Fine-tuning the energy barrier for metal-mediated dinitrogen n≡n bond cleavage.
Keane, Andrew J.; Yonke, Brendan L.; Hirotsu, Masakazu; Zavalij, Peter Y.; Sita, Lawrence R.; Journal of the American Chemical Society 136 (2014) 9906–9909; doi:10.1021/ja505309j

data_4122176
_publ_section_title
;
 Fine-tuning the energy barrier for metal-mediated dinitrogen n\\tb n bond
 cleavage.
;
_journal_issue                   28
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              9906
_journal_page_last               9909
_journal_paper_doi               10.1021/ja505309j
_journal_volume                  136
_journal_year                    2014
_chemical_formula_moiety         'C46 H68 N6 Nb2'
_chemical_formula_sum            'C46 H68 N6 Nb2'
_chemical_formula_weight         890.88
_chemical_name_common            cmpd_trans_4b
_chemical_name_systematic
;
cmpd_trans_4b
;
_space_group_crystal_system      orthorhombic
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_space_group_name_Hall           '-P 2ac 2ab'
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_symmetry_space_group_name_Hall  '-P 2ac 2ab'
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_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
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_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   16.5274(18)
_cell_length_b                   15.3353(17)
_cell_length_c                   17.1720(19)
_cell_measurement_reflns_used    14221
_cell_measurement_temperature    150(2)
_cell_measurement_theta_max      31.8
_cell_measurement_theta_min      2.2
_cell_volume                     4352.3(8)
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_computing_data_collection       'Apex2 (Bruker, 2010)'
_computing_data_reduction        'Apex2, Saint'
_computing_molecular_graphics    'XSHEL (Bruker, 2004)'
_computing_publication_material  'Apex2, SHELXL-2012'
_computing_structure_refinement  'ShelXL-2012 (Sheldrick, 2012)'
_computing_structure_solution    'ShelXS-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      150(2)
_diffrn_detector                 'CCD area detector'
_diffrn_detector_area_resol_mean 8.333
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_device_type  'Bruker Smart Apex II diffractometer'
_diffrn_measurement_method       '\f and \w scans'
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_diffrn_orient_matrix_UB_12      0.0042596
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_diffrn_orient_matrix_UB_22      0.0347858
_diffrn_orient_matrix_UB_23      -0.0322969
_diffrn_orient_matrix_UB_31      -0.0312533
_diffrn_orient_matrix_UB_32      -0.0493225
_diffrn_orient_matrix_UB_33      -0.0189501
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0410
_diffrn_reflns_av_unetI/netI     0.0241
_diffrn_reflns_Laue_measured_fraction_full 1.000
_diffrn_reflns_Laue_measured_fraction_max 1.000
_diffrn_reflns_limit_h_max       23
_diffrn_reflns_limit_h_min       -23
_diffrn_reflns_limit_k_max       21
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_diffrn_reflns_limit_l_min       -24
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_diffrn_reflns_point_group_measured_fraction_full 1.000
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_diffrn_reflns_theta_full        25.000
_diffrn_reflns_theta_max         29.998
_diffrn_reflns_theta_min         2.165
_diffrn_source                   'sealed tube'
_exptl_absorpt_coefficient_mu    0.565
_exptl_absorpt_correction_T_max  0.888
_exptl_absorpt_correction_T_min  0.809
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS (Sheldrick, 2008)'
_exptl_crystal_colour            orange
_exptl_crystal_density_diffrn    1.360
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             1872
_exptl_crystal_size_max          0.28
_exptl_crystal_size_mid          0.26
_exptl_crystal_size_min          0.21
_refine_diff_density_max         0.365
_refine_diff_density_min         -0.370
_refine_diff_density_rms         0.059
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.000
_refine_ls_hydrogen_treatment    refU
_refine_ls_matrix_type           full
_refine_ls_number_parameters     269
_refine_ls_number_reflns         6351
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.000
_refine_ls_R_factor_all          0.0311
_refine_ls_R_factor_gt           0.0234
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
;
 w=1/[\s^2^(Fo^2^)+(0.0100P)^2^+3.8300P]
 where P=(Fo^2^+2Fc^2^)/3
;
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0496
_refine_ls_wR_factor_ref         0.0533
_reflns_Friedel_coverage         0.000
_reflns_number_gt                5334
_reflns_number_total             6351
_reflns_threshold_expression     'I > 2\s(I)'
_iucr_refine_instructions_details 'See _shelx_res_file'
_cod_data_source_file            ja505309j_si_002.cif
_cod_data_source_block           cmpd_trans_4b
_cod_depositor_comments
;
The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Orthorhombic' changed to
'orthorhombic' according to
/usr/data/users/saulius/crontab/automatic-downloads/rss-feeds/ACS/lib/dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.2 from 2011-04-26.

Automatic conversion script
Id: cif_fix_values 2281 2013-09-26 08:29:07Z andrius 

 Adding full bibliography for 4122168--4122182.cif.
;
_cod_original_sg_symbol_H-M      Pbca
_cod_database_code               4122176
_shelx_estimated_absorpt_t_min   0.858
_shelx_estimated_absorpt_t_max   0.891
_iucr_refine_reflections_details 'Available on request'