#------------------------------------------------------------------------------ #$Date: 2020-10-06 10:16:58 +0300 (Tue, 06 Oct 2020) $ #$Revision: 257342 $ #$URL: file:///home/coder/svn-repositories/cod/cif/1/55/79/1557997.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_1557997 loop_ _publ_author_name 'Wang, Bin' 'Ong, Derek Yiren' 'Li, Yihang' 'Pang, Jia Hao' 'Watanabe, Kohei' 'Takita, Ryo' 'Chiba, Shunsuke' _publ_section_title ; Stereo-controlled anti-hydromagnesiation of aryl alkynes by magnesium hydrides ; _journal_issue 20 _journal_name_full 'Chemical Science' _journal_page_first 5267 _journal_page_last 5272 _journal_paper_doi 10.1039/D0SC01773F _journal_volume 11 _journal_year 2020 _chemical_formula_sum 'C21 H18' _chemical_formula_weight 270.35 _space_group_crystal_system monoclinic _space_group_IT_number 14 _space_group_name_Hall '-P 2ybc' _space_group_name_H-M_alt 'P 1 21/c 1' _atom_sites_solution_hydrogens geom _atom_sites_solution_primary dual _audit_update_record ; 2020-03-03 deposited with the CCDC. 2020-05-04 downloaded from the CCDC. ; _cell_angle_alpha 90 _cell_angle_beta 91.2503(14) _cell_angle_gamma 90 _cell_formula_units_Z 4 _cell_length_a 7.2298(2) _cell_length_b 10.3241(3) _cell_length_c 19.9155(5) _cell_measurement_reflns_used 5485 _cell_measurement_temperature 100.(2) _cell_measurement_theta_max 33.5071 _cell_measurement_theta_min 2.8180 _cell_volume 1486.16(7) _computing_cell_refinement 'SAINT V8.38A (Bruker AXS Inc., 2017)' _computing_data_collection 'APEX3 (Bruker AXS Inc., 2018)' _computing_data_reduction 'SAINT V8.38A (Bruker AXS Inc., 2017)' _computing_molecular_graphics 'XP (Bruker AXS Inc., 2018)' _computing_publication_material 'APEX3 (Bruker AXS Inc., 2018)' _computing_structure_refinement 'SHELXL-2018/3 (Sheldrick, 2018)' _computing_structure_solution 'XT, VERSION 2014/5' _diffrn_ambient_temperature 100.(2) _diffrn_detector_area_resol_mean 7.4074 _diffrn_measured_fraction_theta_full 0.979 _diffrn_measured_fraction_theta_max 0.979 _diffrn_measurement_device_type 'Photon II CPADs detector' _diffrn_measurement_method 'phi and omega scans' _diffrn_radiation_monochromator 'Multilayer Mirror' _diffrn_radiation_type MoK\a _diffrn_radiation_wavelength 0.71073 _diffrn_reflns_av_R_equivalents 0.0471 _diffrn_reflns_av_unetI/netI 0.0547 _diffrn_reflns_limit_h_max 11 _diffrn_reflns_limit_h_min -10 _diffrn_reflns_limit_k_max 15 _diffrn_reflns_limit_k_min -16 _diffrn_reflns_limit_l_max 31 _diffrn_reflns_limit_l_min -25 _diffrn_reflns_number 18475 _diffrn_reflns_theta_full 33.73 _diffrn_reflns_theta_max 33.73 _diffrn_reflns_theta_min 2.82 _diffrn_source 'Incoatec microfocus source' _diffrn_source_type 'Bruker D8 Quest' _exptl_absorpt_coefficient_mu 0.068 _exptl_absorpt_correction_T_max 0.99 _exptl_absorpt_correction_T_min 0.89 _exptl_absorpt_correction_type multi-scan _exptl_absorpt_process_details ; SADABS-2016/2 - Bruker AXS area detector scaling and absorption correction ; _exptl_crystal_colour colourless _exptl_crystal_density_diffrn 1.208 _exptl_crystal_density_method 'not measured' _exptl_crystal_description block _exptl_crystal_F_000 576 _exptl_crystal_size_max 0.240 _exptl_crystal_size_mid 0.200 _exptl_crystal_size_min 0.120 _refine_diff_density_max 0.365 _refine_diff_density_min -0.222 _refine_ls_extinction_method none _refine_ls_goodness_of_fit_ref 1.031 _refine_ls_hydrogen_treatment constr _refine_ls_matrix_type full _refine_ls_number_parameters 190 _refine_ls_number_reflns 5820 _refine_ls_number_restraints 0 _refine_ls_restrained_S_all 1.031 _refine_ls_R_factor_all 0.0776 _refine_ls_R_factor_gt 0.0523 _refine_ls_shift/su_max 0.001 _refine_ls_shift/su_mean 0.000 _refine_ls_structure_factor_coef Fsqd _refine_ls_weighting_details 'w=1/[\s^2^(Fo^2^)+(0.0515P)^2^+0.5499P] where P=(Fo^2^+2Fc^2^)/3' _refine_ls_weighting_scheme calc _refine_ls_wR_factor_gt 0.1170 _refine_ls_wR_factor_ref 0.1328 _reflns_number_gt 4364 _reflns_number_total 5820 _reflns_threshold_expression 'I > 2\s(I)' _cod_data_source_file