A quadruply-bonded [Cr2(guanidinate)4]4? tetraanion
Joanna Haywood; Francesca A. Stokes; Robert J. Less; Mary McPartlin; Andrew E. H. Wheatley; Dominic S. Wright; Chem.Commun. 47 (2011) 4120–; doi:10.1039/c1cc10194c

data_7106204
_publ_section_title
;
 A quadruply-bonded [Cr2(guanidinate)4]4? tetraanion
;
_journal_name_full               Chem.Commun.
_journal_page_first              4120
_journal_paper_doi               10.1039/c1cc10194c
_journal_volume                  47
_journal_year                    2011
_chemical_formula_moiety         'C12 H28 Cr2 N8'
_chemical_formula_sum            'C12 H28 Cr2 N8'
_chemical_formula_weight         388.42
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2ybc'
_symmetry_space_group_name_H-M   'P 1 21/c 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 106.181(1)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   8.4194(3)
_cell_length_b                   7.4038(2)
_cell_length_c                   15.0492(6)
_cell_measurement_reflns_used    4464
_cell_measurement_temperature    180(2)
_cell_measurement_theta_max      27.48
_cell_measurement_theta_min      1.02
_cell_volume                     900.94(5)
_computing_cell_refinement       'HKL Scalepack (Otwinowski & Minor 1997)'
_computing_data_collection       'Collect (Nonius B.V. 1998)'
_computing_data_reduction
;
HKL Denzo and Scalepack (Otwinowski & Minor 1997)
;
_computing_publication_material  'SHELXL-97 (Sheldrick 1997)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick 1997)'
_computing_structure_solution    'SIR-92 (Altomare et al. 1994)'
_diffrn_ambient_temperature      180(2)
_diffrn_measured_fraction_theta_full 0.990
_diffrn_measured_fraction_theta_max 0.990
_diffrn_measurement_device_type  'Nonius Kappa CCD'
_diffrn_measurement_method       'Thin slice \w and \f scans'
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0378
_diffrn_reflns_av_sigmaI/netI    0.0420
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       9
_diffrn_reflns_limit_k_min       -9
_diffrn_reflns_limit_l_max       19
_diffrn_reflns_limit_l_min       -16
_diffrn_reflns_number            6533
_diffrn_reflns_theta_full        27.44
_diffrn_reflns_theta_max         27.44
_diffrn_reflns_theta_min         3.73
_exptl_absorpt_coefficient_mu    1.215
_exptl_absorpt_correction_T_max  0.978
_exptl_absorpt_correction_T_min  0.834
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
multi-scan from symmetry-related measurements
Sortav (Blessing 1995)
;
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.432
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             408
_exptl_crystal_size_max          0.23
_exptl_crystal_size_mid          0.05
_exptl_crystal_size_min          0.02
_refine_diff_density_max         0.314
_refine_diff_density_min         -0.312
_refine_diff_density_rms         0.059
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.028
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     106
_refine_ls_number_reflns         2045
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.028
_refine_ls_R_factor_all          0.0444
_refine_ls_R_factor_gt           0.0319
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0496P)^2^+0.1049P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0836
_refine_ls_wR_factor_ref         0.0882
_reflns_number_gt                1665
_reflns_number_total             2045
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c1cc10194c.txt
_cod_data_source_block           dw1050
_cod_original_sg_symbol_H-M      P2(1)/c
_cod_database_code               7106204