Characterization of two conformers in the co-ordination chemistry of 3,4-bis(cyanamido)cyclobutane-1,2-dione dianion: syntheses, crystal structures, and electrochemical study of nickel(ii) complexes
Galibert, Anne Marie; Cortadellas, Olivier; Soula, Brigitte; Donnadieu, Bruno; Fabre, Paul-Louis; Journal of the Chemical Society, Dalton Transactions  (2002) 3743–; doi:10.1039/b202085h

data_7011595
_publ_section_title
;
 Characterization of two conformers in the co-ordination chemistry of
 3,4-bis(cyanamido)cyclobutane-1,2-dione dianion: syntheses, crystal
 structures, and electrochemical study of nickel(ii) complexes
;
_journal_issue                   19
_journal_name_full
'Journal of the Chemical Society, Dalton Transactions'
_journal_page_first              3743
_journal_paper_doi               10.1039/b202085h
_journal_year                    2002
_chemical_formula_sum            'C18 H20 N12 Ni O4'
_chemical_formula_weight         527.17
_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                70.385(12)
_cell_angle_beta                 84.461(13)
_cell_angle_gamma                74.842(13)
_cell_formula_units_Z            2
_cell_length_a                   8.9936(10)
_cell_length_b                   10.8364(12)
_cell_length_c                   12.3532(13)
_cell_measurement_reflns_used    5000
_cell_measurement_temperature    160(2)
_cell_measurement_theta_max      25.89
_cell_measurement_theta_min      2.2
_cell_volume                     1094.6(2)
_computing_cell_refinement       'Stoe IPDS software (Stoe, 1996)'
_computing_data_collection       'Stoe IPDS software (Stoe, 1996)'
_computing_data_reduction        'XRED (Stoe, 1.08, 1996)'
_computing_molecular_graphics    'ORTEP3 for Windows (Farrugia, 1997)'
_computing_publication_material  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SIR92 (Giacovazzo et al, 1992)'
_diffrn_ambient_temperature      160(2)
_diffrn_measured_fraction_theta_full 0.924
_diffrn_measured_fraction_theta_max 0.924
_diffrn_measurement_device       'Stoe IPDS'
_diffrn_measurement_method       \f
_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  0.0356
_diffrn_reflns_av_sigmaI/netI    0.0263
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       13
_diffrn_reflns_limit_k_min       -13
_diffrn_reflns_limit_l_max       15
_diffrn_reflns_limit_l_min       -15
_diffrn_reflns_number            10615
_diffrn_reflns_theta_full        25.89
_diffrn_reflns_theta_max         25.89
_diffrn_reflns_theta_min         2.23
_diffrn_standards_decay_%        <0.1
_diffrn_standards_interval_time  'every frame'
_diffrn_standards_number         200
_exptl_absorpt_coefficient_mu    0.942
_exptl_absorpt_correction_T_max  0.2828
_exptl_absorpt_correction_T_min  0.471
_exptl_absorpt_correction_type   semi-empirical
_exptl_crystal_colour            green
_exptl_crystal_density_diffrn    1.600
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       rod
_exptl_crystal_F_000             544
_exptl_crystal_size_max          0.65
_exptl_crystal_size_mid          0.22
_exptl_crystal_size_min          0.10
_refine_diff_density_max         0.392
_refine_diff_density_min         -0.316
_refine_diff_density_rms         0.057
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.065
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     348
_refine_ls_number_reflns         3925
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.065
_refine_ls_R_factor_all          0.0316
_refine_ls_R_factor_gt           0.0268
_refine_ls_shift/su_max          0.005
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0395P)^2^+0.4270P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0681
_refine_ls_wR_factor_ref         0.0706
_reflns_number_gt                3488
_reflns_number_total             3925
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b202085h.txt
_cod_data_source_block           (1)
_cod_original_sg_symbol_H-M      P-1
_cod_database_code               7011595
_computing_corr_abs              DIFABS