# Copyright The Royal Society of Chemistry, 1999 # CCDC Number: 182/1209 data_free _audit_creation_method SHELXL-97 _chemical_name_systematic ; ? ; _chemical_name_common ? _chemical_melting_point ? _chemical_formula_moiety ? _chemical_formula_sum 'C20 H33 Ta' _chemical_formula_weight 454.41 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' 'Ta' 'Ta' -0.7052 6.5227 '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 13.0260(6) _cell_length_b 19.2190(9) _cell_length_c 16.1034(7) _cell_angle_alpha 90.00 _cell_angle_beta 110.5170(10) _cell_angle_gamma 90.00 _cell_volume 3775.7(3) _cell_formula_units_Z 8 _cell_measurement_temperature 203(2) _cell_measurement_reflns_used ? _cell_measurement_theta_min ? _cell_measurement_theta_max ? _exptl_crystal_description ? _exptl_crystal_colour ? _exptl_crystal_size_max 0.30 _exptl_crystal_size_mid 0.20 _exptl_crystal_size_min 0.20 _exptl_crystal_density_meas ? _exptl_crystal_density_diffrn 1.599 _exptl_crystal_density_method 'not measured' _exptl_crystal_F_000 1808 _exptl_absorpt_coefficient_mu 5.816 _exptl_absorpt_correction_type none _exptl_absorpt_correction_T_min 0.2743 _exptl_absorpt_correction_T_max 0.3892 _exptl_absorpt_process_details ? _exptl_special_details ; ? ; _diffrn_ambient_temperature 203(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 ? _diffrn_measurement_method '\w scans' _diffrn_detector_area_resol_mean ? _diffrn_standards_number ? _diffrn_standards_interval_count ? _diffrn_standards_interval_time ? _diffrn_standards_decay_% ? _diffrn_reflns_number 27469 _diffrn_reflns_av_R_equivalents 0.0282 _diffrn_reflns_av_sigmaI/netI 0.0281 _diffrn_reflns_limit_h_min -17 _diffrn_reflns_limit_h_max 16 _diffrn_reflns_limit_k_min -24 _diffrn_reflns_limit_k_max 24 _diffrn_reflns_limit_l_min -21 _diffrn_reflns_limit_l_max 20 _diffrn_reflns_theta_min 1.72 _diffrn_reflns_theta_max 28.45 _reflns_number_total 8823 _reflns_number_gt 8013 _reflns_threshold_expression >2sigma(I) _computing_data_collection 'Siemens XSCANS' _computing_cell_refinement 'Siemens XSCANS' _computing_data_reduction 'Siemens SHELXTL' _computing_structure_solution 'SHELXS-97 (Sheldrick, 1990)' _computing_structure_refinement 'SHELXL-97 (Sheldrick, 1997)' _computing_molecular_graphics 'Siemens SHELXTL' _computing_publication_material 'Siemens SHELXTL' _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^)+(0.0186P)^2^+3.9817P] where P=(Fo^2^+2Fc^2^)/3' _atom_sites_solution_primary direct _atom_sites_solution_secondary difmap _atom_sites_solution_hydrogens geom _refine_ls_hydrogen_treatment mixed _refine_ls_extinction_method SHELXL _refine_ls_extinction_coef 0.00042(3) _refine_ls_extinction_expression 'Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^' _refine_ls_number_reflns 8823 _refine_ls_number_parameters 424 _refine_ls_number_restraints 0 _refine_ls_R_factor_all 0.0270 _refine_ls_R_factor_gt 0.0227 _refine_ls_wR_factor_ref 0.0522 _refine_ls_wR_factor_gt 0.0508 _refine_ls_goodness_of_fit_ref 1.032 _refine_ls_restrained_S_all 1.032 _refine_ls_shift/su_max 0.003 _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 Ta1 Ta 0.254909(10) 0.141384(6) 0.655798(8) 0.02900(4) Uani 1 1 d . . . H11 H 0.189(4) 0.118(2) 0.545(3) 0.083(16) Uiso 1 1 d . . . H12 H 0.307(4) 0.184(3) 0.587(3) 0.100(17) Uiso 1 1 d . . . H13 H 0.339(4) 0.199(2) 0.692(3) 0.078(14) Uiso 1 1 d . . . C11 C 0.0726(3) 0.18401(19) 0.5746(2) 0.0371(7) Uani 1 1 d . . . C12 C 0.0651(2) 0.13881(17) 0.6420(2) 0.0345(7) Uani 1 1 d . . . C13 C 0.1226(2) 0.17057(17) 0.72528(19) 0.0304(6) Uani 1 1 d . . . C14 C 0.1688(2) 0.23382(16) 0.7094(2) 0.0309(6) Uani 1 1 d . . . C15 C 0.1386(2) 0.24218(17) 0.6156(2) 0.0333(7) Uani 1 1 d . . . C21 C 0.3991(2) 0.06691(16) 0.6449(2) 0.0314(6) Uani 1 1 d . . . C22 C 0.4420(2) 0.09993(16) 0.7282(2) 0.0319(6) Uani 1 1 d . . . C23 C 0.3786(3) 0.07918(16) 0.78005(19) 0.0318(6) Uani 1 1 d . . . C24 C 0.2984(2) 0.03016(15) 0.7296(2) 0.0303(6) Uani 1 1 d . . . C25 C 0.3103(2) 0.02319(16) 0.6452(2) 0.0310(6) Uani 1 1 d . . . C31 C 0.0103(3) 0.1763(3) 0.4769(2) 0.0613(12) Uani 1 1 d . . . H31A H 0.0497 0.1997 0.4438 0.092 Uiso 1 1 calc R . . H31B H -0.0619 0.1968 0.4624 0.092 Uiso 1 1 calc R . . H31C H 0.0030 0.1273 0.4614 0.092 Uiso 1 1 calc R . . C32 C -0.0073(3) 0.0757(2) 0.6263(3) 0.0523(10) Uani 1 1 d . . . H32A H 0.0111 0.0490 0.6807 0.078 Uiso 1 1 calc R . . H32B H 0.0036 0.0472 0.5804 0.078 Uiso 1 1 calc R . . H32C H -0.0834 0.0902 0.6078 0.078 Uiso 1 1 calc R . . C33 C 0.1201(3) 0.14785(19) 0.8141(2) 0.0405(8) Uani 1 1 d . . . H33A H 0.0617 0.1721 0.8263 0.061 Uiso 1 1 calc R . . H33B H 0.1897 0.1587 0.8598 0.061 Uiso 1 1 calc R . . H33C H 0.1072 0.0981 0.8132 0.061 Uiso 1 1 calc R . . C34 C 0.2253(3) 0.2868(2) 0.7778(3) 0.0494(9) Uani 1 1 d . . . H34A H 0.2672 0.2635 0.8326 0.074 Uiso 1 1 calc R . . H34B H 0.1712 0.3170 0.7879 0.074 Uiso 1 1 calc R . . H34C H 0.2742 0.3143 0.7573 0.074 Uiso 1 1 calc R . . C35 C 0.1620(3) 0.30426(19) 0.5690(3) 0.0470(9) Uani 1 1 d . . . H35A H 0.2304 0.3254 0.6059 0.070 Uiso 1 1 calc R . . H35B H 0.1030 0.3377 0.5580 0.070 Uiso 1 1 calc R . . H35C H 0.1678 0.2899 0.5131 0.070 Uiso 1 1 calc R . . C41 C 0.4464(3) 0.0715(2) 0.5725(2) 0.0493(9) Uani 1 1 d . . . H41A H 0.3885 0.0656 0.5155 0.074 Uiso 1 1 calc R . . H41B H 0.5009 0.0353 0.5807 0.074 Uiso 1 1 calc R . . H41C H 0.4805 0.1167 0.5747 0.074 Uiso 1 1 calc R . . C42 C 0.5442(3) 0.14267(19) 0.7607(3) 0.0480(9) Uani 1 1 d . . . H42A H 0.6067 0.1125 0.7878 0.072 Uiso 1 1 calc R . . H42B H 0.5386 0.1760 0.8041 0.072 Uiso 1 1 calc R . . H42C H 0.5535 