# Supplementary Material (ESI) for Perkin Transactions # This journal is © The Royal Society of Chemistry 2002 data_global _journal_coden_Cambridge 207 loop_ _publ_author_name 'Anderson, James C.' 'Skerratt, Sarah' _publ_contact_author_name 'Dr James C. Anderson' _publ_contact_author_address ; Department of Chemistry University of Nottingham Nottingham NG7 2RD UNITED KINGDOM ; _publ_contact_author_email 'J.ANDERSON@NOTTINGHAM.AC.UK' _publ_requested_journal 'Perkin Transactions 1' _publ_section_title ; Synthesis of a,a-Disubstituted Unnatural Amino Acid Derivatives using the Aza-[2,3]-Wittig Sigmatropic Rearrangement ; data_sicbes _database_code_CSD 191677 _audit_creation_method SHELXL-97 _chemical_name_systematic ; ? ; _chemical_name_common ? _chemical_melting_point ? _chemical_formula_moiety ? _chemical_formula_sum 'C24 H40 N2 O3 Si' _chemical_formula_weight 432.67 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' 'Si' 'Si' 0.0817 0.0704 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' _symmetry_cell_setting Monoclinic _symmetry_space_group_name_H-M P2(1)/n 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' _cell_length_a 9.4034(8) _cell_length_b 18.252(2) _cell_length_c 15.3571(13) _cell_angle_alpha 90.00 _cell_angle_beta 103.981(2) _cell_angle_gamma 90.00 _cell_volume 2557.7(4) _cell_formula_units_Z 4 _cell_measurement_temperature 150(2) _cell_measurement_reflns_used 3282 _cell_measurement_theta_min 2.3 _cell_measurement_theta_max 25.2 _exptl_crystal_description plate _exptl_crystal_colour colourless _exptl_crystal_size_max 0.32 _exptl_crystal_size_mid 0.30 _exptl_crystal_size_min 0.10 _exptl_crystal_density_meas ? _exptl_crystal_density_diffrn 1.124 _exptl_crystal_density_method 'not measured' _exptl_crystal_F_000 944 _exptl_absorpt_coefficient_mu 0.117 _exptl_absorpt_correction_type none _exptl_absorpt_correction_T_min ? _exptl_absorpt_correction_T_max ? _exptl_absorpt_process_details ? _exptl_special_details ; ? ; _diffrn_ambient_temperature 150(2) _diffrn_radiation_wavelength 0.71073 _diffrn_radiation_type MoK\a _diffrn_radiation_source 'fine-focus sealed tube' _diffrn_radiation_monochromator graphite _diffrn_measurement_device_type 'Bruker SMART1000 CCD area detector' _diffrn_measurement_method omega _diffrn_detector_area_resol_mean ? _diffrn_standards_number ? _diffrn_standards_interval_count ? _diffrn_standards_interval_time ? _diffrn_standards_decay_% none _diffrn_reflns_number 16173 _diffrn_reflns_av_R_equivalents 0.074 _diffrn_reflns_av_sigmaI/netI 0.0789 _diffrn_reflns_limit_h_min -12 _diffrn_reflns_limit_h_max 10 _diffrn_reflns_limit_k_min -24 _diffrn_reflns_limit_k_max 23 _diffrn_reflns_limit_l_min -17 _diffrn_reflns_limit_l_max 20 _diffrn_reflns_theta_min 1.76 _diffrn_reflns_theta_max 28.86 _reflns_number_total 5953 _reflns_number_gt 3317 _reflns_threshold_expression >2sigma(I) _computing_data_collection 'Bruker SMART version 5.624 (Bruker, 2001)' _computing_cell_refinement 'Bruker SAINT version 6.02a (Bruker, 2000)' _computing_data_reduction 'Bruker SAINT; Bruker SHELXTL (Bruker, 1997)' _computing_structure_solution 'SHELXS-97 (Sheldrick, 1990)' _computing_structure_refinement 'SHELXL-97 (Sheldrick, 1997)' _computing_molecular_graphics ? _computing_publication_material 'SHELXL-97; PLATON (Spek, 2001)' _refine_special_details ; Refinement of F^2^ against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F^2^, conventional R-factors R are based on F, with F set to zero for negative F^2^. The threshold expression of F^2^ > 2sigma(F^2^) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F^2^ are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger. ; _refine_ls_structure_factor_coef Fsqd _refine_ls_matrix_type full _refine_ls_weighting_scheme calc _refine_ls_weighting_details 