#------------------------------------------------------------------------------ #$Date: 2012-06-14 12:39:49 +0300 (Thu, 14 Jun 2012) $ #$Revision: 60186 $ #$URL: file:///home/coder/svn-repositories/cod/cif/4/11/09/4110976.cif $ #------------------------------------------------------------------------------ # # This file is available in the Crystallography Open Database (COD), # http://www.crystallography.net/ # # All data on this site have been placed in the public domain by the # contributors. # data_4110976 loop_ _publ_author_name 'Xuyang He' 'J. Jacob Morris' 'Bruce C. Noll' 'Seth N. Brown' 'Kenneth W. Henderson' _publ_contact_author_address ;University of Notre Dame Department of Chemistry Notre Dame, IN 46556-5670 ; _publ_contact_author_email khenders@nd.edu _publ_contact_author_fax 574.631.6652 _publ_contact_author_name 'Kenneth W. Henderson' _publ_contact_author_phone 574.631.8025 _publ_section_title ; Kinetics and Mechanism of Ketone Enolization Mediated by Magnesium Bis(hexamethyldisilazide) ; _journal_name_full 'Journal of the American Chemical Society' _journal_page_first 13599 _journal_page_last 13610 _journal_volume 128 _journal_year 2006 _chemical_compound_source synthesized _chemical_formula_moiety 'C23 H50 Mg N2 O Si4' _chemical_formula_sum 'C23 H50 Mg N2 O Si4' _chemical_formula_weight 507.32 _chemical_name_common 'Mg(HMDS)2 Pivalophenone' _space_group_IT_number 14 _symmetry_cell_setting monoclinic _symmetry_Int_Tables_number 14 _symmetry_space_group_name_Hall '-P 2yn' _symmetry_space_group_name_H-M 'P 1 21/n 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 100.694(1) _cell_angle_gamma 90.00 _cell_formula_units_Z 4 _cell_length_a 8.3655(2) _cell_length_b 20.6214(6) _cell_length_c 18.7658(5) _cell_measurement_reflns_used 9255 _cell_measurement_temperature 100(2) _cell_measurement_theta_max 31.5136 _cell_measurement_theta_min 2.5186 _cell_volume 3181.03(15) _computing_cell_refinement 'APEX2/SAINT (Bruker, 2004)' _computing_data_collection 'APEX2 (Bruker, 2004)' _computing_data_reduction 'SAINT/XPREP (Bruker, 2004; Sheldrick, 2003)' _computing_molecular_graphics 'XP (Sheldrick, 1998)' _computing_publication_material 'XCIF (Sheldrick, 2001)/enCIFer (CCDC, 2004)' _computing_structure_refinement 'XL (Sheldrick, 2001)' _computing_structure_solution 'XS (Sheldrick, 2001)' _diffrn_ambient_temperature 100(2) _diffrn_detector_area_resol_mean 8.33 _diffrn_measured_fraction_theta_full 0.999 _diffrn_measured_fraction_theta_max 0.999 _diffrn_measurement_device_type 'Bruker x8-ApexII CCD diffractometer' _diffrn_measurement_method '\f and \w scans' _diffrn_radiation_monochromator graphite _diffrn_radiation_probe x-ray _diffrn_radiation_type MoK\a _diffrn_radiation_wavelength 0.71073 _diffrn_reflns_av_R_equivalents 0.0367 _diffrn_reflns_av_sigmaI/netI 0.0201 _diffrn_reflns_limit_h_max 12 _diffrn_reflns_limit_h_min -12 _diffrn_reflns_limit_k_max 30 _diffrn_reflns_limit_k_min -30 _diffrn_reflns_limit_l_max 27 _diffrn_reflns_limit_l_min -26 _diffrn_reflns_number 116269 _diffrn_reflns_theta_full 31.56 _diffrn_reflns_theta_max 31.56 _diffrn_reflns_theta_min 1.48 _diffrn_source 'fine-focus sealed tube' _diffrn_source_type 'Siemens KFFMO2K-90' _exptl_absorpt_coefficient_mu 0.223 _exptl_absorpt_correction_T_max 0.9652 _exptl_absorpt_correction_T_min 0.9044 _exptl_absorpt_correction_type multi-scan _exptl_absorpt_process_details ;Blessing, R. H. (1995) Acta Cryst. A51, 33-38. Sheldrick, G. M. (2004) SADABS. University of G\"ottingen, Germany. ; _exptl_crystal_colour colorless _exptl_crystal_density_diffrn 1.059 _exptl_crystal_description plate _exptl_crystal_F_000 1112 _exptl_crystal_recrystallization_method 'crystallized on cooling in hexane solution from 20 \%C to 0 \%C.' _exptl_crystal_size_max 0.46 _exptl_crystal_size_mid 0.43 _exptl_crystal_size_min 0.16 _refine_diff_density_max 0.459 _refine_diff_density_min -0.176 _refine_diff_density_rms 0.046 _refine_ls_extinction_method none _refine_ls_goodness_of_fit_ref 1.028 _refine_ls_hydrogen_treatment constr _refine_ls_matrix_type full _refine_ls_number_parameters 298 _refine_ls_number_reflns 10635 _refine_ls_number_restraints 0 _refine_ls_restrained_S_all 1.028 _refine_ls_R_factor_all 0.0389 _refine_ls_R_factor_gt 0.0286 _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^)+(0.0367P)^2^+0.9217P] where P=(Fo^2^+2Fc^2^)/3' _refine_ls_weighting_scheme calc _refine_ls_wR_factor_gt 0.0734 _refine_ls_wR_factor_ref 0.0791 _reflns_number_gt 8965 _reflns_number_total 10635 _reflns_threshold_expression >2sigma(I) _[local]_cod_data_source_file ja064927wsi20060711_044509.cif _[local]_cod_data_source_block bcn261 _[local]_cod_cif_authors_sg_H-M 'P 21/n' _cod_database_code 4110976 loop_ _symmetry_equiv_pos_as_xyz 'x, y, z' '-x+1/2, y+1/2, -z+1/2' '-x, -y, -z' 'x-1/2, -y-1/2, z-1/2' loop_ _atom_site_label _atom_site_type_symbol _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_U_iso_or_equiv _atom_site_adp_type _atom_site_occupancy _atom_site_symmetry_multiplicity _atom_site_calc_flag _atom_site_refinement_flags Mg1 Mg 0.58301(4) 0.032614(14) 0.740775(15) 0.01445(6) Uani 1 1 d . N1 N 0.60744(9) -0.05533(4) 0.78132(4) 0.01520(13) Uani 1 1 d . N2 N 0.47547(9) 0.07978(4) 0.65393(4) 0.01434(13) Uani 1 1 d . O1 O 0.66418(9) 0.09166(3) 0.82143(3) 0.02181(14) Uani 1 1 d . Si1 Si 0.56270(3) 0.146120(12) 0.622660(13) 0.01534(5) Uani 1 1 d . Si2 Si 0.28791(3) 0.052572(12) 0.613010(13) 0.01680(5) Uani 1 1 d . Si3 Si 0.74668(3) -0.095292(12) 0.742929(13) 0.01677(5) Uani 1 1 d . Si4 Si 0.50265(3) -0.078741(13) 0.845833(13) 0.01706(5) Uani 1 1 d . C1 C 0.70334(11) 0.13052(4) 0.87150(4) 0.01601(16) Uani 1 1 d . C2 C 0.58204(11) 0.18066(4) 0.88173(5) 0.01732(16) Uani 1 1 d . C3 C 0.44698(12) 0.18840(5) 0.82579(5) 0.02329(19) Uani 1 1 d . H3 H 0.4352 0.1613 0.7842 0.028 Uiso 1 1 calc R C4 C 0.33098(14) 0.23500(6) 0.83037(6) 0.0309(2) Uani 1 1 d . H4 H 0.2403 0.2400 0.7919 0.037 Uiso 1 1 calc R C5 C 0.34654(14) 0.27463(6) 0.89101(7) 0.0339(2) Uani 1 1 d . H5 H 0.2670 0.3069 0.8940 0.041 Uiso 1 1 calc R C6 C 0.47800(14) 0.26712(6) 0.94708(7) 0.0328(2) Uani 1 1 d . H6 H 0.4878 0.2939 0.9888 0.039 Uiso 1 1 calc R C7 C 0.59563(12) 0.22065(5) 0.94267(6) 0.02434(19) Uani 1 1 d . H7 H 0.6860 0.2160 0.9813 0.029 Uiso 1 1 calc R C8 C 0.87283(11) 0.12411(5) 0.91802(5) 0.01826(16) Uani 1 1 d . C9 C 0.96600(12) 0.18836(5) 0.92188(6) 0.02471(19) Uani 1 1 d . H9A H 0.9745 0.2022 0.8728 0.037 Uiso 1 1 calc R H9B H 1.0753 0.1825 0.9508 0.037 Uiso 1 1 calc R H9C H 0.9078 0.2214 0.9446 0.037 Uiso 1 1 calc R C10 C 0.96855(14) 0.07295(6) 0.88447(6) 0.0317(2) Uani 1 1 d . H10A H 0.9112 0.0313 0.8821 0.048 Uiso 1 1 calc R H10B H 1.0771 0.0682 0.9144 0.048 Uiso 1 1 calc R H10C H 0.9787 0.0865 0.8354 0.048 Uiso 1 1 calc R C11 C 0.85554(14) 0.10016(6) 0.99400(5) 0.0276(2) Uani 1 1 d . H11A H 0.8058 0.1343 1.0190 0.041 Uiso 1 1 calc R H11B H 0.9632 0.0895 1.0220 0.041 Uiso 1 1 calc R H11C H 0.7866 0.0614 0.9893 0.041 Uiso 1 1 calc R C12 C 0.73982(12) 0.17742(5) 0.69053(5) 0.02155(18) Uani 1 1 d . H12A H 0.7004 0.1956 0.7323 0.032 Uiso 1 1 calc R H12B H 0.7961 0.2112 0.6680 0.032 Uiso 1 1 calc R H12C H 0.8153 0.1418 0.7066 0.032 Uiso 1 1 calc R C13 C 0.64460(14) 0.13012(6) 