Cerium-based triple-stranded helicates as luminescent chemosensors for the selective sensing of magnesium ions.
Zhu, Xiang; He, Cheng; Dong, Dapeng; Liu, Yang; Duan, Chunying; Dalton transactions (Cambridge, England : 2003) 39 (2010) 10051–10055; doi:10.1039/c002278k

data_7025619
_publ_section_title
;
 Cerium-based triple-stranded helicates as luminescent chemosensors for
 the selective sensing of magnesium ions.
;
_journal_issue                   42
_journal_name_full
'Dalton transactions (Cambridge, England : 2003)'
_journal_page_first              10051
_journal_page_last               10055
_journal_paper_doi               10.1039/c002278k
_journal_volume                  39
_journal_year                    2010
_chemical_formula_moiety         'C51 H42 Ce2 N12 O12. 6(C H4 O). 6(H2 O)'
_chemical_formula_sum            'C57 H78 Ce2 N12 O24'
_chemical_formula_weight         1595.21
_chemical_name_systematic
;
?
;
_space_group_IT_number           167
_symmetry_cell_setting           rhombohedral
_symmetry_space_group_name_Hall  '-R 3 2"c'
_symmetry_space_group_name_H-M   'R -3 c :H'
_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                120.00
_cell_formula_units_Z            6
_cell_length_a                   14.5854(4)
_cell_length_b                   14.5854(4)
_cell_length_c                   54.524(4)
_cell_measurement_temperature    298(2)
_cell_volume                     10045.1(8)
_computing_cell_refinement       'Bruker SMART'
_computing_data_collection       'Bruker SMART'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'Bruker SHELXTL'
_computing_structure_solution    'Bruker SHELXTL'
_diffrn_ambient_temperature      298(2)
_diffrn_measured_fraction_theta_full 0.990
_diffrn_measured_fraction_theta_max 0.990
_diffrn_measurement_device_type  'CCD area detector'
_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  0.0366
_diffrn_reflns_av_sigmaI/netI    0.0353
_diffrn_reflns_limit_h_max       0
_diffrn_reflns_limit_h_min       -16
_diffrn_reflns_limit_k_max       0
_diffrn_reflns_limit_k_min       -16
_diffrn_reflns_limit_l_max       0
_diffrn_reflns_limit_l_min       -70
_diffrn_reflns_number            2575
_diffrn_reflns_theta_full        27.61
_diffrn_reflns_theta_max         27.61
_diffrn_reflns_theta_min         2.24
_exptl_absorpt_coefficient_mu    1.423
_exptl_absorpt_correction_T_max  0.7643
_exptl_absorpt_correction_T_min  0.6362
_exptl_absorpt_correction_type   empirical
_exptl_absorpt_process_details   SADABS
_exptl_crystal_colour            black
_exptl_crystal_density_diffrn    1.515
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             4872
_exptl_crystal_size_max          0.35
_exptl_crystal_size_mid          0.22
_exptl_crystal_size_min          0.20
_platon_squeeze_details
;

With Z = 36 in space group R-3c this would correspond with approximately 25
electrons per asymmetric unit.
The asymmetric unit has 1/6 of the metal complex and has crystallograpgically
imposed 32 symmetry
A formulation with 1 methanol amd 1 water per asymmetric unit would correspond
with CH~4~O.H~2~O or CH~6~O~2~ which would have 28 electrons
per asymmetric unit.
Accordingly the overall formula would then be reported as:
'C57 H42 Ce2 N12 O22'. 6(C H4 O). 6(H2 O)' with a formula weight of 1595.21

;
_refine_diff_density_max         0.662
_refine_diff_density_min         -0.829
_refine_diff_density_rms         0.081
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.116
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     117
_refine_ls_number_reflns         2575
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.116
_refine_ls_R_factor_all          0.0971
_refine_ls_R_factor_gt           0.0536
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0803P)^2^+21.1945P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1585
_refine_ls_wR_factor_ref         0.1898
_reflns_number_gt                1290
_reflns_number_total             2575
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c002278k.txt
_cod_data_source_block           ref2278ksq
_cod_depositor_comments
;
The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Rhombohedral' changed to
'rhombohedral' according to
/home/saulius/struct/CIF-dictionaries/cif_core.dic dictionary named
'cif_core.dic' version 2.4.2 from 2011-04-26.

Automatic conversion script
Id: cif_fix_values 1891 2012-01-12 08:04:46Z andrius 

The following automatic conversions were performed:

'_refine_ls_hydrogen_treatment' value 'const' was replaced with the
value 'constr' as specified in the replacement file
'src/cod-tools/trunk/data/replacement-values/replacement_values.lst'.

Automatic conversion script
Id: cif_fix_values 5376 2017-05-30 11:51:03Z andrius 
;
_cod_original_sg_symbol_H-M      'R -3 c'
_cod_database_code               7025619