'calc w=1/[\s^2^(Fo^2^)+(0.0559P)^2^] where P=(Fo^2^+2Fc^2^)/3' _atom_sites_solution_primary direct _atom_sites_solution_secondary difmap _atom_sites_solution_hydrogens 'geometrically placed' _refine_ls_hydrogen_treatment 'riding model' _refine_ls_extinction_method none _refine_ls_extinction_coef ? _refine_ls_number_reflns 5953 _refine_ls_number_parameters 271 _refine_ls_number_restraints 0 _refine_ls_R_factor_all 0.1003 _refine_ls_R_factor_gt 0.0447 _refine_ls_wR_factor_ref 0.1209 _refine_ls_wR_factor_gt 0.1001 _refine_ls_goodness_of_fit_ref 0.931 _refine_ls_restrained_S_all 0.931 _refine_ls_shift/su_max 0.000 _refine_ls_shift/su_mean 0.000 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 _atom_site_disorder_assembly _atom_site_disorder_group Si1 Si 0.25307(6) 0.07808(3) 0.10664(4) 0.02709(15) Uani 1 1 d . . . O1 O 0.62027(16) 0.32091(8) 0.33464(10) 0.0380(4) Uani 1 1 d . . . N1 N 0.48410(17) 0.23157(9) 0.25083(11) 0.0268(4) Uani 1 1 d . . . H1A H 0.4773 0.2034 0.2035 0.032 Uiso 1 1 calc R . . C1 C 0.3987(2) 0.21426(10) 0.31703(13) 0.0242(4) Uani 1 1 d . . . O2 O 0.60385(16) 0.31080(8) 0.18504(9) 0.0361(4) Uani 1 1 d . . . N2 N 0.62258(17) 0.16349(9) 0.42986(11) 0.0300(4) Uani 1 1 d . . . C2 C 0.3160(2) 0.14012(11) 0.28826(13) 0.0243(4) Uani 1 1 d . . . H2A H 0.3933 0.1029 0.2864 0.029 Uiso 1 1 calc R . . O3 O 0.45496(15) 0.23049(8) 0.47603(9) 0.0344(4) Uani 1 1 d . . . C3 C 0.2130(2) 0.14079(11) 0.19467(13) 0.0262(5) Uani 1 1 d . . . C4 C 0.0868(2) 0.17761(12) 0.17761(16) 0.0376(5) Uani 1 1 d . . . H4A H 0.0594 0.2042 0.2242 0.045 Uiso 1 1 calc R . . H4B H 0.0243 0.1773 0.1189 0.045 Uiso 1 1 calc R . . C5 C 0.2370(2) 0.11284(12) 0.35863(14) 0.0345(5) Uani 1 1 d . . . H5A H 0.1876 0.0664 0.3386 0.052 Uiso 1 1 calc R . . H5B H 0.1643 0.1493 0.3662 0.052 Uiso 1 1 calc R . . H5C H 0.3085 0.1055 0.4160 0.052 Uiso 1 1 calc R . . C6 C 0.2957(2) 0.27834(11) 0.32000(14) 0.0323(5) Uani 1 1 d . . . H6A H 0.3533 0.3229 0.3382 0.048 Uiso 1 1 calc R . . H6B H 0.2371 0.2677 0.3633 0.048 Uiso 1 1 calc R . . H6C H 0.2304 0.2855 0.2604 0.048 Uiso 1 1 calc R . . C7 C 0.4970(2) 0.20402(11) 0.41326(14) 0.0267(5) Uani 1 1 d . . . C8 C 0.6853(2) 0.12365(12) 0.36546(15) 0.0331(5) Uani 1 1 d . . . H8A H 0.6127 0.1226 0.3068 0.040 Uiso 1 1 calc R . . H8B H 0.7042 0.0724 0.3862 0.040 Uiso 1 1 calc R . . C9 C 0.8270(2) 0.15670(13) 0.35253(16) 0.0423(6) Uani 1 1 d . . . H9A H 0.8635 0.1273 0.3091 0.064 Uiso 1 1 calc R . . H9B H 0.9002 0.1572 0.4100 0.064 Uiso 1 1 calc R . . H9C H 0.8088 0.2069 0.3301 0.064 Uiso 1 1 calc R . . C10 C 0.7004(2) 0.15566(13) 0.52429(15) 0.0417(6) Uani 1 1 d . . . H10A H 0.6907 0.2017 0.5564 0.050 Uiso 1 1 calc R . . H10B H 0.8058 0.1477 0.5281 0.050 Uiso 1 1 calc R . . C11 C 0.6428(3) 0.09273(15) 0.57016(17) 0.0608(8) Uani 1 1 d . . . H11A H 0.6979 0.0900 0.6330 0.091 Uiso 1 1 calc R . . H11B H 0.6546 0.0467 0.5397 0.091 Uiso 1 1 calc R . . H11C H 0.5388 0.1007 0.5675 0.091 Uiso 1 1 calc R . . C12 C 0.5731(2) 0.29102(11) 0.26310(14) 0.0282(5) Uani 1 1 d . . . C13 C 0.6950(2) 0.37575(12) 0.18236(15) 0.0369(5) Uani 1 1 d . . . C14 C 0.8481(3) 0.36431(15) 0.24011(18) 0.0552(7) Uani 1 1 d . . . H14A H 0.8450 0.3625 0.3034 0.083 Uiso 1 1 calc R . . H14B H 0.9110 0.4049 0.2309 0.083 Uiso 1 1 calc R . . H14C H 0.8876 0.3181 0.2235 0.083 Uiso 1 1 calc R . . C15 C 0.6214(3) 0.44297(13) 0.20918(19) 0.0595(8) Uani 1 1 d . . . H15A H 0.6222 0.4400 0.2730 0.089 Uiso 1 1 calc R . . H15B H 0.5199 0.4455 0.1735 0.089 Uiso 1 1 calc R . . H15C H 0.6744 0.4870 0.1984 0.089 Uiso 1 1 calc R . . C16 C 0.6978(3) 0.37955(15) 0.08384(16) 0.0539(7) Uani 1 1 d . . . H16A H 0.5980 0.3872 0.0472 0.081 Uiso 1 1 calc R . . H16B H 0.7368 0.3336 0.0662 0.081 Uiso 1 1 calc R . . H16C H 0.7603 0.4204 0.0746 0.081 Uiso 1 1 