0.53781(5) 0.0290(2) Uani 1 1 d . H13A H 0.7254 0.0952 0.5467 0.044 Uiso 1 1 calc R H13B H 0.6958 0.1696 0.5235 0.044 Uiso 1 1 calc R H13C H 0.5554 0.1172 0.4989 0.044 Uiso 1 1 calc R C14 C 0.41602(13) 0.21541(5) 0.60192(6) 0.0257(2) Uani 1 1 d . H14A H 0.3225 0.2018 0.5655 0.039 Uiso 1 1 calc R H14B H 0.4702 0.2521 0.5832 0.039 Uiso 1 1 calc R H14C H 0.3787 0.2286 0.6463 0.039 Uiso 1 1 calc R C15 C 0.24577(15) 0.05957(6) 0.51153(6) 0.0317(2) Uani 1 1 d . H15A H 0.2497 0.1053 0.4977 0.048 Uiso 1 1 calc R H15B H 0.1376 0.0419 0.4922 0.048 Uiso 1 1 calc R H15C H 0.3280 0.0351 0.4917 0.048 Uiso 1 1 calc R C16 C 0.12166(13) 0.09691(6) 0.64726(7) 0.0307(2) Uani 1 1 d . H16A H 0.1349 0.0911 0.6999 0.046 Uiso 1 1 calc R H16B H 0.0159 0.0796 0.6237 0.046 Uiso 1 1 calc R H16C H 0.1273 0.1432 0.6361 0.046 Uiso 1 1 calc R C17 C 0.26459(12) -0.03589(5) 0.63188(5) 0.02193(18) Uani 1 1 d . H17A H 0.3516 -0.0604 0.6156 0.033 Uiso 1 1 calc R H17B H 0.1588 -0.0511 0.6058 0.033 Uiso 1 1 calc R H17C H 0.2713 -0.0424 0.6841 0.033 Uiso 1 1 calc R C18 C 0.34848(14) -0.01466(6) 0.85510(6) 0.0298(2) Uani 1 1 d . H18A H 0.4044 0.0262 0.8705 0.045 Uiso 1 1 calc R H18B H 0.2848 -0.0283 0.8914 0.045 Uiso 1 1 calc R H18C H 0.2757 -0.0084 0.8083 0.045 Uiso 1 1 calc R C19 C 0.39210(14) -0.15722(5) 0.82410(7) 0.0298(2) Uani 1 1 d . H19A H 0.3186 -0.1536 0.7771 0.045 Uiso 1 1 calc R H19B H 0.3289 -0.1671 0.8618 0.045 Uiso 1 1 calc R H19C H 0.4709 -0.1920 0.8220 0.045 Uiso 1 1 calc R C20 C 0.63295(15) -0.08947(7) 0.93799(6) 0.0345(3) Uani 1 1 d . H20A H 0.7084 -0.1256 0.9367 0.052 Uiso 1 1 calc R H20B H 0.5636 -0.0988 0.9735 0.052 Uiso 1 1 calc R H20C H 0.6948 -0.0496 0.9519 0.052 Uiso 1 1 calc R C21 C 0.83952(13) -0.03280(6) 0.68998(6) 0.0273(2) Uani 1 1 d . H21A H 0.8916 0.0011 0.7230 0.046(4) Uiso 1 1 calc R H21B H 0.7543 -0.0134 0.6533 0.043(4) Uiso 1 1 calc R H21C H 0.9210 -0.0535 0.6661 0.060(5) Uiso 1 1 calc R C22 C 0.91591(14) -0.13218(6) 0.80939(6) 0.0336(2) Uani 1 1 d . H22A H 0.9737 -0.0981 0.8403 0.050 Uiso 1 1 calc R H22B H 0.9915 -0.1541 0.7832 0.050 Uiso 1 1 calc R H22C H 0.8713 -0.1637 0.8395 0.050 Uiso 1 1 calc R C23 C 0.66051(14) -0.16120(5) 0.67857(6) 0.0296(2) Uani 1 1 d . H23A H 0.6122 -0.1948 0.7049 0.044 Uiso 1 1 calc R H23B H 0.7475 -0.1803 0.6568 0.044 Uiso 1 1 calc R H23C H 0.5767 -0.1431 0.6403 0.044 Uiso 1 1 calc R loop_ _atom_site_aniso_label _atom_site_aniso_U_11 _atom_site_aniso_U_22 _atom_site_aniso_U_33 _atom_site_aniso_U_23 _atom_site_aniso_U_13 _atom_site_aniso_U_12 Mg1 0.01739(14) 0.01281(14) 0.01206(13) -0.00002(10) -0.00014(10) 0.00131(11) N1 0.0176(3) 0.0140(3) 0.0143(3) 0.0015(2) 0.0037(3) 0.0014(3) N2 0.0148(3) 0.0147(3) 0.0126(3) 0.0014(2) 0.0002(2) -0.0002(3) O1 0.0321(4) 0.0163(3) 0.0149(3) -0.0026(2) -0.0013(3) -0.0002(3) Si1 0.01789(11) 0.01497(11) 0.01294(10) 0.00151(8) 0.00228(8) -0.00088(8) Si2 0.01498(11) 0.01775(12) 0.01608(11) 0.00156(8) -0.00127(8) -0.00054(9) Si3 0.01761(11) 0.01585(11) 0.01633(11) -0.00073(8) 0.00177(8) 0.00345(9) Si4 0.01908(12) 0.01708(12) 0.01517(11) 0.00246(8) 0.00358(8) -0.00192(9) C1 0.0217(4) 0.0144(4) 0.0116(3) 0.0016(3) 0.0022(3) -0.0012(3) C2 0.0187(4) 0.0165(4) 0.0172(4) -0.0002(3) 0.0043(3) -0.0019(3) C3 0.0240(5) 0.0256(5) 0.0196(4) 0.0023(3) 0.0022(3) 0.0027(4) C4 0.0256(5) 0.0350(6) 0.0318(5) 0.0065(4) 0.0044(4) 0.0085(4) C5 0.0289(5) 0.0302(6) 0.0460(7) 0.0011(5) 0.0154(5) 0.0093(4) C6 0.0302(5) 0.0307(6) 0.0399(6) -0.0131(5) 0.0130(5) 0.0012(4) C7 0.0219(5) 0.0252(5) 0.0262(5) -0.0086(4) 0.0053(4) -0.0015(4) C8 0.0209(4) 0.0185(4) 0.0142(4) -0.0002(3) 0.0002(3) 0.0023(3) C9 0.0194(4) 0.0261(5) 0.0281(5) 0.0020(4) 0.0031(3) -0.0026(4) C10 0.0324(6) 0.0323(6) 0.0281(5) -0.0047(4) -0.0004(4) 0.0146(5) C11 0.0347(5) 0.0302(5) 0.0156(4) 0.0047(4) -0.0013(4) -0.0025(4) C12 0.0203(4) 0.0219(4) 0.0218(4) 0.0002(3) 0.0023(3) -0.0044(3) C13 0.0342(6) 0.0354(6) 0.0200(4) -0.0012(4) 0.0113(4) -0.0069(4) C14 0.0285(5) 0.0172(4) 0.0282(5) 0.0055(4) -0.0030(4) 0.0008(4) C15 0.0368(6) 0.0350(6) 0.0183(4) 0.0036(4) -0.0080(4) -0.0095(5) C16 0.0183(5) 0.0265(5) 0.0478(7) 0.0025(4) 0.0073(4) 0.0032(4) C17 0.0202(4) 0.0197(4) 0.0244(4) 0.0001(3) 0.0003(3) -0.0033(3) C18 0.0352(6) 0.0284(5) 0.0309(5) 0.0017(4) 0.0191(4) 0.0051(4) C19 0.0274(5) 0.0242(5) 0.0394(6) -0.0012(4) 0.0103(4) -0.0082(4) C20 0.0357(6) 0.0482(7) 0.0181(4) 0.0097(4) 0.0008(4) -0.0086(5) C21 0.0276(5) 0.0314(5) 0.0260(5) 0.0007(4) 0.0133(4) -0.0002(4) C22 0.0290(5) 0.0377(6) 0.0312(5) 0.0020(5) -0.0017(4) 0.0148(5) C23 0.0345(6) 0.0235(5) 0.0297(5) -0.0098(4) 0.0028(4) 0.0038(4) loop_ _atom_type_symbol _atom_type_description _atom_type_scat_dispersion_real _atom_type_scat_dispersion_imag _atom_type_scat_source C C 0.0033 0.0016 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' H H 0.0000 0.0000 