Self-assembly of tetrametallic square [Re4(CO)12Br4(μ-pz)4] (pz = pyrazine) from [Re(CO)4Br(pz)]. A mechanistic approach
T. Rajendran; Bala Manimaran; Fang-Yuan Lee; Po-Jui Chen; Su-Ching Lin; Gene-Hsiang Lee; Shie-Ming Peng; Yu-Ju Chen; Kuang-Lieh Lu; J. Chem. Soc., Dalton Trans.  (2001) 3346–3351; doi:10.1039/b101992i

data_7010665
_publ_section_title
;
 Self-assembly of tetrametallic square [Re4(CO)12Br4(\m-pz)4] (pz =
 pyrazine) from [Re(CO)4Br(pz)]. A mechanistic approach
;
_journal_issue                   22
_journal_name_full               'J. Chem. Soc., Dalton Trans.'
_journal_page_first              3346
_journal_page_last               3351
_journal_paper_doi               10.1039/b101992i
_journal_year                    2001
_chemical_formula_sum            'C34 H28 Br4 N8 O14 Re4'
_chemical_formula_weight         1837.08
_chemical_name_systematic
; 
? 
;
_space_group_IT_number           88
_symmetry_cell_setting           tetragonal
_symmetry_space_group_name_Hall  '-I 4ad'
_symmetry_space_group_name_H-M   'I 41/a :2'
_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                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   21.3363(5)
_cell_length_b                   21.3363(5)
_cell_length_c                   15.5207(6)
_cell_measurement_reflns_used    all
_cell_measurement_temperature    200(1)
_cell_measurement_theta_max      27.50
_cell_measurement_theta_min      2.51
_cell_volume                     7065.6(4)
_computing_cell_refinement       DENZO-SMN
_computing_data_collection       'NONIUS KappaCCD'
_computing_data_reduction        DENZO-SMN
_computing_molecular_graphics    SHELXTL
_computing_publication_material  SHELXTL
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      200(1)
_diffrn_measured_fraction_theta_full 0.997
_diffrn_measured_fraction_theta_max 0.997
_diffrn_measurement_device_type  'NONIUS KappaCCD'
_diffrn_measurement_method       'phi and omega 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  0.0556
_diffrn_reflns_av_sigmaI/netI    0.0395
_diffrn_reflns_limit_h_max       27
_diffrn_reflns_limit_h_min       -27
_diffrn_reflns_limit_k_max       27
_diffrn_reflns_limit_k_min       -27
_diffrn_reflns_limit_l_max       20
_diffrn_reflns_limit_l_min       -20
_diffrn_reflns_number            16937
_diffrn_reflns_theta_full        27.50
_diffrn_reflns_theta_max         27.50
_diffrn_reflns_theta_min         2.51
_diffrn_standards_decay_%        0
_exptl_absorpt_coefficient_mu    9.138
_exptl_absorpt_correction_T_max  0.228
_exptl_absorpt_correction_T_min  0.157
_exptl_absorpt_correction_type   multi-scan
_exptl_crystal_colour            orange-yellow
_exptl_crystal_density_diffrn    1.727
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             3360
_exptl_crystal_size_max          0.35
_exptl_crystal_size_mid          0.35
_exptl_crystal_size_min          0.25
_refine_diff_density_max         1.287
_refine_diff_density_min         -1.685
_refine_diff_density_rms         0.191
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.088
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     162
_refine_ls_number_reflns         4030
_refine_ls_number_restraints     6
_refine_ls_restrained_S_all      1.092
_refine_ls_R_factor_all          0.0713
_refine_ls_R_factor_gt           0.0483
_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^)+(0.0931P)^2^+42.4831P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1404
_refine_ls_wR_factor_ref         0.1674
_reflns_number_gt                2965
_reflns_number_total             4030
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b101992i.txt
_cod_data_source_block           ic8222
_cod_depositor_comments
;
The following automatic conversions were performed:
'_symmetry_cell_setting' value 'Tetragonal' changed to 'tetragonal'
according to '/home/saulius/struct/CIF-dictionaries/cif_core.dic'
dictionary named 'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_enum 1527 2010-12-29 10:47:43Z saulius 

The following automatic conversions were performed:

'_exptl_crystal_density_meas' value 'not_measured' 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 
;
_cod_original_sg_symbol_H-M      I4(1)/a
_cod_database_code               7010665