calc R . . C17 C 0.2731(2) -0.01635(11) 0.15503(14) 0.0364(5) Uani 1 1 d . . . H17A H 0.1812 -0.0310 0.1695 0.055 Uiso 1 1 calc R . . H17B H 0.3525 -0.0169 0.2097 0.055 Uiso 1 1 calc R . . H17C H 0.2960 -0.0506 0.1112 0.055 Uiso 1 1 calc R . . C18 C 0.1011(2) 0.08329(12) 0.00469(14) 0.0361(5) Uani 1 1 d . . . H18A H 0.0934 0.1334 -0.0189 0.054 Uiso 1 1 calc R . . H18B H 0.0091 0.0697 0.0197 0.054 Uiso 1 1 calc R . . H18C H 0.1203 0.0496 -0.0408 0.054 Uiso 1 1 calc R . . C19 C 0.4285(2) 0.10613(11) 0.07825(13) 0.0266(5) Uani 1 1 d . . . C20 C 0.5637(2) 0.07342(12) 0.11603(14) 0.0361(5) Uani 1 1 d . . . H20A H 0.5678 0.0336 0.1563 0.043 Uiso 1 1 calc R . . C21 C 0.6928(2) 0.09775(13) 0.09610(15) 0.0409(6) Uani 1 1 d . . . H21A H 0.7834 0.0749 0.1233 0.049 Uiso 1 1 calc R . . C22 C 0.6892(2) 0.15488(13) 0.03696(15) 0.0378(6) Uani 1 1 d . . . H22A H 0.7768 0.1715 0.0230 0.045 Uiso 1 1 calc R . . C23 C 0.5572(2) 0.18758(12) -0.00165(15) 0.0364(5) Uani 1 1 d . . . H23A H 0.5541 0.2270 -0.0425 0.044 Uiso 1 1 calc R . . C24 C 0.4290(2) 0.16375(11) 0.01821(14) 0.0311(5) Uani 1 1 d . . . H24A H 0.3391 0.1870 -0.0096 0.037 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 Si1 0.0283(3) 0.0281(3) 0.0249(3) 0.0012(3) 0.0066(2) -0.0042(3) O1 0.0464(9) 0.0407(9) 0.0296(9) -0.0090(7) 0.0144(7) -0.0159(7) N1 0.0327(9) 0.0276(9) 0.0248(9) -0.0064(7) 0.0163(8) -0.0069(7) C1 0.0242(10) 0.0277(11) 0.0234(11) -0.0011(8) 0.0110(9) -0.0008(8) O2 0.0455(9) 0.0399(9) 0.0269(8) -0.0064(7) 0.0167(7) -0.0194(7) N2 0.0270(9) 0.0384(11) 0.0256(10) -0.0018(8) 0.0083(8) 0.0037(8) C2 0.0213(10) 0.0269(11) 0.0269(11) 0.0006(8) 0.0101(9) -0.0009(8) O3 0.0388(9) 0.0419(9) 0.0252(8) -0.0056(7) 0.0133(7) 0.0033(7) C3 0.0209(10) 0.0293(11) 0.0300(12) 0.0051(9) 0.0093(9) -0.0041(8) C4 0.0270(11) 0.0442(14) 0.0406(14) -0.0021(11) 0.0065(10) 0.0026(10) C5 0.0355(13) 0.0403(13) 0.0310(12) 0.0038(10) 0.0142(10) -0.0062(10) C6 0.0327(12) 0.0327(12) 0.0337(12) -0.0003(10) 0.0123(10) 0.0039(10) C7 0.0282(11) 0.0262(11) 0.0277(12) -0.0012(9) 0.0105(9) -0.0033(9) C8 0.0277(11) 0.0355(13) 0.0383(13) -0.0021(10) 0.0122(10) 0.0030(9) C9 0.0274(12) 0.0555(16) 0.0465(15) -0.0066(12) 0.0135(11) -0.0012(11) C10 0.0338(12) 0.0572(16) 0.0330(13) 0.0039(11) 0.0061(10) 0.0067(11) C11 0.0715(19) 0.067(2) 0.0428(16) 0.0185(14) 0.0115(14) 0.0058(15) C12 0.0316(11) 0.0300(12) 0.0266(12) -0.0023(9) 0.0137(9) -0.0025(9) C13 0.0438(13) 0.0346(13) 0.0377(13) -0.0041(10) 0.0203(11) -0.0178(10) C14 0.0432(15) 0.0644(18) 0.0597(18) 0.0012(14) 0.0160(13) -0.0182(13) C15 0.080(2) 0.0392(15) 0.072(2) 0.0025(13) 0.0429(17) -0.0059(14) C16 0.0670(18) 0.0616(17) 0.0386(15) -0.0002(13) 0.0234(13) -0.0265(14) C17 0.0438(13) 0.0323(12) 0.0334(13) 0.0011(10) 0.0100(10) -0.0043(10) C18 0.0371(12) 0.0383(13) 0.0319(12) 0.0028(10) 0.0064(10) -0.0110(10) C19 0.0314(11) 0.0282(11) 0.0214(11) -0.0041(9) 0.0087(9) -0.0013(9) C20 0.0388(13) 0.0402(13) 0.0308(12) 0.0064(10) 0.0113(10) 0.0050(11) C21 0.0287(12) 0.0559(16) 0.0393(14) 0.0041(12) 0.0104(10) 0.0087(11) C22 0.0290(12) 0.0535(15) 0.0344(13) -0.0011(11) 0.0147(10) -0.0029(11) C23 0.0342(12) 0.0418(13) 0.0361(13) 0.0068(10) 0.0142(11) -0.0009(10) C24 0.0272(11) 0.0347(12) 0.0323(13) 0.0032(10) 0.0087(10) 0.0013(9) _geom_special_details ; All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes. ; loop_ _geom_bond_atom_site_label_1 _geom_bond_atom_site_label_2 _geom_bond_distance _geom_bond_site_symmetry_2 _geom_bond_publ_flag Si1 C18 1.850(2) . ? Si1 C17 1.868(2) . ? Si1 C19 1.876(2) . ? Si1 C3 1.878(2) . ? O1 C12 1.211(2) . ? N1 C12 1.356(2) . ? N1 C1 1.474(2) . ? C1 C6 1.527(3) . ? C1 C7 1.553(3) . ? C1 C2 1.570(3) . ? O2 C12 1.348(2) . ? O2 C13 1.469(2) . ? N2 C7 1.364(2) . ? N2 C8 1.462(3) . ? N2 C10 1.465(3) . ? C2 C3 