0.1672 0.7112 0.072 Uiso 1 1 calc R . . C43 C 0.4039(3) 0.0982(2) 0.8758(2) 0.0481(9) Uani 1 1 d . . . H43A H 0.3424 0.0856 0.8934 0.072 Uiso 1 1 calc R . . H43B H 0.4169 0.1478 0.8833 0.072 Uiso 1 1 calc R . . H43C H 0.4688 0.0732 0.9123 0.072 Uiso 1 1 calc R . . C44 C 0.2278(3) -0.01526(17) 0.7632(2) 0.0423(8) Uani 1 1 d . . . H44A H 0.2020 0.0112 0.8033 0.063 Uiso 1 1 calc R . . H44B H 0.2701 -0.0548 0.7944 0.063 Uiso 1 1 calc R . . H44C H 0.1654 -0.0316 0.7136 0.063 Uiso 1 1 calc R . . C45 C 0.2497(3) -0.0277(2) 0.5742(2) 0.0490(9) Uani 1 1 d . . . H45A H 0.2876 -0.0720 0.5854 0.074 Uiso 1 1 calc R . . H45B H 0.2462 -0.0100 0.5169 0.074 Uiso 1 1 calc R . . H45C H 0.1759 -0.0339 0.5746 0.074 Uiso 1 1 calc R . . Ta2 Ta 0.701434(10) 0.376820(6) 0.631588(7) 0.02777(4) Uani 1 1 d . . . H21 H 0.582(4) 0.411(3) 0.585(3) 0.088(16) Uiso 1 1 d . . . H22 H 0.635(5) 0.387(3) 0.522(4) 0.097(18) Uiso 1 1 d . . . H23 H 0.764(4) 0.344(3) 0.557(3) 0.083(16) Uiso 1 1 d . . . C51 C 0.7322(3) 0.25827(18) 0.6825(2) 0.0396(7) Uani 1 1 d . . . C52 C 0.6511(3) 0.25628(17) 0.5956(2) 0.0378(7) Uani 1 1 d . . . C53 C 0.5574(2) 0.29086(16) 0.59815(19) 0.0323(6) Uani 1 1 d . . . C54 C 0.5788(2) 0.31457(17) 0.6867(2) 0.0327(6) Uani 1 1 d . . . C55 C 0.6862(2) 0.29291(17) 0.7387(2) 0.0339(7) Uani 1 1 d . . . C61 C 0.7130(3) 0.50078(17) 0.6590(2) 0.0357(7) Uani 1 1 d . . . C62 C 0.7745(3) 0.48529(16) 0.6044(2) 0.0330(6) Uani 1 1 d . . . C63 C 0.8657(2) 0.44335(16) 0.6530(2) 0.0319(6) Uani 1 1 d . . . C64 C 0.8595(2) 0.43165(16) 0.73818(19) 0.0304(6) Uani 1 1 d . . . C65 C 0.7649(3) 0.46717(16) 0.74194(19) 0.0329(6) Uani 1 1 d . . . C71 C 0.8419(4) 0.2221(2) 0.7112(4) 0.0704(13) Uani 1 1 d . . . H71A H 0.8839 0.2347 0.7720 0.106 Uiso 1 1 calc R . . H71B H 0.8815 0.2362 0.6730 0.106 Uiso 1 1 calc R . . H71C H 0.8309 0.1721 0.7071 0.106 Uiso 1 1 calc R . . C72 C 0.6621(4) 0.2175(2) 0.5184(3) 0.0662(13) Uani 1 1 d . . . H72A H 0.7374 0.2199 0.5208 0.099 Uiso 1 1 calc R . . H72B H 0.6143 0.2383 0.4636 0.099 Uiso 1 1 calc R . . H72C H 0.6416 0.1692 0.5210 0.099 Uiso 1 1 calc R . . C73 C 0.4489(3) 0.2958(2) 0.5232(2) 0.0518(10) Uani 1 1 d . . . H73A H 0.4038 0.2561 0.5251 0.078 Uiso 1 1 calc R . . H73B H 0.4611 0.2961 0.4671 0.078 Uiso 1 1 calc R . . H73C H 0.4120 0.3383 0.5290 0.078 Uiso 1 1 calc R . . C74 C 0.4957(3) 0.3474(2) 0.7198(3) 0.0511(9) Uani 1 1 d . . . H74A H 0.4466 0.3765 0.6737 0.077 Uiso 1 1 calc R . . H74B H 0.5330 0.3757 0.7716 0.077 Uiso 1 1 calc R . . H74C H 0.4538 0.3113 0.7357 0.077 Uiso 1 1 calc R . . C75 C 0.7336(3) 0.2948(2) 0.8387(2) 0.0559(11) Uani 1 1 d . . . H75A H 0.6993 0.3320 0.8604 0.084 Uiso 1 1 calc R . . H75B H 0.8120 0.3029 0.8578 0.084 Uiso 1 1 calc R . . H75C H 0.7199 0.2507 0.8623 0.084 Uiso 1 1 calc R . . C81 C 0.6187(4) 0.5502(2) 0.6377(3) 0.0608(12) Uani 1 1 d . . . H81A H 0.5734 0.5381 0.6722 0.091 Uiso 1 1 calc R . . H81B H 0.5754 0.5473 0.5750 0.091 Uiso 1 1 calc R . . H81C H 0.6462 0.5972 0.6520 0.091 Uiso 1 1 calc R . . C82 C 0.7527(3) 0.51634(19) 0.5133(2) 0.0482(9) Uani 1 1 d . . . H82A H 0.7879 0.5615 0.5193 0.072 Uiso 1 1 calc R . . H82B H 0.6743 0.5216 0.4831 0.072 Uiso 1 1 calc R . . H82C H 0.7820 0.4858 0.4791 0.072 Uiso 1 1 calc R . . C83 C 0.9596(3) 0.4209(2) 0.6257(3) 0.0512(9) Uani 1 1 d . . . H83A H 1.0196 0.4537 0.6486 0.077 Uiso 1 1 calc R . . H83B H 0.9360 0.4196 0.5615 0.077 Uiso 1 1 calc R . . H83C H 0.9839 0.3750 0.6494 0.077 Uiso 1 1 calc R . . C84 C 0.9485(3) 0.39690(19) 0.8135(2) 0.0410(7) Uani 1 1 d . . . H84A H 0.9241 0.3914 0.8636 0.062 Uiso 1 1 calc R . . H84B H 1.0141 0.4254 0.8310 0.062 Uiso 1 1 calc R . . H84C H 0.9645 0.3516 0.7945 0.062 Uiso 1 1 calc R . . C85 C 0.7345(3) 0.4780(2) 0.8232(2) 0.0479(9) Uani 1 1 d . . . H85A H 0.7703 0.4429 0.8672 0.072 Uiso 1 1 calc R . . H85B H 0.6557 0.4740 0.8071 0.072 Uiso 1 1 calc R . . H85C H 0.7581 0.5238 0.8475 0.072 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 Ta1 0.02911(7) 0.02642(7) 0.03584(7) 0.00616(5) 0.01684(5) 0.00255(4) C11 0.0298(15) 0.051(2) 0.0280(15) 0.0018(14) 0.0075(12) 0.0013(13) C12 0.0261(14) 0.0437(19) 0.0356(16) -0.0044(13) 0.0135(12) -0.0059(12) C13 0.0250(14) 0.0383(17) 0.0298(14) 0.0014(12) 0.0119(11) 0.0027(11) C14 0.0281(14) 0.0322(16) 0.0338(15) -0.0025(12) 0.0125(12) 0.0030(11) C15 0.0265(14) 0.0367(17) 0.0379(16) 0.0081(13) 0.0130(12) 0.0103(12) C21 0.0278(14) 0.0328(16) 0.0354(16) 0.0058(12) 0.0134(12) 0.0065(11) C22 0.0292(14) 0.0291(15) 0.0351(15) 0.0044(12) 0.0085(12) -0.0017(11) C23 0.0359(16) 0.0276(15) 0.0286(14) 0.0040(11) 0.0070(12) -0.0013(12) C24 0.0326(15) 0.0230(14) 0.0338(15) 0.0030(11) 0.0098(12) -0.0032(11) C25 0.0300(15) 0.0283(15) 0.0323(15) -0.0024(12) 0.0078(12) 0.0016(11) C31 0.048(2) 0.096(4) 0.0323(18) 0.001(2) 0.0047(16) 0.000(2) C32 0.0401(19) 0.063(3) 0.054(2) -0.0114(19) 0.0175(17) -0.0213(17) C33 0.0422(18) 0.051(2) 0.0343(17) 0.0047(14) 0.0207(14) 0.0018(15) C34 0.052(2) 0.044(2) 0.053(2) -0.0139(17) 0.0201(18) -0.0083(16) C35 0.049(2) 0.042(2) 0.057(2) 0.0211(17) 0.0279(17) 0.0177(16) C41 0.047(2) 0.062(3) 0.048(2) 0.0099(18) 0.0287(17) 0.0124(17) C42 0.0348(18) 0.042(2) 0.062(2) 0.0057(17) 0.0105(16) -0.0067(14) C43 0.058(2) 0.053(2) 0.0286(16) -0.0041(15) 0.0097(15) -0.0072(17) C44 0.048(2) 0.0306(17) 0.052(2) 0.0086(15) 0.0216(16) -0.0077(14) C45 0.052(2) 0.046(2) 0.0424(19) -0.0130(16) 0.0082(16) -0.0057(16) Ta2 0.02894(7) 0.02796(7) 0.02386(6) 0.00299(4) 0.00605(5) -0.00399(4) C51 0.0369(17) 0.0341(18) 0.0469(19) 0.0152(14) 0.0136(14) 0.0066(13) C52 0.055(2) 0.0271(16) 0.0358(16) -0.0003(13) 