'CrystalStructure 4.0'
_computing_publication_material  'CrystalStructure 4.0 (Rigaku, 2010)'
_computing_structure_refinement  'SHELXL97 (Sheldrick, 2008)'
_computing_structure_solution    SIR97
_diffrn_ambient_temperature      93
_diffrn_detector_area_resol_mean 14.629
_diffrn_measured_fraction_theta_full 0.994
_diffrn_measured_fraction_theta_max 0.994
_diffrn_measurement_device_type  'Rigaku Mercury70'
_diffrn_measurement_method       \w
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.71075
_diffrn_reflns_av_R_equivalents  0.0591
_diffrn_reflns_limit_h_max       26
_diffrn_reflns_limit_h_min       -17
_diffrn_reflns_limit_k_max       6
_diffrn_reflns_limit_k_min       -6
_diffrn_reflns_limit_l_max       17
_diffrn_reflns_limit_l_min       -18
_diffrn_reflns_number            10530
_diffrn_reflns_theta_full        25.35
_diffrn_reflns_theta_max         25.35
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    4.045
_exptl_absorpt_correction_T_max  0.960
_exptl_absorpt_correction_T_min  0.656
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'REQAB (Rigaku, 1998)'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.685
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       platelet
_exptl_crystal_F_000             920.00
_exptl_crystal_size_max          0.200
_exptl_crystal_size_mid          0.100
_exptl_crystal_size_min          0.010
_refine_diff_density_max         0.590
_refine_diff_density_min         -0.670
_refine_ls_abs_structure_details
'Flack, H. D. (1983), Acta Cryst. A39, 876-881. 1464 Friedel Pairs'
_refine_ls_abs_structure_Flack   0.011(18)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.765
_refine_ls_hydrogen_treatment    constr
_refine_ls_number_parameters     235
_refine_ls_number_reflns         3200
_refine_ls_number_restraints     1
_refine_ls_R_factor_gt           0.0406
_refine_ls_shift/su_max          0.002
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w = 1/[\s^2^(Fo^2^)+(0.0508P)^2^+5.9943P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_ref         0.0943
_reflns_number_gt                2771
_reflns_number_total             3200
_reflns_threshold_expression     F^2^>2.0\s(F^2^)
_cod_data_source_file            c1dt11697e.txt
_cod_data_source_block           LARA3n
_cod_original_cell_volume        1830.3(15)
_cod_database_code               7018104