1.527(3) . ? C2 C5 1.535(3) . ? O3 C7 1.226(2) . ? C3 C4 1.333(3) . ? C8 C9 1.518(3) . ? C10 C11 1.514(3) . ? C13 C14 1.512(3) . ? C13 C15 1.514(3) . ? C13 C16 1.521(3) . ? C19 C20 1.398(3) . ? C19 C24 1.399(3) . ? C20 C21 1.394(3) . ? C21 C22 1.378(3) . ? C22 C23 1.375(3) . ? C23 C24 1.384(3) . ? loop_ _geom_angle_atom_site_label_1 _geom_angle_atom_site_label_2 _geom_angle_atom_site_label_3 _geom_angle _geom_angle_site_symmetry_1 _geom_angle_site_symmetry_3 _geom_angle_publ_flag C18 Si1 C17 111.53(10) . . ? C18 Si1 C19 109.39(9) . . ? C17 Si1 C19 109.54(10) . . ? C18 Si1 C3 109.25(10) . . ? C17 Si1 C3 107.12(9) . . ? C19 Si1 C3 109.99(9) . . ? C12 N1 C1 119.78(16) . . ? N1 C1 C6 108.18(16) . . ? N1 C1 C7 112.58(15) . . ? C6 C1 C7 107.45(16) . . ? N1 C1 C2 107.81(14) . . ? C6 C1 C2 113.19(16) . . ? C7 C1 C2 107.72(15) . . ? C12 O2 C13 119.51(16) . . ? C7 N2 C8 128.02(17) . . ? C7 N2 C10 116.14(17) . . ? C8 N2 C10 115.76(17) . . ? C3 C2 C5 111.09(16) . . ? C3 C2 C1 114.61(16) . . ? C5 C2 C1 111.88(16) . . ? C4 C3 C2 121.42(19) . . ? C4 C3 Si1 119.32(17) . . ? C2 C3 Si1 118.71(14) . . ? O3 C7 N2 119.72(19) . . ? O3 C7 C1 118.02(17) . . ? N2 C7 C1 122.16(17) . . ? N2 C8 C9 113.65(18) . . ? N2 C10 C11 112.7(2) . . ? O1 C12 O2 125.17(19) . . ? O1 C12 N1 124.43(19) . . ? O2 C12 N1 110.39(17) . . ? O2 C13 C14 110.58(19) . . ? O2 C13 C15 109.78(18) . . ? C14 C13 C15 112.7(2) . . ? O2 C13 C16 102.41(17) . . ? C14 C13 C16 110.3(2) . . ? C15 C13 C16 110.6(2) . . ? C20 C19 C24 116.54(19) . . ? C20 C19 Si1 123.36(16) . . ? C24 C19 Si1 120.08(15) . . ? C21 C20 C19 121.7(2) . . ? C22 C21 C20 120.1(2) . . ? C23 C22 C21 119.3(2) . . ? C22 C23 C24 120.8(2) . . ? C23 C24 C19 121.6(2) . . ? loop_ _geom_torsion_atom_site_label_1 _geom_torsion_atom_site_label_2 _geom_torsion_atom_site_label_3 _geom_torsion_atom_site_label_4 _geom_torsion _geom_torsion_site_symmetry_1 _geom_torsion_site_symmetry_2 _geom_torsion_site_symmetry_3 _geom_torsion_site_symmetry_4 _geom_torsion_publ_flag C12 N1 C1 C6 61.2(2) . . . . ? C12 N1 C1 C7 -57.4(2) . . . . ? C12 N1 C1 C2 -176.04(17) . . . . ? N1 C1 C2 C3 -58.6(2) . . . . ? C6 C1 C2 C3 61.0(2) . . . . ? C7 C1 C2 C3 179.64(15) . . . . ? N1 C1 C2 C5 173.75(15) . . . . ? C6 C1 C2 C5 -66.6(2) . . . . ? C7 C1 C2 C5 52.0(2) . . . . ? C5 C2 C3 C4 56.0(3) . . . . ? C1 C2 C3 C4 -72.0(2) . . . . ? C5 C2 C3 Si1 -115.47(16) . . . . ? C1 C2 C3 Si1 116.51(16) . . . . ? C18 Si1 C3 C4 2.4(2) . . . . ? C17 Si1 C3 C4 -118.56(18) . . . . ? C19 Si1 C3 C4 122.47(17) . . . . ? C18 Si1 C3 C2 174.06(14) . . . . ? C17 Si1 C3 C2 53.11(16) . . . . ? C19 Si1 C3 C2 -65.86(16) . . . . ? C8 N2 C7 O3 175.58(18) . . . . ? C10 N2 C7 O3 -0.9(3) . . . . ? C8 N2 C7 C1 -0.6(3) . . . . ? C10 N2 C7 C1 -177.11(17) . . . . ? N1 C1 C7 O3 138.50(18) . . . . ? C6 C1 C7 O3 19.5(2) . . . . ? C2 C1 C7 O3 -102.8(2) . . . . ? N1 C1 C7 N2 -45.3(2) . . . . ? C6 C1 C7 N2 -164.26(18) . . . . ? C2 C1 C7 N2 73.5(2) . . . . ? C7 N2 C8 C9 111.1(2) . . . . ? C10 N2 C8 C9 -72.4(2) . . . . ? C7 N2 C10 C11 85.7(2) . . . . ? C8 N2 C10 C11 -91.2(2) . . . . ? C13 O2 C12 O1 -3.4(3) . . . . ? C13 O2 C12 N1 177.92(17) . . . . ? C1 N1 C12 O1 20.8(3) . . . . ? C1 N1 C12 O2 -160.52(16) . . . . ? C12 O2 C13 C14 64.3(2) . . . . ? C12 O2 C13 C15 -60.6(3) . . . . ? C12 O2 C13 C16 -178.19(19) . . . . ? C18 Si1 C19 C20 -143.10(18) . . . . ? C17 Si1 C19 C20 -20.6(2) . . . . ? C3 Si1 C19 C20 96.91(19) . . . . ? C18 Si1 C19 C24 38.60(19) . . . . ? C17 Si1 C19 C24 161.13(16) . . . . ? C3 Si1 C19 C24 -81.39(18) . . . . ? C24 C19 C20 C21 1.1(3) . . . . ? Si1 C19 C20 C21 -177.30(17) . . . . ? C19 C20 C21 C22 -0.8(4) . . . . ? C20 C21 C22 C23 0.2(4) . . . . ? C21 C22 C23 C24 0.0(3) . . . . ? C22 C23 C24 C19 0.3(3) . . . . ? C20 C19 C24 C23 -0.8(3) . . . . ? Si1 C19 C24 C23 