0.0209(15) -0.0060(14) C53 0.0329(15) 0.0313(16) 0.0276(14) 0.0051(12) 0.0042(12) -0.0081(12) C54 0.0297(15) 0.0352(17) 0.0335(15) 0.0045(12) 0.0114(12) -0.0047(12) C55 0.0318(15) 0.0381(17) 0.0287(15) 0.0100(12) 0.0067(12) -0.0062(12) C61 0.0452(18) 0.0291(16) 0.0332(16) -0.0058(12) 0.0144(14) 0.0080(13) C62 0.0442(18) 0.0233(15) 0.0342(16) 0.0009(12) 0.0172(14) -0.0028(12) C63 0.0331(15) 0.0298(16) 0.0355(16) -0.0056(12) 0.0155(13) -0.0055(12) C64 0.0292(14) 0.0299(15) 0.0296(14) -0.0053(12) 0.0072(12) -0.0043(11) C65 0.0379(16) 0.0337(16) 0.0262(14) -0.0059(12) 0.0102(12) 0.0039(12) C71 0.056(3) 0.059(3) 0.099(4) 0.028(3) 0.031(3) 0.025(2) C72 0.105(4) 0.038(2) 0.074(3) -0.015(2) 0.054(3) -0.012(2) C73 0.043(2) 0.057(2) 0.0386(19) 0.0083(16) -0.0064(15) -0.0190(17) C74 0.041(2) 0.063(3) 0.057(2) -0.0020(19) 0.0269(18) -0.0024(17) C75 0.054(2) 0.073(3) 0.0295(17) 0.0181(17) 0.0008(16) -0.0201(19) C81 0.072(3) 0.061(3) 0.047(2) 0.0025(19) 0.017(2) 0.037(2) C82 0.072(3) 0.038(2) 0.0407(19) 0.0077(15) 0.0265(18) 0.0008(17) C83 0.0407(19) 0.066(3) 0.056(2) -0.0025(19) 0.0284(17) -0.0016(17) C84 0.0327(16) 0.044(2) 0.0383(17) -0.0020(15) 0.0029(13) 0.0005(14) C85 0.054(2) 0.060(2) 0.0325(17) -0.0080(16) 0.0191(16) 0.0104(17) _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 Ta1 H13 1.52(5) . ? Ta1 H12 1.70(5) . ? Ta1 H11 1.75(5) . ? Ta1 C23 2.402(3) . ? Ta1 C12 2.404(3) . ? Ta1 C15 2.404(3) . ? Ta1 C25 2.408(3) . ? Ta1 C24 2.415(3) . ? Ta1 C21 2.416(3) . ? Ta1 C14 2.416(3) . ? Ta1 C11 2.417(3) . ? Ta1 C13 2.427(3) . ? Ta1 C22 2.437(3) . ? C11 C12 1.420(5) . ? C11 C15 1.423(5) . ? C11 C31 1.503(5) . ? C12 C13 1.424(4) . ? C12 C32 1.503(5) . ? C13 C14 1.419(4) . ? C13 C33 1.506(4) . ? C14 C15 1.430(4) . ? C14 C34 1.491(4) . ? C15 C35 1.496(5) . ? C21 C22 1.411(4) . ? C21 C25 1.430(4) . ? C21 C41 1.500(4) . ? C22 C23 1.421(4) . ? C22 C42 1.494(4) . ? C23 C24 1.430(4) . ? C23 C43 1.504(4) . ? C24 C25 1.428(4) . ? C24 C44 1.500(4) . ? C25 C45 1.501(4) . ? Ta2 H21 1.61(5) . ? Ta2 H22 1.69(5) . ? Ta2 H23 1.79(5) . ? Ta2 C62 2.395(3) . ? Ta2 C54 2.401(3) . ? Ta2 C51 2.407(3) . ? Ta2 C63 2.411(3) . ? Ta2 C64 2.412(3) . ? Ta2 C65 2.414(3) . ? Ta2 C53 2.415(3) . ? Ta2 C61 2.418(3) . ? Ta2 C55 2.420(3) . ? Ta2 C52 2.422(3) . ? C51 C55 1.415(5) . ? C51 C52 1.427(5) . ? C51 C71 1.510(5) . ? C52 C53 1.404(5) . ? C52 C72 1.498(5) . ? C53 C54 1.429(4) . ? C53 C73 1.506(4) . ? C54 C55 1.418(4) . ? C54 C74 1.504(5) . ? C55 C75 1.510(4) . ? C61 C62 1.413(4) . ? C61 C65 1.424(4) . ? C61 C81 1.494(5) . ? C62 C63 1.421(4) . ? C62 C82 1.516(4) . ? C63 C64 1.419(4) . ? C63 C83 1.501(4) . ? C64 C65 1.429(4) . ? C64 C84 1.508(4) . ? C65 C85 1.508(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 H13 Ta1 H12 60(2) . . ? H13 Ta1 H11 127(2) . . ? H12 Ta1 H11 68(2) . . ? H13 Ta1 C23 82.3(17) . . ? H12 Ta1 C23 118.5(18) . . ? H11 Ta1 C23 131.9(16) . . ? H13 Ta1 C12 128.8(17) . . ? H12 Ta1 C12 125.7(18) . . ? H11 Ta1 C12 77.5(17) . . ? C23 Ta1 C12 115.77(11) . . ? H13 Ta1 C15 79.2(17) . . ? H12 Ta1 C15 78.1(18) . . ? H11 Ta1 C15 84.1(16) . . ? C23 Ta1 C15 143.21(11) . . ? C12 Ta1 C15 57.39(11) . . ? H13 Ta1 C25 121.6(17) . . ? H12 Ta1 C25 102.3(19) . . ? H11 Ta1 C25 74.6(16) . . ? C23 Ta1 C25 57.27(10) . . ? C12 Ta1 C25 107.35(11) . . ? C15 Ta1 C25 156.55(11) . . ? H13 Ta1 C24 116.6(17) . . ? H12 Ta1 C24 132.1(18) . . ? H11 Ta1 C24 102.8(16) . . ? C23 Ta1 C24 34.53(10) . . ? C12 Ta1 C24 94.79(11) . . ? C15 Ta1 C24 149.63(10) . . ? C25 Ta1 C24 34.45(10) . . ? H13 Ta1 C21 89.4(17) . . ? H12 Ta1 C21 75.0(18) . . ? H11 Ta1 C21 83.5(16) . . ? C23 Ta1 C21 56.90(10) . . ? C12 Ta1 C21 141.40(11) . . ? C15 Ta1 C21 152.93(10) . . ? C25 Ta1 C21 34.50(10) . . ? C24 Ta1 C21 57.11(10) . . ? H13 Ta1 C14 71.8(17) . . ? H12 Ta1 C14 102.6(19) . . ? H11 Ta1 C14 115.7(16) . . ? C23 Ta1 C14 109.18(10) . . ? C12 Ta1 C14 57.10(10) . . ? C15 Ta1 C14 34.51(10) . . ? C25 Ta1 C14 155.15(11) . . ? C24 Ta1 C14 122.23(11) . . ? C21 Ta1 C14 158.68(10) . . ? H13 Ta1 C11 113.2(17) . . ? H12 Ta1 C11 91.5(18) . . ? H11 Ta1 C11 60.0(16) . . ? C23 Ta1 C11 149.82(11) . . ? C12 Ta1 C11 34.27(11) . . ? C15 Ta1 C11 34.34(11) . . ? C25 Ta1 C11 122.91(11) . . ? C24 Ta1 C11 125.66(11) . . ? C21 Ta1 C11 143.39(11) . . ? C14 Ta1 C11 56.83(11) . . ? H13 Ta1 C13 100.7(17) . . ? H12 Ta1 C13 134.3(18) . . ? H11 Ta1 C13 111.1(17) . . ? C23 Ta1 C13 96.23(10) . . ? C12 Ta1 C13 34.29(10) . . ? C15 Ta1 C13 57.01(10) . . ? C25 Ta1 C13 122.00(11) . . ? C24 Ta1 C13 93.42(10) . . ? C21 Ta1 C13 150.01(10) . . ? C14 Ta1 C13 34.07(10) . . ? C11 Ta1 C13 56.59(10) . . ? H13 Ta1 C22 66.1(17) . . ? H12 Ta1 C22 84.7(18) . . ? H11 Ta1 C22 116.9(16) . . ? C23 Ta1 C22 34.14(10) . . ? C12 Ta1 C22 149.40(11) . . ? C15 Ta1 C22 145.31(11) . . ? C25 Ta1 C22 56.73(10) . . ? C24 Ta1 C22 56.79(10) . . ? C21 Ta1 C22 33.79(10) . . ? C14 Ta1 C22 125.52(10) . . ? C11 Ta1 C22 175.90(10) . . ? C13 Ta1 C22 127.40(10) . . ? C12 C11 C15 108.5(3) . . ? C12 C11 C31 125.7(3) . . ? C15 C11 C31 125.4(3) . . ? C12 C11 Ta1 72.35(18) . . ? C15 C11 Ta1 72.32(17) . . ? C31 C11 Ta1 126.9(3) . . ? C11 C12 C13 107.7(3) . . ? C11 C12 C32 124.9(3) . . ? C13 C12 C32 126.6(3) . . ? C11 C12 Ta1 73.38(18) . . ? C13 C12 Ta1 73.73(17) . . ? C32 C12 Ta1 126.7(3) . . ? C14 C13 C12 108.3(3) . . ? C14 C13 C33 124.9(3) . . ? C12 C13 C33 126.2(3) . . ? C14 C13 Ta1 72.55(17) . . ? C12 C13 Ta1 71.98(17) . . ? C33 C13 Ta1 128.7(2) . . ? C13 C14 C15 108.1(3) . . ? C13 C14 C34 125.6(3) . . ? C15 C14 C34 125.8(3) . . ? C13 C14 Ta1 73.38(17) . . ? C15 C14 Ta1 72.30(17) . . ? C34 C14 Ta1 