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' N N 0.0061 0.0033 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' O O 0.0106 0.0060 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' Mg Mg 0.0486 0.0363 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' Si Si 0.0817 0.0704 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' loop_ _geom_angle_atom_site_label_1 _geom_angle_atom_site_label_2 _geom_angle_atom_site_label_3 _geom_angle N1 Mg1 O1 106.14(3) N1 Mg1 N2 140.99(3) O1 Mg1 N2 111.83(3) Si4 N1 Si3 130.89(5) Si4 N1 Mg1 120.71(4) Si3 N1 Mg1 108.37(4) Si1 N2 Si2 121.65(4) Si1 N2 Mg1 121.53(4) Si2 N2 Mg1 116.80(4) C1 O1 Mg1 175.16(7) N2 Si1 C13 113.46(5) N2 Si1 C14 112.15(4) C13 Si1 C14 106.60(5) N2 Si1 C12 112.10(4) C13 Si1 C12 105.63(5) C14 Si1 C12 106.37(5) N2 Si2 C16 111.32(5) N2 Si2 C17 110.71(4) C16 Si2 C17 107.45(5) N2 Si2 C15 114.50(5) C16 Si2 C15 107.38(6) C17 Si2 C15 105.06(5) N1 Si3 C22 114.24(5) N1 Si3 C23 114.52(5) C22 Si3 C23 106.79(5) N1 Si3 C21 105.99(4) C22 Si3 C21 107.21(6) C23 Si3 C21 107.70(5) N1 Si4 C19 113.06(5) N1 Si4 C18 108.76(4) C19 Si4 C18 107.99(5) N1 Si4 C20 113.78(5) C19 Si4 C20 106.13(6) C18 Si4 C20 106.80(6) O1 C1 C2 117.38(8) O1 C1 C8 117.84(8) C2 C1 C8 124.78(8) C7 C2 C3 118.53(9) C7 C2 C1 124.24(8) C3 C2 C1 117.22(8) C4 C3 C2 120.75(10) C4 C3 H3 119.6 C2 C3 H3 119.6 C3 C4 C5 120.09(10) C3 C4 H4 120.0 C5 C4 H4 120.0 C6 C5 C4 119.91(10) C6 C5 H5 120.0 C4 C5 H5 120.0 C5 C6 C7 120.34(10) C5 C6 H6 119.8 C7 C6 H6 119.8 C6 C7 C2 120.38(10) C6 C7 H7 119.8 C2 C7 H7 119.8 C1 C8 C10 109.03(8) C1 C8 C9 111.25(8) C10 C8 C9 108.38(9) C1 C8 C11 108.68(8) C10 C8 C11 107.83(8) C9 C8 C11 111.57(8) C8 C9 H9A 109.5 C8 C9 H9B 109.5 H9A C9 H9B 109.5 C8 C9 H9C 109.5 H9A C9 H9C 109.5 H9B C9 H9C 109.5 C8 C10 H10A 109.5 C8 C10 H10B 109.5 H10A C10 H10B 109.5 C8 C10 H10C 109.5 H10A C10 H10C 109.5 H10B C10 H10C 109.5 C8 C11 H11A 109.5 C8 C11 H11B 109.5 H11A C11 H11B 109.5 C8 C11 H11C 109.5 H11A C11 H11C 109.5 H11B C11 H11C 109.5 Si1 C12 H12A 109.5 Si1 C12 H12B 109.5 H12A C12 H12B 109.5 Si1 C12 H12C 109.5 H12A C12 H12C 109.5 H12B C12 H12C 109.5 Si1 C13 H13A 109.5 Si1 C13 H13B 109.5 H13A C13 H13B 109.5 Si1 C13 H13C 109.5 H13A C13 H13C 109.5 H13B C13 H13C 109.5 Si1 C14 H14A 109.5 Si1 C14 H14B 109.5 H14A C14 H14B 109.5 Si1 C14 H14C 109.5 H14A C14 H14C 109.5 H14B C14 H14C 109.5 Si2 C15 H15A 109.5 Si2 C15 H15B 109.5 H15A C15 H15B 109.5 Si2 C15 