Is ferrocene more aromatic than benzene?
Laskoski, Matthew; Steffen, Winfried; Smith, Mark D.; Bunz, Uwe H. F.; Chemical Communications  (2001) 691–; doi:10.1039/b009696m

data_7114965
_publ_section_title
;
 Is ferrocene more aromatic than benzene?
;
_journal_issue                   8
_journal_name_full               'Chemical Communications'
_journal_page_first              691
_journal_paper_doi               10.1039/b009696m
_journal_year                    2001
_chemical_formula_sum            'C42 H41 Fe O1.25'
_chemical_formula_weight         621.60
_chemical_name_systematic
; 
? 
;
_space_group_IT_number           2
_symmetry_cell_setting           triclinic
_symmetry_space_group_name_Hall  '-P 1'
_symmetry_space_group_name_H-M   'P -1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                68.628(2)
_cell_angle_beta                 80.126(2)
_cell_angle_gamma                73.762(2)
_cell_formula_units_Z            4
_cell_length_a                   14.3045(13)
_cell_length_b                   14.9809(13)
_cell_length_c                   19.1578(17)
_cell_measurement_reflns_used    8282
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      24.292
_cell_measurement_theta_min      2.172
_cell_volume                     3659.5(6)
_computing_cell_refinement       'SAINT+ NT V6.02a (Bruker, 1998)'
_computing_data_collection       'SMART NT V5.619 (Bruker, 2000)'
_computing_data_reduction        'SAINT+ NT V6.02a'
_computing_molecular_graphics    'SHELXTL V5.1 (Sheldrick, 1997)'
_computing_publication_material  'SHELXTL V5.1'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.989
_diffrn_measured_fraction_theta_max 0.989
_diffrn_measurement_device_type  'Bruker SMART APEX CCD diffractometer'
_diffrn_measurement_method       'omega scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0441
_diffrn_reflns_av_sigmaI/netI    0.0679
_diffrn_reflns_limit_h_max       17
_diffrn_reflns_limit_h_min       -17
_diffrn_reflns_limit_k_max       17
_diffrn_reflns_limit_k_min       -17
_diffrn_reflns_limit_l_max       22
_diffrn_reflns_limit_l_min       -22
_diffrn_reflns_number            30460
_diffrn_reflns_theta_full        25.18
_diffrn_reflns_theta_max         25.18
_diffrn_reflns_theta_min         1.49
_diffrn_standards_decay_%        -0.5
_exptl_absorpt_coefficient_mu    0.442
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            red
_exptl_crystal_density_diffrn    1.128
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             1316
_exptl_crystal_size_max          0.48
_exptl_crystal_size_mid          0.34
_exptl_crystal_size_min          0.18
_refine_diff_density_max         0.993
_refine_diff_density_min         -0.343
_refine_diff_density_rms         0.083
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.016
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     794
_refine_ls_number_reflns         12983
_refine_ls_number_restraints     48
_refine_ls_restrained_S_all      1.017
_refine_ls_R_factor_all          0.1122
_refine_ls_R_factor_gt           0.0712
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
; calc 
[0.00000+1.00000exp(0.90(sin\q/\l)^2^)]/ 
[\s^2^(Fo^2^)+0.0000+0.0000*P+(0.1306P)^2^+0.0000sin\q/\l] 
where P = 0.33333Fo^2^ + 0.66667Fc^2^ 
;
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1962
_refine_ls_wR_factor_ref         0.2221
_reflns_number_gt                7496
_reflns_number_total             12983
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b009696m.txt
_cod_data_source_block           tbuf1t
_cod_original_sg_symbol_H-M      P-1
_cod_database_code               7114965