177.59(16) . . . . ? _diffrn_measured_fraction_theta_max 0.887 _diffrn_reflns_theta_full 27.50 _diffrn_measured_fraction_theta_full 0.980 _refine_diff_density_max 0.378 _refine_diff_density_min -0.301 _refine_diff_density_rms 0.046 data_phsion _database_code_CSD 191678 _audit_creation_method SHELXL-97 _chemical_name_systematic ; 5-[2-(dimethyl-phenyl-silanyl)-1-methyl-allyl]-5-isopropyl-3 -phenyl-imidazolidine-2,4-dione ; _chemical_name_common ? _chemical_melting_point ? _chemical_formula_moiety ? _chemical_formula_sum 'C24 H30 N2 O2 Si' _chemical_formula_weight 406.59 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' 'Si' 'Si' 0.0817 0.0704 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' _symmetry_cell_setting Monoclinic _symmetry_space_group_name_H-M P2(1)/n 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' _cell_length_a 12.9645(10) _cell_length_b 7.7486(6) _cell_length_c 23.421(2) _cell_angle_alpha 90.00 _cell_angle_beta 92.797(1) _cell_angle_gamma 90.00 _cell_volume 2350.0(3) _cell_formula_units_Z 4 _cell_measurement_temperature 150(2) _cell_measurement_reflns_used 5752 _cell_measurement_theta_min 2.75 _cell_measurement_theta_max 25.95 _exptl_crystal_description lath _exptl_crystal_colour colourless _exptl_crystal_size_max 0.54 _exptl_crystal_size_mid 0.24 _exptl_crystal_size_min 0.13 _exptl_crystal_density_meas ? _exptl_crystal_density_diffrn 1.149 _exptl_crystal_density_method 'not measured' _exptl_crystal_F_000 872 _exptl_absorpt_coefficient_mu 0.121 _exptl_absorpt_correction_type none _exptl_absorpt_correction_T_min ? _exptl_absorpt_correction_T_max ? _exptl_absorpt_process_details ? _exptl_special_details ; ? ; _diffrn_ambient_temperature 150(2) _diffrn_radiation_wavelength 0.71073 _diffrn_radiation_type MoK\a _diffrn_radiation_source 'fine-focus sealed tube' _diffrn_radiation_monochromator graphite _diffrn_measurement_device_type 'Bruker SMART1000 CCD area detector' _diffrn_measurement_method omega _diffrn_detector_area_resol_mean ? _diffrn_standards_number ? _diffrn_standards_interval_count ? _diffrn_standards_interval_time ? _diffrn_standards_decay_% <1 _diffrn_reflns_number 21085 _diffrn_reflns_av_R_equivalents 0.037 _diffrn_reflns_av_sigmaI/netI 0.0375 _diffrn_reflns_limit_h_min -16 _diffrn_reflns_limit_h_max 16 _diffrn_reflns_limit_k_min -10 _diffrn_reflns_limit_k_max 10 _diffrn_reflns_limit_l_min -31 _diffrn_reflns_limit_l_max 31 _diffrn_reflns_theta_min 1.74 _diffrn_reflns_theta_max 28.83 _reflns_number_total 5587 _reflns_number_gt 3788 _reflns_threshold_expression >2sigma(I) _computing_data_collection 'Bruker SMART version 5.624 (Bruker, 2001)' _computing_cell_refinement 'Bruker SAINT version 6.02a (Bruker, 2000)' _computing_data_reduction 'Bruker SAINT; Bruker SHELXTL (Bruker, 1997)' _computing_structure_solution 'SHELXS-97 (Sheldrick, 1990)' _computing_structure_refinement 'SHELXL-97 (Sheldrick, 1997)' _computing_molecular_graphics ? _computing_publication_material 'SHELXL-97; PLATON (Spek, 2001)' _refine_special_details ; Refinement of F^2^ against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F^2^, conventional R-factors R are based on F, with F set to zero for negative F^2^. The threshold expression of F^2^ > 2sigma(F^2^) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F^2^ are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger. ; _refine_ls_structure_factor_coef Fsqd _refine_ls_matrix_type full _refine_ls_weighting_scheme calc _refine_ls_weighting_details 'calc w=1/[\s^2^(Fo^2^)+(0.0816P)^2^+0.3330P] where P=(Fo^2^+2Fc^2^)/3' _atom_sites_solution_primary direct _atom_sites_solution_secondary difmap _atom_sites_solution_hydrogens 'geometrically placed' _refine_ls_hydrogen_treatment 'riding model' _refine_ls_extinction_method none _refine_ls_extinction_coef ? _refine_ls_number_reflns 5581 _refine_ls_number_parameters 262 _refine_ls_number_restraints 6 _refine_ls_R_factor_all 0.0772 _refine_ls_R_factor_gt 0.0500 _refine_ls_wR_factor_ref 0.1493 _refine_ls_wR_factor_gt 0.1340 _refine_ls_goodness_of_fit_ref 1.032 _refine_ls_restrained_S_all 1.036 _refine_ls_shift/su_max 0.001 _refine_ls_shift/su_mean 0.000 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 _atom_site_disorder_assembly _atom_site_disorder_group Si1 Si 0.79659(4) 0.43408(7) 0.10607(2) 0.03350(16) Uani 1 1 d . . . O1 O 0.53100(9) 0.36130(15) -0.06068(5) 0.0295(3) Uani 1 1 d . . . N1 N 0.62074(11) 0.59643(18) -0.02371(6) 0.0252(3) Uani 1 1 d . . . H1A H 0.5828 0.6179 0.0056 0.030 Uiso 1 1 calc R . . C1 C 0.71106(13) 0.6999(2) -0.03705(7) 0.0262(4) Uani 1 1 d . . . O2 O 0.81918(10) 0.64179(18) -0.11820(5) 0.0374(3) Uani 1 1 d . . . N2 N 0.67913(11) 0.46924(19) -0.10017(6) 0.0265(3) Uani 1 1 d . . . C2 C 0.79167(13) 0.6940(2) 0.01440(8) 0.0289(4) Uani 1 1 d . . . H2A H 0.7567 0.7450 0.0476 0.035 Uiso 1 1 calc R . . C3 C 0.82257(13) 0.5101(2) 0.03217(8) 0.0303(4) Uani 1 1 d . . . C4 C 0.87455(15) 0.4080(3) -0.00208(9) 0.0404(5) Uani 1 1 d . . . H4A H 0.8932 0.4488 -0.0384 0.048 Uiso 1 1 calc R . . H4B H 0.8929 0.2944 0.0098 0.048 Uiso 1 1 calc R . . C5 C 0.88658(15) 0.8059(3) 0.00572(9) 0.0394(5) Uani 1 1 d . . . H5A H 0.9341 0.7974 0.0394 0.059 Uiso 1 1 calc R . . H5B H 0.8652 0.9263 0.0002 0.059 Uiso 1 1 calc R . . H5C H 0.9214 0.7658 -0.0281 0.059 Uiso 1 1 calc R . . C6 C 0.68012(15) 0.8866(2) -0.05465(8) 0.0338(4) Uani 1 1 d . . . H6A H 0.7429 0.9440 -0.0689 0.041 Uiso 1 1 calc R . . C7 C 0.64554(17) 0.9912(3) -0.00389(10) 0.0432(5) Uani 1 1 d . . . H7A H 0.6269 1.1082 -0.0165 0.065 Uiso 1 1 calc R . . H7B H 0.7020 0.9971 0.0254 0.065 Uiso 1 1 calc R . . H7C H 0.5855 0.9356 0.0121 0.065 Uiso 1 1 calc R . . C8 C 0.59717(16) 0.8891(3) -0.10334(10) 0.0432(5) Uani 1 1 d . . . H8A H 0.5798 1.0089 -0.1132 0.065 Uiso 1 1 calc R . . H8B H 0.5353 0.8295 -0.0912 0.065 Uiso 1 1 calc R . . H8C H 0.6232 0.8306 -0.1368 0.065 Uiso 1 1 calc R . . C9 C 0.60136(13) 0.4667(2) -0.06013(7) 0.0247(4) Uani 1 1 d . . . C10 C 0.74686(14) 0.6052(2) -0.08975(7) 0.0280(4) Uani 1 1 d . . . C11 C 0.68328(14) 0.3497(2) -0.14657(7) 0.0309(4) Uani 1 1 d . . . C12 C 0.60319(18) 0.3444(3) -0.18754(8) 0.0439(5) Uani 1 1 d . . . H12A H 0.5455 0.4192 -0.1850 0.053 Uiso 1 1 calc R . . C13 C 0.6078(2) 0.2283(3) -0.23266(9) 0.0576(7) Uani 1 1 d . . . H13A H 0.5530 0.2234 -0.2610 0.069 Uiso 1 1 calc R . . C14 C 0.6914(2) 0.1209(3) -0.23622(10) 0.0614(7) Uani 1 1 d . . . H14A H 0.6943 0.0423 -0.2672 0.074 Uiso 1 1 calc R . . C15 C 0.7713(2) 0.1261(3) -0.19512(11) 0.0558(6) Uani 1 1 d . . . H15A H 0.8286 0.0505 -0.1976 0.067 Uiso 1 1 calc R . . C16 C 0.76761(16) 0.2424(3) -0.15010(9) 0.0407(5) Uani 1 1 d . . . H16A H 0.8228 0.2480 -0.1219 0.049 Uiso 1 1 calc R . . C17 C 0.88806(19) 0.2567(3) 0.12735(11) 0.0570(6) Uani 1 1 d . . . H17A H 0.8770 0.1585 0.1014 0.086 Uiso 1 1 calc R . . H17B H 0.8760 0.2203 0.1665 0.086 Uiso 1 1 calc R . . H17C H 0.9592 0.2980 0.1253 0.086 Uiso 1 1 calc R . . C18 C 0.66146(16) 0.3547(3) 0.10971(9) 0.0427(5) Uani 1 1 d . . . H18A H 0.6507 0.2567 0.0836 0.064 Uiso 1 1 calc R . . H18B H 0.6133 0.4476 0.0986 0.064 Uiso 1 1 calc R . . H18C H 0.6493 0.3179 0.1489 0.064 Uiso 1 1 calc R . . C19 C 0.81863(18) 0.6212(3) 0.15576(9) 0.0471(6) Uani 1 1 d D . . C20 C 0.9166(2) 0.6503(4) 0.18265(10) 0.0650(7) Uani 1 1 d D . . H20A H 0.9712 0.5736 0.1747 0.078 Uiso 1 1 calc R . . C21 C 0.9368(3) 0.7842(4) 0.21984(12) 0.0854(10) Uani 1 1 d D . . H21A H 1.0036 0.7998 0.2376 0.102 Uiso 1 1 calc R . . C22 C 0.8578(3) 0.8943(4) 0.23053(13) 0.0817(10) Uani 1 1 d D . . H22A H 0.8711 0.9883 0.2559 0.098 Uiso 1 1 calc R . . C23 C 0.7600(3) 