126.5(2) . . ? C11 C15 C14 107.4(3) . . ? C11 C15 C35 126.1(3) . . ? C14 C15 C35 126.1(3) . . ? C11 C15 Ta1 73.33(18) . . ? C14 C15 Ta1 73.20(16) . . ? C35 C15 Ta1 123.9(2) . . ? C22 C21 C25 108.2(3) . . ? C22 C21 C41 125.4(3) . . ? C25 C21 C41 126.1(3) . . ? C22 C21 Ta1 73.94(17) . . ? C25 C21 Ta1 72.43(16) . . ? C41 C21 Ta1 124.2(2) . . ? C21 C22 C23 108.3(3) . . ? C21 C22 C42 126.0(3) . . ? C23 C22 C42 125.4(3) . . ? C21 C22 Ta1 72.27(16) . . ? C23 C22 Ta1 71.57(17) . . ? C42 C22 Ta1 127.3(2) . . ? C22 C23 C24 108.1(3) . . ? C22 C23 C43 124.7(3) . . ? C24 C23 C43 126.6(3) . . ? C22 C23 Ta1 74.29(17) . . ? C24 C23 Ta1 73.23(16) . . ? C43 C23 Ta1 125.1(2) . . ? C25 C24 C23 107.5(3) . . ? C25 C24 C44 125.0(3) . . ? C23 C24 C44 126.7(3) . . ? C25 C24 Ta1 72.49(17) . . ? C23 C24 Ta1 72.24(16) . . ? C44 C24 Ta1 128.7(2) . . ? C24 C25 C21 107.8(3) . . ? C24 C25 C45 125.6(3) . . ? C21 C25 C45 126.2(3) . . ? C24 C25 Ta1 73.06(17) . . ? C21 C25 Ta1 73.07(17) . . ? C45 C25 Ta1 125.3(2) . . ? H21 Ta2 H22 54(2) . . ? H21 Ta2 H23 115(2) . . ? H22 Ta2 H23 62(2) . . ? H21 Ta2 C62 86.6(18) . . ? H22 Ta2 C62 78.2(18) . . ? H23 Ta2 C62 82.9(16) . . ? H21 Ta2 C54 73.5(18) . . ? H22 Ta2 C54 106.4(19) . . ? H23 Ta2 C54 126.5(16) . . ? C62 Ta2 C54 149.31(11) . . ? H21 Ta2 C51 124.3(18) . . ? H22 Ta2 C51 115.7(18) . . ? H23 Ta2 C51 80.6(16) . . ? C62 Ta2 C51 148.97(11) . . ? C54 Ta2 C51 57.00(11) . . ? H21 Ta2 C63 120.9(18) . . ? H22 Ta2 C63 101.0(19) . . ? H23 Ta2 C63 71.9(16) . . ? C62 Ta2 C63 34.41(10) . . ? C54 Ta2 C63 152.03(10) . . ? C51 Ta2 C63 114.83(11) . . ? H21 Ta2 C64 126.6(18) . . ? H22 Ta2 C64 133.7(19) . . ? H23 Ta2 C64 98.8(16) . . ? C62 Ta2 C64 56.98(10) . . ? C54 Ta2 C64 117.85(10) . . ? C51 Ta2 C64 99.94(11) . . ? C63 Ta2 C64 34.22(10) . . ? H21 Ta2 C65 94.2(18) . . ? H22 Ta2 C65 127.1(18) . . ? H23 Ta2 C65 128.8(16) . . ? C62 Ta2 C65 56.84(10) . . ? C54 Ta2 C65 100.77(11) . . ? C51 Ta2 C65 117.21(11) . . ? C63 Ta2 C65 56.99(10) . . ? C64 Ta2 C65 34.43(10) . . ? H21 Ta2 C53 68.1(18) . . ? H22 Ta2 C53 77.0(18) . . ? H23 Ta2 C53 96.5(16) . . ? C62 Ta2 C53 151.91(10) . . ? C54 Ta2 C53 34.51(10) . . ? C51 Ta2 C53 56.76(11) . . ? C63 Ta2 C53 167.38(11) . . ? C64 Ta2 C53 149.35(10) . . ? C65 Ta2 C53 134.05(11) . . ? H21 Ta2 C61 70.8(18) . . ? H22 Ta2 C61 92.8(18) . . ? H23 Ta2 C61 116.9(16) . . ? C62 Ta2 C61 34.14(10) . . ? C54 Ta2 C61 115.51(11) . . ? C51 Ta2 C61 151.45(12) . . ? C63 Ta2 C61 57.02(11) . . ? C64 Ta2 C61 57.09(11) . . ? C65 Ta2 C61 34.27(10) . . ? C53 Ta2 C61 135.13(11) . . ? H21 Ta2 C55 107.2(18) . . ? H22 Ta2 C55 133.4(18) . . ? H23 Ta2 C55 114.7(16) . . ? C62 Ta2 C55 147.96(10) . . ? C54 Ta2 C55 34.21(10) . . ? C51 Ta2 C55 34.09(12) . . ? C63 Ta2 C55 122.80(10) . . ? C64 Ta2 C55 92.68(10) . . ? C65 Ta2 C55 92.71(11) . . ? C53 Ta2 C55 56.74(10) . . ? C61 Ta2 C55 122.84(11) . . ? H21 Ta2 C52 98.3(18) . . ? H22 Ta2 C52 82.4(18) . . ? H23 Ta2 C52 69.7(16) . . ? C62 Ta2 C52 151.68(11) . . ? C54 Ta2 C52 56.81(11) . . ? C51 Ta2 C52 34.38(12) . . ? C63 Ta2 C52 133.92(11) . . ? C64 Ta2 C52 132.83(11) . . ? C65 Ta2 C52 149.13(11) . . ? C53 Ta2 C52 33.74(11) . . ? C61 Ta2 C52 168.66(12) . . ? C55 Ta2 C52 56.64(11) . . ? C55 C51 C52 107.8(3) . . ? C55 C51 C71 126.0(3) . . ? C52 C51 C71 125.7(4) . . ? C55 C51 Ta2 73.46(18) . . ? C52 C51 Ta2 73.39(18) . . ? C71 C51 Ta2 124.6(3) . . ? C53 C52 C51 108.1(3) . . ? C53 C52 C72 126.6(4) . . ? C51 C52 C72 125.0(4) . . ? C53 C52 Ta2 72.86(18) . . ? C51 C52 Ta2 72.23(18) . . ? C72 C52 Ta2 125.3(2) . . ? C52 C53 C54 108.2(3) . . ? C52 C53 C73 126.0(3) . . ? C54 C53 C73 125.5(3) . . ? C52 C53 Ta2 73.40(18) . . ? C54 C53 Ta2 72.22(17) . . ? C73 C53 Ta2 125.0(2) . . ? C55 C54 C53 107.6(3) . . ? C55 C54 C74 126.7(3) . . ? C53 C54 C74 125.1(3) . . ? C55 C54 Ta2 73.60(17) . . ? C53 C54 Ta2 73.27(17) . . ? C74 C54 Ta2 125.2(2) . . ? C51 C55 C54 108.2(3) . . ? C51 C55 C75 126.0(3) . . ? C54 C55 C75 124.9(3) . . ? C51 C55 Ta2 72.46(17) . . ? C54 C55 Ta2 72.19(17) . . ? C75 C55 Ta2 129.7(2) . . ? C62 C61 C65 107.6(3) . . ? C62 C61 C81 126.2(3) . . ? C65 C61 C81 125.8(3) . . ? C62 C61 Ta2 72.05(17) . . ? C65 C61 Ta2 72.72(18) . . ? C81 C61 Ta2 126.2(3) . . ? C61 C62 C63 108.8(3) . . ? C61 C62 C82 124.4(3) . . ? C63 C62 C82 126.4(3) . . ? C61 C62 Ta2 73.82(18) . . ? C63 C62 Ta2 73.41(17) . . ? C82 C62 Ta2 124.6(2) . . ? C64 C63 C62 107.7(3) . . ? C64 C63 C83 124.4(3) . . ? C62 C63 C83 127.6(3) . . ? C64 C63 Ta2 72.95(17) . . ? C62 C63 Ta2 72.19(17) . . ? C83 C63 Ta2 125.4(2) . . ? C63 C64 C65 107.9(3) . . ? C63 C64 C84 124.1(3) . . ? C65 C64 C84 127.5(3) . . ? C63 C64 Ta2 72.83(17) . . ? C65 C64 Ta2 72.84(17) . . ? C84 C64 Ta2 127.0(2) . . ? C61 C65 C64 108.1(3) . . ? C61 C65 C85 124.7(3) . . ? C64 C65 C85 126.5(3) . . ? C61 C65 Ta2 73.01(17) . . ? C64 C65 Ta2 72.73(16) . . ? C85 C65 Ta2 127.7(2) . . ? _diffrn_measured_fraction_theta_max 0.925 _diffrn_reflns_theta_full 28.45 _diffrn_measured_fraction_theta_full 0.925 _refine_diff_density_max 1.387 _refine_diff_density_min -1.171 _refine_diff_density_rms 0.090 data_ged10 _audit_creation_method SHELXL _chemical_name_systematic ; ? ; _chemical_name_common ? _chemical_formula_moiety ? _chemical_formula_structural ? _chemical_formula_analytical ? _chemical_formula_sum 'C21 H25 O Si Ta' _chemical_formula_weight 502.45 _chemical_melting_point ? _chemical_compound_source ? 