An Alternative Approach to Al202 Ring Systems by Unexpected Cleavage of Stable Al-F- and Si-O- Bonds
Carsten Rennekamp; Helge Wessel; Herbert W. Roesky; Peter Müller; Hans-Georg Schmidt; Mathias Noltemeyer; Isabel Usón; Andrew R. Barron; Inorganic Chemistry 38 (1999) 5235–5240; doi:10.1021/ic990185e

data_4322377
_publ_section_title
;
 An Alternative Approach to Al202 Ring Systems by Unexpected Cleavage of
 Stable Al-F- and Si-O- Bonds
;
_journal_name_full               'Inorganic Chemistry'
_journal_page_first              5235
_journal_page_last               5240
_journal_paper_doi               10.1021/ic990185e
_journal_volume                  38
_journal_year                    1999
_chemical_formula_sum            'C22 H54 Al2 O2 Si2'
_chemical_formula_weight         460.79
_chemical_name_systematic
; 
 compound 3 
;
_chemical_temperature_decomposition 433
_space_group_IT_number           61
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_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
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_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   17.090(2)
_cell_length_b                   10.260(2)
_cell_length_c                   17.521(4)
_cell_measurement_reflns_used    36
_cell_measurement_temperature    203(2)
_cell_measurement_theta_max      12.5
_cell_measurement_theta_min      10
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_computing_cell_refinement       'STOE DIF4'
_computing_data_collection       'STOE DIF4'
_computing_data_reduction        'STOE REDU4'
_computing_molecular_graphics    SHELXTL
_computing_publication_material  SHELXTL
_computing_structure_refinement  'SHELXL-93 (Sheldrick, 1993)'
_computing_structure_solution    'SHELXS-86 (Sheldrick, 1990)'
_diffrn_ambient_temperature      203(2)
_diffrn_measurement_device       'STOE AED2 four circle diffractometer'
_diffrn_measurement_method       'profile fitted theta 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  0.0422
_diffrn_reflns_av_sigmaI/netI    0.0680
_diffrn_reflns_limit_h_max       20
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_diffrn_reflns_limit_k_min       0
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_diffrn_reflns_theta_min         3.88
_diffrn_standards_decay_%        none
_diffrn_standards_interval_time  '90 min'
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    0.186
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            none
_exptl_crystal_density_diffrn    0.996
_exptl_crystal_density_meas      ?
_exptl_crystal_description       plates
_exptl_crystal_F_000             1024
_exptl_crystal_size_max          0.80
_exptl_crystal_size_mid          0.60
_exptl_crystal_size_min          0.30
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_refine_diff_density_min         -0.516
_refine_diff_density_rms         0.060
_refine_ls_extinction_method     none
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_refine_ls_goodness_of_fit_obs   1.051
_refine_ls_hydrogen_treatment    riding
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_refine_ls_restrained_S_obs      1.051
_refine_ls_R_factor_all          0.1168
_refine_ls_R_factor_obs          0.0725
_refine_ls_shift/esd_max         0.000
_refine_ls_shift/esd_mean        0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0415P)^2^+6.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_all         0.1903
_refine_ls_wR_factor_obs         0.1388
_reflns_number_observed          1784
_reflns_number_total             2676
_reflns_observed_criterion       >2sigma(I)
_cod_data_source_file            ic990185e_3.cif
_cod_data_source_block           roe753x
_cod_depositor_comments
;
The following automatic conversions were performed:

'_exptl_crystal_density_meas' value 'none' 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 

The following automatic conversions were performed:

'_refine_ls_weighting_scheme' value 'calc
w=1/[\s^2^(Fo^2^)+(0.0415P)^2^+6.0000P] where P=(Fo^2^+2Fc^2^)/3' was
changed to 'calc'. New tag '_refine_ls_weighting_details' was
created. The value of the new tag was set to
'w=1/[\s^2^(Fo^2^)+(0.0415P)^2^+6.0000P] where P=(Fo^2^+2Fc^2^)/3'.

Automatic conversion script
Id: cif_fix_values 3143 2015-03-26 13:38:13Z robertas 
;
_cod_original_cell_volume        3072.0(10)
_cod_database_code               4322377