0.8753(4) 0.20628(12) 0.0820(10) Uani 1 1 d D . . H23A H 0.7066 0.9536 0.2149 0.098 Uiso 1 1 calc R . . C24 C 0.7403(2) 0.7347(3) 0.16774(10) 0.0621(7) Uani 1 1 d D . . H24A H 0.6732 0.7192 0.1503 0.075 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 Si1 0.0327(3) 0.0362(3) 0.0311(3) 0.0019(2) -0.0030(2) 0.0001(2) O1 0.0281(6) 0.0270(6) 0.0339(7) -0.0007(5) 0.0082(5) -0.0015(5) N1 0.0230(7) 0.0268(7) 0.0263(7) 0.0002(6) 0.0069(6) 0.0015(6) C1 0.0223(8) 0.0297(9) 0.0271(9) 0.0001(7) 0.0046(7) -0.0012(7) O2 0.0316(7) 0.0500(8) 0.0314(7) 0.0002(6) 0.0114(6) -0.0081(6) N2 0.0264(7) 0.0304(8) 0.0232(7) 0.0000(6) 0.0057(6) 0.0000(6) C2 0.0266(9) 0.0333(10) 0.0268(9) -0.0037(7) 0.0016(7) 0.0027(7) C3 0.0241(9) 0.0355(10) 0.0309(9) -0.0023(8) -0.0036(7) 0.0033(7) C4 0.0382(11) 0.0458(12) 0.0367(11) -0.0029(9) -0.0019(9) 0.0131(9) C5 0.0302(10) 0.0437(11) 0.0437(11) -0.0038(9) -0.0034(8) -0.0033(8) C6 0.0310(10) 0.0294(9) 0.0408(11) 0.0065(8) 0.0002(8) -0.0017(7) C7 0.0422(12) 0.0308(10) 0.0565(13) 0.0002(9) 0.0010(10) 0.0085(9) C8 0.0412(12) 0.0369(11) 0.0504(12) 0.0150(9) -0.0099(10) -0.0037(9) C9 0.0242(8) 0.0254(9) 0.0246(8) 0.0037(7) 0.0026(7) 0.0051(7) C10 0.0269(9) 0.0333(9) 0.0238(8) 0.0028(7) 0.0023(7) 0.0013(7) C11 0.0394(10) 0.0321(10) 0.0219(8) 0.0010(7) 0.0090(7) -0.0034(8) C12 0.0568(13) 0.0449(12) 0.0296(10) 0.0009(9) -0.0017(9) -0.0023(10) C13 0.0835(18) 0.0594(15) 0.0291(11) -0.0039(10) -0.0069(11) -0.0152(14) C14 0.096(2) 0.0533(15) 0.0371(13) -0.0164(11) 0.0262(14) -0.0167(14) C15 0.0620(15) 0.0506(14) 0.0574(15) -0.0156(11) 0.0305(13) -0.0013(12) C16 0.0404(11) 0.0428(11) 0.0400(11) -0.0067(9) 0.0139(9) -0.0005(9) C17 0.0540(14) 0.0615(15) 0.0551(14) 0.0182(12) -0.0027(11) 0.0111(12) C18 0.0407(11) 0.0485(12) 0.0389(11) -0.0005(9) 0.0025(9) -0.0039(10) C19 0.0649(15) 0.0488(13) 0.0279(10) -0.0002(9) 0.0071(10) -0.0156(11) C20 0.0807(19) 0.0728(18) 0.0404(13) -0.0019(12) -0.0072(12) -0.0308(15) C21 0.106(3) 0.092(2) 0.0563(17) -0.0073(17) -0.0080(17) -0.042(2) C22 0.125(3) 0.0669(19) 0.0540(17) -0.0088(14) 0.0118(19) -0.035(2) C23 0.124(3) 0.0672(19) 0.0579(18) -0.0036(14) 0.0409(19) -0.0049(19) C24 0.093(2) 0.0485(14) 0.0467(14) -0.0051(11) 0.0231(14) -0.0077(14) _geom_special_details ; All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes. ; loop_ _geom_bond_atom_site_label_1 _geom_bond_atom_site_label_2 _geom_bond_distance _geom_bond_site_symmetry_2 _geom_bond_publ_flag Si1 C18 1.863(2) . ? Si1 C17 1.867(2) . ? Si1 C19 1.873(2) . ? Si1 C3 1.8741(19) . ? O1 C9 1.224(2) . ? N1 C9 1.334(2) . ? N1 C1 1.465(2) . ? C1 C10 1.527(2) . ? C1 C6 1.552(2) . ? C1 C2 1.557(2) . ? O2 C10 1.210(2) . ? N2 C10 1.386(2) . ? N2 C9 1.410(2) . ? N2 C11 1.431(2) . ? C2 C5 1.527(3) . ? C2 C3 1.533(3) . ? C3 C4 1.333(3) . ? C6 C7 1.524(3) . ? C6 C8 1.529(3) . ? C11 C16 1.379(3) . ? C11 C12 1.380(3) . ? C12 C13 1.391(3) . ? C13 C14 1.373(4) . ? C14 C15 1.380(4) . ? C15 C16 1.390(3) . ? C19 C24 1.382(3) . ? C19 C20 1.408(3) . ? C20 C21 1.372(4) . ? C21 C22 1.366(4) . ? C22 C23 1.371(4) . ? C23 C24 1.430(4) . ? loop_ _geom_angle_atom_site_label_1 _geom_angle_atom_site_label_2 _geom_angle_atom_site_label_3 _geom_angle _geom_angle_site_symmetry_1 _geom_angle_site_symmetry_3 _geom_angle_publ_flag C18 Si1 C17 109.32(11) . . ? C18 Si1 C19 110.04(10) . . ? C17 Si1 C19 109.18(12) . . ? C18 Si1 C3 110.97(9) . . ? C17 Si1 C3 109.72(10) . . ? C19 Si1 C3 107.57(9) . . ? C9 N1 C1 113.78(14) . . ? N1 C1 C10 100.79(13) . . ? N1 C1 C6 111.57(14) . . ? C10 C1 C6 108.53(14) . . ? N1 C1 C2 109.41(14) . . ? C10 C1 C2 113.12(14) . . ? C6 C1 C2 112.82(14) . . ? C10 N2 C9 111.15(14) . . ? C10 N2 C11 125.38(14) . . ? C9 N2 C11 123.41(14) . . ? C5 C2 C3 111.25(15) . . ? C5 C2 C1 113.30(15) . . ? C3 C2 C1 113.20(14) . . ? C4 C3 