H15C 109.5 H15A C15 H15C 109.5 H15B C15 H15C 109.5 Si2 C16 H16A 109.5 Si2 C16 H16B 109.5 H16A C16 H16B 109.5 Si2 C16 H16C 109.5 H16A C16 H16C 109.5 H16B C16 H16C 109.5 Si2 C17 H17A 109.5 Si2 C17 H17B 109.5 H17A C17 H17B 109.5 Si2 C17 H17C 109.5 H17A C17 H17C 109.5 H17B C17 H17C 109.5 Si4 C18 H18A 109.5 Si4 C18 H18B 109.5 H18A C18 H18B 109.5 Si4 C18 H18C 109.5 H18A C18 H18C 109.5 H18B C18 H18C 109.5 Si4 C19 H19A 109.5 Si4 C19 H19B 109.5 H19A C19 H19B 109.5 Si4 C19 H19C 109.5 H19A C19 H19C 109.5 H19B C19 H19C 109.5 Si4 C20 H20A 109.5 Si4 C20 H20B 109.5 H20A C20 H20B 109.5 Si4 C20 H20C 109.5 H20A C20 H20C 109.5 H20B C20 H20C 109.5 Si3 C21 H21A 109.5 Si3 C21 H21B 109.5 H21A C21 H21B 109.5 Si3 C21 H21C 109.5 H21A C21 H21C 109.5 H21B C21 H21C 109.5 Si3 C22 H22A 109.5 Si3 C22 H22B 109.5 H22A C22 H22B 109.5 Si3 C22 H22C 109.5 H22A C22 H22C 109.5 H22B C22 H22C 109.5 Si3 C23 H23A 109.5 Si3 C23 H23B 109.5 H23A C23 H23B 109.5 Si3 C23 H23C 109.5 H23A C23 H23C 109.5 H23B C23 H23C 109.5 loop_ _geom_bond_atom_site_label_1 _geom_bond_atom_site_label_2 _geom_bond_distance Mg1 N1 1.9627(8) Mg1 O1 1.9630(7) Mg1 N2 1.9665(7) N1 Si4 1.6914(8) N1 Si3 1.6930(8) N2 Si1 1.7051(8) N2 Si2 1.7086(8) O1 C1 1.2321(11) Si1 C13 1.8758(10) Si1 C14 1.8765(10) Si1 C12 1.8799(10) Si2 C16 1.8749(11) Si2 C17 1.8752(10) Si2 C15 1.8768(10) Si3 C22 1.8663(11) Si3 C23 1.8714(11) Si3 C21 1.8808(11) Si4 C19 1.8710(11) Si4 C18 1.8770(11) Si4 C20 1.8783(11) C1 C2 1.4858(13) C1 C8 1.5267(12) C2 C7 1.3973(13) C2 C3 1.4014(13) C3 C4 1.3796(15) C3 H3 0.9500 C4 C5 1.3875(17) C4 H4 0.9500 C5 C6 1.3823(18) C5 H5 0.9500 C6 C7 1.3870(15) C6 H6 0.9500 C7 H7 0.9500 C8 C10 1.5290(14) C8 C9 1.5321(14) C8 C11 1.5409(13) C9 H9A 0.9800 C9 H9B 0.9800 C9 H9C 0.9800 C10 H10A 0.9800 C10 H10B 0.9800 C10 H10C 0.9800 C11 H11A 0.9800 C11 H11B 0.9800 C11 H11C 0.9800 C12 H12A 0.9800 C12 H12B 0.9800 C12 H12C 0.9800 C13 H13A 0.9800 C13 H13B 0.9800 C13 H13C 0.9800 C14 H14A 0.9800 C14 H14B 0.9800 C14 H14C 0.9800 C15 H15A 0.9800 C15 H15B 0.9800 C15 H15C 0.9800 C16 H16A 0.9800 C16 H16B 0.9800 C16 H16C 0.9800 C17 H17A 0.9800 C17 H17B 0.9800 C17 H17C 0.9800 C18 H18A 0.9800 C18 H18B 0.9800 C18 H18C 0.9800 C19 H19A 0.9800 C19 H19B 0.9800 C19 H19C 0.9800 C20 H20A 0.9800 C20 H20B 0.9800 C20 H20C 0.9800 C21 H21A 0.9800 C21 H21B 0.9800 C21 H21C 0.9800 C22 H22A 0.9800 C22 H22B 0.9800 C22 H22C 0.9800 C23 H23A 0.9800 C23 H23B 0.9800 C23 H23C 0.9800