Alkyl Complexes of Strontium and Barium: Synthesis and Structural Characterization of {(Me3Si)2(MeOMe2Si)C}2Sr(THF) and {(Me3Si)2(MeOMe2Si)C}2Ba(MeOCH2CH2OMe)
Keith Izod; Stephen T. Liddle; William Clegg; Journal of the American Chemical Society 125 (2003) 7534–7535; doi:10.1021/ja0352404

data_4113837
_publ_section_title
;
 Alkyl Complexes of Strontium and Barium: Synthesis and Structural
 Characterization of {(Me3Si)2(MeOMe2Si)C}2Sr(THF) and
 {(Me3Si)2(MeOMe2Si)C}2Ba(MeOCH2CH2OMe)
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              7534
_journal_page_last               7535
_journal_paper_doi               10.1021/ja0352404
_journal_volume                  125
_journal_year                    2003
_chemical_formula_sum            'C24 H64 Ba O4 Si6'
_chemical_formula_weight         722.63
_chemical_name_systematic
;
 ?
;
_space_group_IT_number           29
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2c -2ac'
_symmetry_space_group_name_H-M   'P c a 21'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     heavy
_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                   17.7600(7)
_cell_length_b                   13.1490(5)
_cell_length_c                   16.8334(6)
_cell_measurement_reflns_used    27353
_cell_measurement_temperature    150(2)
_cell_measurement_theta_max      28.62
_cell_measurement_theta_min      2.27
_cell_volume                     3931.0(3)
_computing_cell_refinement       'Bruker SAINT'
_computing_data_collection       'Bruker SMART'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL and local programs'
_computing_structure_refinement  'Bruker SHELXTL'
_computing_structure_solution    'Bruker SHELXTL'
_diffrn_ambient_temperature      150(2)
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.953
_diffrn_measurement_device_type  'Bruker SMART 1K CCD diffractometer'
_diffrn_measurement_method       '\w rotation with narrow frames'
_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  0.0257
_diffrn_reflns_av_sigmaI/netI    0.0316
_diffrn_reflns_limit_h_max       22
_diffrn_reflns_limit_h_min       -23
_diffrn_reflns_limit_k_max       17
_diffrn_reflns_limit_k_min       -17
_diffrn_reflns_limit_l_max       21
_diffrn_reflns_limit_l_min       -21
_diffrn_reflns_number            32975
_diffrn_reflns_theta_full        26.00
_diffrn_reflns_theta_max         28.70
_diffrn_reflns_theta_min         1.55
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    1.217
_exptl_absorpt_correction_T_max  0.529
_exptl_absorpt_correction_T_min  0.450
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   SADABS
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.221
_exptl_crystal_description       block
_exptl_crystal_F_000             1520
_exptl_crystal_size_max          0.78
_exptl_crystal_size_mid          0.62
_exptl_crystal_size_min          0.60
_refine_diff_density_max         0.479
_refine_diff_density_min         -0.240
_refine_diff_density_rms         0.049
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.002(7)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.035
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     336
_refine_ls_number_reflns         9266
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.035
_refine_ls_R_factor_all          0.0251
_refine_ls_R_factor_gt           0.0196
_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^)+(0.0143P)^2^+0.3156P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0417
_refine_ls_wR_factor_ref         0.0434
_reflns_number_gt                8482
_reflns_number_total             9266
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            ja0352404si20030320_035956.cif
_cod_data_source_block           3
_cod_database_code               4113837