C2 121.44(18) . . ? C4 C3 Si1 119.23(15) . . ? C2 C3 Si1 119.13(12) . . ? C7 C6 C8 110.60(17) . . ? C7 C6 C1 111.77(16) . . ? C8 C6 C1 111.93(15) . . ? O1 C9 N1 128.78(16) . . ? O1 C9 N2 123.98(15) . . ? N1 C9 N2 107.23(14) . . ? O2 C10 N2 125.61(17) . . ? O2 C10 C1 127.37(17) . . ? N2 C10 C1 107.01(14) . . ? C16 C11 C12 120.82(18) . . ? C16 C11 N2 119.67(17) . . ? C12 C11 N2 119.51(17) . . ? C11 C12 C13 119.3(2) . . ? C14 C13 C12 120.1(2) . . ? C13 C14 C15 120.5(2) . . ? C14 C15 C16 119.7(2) . . ? C11 C16 C15 119.6(2) . . ? C24 C19 C20 117.6(2) . . ? C24 C19 Si1 121.82(18) . . ? C20 C19 Si1 120.59(19) . . ? C21 C20 C19 123.0(3) . . ? C22 C21 C20 117.9(3) . . ? C21 C22 C23 122.9(3) . . ? C22 C23 C24 118.5(3) . . ? C19 C24 C23 120.1(3) . . ? loop_ _geom_torsion_atom_site_label_1 _geom_torsion_atom_site_label_2 _geom_torsion_atom_site_label_3 _geom_torsion_atom_site_label_4 _geom_torsion _geom_torsion_site_symmetry_1 _geom_torsion_site_symmetry_2 _geom_torsion_site_symmetry_3 _geom_torsion_site_symmetry_4 _geom_torsion_publ_flag C9 N1 C1 C10 -1.04(18) . . . . ? C9 N1 C1 C6 114.00(16) . . . . ? C9 N1 C1 C2 -120.45(15) . . . . ? N1 C1 C2 C5 -177.08(14) . . . . ? C10 C1 C2 C5 71.43(19) . . . . ? C6 C1 C2 C5 -52.2(2) . . . . ? N1 C1 C2 C3 55.05(18) . . . . ? C10 C1 C2 C3 -56.44(19) . . . . ? C6 C1 C2 C3 179.88(15) . . . . ? C5 C2 C3 C4 -62.5(2) . . . . ? C1 C2 C3 C4 66.4(2) . . . . ? C5 C2 C3 Si1 112.16(15) . . . . ? C1 C2 C3 Si1 -118.91(14) . . . . ? C18 Si1 C3 C4 -101.40(17) . . . . ? C17 Si1 C3 C4 19.53(19) . . . . ? C19 Si1 C3 C4 138.19(17) . . . . ? C18 Si1 C3 C2 83.78(15) . . . . ? C17 Si1 C3 C2 -155.29(15) . . . . ? C19 Si1 C3 C2 -36.63(16) . . . . ? N1 C1 C6 C7 71.07(19) . . . . ? C10 C1 C6 C7 -178.76(15) . . . . ? C2 C1 C6 C7 -52.6(2) . . . . ? N1 C1 C6 C8 -53.6(2) . . . . ? C10 C1 C6 C8 56.5(2) . . . . ? C2 C1 C6 C8 -177.28(16) . . . . ? C1 N1 C9 O1 -178.56(16) . . . . ? C1 N1 C9 N2 1.66(18) . . . . ? C10 N2 C9 O1 178.58(16) . . . . ? C11 N2 C9 O1 1.0(3) . . . . ? C10 N2 C9 N1 -1.63(19) . . . . ? C11 N2 C9 N1 -179.22(15) . . . . ? C9 N2 C10 O2 -177.82(17) . . . . ? C11 N2 C10 O2 -0.3(3) . . . . ? C9 N2 C10 C1 0.97(18) . . . . ? C11 N2 C10 C1 178.50(15) . . . . ? N1 C1 C10 O2 178.76(18) . . . . ? C6 C1 C10 O2 61.5(2) . . . . ? C2 C1 C10 O2 -64.5(2) . . . . ? N1 C1 C10 N2 0.00(17) . . . . ? C6 C1 C10 N2 -117.30(15) . . . . ? C2 C1 C10 N2 116.70(16) . . . . ? C10 N2 C11 C16 63.6(2) . . . . ? C9 N2 C11 C16 -119.16(19) . . . . ? C10 N2 C11 C12 -115.8(2) . . . . ? C9 N2 C11 C12 61.4(2) . . . . ? C16 C11 C12 C13 0.4(3) . . . . ? N2 C11 C12 C13 179.80(18) . . . . ? C11 C12 C13 C14 -0.2(3) . . . . ? C12 C13 C14 C15 0.4(4) . . . . ? C13 C14 C15 C16 -0.7(4) . . . . ? C12 C11 C16 C15 -0.8(3) . . . . ? N2 C11 C16 C15 179.83(18) . . . . ? C14 C15 C16 C11 0.9(3) . . . . ? C18 Si1 C19 C24 -31.3(2) . . . . ? C17 Si1 C19 C24 -151.32(19) . . . . ? C3 Si1 C19 C24 89.67(19) . . . . ? C18 Si1 C19 C20 148.27(18) . . . . ? C17 Si1 C19 C20 28.3(2) . . . . ? C3 Si1 C19 C20 -90.73(19) . . . . ? C24 C19 C20 C21 0.3(4) . . . . ? Si1 C19 C20 C21 -179.3(2) . . . . ? C19 C20 C21 C22 -0.6(4) . . . . ? C20 C21 C22 C23 0.7(5) . . . . ? C21 C22 C23 C24 -0.6(5) . . . . ? C20 C19 C24 C23 -0.1(3) . . . . ? Si1 C19 C24 C23 179.51(19) . . . . ? C22 C23 C24 C19 0.2(4) . . . . ? loop_ _geom_hbond_atom_site_label_D _geom_hbond_atom_site_label_H _geom_hbond_atom_site_label_A _geom_hbond_distance_DH _geom_hbond_distance_HA _geom_hbond_distance_DA _geom_hbond_angle_DHA _geom_hbond_site_symmetry_A N1 H1A O1 0.88 2.01 2.8746(18) 166.0 3_665 _diffrn_measured_fraction_theta_max 0.905 _diffrn_reflns_theta_full 27.50 _diffrn_measured_fraction_theta_full 0.990 _refine_diff_density_max 0.727 _refine_diff_density_min -0.252 _refine_diff_density_rms 0.053