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' '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' 'Ta' 'Ta' -0.7052 6.5227 '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 8.6366(5) _cell_length_b 15.9753(9) _cell_length_c 14.8619(8) _cell_angle_alpha 90.00 _cell_angle_beta 100.5390(10) _cell_angle_gamma 90.00 _cell_volume 2015.9(2) _cell_formula_units_Z 4 _cell_measurement_temperature 203(2) _cell_measurement_reflns_used ? _cell_measurement_theta_min ? _cell_measurement_theta_max ? _exptl_crystal_description ? _exptl_crystal_colour ? _exptl_crystal_size_max 0.30 _exptl_crystal_size_mid 0.20 _exptl_crystal_size_min 0.20 _exptl_crystal_density_meas ? _exptl_crystal_density_diffrn 1.655 _exptl_crystal_density_method ? _exptl_crystal_F_000 984 _exptl_absorpt_coefficient_mu 5.516 _exptl_absorpt_correction_type SADABS _exptl_absorpt_correction_T_min ? _exptl_absorpt_correction_T_max ? _exptl_special_details ; ? ; _diffrn_ambient_temperature 203(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 'Siemens P4' _diffrn_measurement_method '\w scans' _diffrn_standards_number ? _diffrn_standards_interval_count ? _diffrn_standards_interval_time ? _diffrn_standards_decay_% ? _diffrn_reflns_number 14647 _diffrn_reflns_av_R_equivalents 0.0254 _diffrn_reflns_av_sigmaI/netI 0.0268 _diffrn_reflns_limit_h_min -11 _diffrn_reflns_limit_h_max 11 _diffrn_reflns_limit_k_min -19 _diffrn_reflns_limit_k_max 21 _diffrn_reflns_limit_l_min -19 _diffrn_reflns_limit_l_max 18 _diffrn_reflns_theta_min 1.89 _diffrn_reflns_theta_max 28.30 _reflns_number_total 4719 _reflns_number_observed 4177 _reflns_observed_criterion >2sigma(I) _computing_data_collection 'Siemens XSCANS' _computing_cell_refinement 'Siemens XSCANS' _computing_data_reduction 'Siemens SHELXTL' _computing_structure_solution 'SHELXS-86 (Sheldrick, 1990)' _computing_structure_refinement 'SHELXL-93 (Sheldrick, 1993)' _computing_molecular_graphics 'Siemens SHELXTL' _computing_publication_material 'Siemens SHELXTL' _refine_special_details ; Refinement on F^2^ for ALL reflections except for 2 with very negative F^2^ or flagged by the user for potential systematic errors. Weighted R-factors wR and all goodnesses 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 observed criterion of F^2^ > 2sigma(F^2^) is used only for calculating _R_factor_obs 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 w=1/[\s^2^(Fo^2^)+(0.0229P)^2^+2.6578P] where P=(Fo^2^+2Fc^2^)/3' _atom_sites_solution_primary direct _atom_sites_solution_secondary difmap _atom_sites_solution_hydrogens geom _refine_ls_hydrogen_treatment ? _refine_ls_extinction_method SHELXL _refine_ls_extinction_coef 0.00034(7) _refine_ls_extinction_expression 'Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^' _refine_ls_number_reflns 4717 _refine_ls_number_parameters 230 _refine_ls_number_restraints 0 _refine_ls_R_factor_all 0.0285 _refine_ls_R_factor_obs 0.0225 _refine_ls_wR_factor_all 0.0563 _refine_ls_wR_factor_obs 0.0535 _refine_ls_goodness_of_fit_all 1.040 _refine_ls_goodness_of_fit_obs 1.073 _refine_ls_restrained_S_all 1.059 _refine_ls_restrained_S_obs 1.073 _refine_ls_shift/esd_max -0.116 _refine_ls_shift/esd_mean 0.002 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_thermal_displace_type _atom_site_occupancy _atom_site_calc_flag _atom_site_refinement_flags _atom_site_disorder_group Ta Ta 0.493610(14) 0.237878(8) 0.377006(9) 0.02409(5) Uani 1 d . . C1 C 0.6079(6) 0.2603(3) 0.2703(3) 0.0475(10) Uani 1 d . . O1 O 0.6849(5) 0.2690(2) 0.2181(3) 0.0791(12) Uani 1 d . . H1 H 0.3204(38) 0.2828(22) 0.3189(23) 0.021(8) Uiso 1 d . . C11 C 0.5268(4) 0.1099(2) 0.4513(2) 0.0287(7) Uani 1 d . . C12 C 0.5911(4) 0.1018(2) 0.3677(2) 0.0306(7) Uani 1 d . . C13 C 0.4625(4) 0.1072(2) 0.2909(2) 0.0301(7) Uani 1 d . . C14 C 0.3215(4) 0.1184(2) 0.3244(2) 0.0297(7) Uani 1 d . . C15 C 0.3568(4) 0.1205(2) 0.4215(2) 0.0277(7) Uani 1 d . . C21 C 0.6216(4) 0.2687(2) 0.5241(2) 0.0274(6) Uani 1 d . . C22 C 0.7158(4) 0.3049(2) 0.4616(2) 0.0315(7) Uani 1 d . . C23 C 0.6265(4) 0.3713(2) 0.4122(3) 0.0337(8) Uani 1 d . . C24 C 0.4796(4) 0.3781(2) 0.4423(2) 0.0311(7) Uani 1 d . . C25 C 0.4750(4) 0.3165(2) 0.5101(2) 0.0272(7) Uani 1 d . . C32 C 0.7560(4) 0.0777(3) 0.3578(3) 0.0407(9) Uani 1 d . . H32A H 0.7613(10) 0.0176(3) 0.3494(21) 0.061 Uiso 1 calc R . H32B H 0.8294(6) 0.0939(17) 0.4125(9) 0.061 Uiso 1 calc R . H32C H 0.7834(14) 0.1059(15) 0.3051(12) 0.061 Uiso 1 calc R . C33 C 0.4735(5) 0.0912(3) 0.1919(3) 0.0426(9) Uani 1 d . . C34 C 0.1579(4) 0.1223(3) 0.2675(3) 0.0404(9) Uani 1 d . . H34A H 0.0916(10) 0.1571(15) 0.2982(10) 0.061 Uiso 1 calc R . H34B H 0.1141(14) 0.0663(3) 0.2597(17) 0.061 Uiso 1 calc R . H34C H 0.1630(6) 0.1461(17) 0.2080(8) 0.061 Uiso 1 calc R . C35 C 0.2317(4) 0.1201(3) 0.4800(3) 0.0380(8) Uani 1 d . . H35A H 0.2780(8) 0.1361(18) 0.5421(5) 0.057 Uiso 1 calc R . H35B H 0.1872(24) 0.0644(5) 0.4803(16) 0.057 Uiso 1 calc R . H35C H 0.1494(17) 0.1595(13) 0.4555(12) 0.057 Uiso 1 calc R . C42 C 0.8859(4) 0.2888(3) 0.4587(3) 0.0490(10) Uani 1 d . . H42A H 0.8982(7) 0.2794(21) 0.3959(4) 0.073 Uiso 1 calc R . H42B H 0.9213(12) 0.2396(13) 0.4951(19) 0.073 Uiso 1 calc R . H42C H 0.9484(7) 0.3368(9) 0.4833(21) 0.073 Uiso 1 calc R . C43 C 0.6852(6) 0.4330(3) 0.3496(3) 0.0518(11) Uani 1 d . . H43A H 0.7608(30) 0.4057(6) 0.3184(17) 0.078 Uiso 1 calc R . H43B H 0.7355(35) 0.4797(10) 0.3852(4) 0.078 Uiso 1 calc R . H43C H 0.5973(8) 0.4533(16) 0.3048(14) 0.078 Uiso 1 calc R . C44 C 0.3544(5) 0.4432(2) 0.4101(3) 0.0442(9) Uani 1 d . . C45 C 0.3477(4) 0.3147(2) 0.5670(3) 0.0357(8) Uani 1 d . . H45A H 0.3563(22) 0.2635(9) 0.6027(15) 0.054 Uiso 1 calc R . H45B H 0.2455(4) 0.3168(18) 0.5272(3) 0.054 Uiso 1 calc R . H45C H 0.3594(21) 0.3625(10) 0.6079(14) 0.054 Uiso 1 