Dearomatization and C‒H Deprotonation with Heavier Group 2 Alkyls: Does Size Matter?
Merle Arrowsmith; Michael S. Hill; Gabriele Kociok-Kḧon; Organometallics 29 (2010) 4203–4206; doi:10.1021/om100649z

data_4063337
_publ_section_title
;
 Dearomatization and C--H Deprotonation with Heavier Group 2 Alkyls: Does
 Size Matter?
;
_journal_issue                   19
_journal_name_full               Organometallics
_journal_page_first              4203
_journal_page_last               4206
_journal_paper_doi               10.1021/om100649z
_journal_volume                  29
_journal_year                    2010
_chemical_formula_moiety         'C22 H54 Mg O2 Si4'
_chemical_formula_sum            'C22 H54 Mg O2 Si4'
_chemical_formula_weight         487.32
_chemical_name_systematic
;
 ?
;
_space_group_IT_number           15
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-C 2yc'
_symmetry_space_group_name_H-M   'C 1 2/c 1'
_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                 109.4520(10)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   18.1694(4)
_cell_length_b                   9.5586(2)
_cell_length_c                   18.6690(5)
_cell_measurement_reflns_used    12167
_cell_measurement_temperature    150(2)
_cell_measurement_theta_max      27.485
_cell_measurement_theta_min      2.910
_cell_volume                     3057.25(13)
_computing_cell_refinement       'HKL Scalepack (Otwinski & Minor, 1997)'
_computing_data_collection       'Collect (Nonius BV, 1997-2000)'
_computing_data_reduction
;
 DENZO-SCALEPACK Z. Otwinowski and W. Minor, " 
 Processing of X-ray Diffraction Data Collected in Oscillation Mode ", 
 Methods in Enzymology, Volume 276: Macromolecular Crystallography, 
 part A, p.307-326, 1997,C.W. Carter, Jr. & R. M. Sweet, Eds., Academic Press.
;
_computing_molecular_graphics
'ORTEP3 for Windows - Farrugia, L. J. J. Appl. Crystallogr. 1997, 30, 565'
_computing_publication_material
;
 'WinGX publication routines, Farrugia, 
 L. J., J. Appl. Crystallogr., 1999, 32, 837-838
;
_computing_structure_refinement
;
 SHELXL97 -Program for Crystal Structure Analysis (Release 97-2). 
 Sheldrick, G.M., Instit\"ut f\"ur Anorganische Chemie der Universit\"at, 
 Tammanstrasse 4, D-3400 G\"ottingen, Germany, 1998 
;
_computing_structure_solution
; 
 SIR2004- Version 1.0 Burla M.C., Caliandro R., Camalli M., Carrazzoni B., 
 Cascarano G.L., De Caro L., Giacovazzo C. , Polidori G., Spagna R. 
;
_diffrn_ambient_temperature      150(2)
_diffrn_measured_fraction_theta_full 0.989
_diffrn_measured_fraction_theta_max 0.989
_diffrn_measurement_device_type  'Nonius Kappa CCD'
_diffrn_measurement_method       '170 2.0 degree images with \w 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  0.0651
_diffrn_reflns_av_sigmaI/netI    0.0339
_diffrn_reflns_limit_h_max       23
_diffrn_reflns_limit_h_min       -23
_diffrn_reflns_limit_k_max       12
_diffrn_reflns_limit_k_min       -12
_diffrn_reflns_limit_l_max       24
_diffrn_reflns_limit_l_min       -24
_diffrn_reflns_number            21287
_diffrn_reflns_theta_full        27.50
_diffrn_reflns_theta_max         27.50
_diffrn_reflns_theta_min         5.20
_diffrn_standards_decay_%        0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.230
_exptl_absorpt_correction_T_max  0.9342
_exptl_absorpt_correction_T_min  0.8840
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
multi-scan from symmetry-related measurements 
 Sortav (Blessing 1995)
;
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.059
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             1080
_exptl_crystal_size_max          0.55
_exptl_crystal_size_mid          0.35
_exptl_crystal_size_min          0.30
_refine_diff_density_max         0.420
_refine_diff_density_min         -0.297
_refine_diff_density_rms         0.048
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.031
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     138
_refine_ls_number_reflns         3470
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.031
_refine_ls_R_factor_all          0.0503
_refine_ls_R_factor_gt           0.0397
_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^)+(0.0501P)^2^+3.2898P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1038
_refine_ls_wR_factor_ref         0.1107
_reflns_number_gt                2895
_reflns_number_total             3470
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            om100649z_si_002.cif
_cod_data_source_block           h09msh15
_cod_original_cell_volume        3057.25(12)
_cod_original_sg_symbol_H-M      'C 2/c'
_cod_database_code               4063337