After 155 Years, A Crystalline Chromium Carboxylate with a Supershort Cr-Cr Bond
F. Albert Cotton; Elizabeth A. Hillard; Carlos A. Murillo; Hong-Cai Zhou; Journal of the American Chemical Society 122 (2000) 416–417; doi:10.1021/ja993755i

data_4115886
_publ_section_title
;
 After 155 Years, A Crystalline Chromium Carboxylate with a Supershort
 Cr-Cr Bond
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              416
_journal_page_last               417
_journal_paper_doi               10.1021/ja993755i
_journal_volume                  122
_journal_year                    2000
_chemical_compound_source        synthesized
_chemical_formula_moiety         'Cr2 (C16 H23 O2)4'
_chemical_formula_structural     'Cr2 (TiPBA)4'
_chemical_formula_sum            'C64 H92 Cr2 O8'
_chemical_formula_weight         1093.38
_chemical_name_common            none
_chemical_name_systematic
;
 Tetrakis(2,4,6-triisopropylbenzoicactato)dichromium(II)
;
_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
_cell_angle_alpha                70.8990(10)
_cell_angle_beta                 70.6910(10)
_cell_angle_gamma                76.1150(10)
_cell_formula_units_Z            1
_cell_length_a                   9.7448(6)
_cell_length_b                   11.7879(7)
_cell_length_c                   14.6524(11)
_cell_measurement_reflns_used    7614
_cell_measurement_temperature    110(2)
_cell_measurement_theta_max      28.66
_cell_measurement_theta_min      2.339
_cell_volume                     1484.52(17)
_computing_cell_refinement       'Siemens XSCANS'
_computing_data_collection       'Siemens XSCANS'
_computing_data_reduction        'Siemens SHELXTL'
_computing_molecular_graphics    'Siemens SHELXTL'
_computing_publication_material  Ciftab
_computing_structure_refinement  'SHELXL-93 (Sheldrick, 1993)'
_computing_structure_solution    'SHELXS-86 (Sheldrick, 1990)'
_diffrn_ambient_temperature      110(2)
_diffrn_measurement_device       'Smart CCD'
_diffrn_measurement_method       '\w 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  0.0433
_diffrn_reflns_av_sigmaI/netI    0.0278
_diffrn_reflns_limit_h_max       13
_diffrn_reflns_limit_h_min       -13
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -15
_diffrn_reflns_limit_l_max       19
_diffrn_reflns_limit_l_min       -19
_diffrn_reflns_number            26200
_diffrn_reflns_theta_max         28.71
_diffrn_reflns_theta_min         1.53
_diffrn_standards_decay_%        none
_diffrn_standards_interval_count none
_diffrn_standards_interval_time  none
_diffrn_standards_number         none
_exptl_absorpt_coefficient_mu    0.419
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            'orange yellow'
_exptl_crystal_density_diffrn    1.223
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    none
_exptl_crystal_description       plate
_exptl_crystal_F_000             588
_exptl_crystal_size_max          0.62
_exptl_crystal_size_mid          0.56
_exptl_crystal_size_min          0.21
_refine_diff_density_max         2.212
_refine_diff_density_min         -0.417
_refine_diff_density_rms         0.106
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_all   1.135
_refine_ls_goodness_of_fit_obs   1.167
_refine_ls_hydrogen_treatment    ref
_refine_ls_matrix_type           full
_refine_ls_number_parameters     510
_refine_ls_number_reflns         6989
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.135
_refine_ls_restrained_S_obs      1.167
_refine_ls_R_factor_all          0.0648
_refine_ls_R_factor_obs          0.0590
_refine_ls_shift/esd_max         0.085
_refine_ls_shift/esd_mean        0.012
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.1092P)^2^+0.3057P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_all         0.1597
_refine_ls_wR_factor_obs         0.1519
_reflns_number_observed          6052
_reflns_number_total             6989
_reflns_observed_criterion       >2sigma(I)
_cod_data_source_file            ja993755i_2.cif
_cod_data_source_block           xl_compound_1
_cod_depositor_comments
;
The following automatic conversions were performed:

'_exptl_crystal_density_meas' value 'none' was changed to '?' - the
value is perceived as not measured.

Automatic conversion script
Id: cif_fix_values 3008 2015-01-20 13:52:24Z robertas 

The following automatic conversions were performed:

'_refine_ls_weighting_scheme' value 'calc
w=1/[\s^2^(Fo^2^)+(0.1092P)^2^+0.3057P] where P=(Fo^2^+2Fc^2^)/3' was
changed to 'calc'. New tag '_refine_ls_weighting_details' was
created. The value of the new tag was set to
'w=1/[\s^2^(Fo^2^)+(0.1092P)^2^+0.3057P] where P=(Fo^2^+2Fc^2^)/3'.

Automatic conversion script
Id: cif_fix_values 3143 2015-03-26 13:38:13Z robertas 
;
_cod_original_cell_volume        1484.5(2)
_cod_database_code               4115886