calc R . Si Si 0.63652(11) 0.15496(6) 0.56279(7) 0.0304(2) Uani 1 d . . C51 C 0.5447(5) 0.1312(3) 0.6640(3) 0.0428(9) Uani 1 d . . H51A H 0.4396(15) 0.1549(17) 0.6550(10) 0.064 Uiso 1 calc R . H51B H 0.6082(20) 0.1552(17) 0.7185(4) 0.064 Uiso 1 calc R . H51C H 0.5384(34) 0.0710(3) 0.6714(13) 0.064 Uiso 1 calc R . C52 C 0.8410(5) 0.1148(3) 0.5977(3) 0.0493(10) Uani 1 d . . H52A H 0.9003(12) 0.1261(18) 0.5495(10) 0.074 Uiso 1 calc R . H52B H 0.8381(5) 0.0550(4) 0.6082(21) 0.074 Uiso 1 calc R . H52C H 0.8911(14) 0.1426(15) 0.6535(12) 0.074 Uiso 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 Ta 0.02527(7) 0.02213(8) 0.02536(8) -0.00066(5) 0.00592(5) 0.00044(5) C1 0.059(3) 0.037(2) 0.051(3) -0.007(2) 0.019(2) -0.005(2) O1 0.107(3) 0.069(3) 0.077(3) -0.011(2) 0.058(3) -0.015(2) C11 0.033(2) 0.022(2) 0.030(2) 0.0007(13) 0.0040(14) 0.0014(13) C12 0.033(2) 0.023(2) 0.035(2) -0.0036(13) 0.0053(14) 0.0020(13) C13 0.035(2) 0.027(2) 0.029(2) -0.0035(13) 0.0064(14) -0.0009(13) C14 0.031(2) 0.025(2) 0.032(2) -0.0029(13) 0.0026(14) -0.0034(13) C15 0.032(2) 0.022(2) 0.029(2) -0.0018(12) 0.0059(14) -0.0044(12) C21 0.027(2) 0.027(2) 0.027(2) -0.0036(13) 0.0011(12) -0.0006(12) C22 0.028(2) 0.031(2) 0.036(2) -0.0051(14) 0.0067(14) -0.0047(13) C23 0.045(2) 0.024(2) 0.034(2) -0.0034(14) 0.012(2) -0.0079(14) C24 0.036(2) 0.021(2) 0.035(2) -0.0035(13) 0.0051(15) 0.0017(13) C25 0.029(2) 0.026(2) 0.027(2) -0.0023(12) 0.0059(13) -0.0001(12) C32 0.037(2) 0.041(2) 0.044(2) -0.007(2) 0.008(2) 0.009(2) C33 0.053(2) 0.048(2) 0.028(2) -0.011(2) 0.011(2) -0.004(2) C34 0.032(2) 0.044(2) 0.042(2) -0.008(2) -0.002(2) -0.005(2) C35 0.037(2) 0.042(2) 0.037(2) -0.004(2) 0.012(2) -0.008(2) C42 0.029(2) 0.057(3) 0.064(3) -0.005(2) 0.014(2) -0.004(2) C43 0.066(3) 0.037(2) 0.058(3) 0.005(2) 0.026(2) -0.010(2) C44 0.052(2) 0.028(2) 0.051(2) 0.000(2) 0.004(2) 0.011(2) C45 0.035(2) 0.037(2) 0.037(2) -0.004(2) 0.013(2) 0.0028(15) Si 0.0341(5) 0.0272(5) 0.0279(5) 0.0004(4) 0.0000(4) 0.0034(4) C51 0.058(2) 0.041(2) 0.028(2) 0.005(2) 0.004(2) -0.001(2) C52 0.051(2) 0.045(2) 0.045(2) -0.005(2) -0.012(2) 0.014(2) _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 Ta C1 2.047(4) . ? Ta C21 2.315(3) . ? Ta C11 2.316(3) . ? Ta C12 2.344(3) . ? Ta C22 2.351(3) . ? Ta C15 2.373(3) . ? Ta C25 2.374(3) . ? Ta C23 2.432(3) . ? Ta C13 2.438(3) . ? Ta C24 2.453(3) . ? Ta C14 2.458(3) . ? C1 O1 1.120(5) . ? C11 C12 1.457(5) . ? C11 C15 1.463(5) . ? C11 Si 1.894(4) . ? C12 C13 1.442(5) . ? C12 C32 1.509(5) . ? C13 C14 1.409(5) . ? C13 C33 1.513(5) . ? C14 C15 1.420(5) . ? C14 C34 1.509(5) . ? C15 C35 1.506(5) . ? C21 C25 1.461(4) . ? C21 C22 1.462(5) . ? C21 Si 1.903(3) . ? C22 C23 1.432(5) . ? C22 C42 1.500(5) . ? C23 C24 1.424(5) . ? C23 C43 1.506(5) . ? C24 C25 1.415(5) . ? C24 C44 1.514(5) . ? C25 C45 1.505(4) . ? Si C52 1.861(4) . ? Si C51 1.864(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 C1 Ta C21 118.7(2) . . ? C1 Ta C11 119.25(15) . . ? C21 Ta C11 75.01(12) . . ? C1 Ta C12 83.52(15) . . ? C21 Ta C12 97.95(12) . . ? C11 Ta C12 36.43(12) . . ? C1 Ta C22 82.7(2) . . ? C21 Ta C22 36.50(11) . . ? C11 Ta C22 97.43(12) . . ? C12 Ta C22 100.77(12) . . ? C1 Ta C15 133.57(14) . . ? C21 Ta C15 94.64(12) . . ? C11 Ta C15 36.34(12) . . ? C12 Ta C15 59.11(11) . . ? C22 Ta C15 127.59(12) . . ? C1 Ta C25 131.96(14) . . ? C21 Ta C25 36.28(11) . . ? C11 Ta C25 95.23(12) . . ? C12 Ta C25 128.31(12) . . ? C22 Ta C25 59.10(11) . . ? C15 Ta C25 94.18(11) . . ? C1 Ta C23 74.79(14) . . ? C21 Ta C23 59.04(12) . . ? C11 Ta C23 131.19(13) . . ? C12 Ta C23 131.67(13) . . ? C22 Ta C23 34.80(13) . . ? C15 Ta C23 150.66(11) . . ? C25 Ta C23 57.18(11) . . ? C1 Ta C13 76.43(14) . . ? C21 Ta C13 131.73(12) . . ? C11 Ta C13 59.12(12) . . ? C12 Ta C13 35.04(12) . . ? C22 Ta C13 132.17(12) . . ? C15 Ta C13 57.14(11) . . ? C25 Ta C13 150.84(11) . . ? C23 Ta C13 149.96(11) . . ? C1 Ta C24 102.24(14) . . ? C21 Ta C24 58.81(12) . . ? C11 Ta C24 128.93(12) . . ? C12 Ta C24 156.12(13) . . ? C22 Ta C24 57.80(12) . . ? C15 Ta C24 123.25(11) . . ? C25 Ta C24 34.04(11) . . ? C23 Ta C24 33.90(11) . . ? C13 Ta C24 168.82(12) . . ? C1 Ta C14 103.81(15) . . ? C21 Ta C14 128.48(12) . . ? C11 Ta C14 58.74(12) . . ? C12 Ta C14 57.57(12) . . ? C22 Ta C14 155.63(12) . . ? C15 Ta C14 34.14(11) . . ? C25 Ta C14 123.18(11) . . ? C23 Ta C14 169.55(12) . . ? C13 Ta C14 33.45(11) . . ? C24 Ta C14 139.88(11) . . ? O1 C1 Ta 172.3(5) . . ? C12 C11 C15 105.7(3) . . ? C12 C11 Si 124.9(2) . . ? C15 C11 Si 122.3(2) . . ? C12 C11 Ta 72.8(2) . . ? C15 C11 Ta 74.0(2) . . ? Si C11 Ta 94.61(14) . . ? C13 C12 C11 108.2(3) . . ? C13 C12 C32 122.8(3) . . ? C11 C12 C32 128.3(3) . . ? C13 C12 Ta 76.0(2) . . ? C11 C12 Ta 70.7(2) . . ? C32 C12 Ta 126.8(3) . . ? C14 C13 C12 108.5(3) . . ? C14 C13 C33 125.2(3) . . ? C12 C13 C33 125.7(3) . . ? C14 C13 Ta 74.1(2) . . ? C12 C13 Ta 68.9(2) . . ? C33 C13 Ta 129.4(3) . . ? C13 C14 C15 108.9(3) . . ? C13 C14 C34 126.1(3) . . ? C15 C14 C34 125.0(3) . . ? C13 C14 Ta 72.5(2) . . ? C15 C14 Ta 69.7(2) . . ? C34 C14 Ta 126.6(2) . . ? C14 C15 C11 108.8(3) . . ? C14 C15 C35 122.9(3) . . ? C11 C15 C35 127.6(3) . . ? C14 C15 Ta 76.2(2) . . ? C11 C15 Ta 69.7(2) . . ? C35 C15 Ta 127.7(2) . . ? C25 C21 C22 105.7(3) . . ? C25 C21 Si 123.5(2) . . ? C22 C21 Si 123.7(2) . . ? C25 C21 Ta 74.1(2) . . ? C22 C21 Ta 73.1(2) . . ? Si C21 Ta 94.40(13) . . ? C23 C22 C21 108.0(3) . . ? C23 C22 C42 123.4(3) . . ? C21 C22 C42 127.7(3) . . ? C23 C22 Ta 75.7(2) . . ? C21 C22 Ta 70.4(2) . . ? C42 C22 Ta 127.9(3) . . ? C24 C23 C22 108.9(3) . . ? C24 