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_4115885
_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 (C2 H3 O2)4 (C2 H3 N)2,2(C2 H3 N)'
_chemical_formula_structural     'Cr2 (O2CCH3)4 (CH3CN)2,2(CH3CN)'
_chemical_formula_sum            'C16 H24 Cr2 N4 O8'
_chemical_formula_weight         504.39
_chemical_name_systematic
;
 Tetrakisacetatodiacetonitriledichromium(II)
;
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2yn'
_symmetry_space_group_name_H-M   'P 1 21/n 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL
_cell_angle_alpha                90.00
_cell_angle_beta                 101.978(4)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   10.701(2)
_cell_length_b                   10.206(2)
_cell_length_c                   10.912(2)
_cell_measurement_reflns_used    4632
_cell_measurement_temperature    213(2)
_cell_measurement_theta_max      28.32
_cell_measurement_theta_min      2.43
_cell_volume                     1165.8(4)
_computing_cell_refinement       Saint
_computing_data_collection       SMART
_computing_data_reduction        Saint
_computing_molecular_graphics    'SHELXTL V.5 (Siemens, 1994)'
_computing_publication_material  CIFTAB
_computing_structure_refinement  'SHELXL-93 (Sheldrick, 1993)'
_computing_structure_solution    'SHELXTL V.5 (Siemens, 1994)'
_diffrn_ambient_temperature      213(2)
_diffrn_measurement_device       'Bruker SMART area detector'
_diffrn_measurement_method       'Ellipsoid-mask fitting'
_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  0.0464
_diffrn_reflns_av_sigmaI/netI    0.0387
_diffrn_reflns_limit_h_max       14
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       13
_diffrn_reflns_limit_k_min       -13
_diffrn_reflns_limit_l_max       14
_diffrn_reflns_limit_l_min       -14
_diffrn_reflns_number            7053
_diffrn_reflns_theta_max         28.47
_diffrn_reflns_theta_min         2.43
_diffrn_standards_decay_%        none
_diffrn_standards_interval_count none
_diffrn_standards_interval_time  none
_diffrn_standards_number         'none (area detector data)'
_exptl_absorpt_coefficient_mu    0.977
_exptl_absorpt_correction_T_max  0.69
_exptl_absorpt_correction_T_min  0.43
_exptl_absorpt_correction_type   muti-scan
_exptl_crystal_colour            red
_exptl_crystal_density_diffrn    1.437
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    none
_exptl_crystal_description       prism
_exptl_crystal_F_000             520
_exptl_crystal_size_max          0.36
_exptl_crystal_size_mid          0.28
_exptl_crystal_size_min          0.26
_refine_diff_density_max         1.071
_refine_diff_density_min         -0.545
_refine_diff_density_rms         0.091
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_all   1.096
_refine_ls_goodness_of_fit_obs   1.117
_refine_ls_hydrogen_treatment    ref
_refine_ls_matrix_type           full
_refine_ls_number_parameters     143
_refine_ls_number_reflns         2708
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.140
_refine_ls_restrained_S_obs      1.117
_refine_ls_R_factor_all          0.0695
_refine_ls_R_factor_obs          0.0527
_refine_ls_shift/esd_max         0.008
_refine_ls_shift/esd_mean        0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0759P)^2^+1.5885P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_all         0.1688
_refine_ls_wR_factor_obs         0.1458
_reflns_number_observed          2123
_reflns_number_total             2710
_reflns_observed_criterion       >2sigma(I)
_cod_data_source_file            ja993755i_1.cif
_cod_data_source_block           xl_compound_3
_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^)+(0.0759P)^2^+1.5885P] 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^)+(0.0759P)^2^+1.5885P] where P=(Fo^2^+2Fc^2^)/3'.

Automatic conversion script
Id: cif_fix_values 3143 2015-03-26 13:38:13Z robertas 
;
_cod_database_code               4115885