C23 C43 124.3(4) . . ? C22 C23 C43 126.2(3) . . ? C24 C23 Ta 73.9(2) . . ? C22 C23 Ta 69.5(2) . . ? C43 C23 Ta 129.8(3) . . ? C25 C24 C23 108.2(3) . . ? C25 C24 C44 126.3(3) . . ? C23 C24 C44 125.4(3) . . ? C25 C24 Ta 69.9(2) . . ? C23 C24 Ta 72.2(2) . . ? C44 C24 Ta 125.9(3) . . ? C24 C25 C21 109.2(3) . . ? C24 C25 C45 122.2(3) . . ? C21 C25 C45 127.8(3) . . ? C24 C25 Ta 76.0(2) . . ? C21 C25 Ta 69.7(2) . . ? C45 C25 Ta 128.7(2) . . ? C52 Si C51 103.1(2) . . ? C52 Si C11 114.2(2) . . ? C51 Si C11 114.2(2) . . ? C52 Si C21 114.9(2) . . ? C51 Si C21 115.1(2) . . ? C11 Si C21 95.89(15) . . ? _refine_diff_density_max 0.979 _refine_diff_density_min -0.757 _refine_diff_density_rms 0.097 data_tas10 _audit_creation_method SHELXL-97 _chemical_name_systematic ; ? ; _chemical_name_common ? _chemical_melting_point ? _chemical_formula_moiety ? _chemical_formula_sum 'C22 H35 Si Ta' _chemical_formula_weight 508.54 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' 'Si' 'Si' 0.0817 0.0704 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' 'Ta' 'Ta' -0.7052 6.5227 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' _symmetry_cell_setting Orthorhombic _symmetry_space_group_name_H-M Pnma loop_ _symmetry_equiv_pos_as_xyz 'x, y, z' '-x+1/2, -y, z+1/2' '-x, y+1/2, -z' 'x+1/2, -y+1/2, -z+1/2' '-x, -y, -z' 'x-1/2, y, -z-1/2' 'x, -y-1/2, z' '-x-1/2, y-1/2, z-1/2' _cell_length_a 10.1777(6) _cell_length_b 14.7904(8) _cell_length_c 13.6189(8) _cell_angle_alpha 90.00 _cell_angle_beta 90.00 _cell_angle_gamma 90.00 _cell_volume 2050.1(2) _cell_formula_units_Z 4 _cell_measurement_temperature 223(2) _cell_measurement_reflns_used ? _cell_measurement_theta_min ? _cell_measurement_theta_max ? _exptl_crystal_description ? _exptl_crystal_colour ? _exptl_crystal_size_max 0.20 _exptl_crystal_size_mid 0.10 _exptl_crystal_size_min 0.10 _exptl_crystal_density_meas ? _exptl_crystal_density_diffrn 1.648 _exptl_crystal_density_method 'not measured' _exptl_crystal_F_000 1016 _exptl_absorpt_coefficient_mu 5.421 _exptl_absorpt_correction_type none _exptl_absorpt_correction_T_min 0.4102 _exptl_absorpt_correction_T_max 0.6132 _exptl_absorpt_process_details ? _exptl_special_details ; ? ; _diffrn_ambient_temperature 223(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 'CCD area detector' _diffrn_measurement_method 'phi and omega scans' _diffrn_detector_area_resol_mean ? _diffrn_standards_number ? _diffrn_standards_interval_count ? _diffrn_standards_interval_time ? _diffrn_standards_decay_% ? _diffrn_reflns_number 14561 _diffrn_reflns_av_R_equivalents 0.0306 _diffrn_reflns_av_sigmaI/netI 0.0181 _diffrn_reflns_limit_h_min -12 _diffrn_reflns_limit_h_max 13 _diffrn_reflns_limit_k_min -19 _diffrn_reflns_limit_k_max 19 _diffrn_reflns_limit_l_min -17 _diffrn_reflns_limit_l_max 14 _diffrn_reflns_theta_min 2.03 _diffrn_reflns_theta_max 28.24 _reflns_number_total 2535 _reflns_number_gt 2249 _reflns_threshold_expression >2sigma(I) _computing_data_collection 'Bruker SMART' _computing_cell_refinement 'Bruker SMART' _computing_data_reduction 'Bruker SHELXTL' _computing_structure_solution 'SHELXS-97 (Sheldrick, 1990)' _computing_structure_refinement 'SHELXL-97 (Sheldrick, 1997)' _computing_molecular_graphics 'Bruker SHELXTL' _computing_publication_material 'Bruker SHELXTL' _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^)+(0.0142P)^2^+6.6290P] where P=(Fo^2^+2Fc^2^)/3' _atom_sites_solution_primary direct _atom_sites_solution_secondary difmap _atom_sites_solution_hydrogens geom _refine_ls_hydrogen_treatment mixed _refine_ls_extinction_method SHELXL _refine_ls_extinction_coef 0.00037(10) _refine_ls_extinction_expression 'Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^' _refine_ls_number_reflns 2535 _refine_ls_number_parameters 128 _refine_ls_number_restraints 0 _refine_ls_R_factor_all 0.0334 _refine_ls_R_factor_gt 0.0285 _refine_ls_wR_factor_ref 0.0650 _refine_ls_wR_factor_gt 0.0634 _refine_ls_goodness_of_fit_ref 1.193 _refine_ls_restrained_S_all 1.193 _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 Ta Ta 0.12480(2) 0.2500 0.465304(17) 0.03212(9) Uani 1 2 d S . . C1 C -0.0089(11) 0.3654(8) 0.4219(10) 0.047(3) Uani 0.50 1 d P . -1 H1A H -0.0456 0.4019 0.4754 0.056 Uiso 0.50 1 calc PR . -1 H1B H 0.0169 0.4008 0.3643 0.056 Uiso 0.50 1 calc PR . -1 C2 C -0.0623(13) 0.2901(16) 0.4061(10) 0.146(17) Uani 0.50 1 d P . -1 H2A H -0.0767 0.2751 0.3368 0.176 Uiso 0.50 1 calc PR . -1 H2B H -0.1388 0.2762 0.4471 0.176 Uiso 0.50 1 calc PR . -1 H1 H 0.032(12) 0.149(9) 0.419(10) 0.050 Uiso 0.50 1 d P A -1 Si Si 0.41175(16) 0.2500 0.55722(13) 0.0364(4) Uani 1 2 d S . . C11 C 0.2422(6) 0.2500 0.6158(4) 0.0342(12) Uani 1 2 d S . . C12 C 0.1582(4) 0.3281(3) 0.6182(3) 0.0447(11) Uani 1 1 d . . . C13 C 0.0253(5) 0.2977(4) 0.6243(4) 0.0577(14) Uani 1 1 d . . . C21 C 0.3513(5) 0.2500 0.4264(4) 0.0317(11) Uani 1 2 d S . . C22 C 0.2960(4) 0.3282(3) 0.3782(3) 0.0348(9) Uani 1 1 d . . . C23 C 0.2119(4) 0.2977(3) 0.3012(3) 0.0410(10) Uani 1 1 d . . . C32 C 0.1964(6) 0.4258(3) 0.6296(4) 0.0629(15) Uani 1 1 d . . . H32A H 0.2906 0.4319 0.6215 0.094 Uiso 1 1 calc R . . H32B H 0.1713 0.4468 0.6944 0.094 Uiso 1 1 calc R . . H32C H 0.1518 0.4617 0.5802 0.094 Uiso 1 1 calc R . . C33 C -0.0941(6) 0.3568(7) 0.6372(6) 0.114(3) Uani 1 1 d . . . H33A H -0.1721 0.3192 0.6401 0.172 Uiso 1 1 calc R . . H33B H -0.1010 0.3980 0.5821 0.172 Uiso 1 1 calc R . . H33C H -0.0861 0.3910 0.6976 0.172 Uiso 1 1 calc R . . C42 C 0.3319(5) 0.4263(3) 0.3919(4) 0.0501(11) Uani 1 1 d . . . H42A H 0.3899 0.4324 0.4480 0.075 Uiso 1 1 calc R . . H42B H 0.2528 0.4614 0.4031 0.075 Uiso 1 1 calc R . . H42C H 0.3760 0.4483 0.3335 0.075 Uiso 1 1 calc R . . C43 C 0.1452(6) 0.3556(4) 0.2267(4) 0.0669(16) Uani 1 1 d . . . H43A H 0.1596 0.4188 0.2425 0.100 Uiso 1 1 calc R . . H43B H 0.0516 0.3430 0.2270 0.100 Uiso 1 1 calc R . . H43C H 0.1808 0.3428 0.1621 0.100 Uiso 1 1 calc R . . C51 C 0.5187(5) 0.3480(4) 0.5893(4) 0.0657(16) Uani 1 1 d . . . H51A H 0.4720 0.4039 0.5762 0.099 Uiso 1 1 calc R . . H51B H 0.5982 0.3459 0.5500 0.099 Uiso 1 1 calc R . . H51C H 0.5416 0.3451 0.6584 0.099 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 Ta 0.02804(13) 0.03400(13) 0.03432(13) 0.000 -0.00242(10) 0.000 C1 0.047(7) 0.042(5) 0.050(6) 0.005(4) 0.007(5) 0.017(5) C2 0.060(7) 0.33(5) 0.047(6) 0.061(14) 0.012(6) 0.097(16) Si 0.0255(7) 0.0365(8) 0.0471(10) 0.000 -0.0080(7) 0.000 C11 0.036(3) 0.037(3) 0.030(3) 0.000 -0.006(2) 0.000 C12 0.041(2) 0.056(3) 0.037(2) -0.008(2) -0.0032(18) 0.015(2) C13 0.039(2) 0.094(4) 0.040(3) -0.011(2) -0.001(2) 0.013(3) C21 0.028(3) 0.032(3) 0.035(3) 0.000 0.001(2) 0.000 C22 0.034(2) 0.032(2) 0.039(2) 0.0045(17) 0.0040(17) 0.0005(17) C23 0.041(2) 0.046(2) 0.036(2) 0.0072(18) 0.0002(18) 0.0016(19) C32 0.080(4) 0.047(3) 0.062(3) -0.023(3) -0.018(3) 0.020(3) C33 0.056(4) 0.199(10) 0.088(5) -0.048(6) 0.000(3) 0.060(5) C42 0.057(3) 0.030(2) 0.063(3) 0.007(2) 0.004(2) -0.004(2) C43 0.069(4) 0.077(4) 0.054(3) 0.026(3) -0.012(3) 0.003(3) C51 0.051(3) 0.078(4) 0.068(4) -0.006(3) -0.014(3) -0.029(3) _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 Ta C2 2.152(12) 7_565 ? Ta C2 2.152(12) . ? Ta C1 2.262(10) 7_565 ? Ta C1 2.262(10) . ? Ta C21 2.365(5) . ? Ta C11 2.373(6) . ? Ta C22 2.404(4) . ? Ta C22 2.404(4) 7_565 ? Ta C12 2.406(4) . ? Ta C12 2.406(4) 7_565 ? Ta C13 2.492(5) . ? Ta C13 2.492(5) 7_565 ? C1 C2 1.26(2) . ? Si C51 1.864(5) . ? Si C51 1.864(5) 7_565 ? Si C21 1.884(6) . ? Si C11 1.901(6) . ? C11 C12 1.438(6) 7_565 ? C11 C12 1.438(6) . ? C12 C13 1.427(7) . ? C12 C32 1.504(7) . ? C13 C13 1.411(12) 7_565 ? C13 C33 1.507(8) . ? C21 C22 1.444(5) 7_565 ? C21 C22 1.444(5) . ? C22 C23 1.427(6) . ? C22 C42 1.509(6) . ? C23 C23 1.411(9) 7_565 ? C23 C43 1.491(6) . ? 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 C2 Ta C2 32.0(13) 7_565 . ? C2 Ta C1 33.0(7) 7_565 7_565 ? C2 Ta C1 65.0(8) . 7_565 ? C2 Ta C1 65.0(8) 7_565 . ? C2 Ta C1 33.0(7) . . ? C1 Ta C1 98.0(7) 7_565 . ? C2 Ta C21 141.1(4) 7_565 . ? C2 Ta C21 141.1(4) . . ? C1 Ta C21 121.9(3) 7_565 . ? C1 Ta C21 121.9(3) . . ? C2 Ta C11 140.3(4) 7_565 . ? C2 Ta C11 140.3(4) . . ? C1 Ta C11 121.9(4) 7_565 . ? C1 Ta C11 121.9(4) . . ? C21 Ta C11 72.7(2) . . ? C2 Ta C22 126.1(4) 7_565 . ? C2 Ta C22 108.9(5) . . ? C1 Ta C22 132.1(3) 7_565 . ? C1 Ta C22 86.8(3) . . ? C21 Ta C22 35.23(12) . . ? C11 Ta C22 93.51(16) . . ? C2 Ta C22 108.9(5) 7_565 7_565 ? C2 Ta C22 126.1(4) . 7_565 ? C1 Ta C22 86.8(3) 7_565 7_565 ? C1 Ta C22 132.1(3) . 7_565 ? C21 Ta C22 35.23(12) . 7_565 ? C11 Ta C22 93.51(16) . 7_565 ? C22 Ta C22 57.48(19) . 7_565 ? C2 Ta C12 125.6(4) 7_565 . ? C2 Ta C12 108.5(5) . . ? C1 Ta C12 132.3(4) 7_565 . ? C1 Ta C12 87.1(4) . . ? C21 Ta C12 93.22(16) . . ? C11 Ta C12 35.01(13) . . ? C22 Ta C12 95.39(16) . . ? C22 Ta C12 123.76(14) 7_565 . ? C2 Ta C12 108.5(5) 7_565 7_565 ? C2 Ta C12 125.6(4) . 7_565 ? C1 Ta C12 87.1(4) 7_565 7_565 ? C1 Ta C12 132.3(4) . 7_565 ? C21 Ta C12 93.22(16) . 7_565 ? C11 Ta C12 35.01(13) . 7_565 ? C22 Ta C12 123.76(14) . 7_565 ? C22 Ta C12 95.39(16) 7_565 7_565 ? C12 Ta C12 57.4(2) . 7_565 ? C2 Ta C13 92.5(4) 7_565 . ? C2 Ta C13 83.6(4) . . ? C1 Ta C13 101.3(4) 7_565 . ? C1 Ta C13 76.6(4) . . ? C21 Ta C13 126.18(17) . . ? C11 Ta C13 56.90(18) . . ? C22 Ta C13 125.94(17) . . ? C22 Ta C13 149.23(15) 7_565 . ? C12 Ta C13 33.82(16) . . ? C12 Ta C13 56.02(18) 7_565 . ? C2 Ta C13 83.6(4) 7_565 7_565 ? C2 Ta C13 92.5(4) . 7_565 ? C1 Ta C13 76.6(4) 7_565 7_565 ? C1 Ta C13 101.3(4) . 7_565 ? C21 Ta C13 126.18(17) . 7_565 ? C11 Ta C13 56.90(18) . 7_565 ? C22 Ta C13 149.23(15) . 7_565 ? C22 Ta C13 125.94(17) 7_565 7_565 ? C12 Ta C13 56.02(18) . 7_565 ? C12 Ta C13 33.82(16) 7_565 7_565 ? C13 Ta C13 32.9(3) . 7_565 ? C2 C1 Ta 68.7(7) . . ? C1 C2 Ta 78.3(8) . . ? C51 Si C51 102.0(4) . 7_565 ? C51 Si C21 114.3(2) . . ? C51 Si C21 114.3(2) 7_565 . ? C51 Si C11 115.6(2) . . ? C51 Si C11 115.6(2) 7_565 . ? C21 Si C11 95.8(2) . . ? C12 C11 C12 106.9(6) 7_565 . ? C12 C11 Si 123.3(3) 7_565 . ? C12 C11 Si 123.3(3) . . ? C12 C11 Ta 73.8(3) 7_565 . ? C12 C11 Ta 73.8(3) . . ? Si C11 Ta 95.4(2) . . ? C13 C12 C11 108.2(5) . . ? C13 C12 C32 122.8(4) . . ? C11 C12 C32 128.3(4) . . ? C13 C12 Ta 76.4(3) . . ? C11 C12 Ta 71.2(3) . . ? C32 C12 Ta 125.9(3) . . ? C13 C13 C12 108.4(3) 7_565 . ? C13 C13 C33 125.4(5) 7_565 . ? C12 C13 C33 126.0(6) . . ? C13 C13 Ta 73.56(14) 7_565 . ? C12 C13 Ta 69.8(3) . . ? C33 C13 Ta 126.3(4) . . ? C22 C21 C22 106.4(5) 7_565 . ? C22 C21 Si 123.9(3) 7_565 . ? C22 C21 Si 123.9(3) . . ? C22 C21 Ta 73.9(3) 7_565 . ? C22 C21 Ta 73.9(3) . . ? Si C21 Ta 96.1(2) . . ? C23 C22 C21 108.4(4) . . ? C23 C22 C42 122.7(4) . . ? C21 C22 C42 128.3(4) . . ? C23 C22 Ta 77.1(2) . . ? C21 C22 Ta 70.9(3) . . ? C42 C22 Ta 125.2(3) . . ? C23 C23 C22 108.4(2) 7_565 . ? C23 C23 C43 125.1(3) 7_565 . ? C22 C23 C43 126.3(4) . . ? C23 C23 Ta 73.64(10) 7_565 . ? C22 C23 Ta 69.2(2) . . ? C43 C23 Ta 127.4(3) . . ? _diffrn_measured_fraction_theta_max 0.962 _diffrn_reflns_theta_full 28.24 _diffrn_measured_fraction_theta_full 0.962 _refine_diff_density_max 1.297 _refine_diff_density_min -1.328 _refine_diff_density_rms 0.099