d0sc01773f2.cif _cod_data_source_block chiba442m _cod_depositor_comments ; The following automatic conversions were performed: data item '_exptl_absorpt_correction_type' value 'Multi-Scan' was changed to 'multi-scan' in accordance with the /home/data/users/saulius/crontab/automatic-downloads/rss-feeds/RSC/lib/dictionaries/cif_core.dic dictionary named 'cif_core.dic' version 2.4.2 last updated on 2011-04-26. Automatic conversion script Id: cif_fix_values 7556 2019-12-06 15:28:31Z antanas Adding full bibliography for 1557997--1557998.cif. Adding full bibliography for 1557997--1557998.cif. ; _cod_database_code 1557997 _shelx_res_file ; TITL chiba442m in P2(1)/c chiba442m.res created by SHELXL-2018/3 at 11:26:40 on 11-Nov-2019 CELL 0.71073 7.22980 10.32410 19.91550 90.0000 91.2503 90.0000 ZERR 4.00 0.00020 0.00030 0.00050 0.0000 0.0014 0.0000 LATT 1 SYMM -X, 1/2+Y, 1/2-Z SFAC C H UNIT 84 72 L.S. 10 ACTA BOND $H FMAP 2 PLAN 5 SIZE 0.12 0.20 0.24 TEMP -173.0 WGHT 0.051500 0.549900 FVAR 0.43817 C1 1 0.806781 0.415173 0.646536 11.00000 0.01263 0.01377 = 0.01065 0.00016 0.00092 0.00064 C2 1 0.628835 0.388564 0.617682 11.00000 0.01384 0.01478 = 0.01401 0.00043 -0.00109 0.00122 AFIX 43 H2 2 0.555131 0.458203 0.601078 11.00000 -1.20000 AFIX 0 C3 1 0.561549 0.264429 0.613351 11.00000 0.01458 0.01640 = 0.01722 -0.00071 -0.00120 -0.00072 AFIX 43 H3 2 0.442102 0.249406 0.594090 11.00000 -1.20000 AFIX 0 C4 1 0.668054 0.159112 0.637216 11.00000 0.01869 0.01280 = 0.01814 -0.00095 0.00154 -0.00102 AFIX 43 H4 2 0.620181 0.073542 0.634429 11.00000 -1.20000 AFIX 0 C5 1 0.840541 0.180599 0.664391 11.00000 0.01690 0.01352 = 0.01503 0.00155 0.00186 0.00303 AFIX 43 H5 2 0.912417 0.109088 0.679815 11.00000 -1.20000 AFIX 0 C6 1 0.914520 0.307675 0.670040 11.00000 0.01372 0.01534 = 0.01136 0.00042 0.00142 0.00175 C7 1 1.093081 0.328632 0.698740 11.00000 0.01393 0.01924 = 0.01445 0.00149 -0.00027 0.00326 AFIX 43 H7 2 1.163472 0.257198 0.715155 11.00000 -1.20000 AFIX 0 C8 1 1.164742 0.451034 0.702961 11.00000 0.01211 0.02246 = 0.01617 -0.00098 -0.00100 0.00086 AFIX 43 H8 2 1.284874 0.464311 0.721997 11.00000 -1.20000 AFIX 0 C9 1 1.060419 0.557556 0.679074 11.00000 0.01442 0.01688 = 0.01488 -0.00086 0.00068 -0.00135 AFIX 43 H9 2 1.113315 0.641705 0.681483 11.00000 -1.20000 AFIX 0 C10 1 0.883687 0.543363 0.652276 11.00000 0.01320 0.01432 = 0.01059 -0.00001 0.00132 -0.00019 C11 1 0.777659 0.661139 0.631091 11.00000 0.01537 0.01277 = 0.01271 -0.00056 -0.00059 -0.00083 C12 1 0.878493 0.755910 0.586902 11.00000 0.01753 0.01542 = 0.02069 0.00420 0.00141 -0.00161 AFIX 23 H12A 2 0.808761 0.838439 0.585913 11.00000 -1.20000 H12B 2 1.001461 0.773761 0.607717 11.00000 -1.20000 AFIX 0 C13 1 0.905552 0.712129 0.515719 11.00000 0.01946 0.02750 = 0.01935 0.00909 0.00555 0.00454 AFIX 43 H13 2 0.988416 0.761222 0.489482 11.00000 -1.20000 AFIX 0 C14 1 0.824832 0.611960 0.486479 11.00000 0.02840 0.03178 = 0.01411 0.00238 0.00377 0.00817 AFIX 93 H14A 2 0.740882 0.560025 0.510759 11.00000 -1.20000 H14B 2 0.850553 0.591635 0.441105 11.00000 -1.20000 AFIX 0 C15 1 0.607842 0.682714 0.654829 11.00000 0.01655 0.01311 = 0.01278 0.00038 0.00139 0.00022 AFIX 43 H15 2 0.563674 0.621260 0.686158 11.00000 -1.20000 AFIX 0 C16 1 0.482332 0.790868 0.637789 11.00000 0.01393 0.01233 = 0.01466 -0.00024 0.00121 -0.00077 C17 1 0.450401 0.831283 0.571352 11.00000 0.01852 0.01869 = 0.01376 -0.00095 0.00224 0.00145 AFIX 43 H17 2 0.511988 0.788852 0.535896 11.00000 -1.20000 AFIX 0 C18 1 0.329586 0.932795 0.556731 11.00000 0.01818 0.01922 = 0.01486 0.00315 0.00048 0.00085 AFIX 43 H18 2 0.309992 0.959541 0.511491 11.00000 -1.20000 AFIX 0 C19 1 0.237489 0.995224 0.607922 11.00000 0.01526 0.01567 = 0.02076 0.00249 0.00124 0.00130 AFIX 43 H19 2 0.156301 1.065292 0.597905 11.00000 -1.20000 AFIX 0 C20 1 0.264915 0.954446 0.674057 11.00000 0.01568 0.01580 = 0.01805 -0.00073 0.00356 0.00189 AFIX 43 H20 2 0.201240 0.996263 0.709210 11.00000 -1.20000 AFIX 0 C21 1 0.385258 0.852670 0.688821 11.00000 0.01482 0.01522 = 0.01338 0.00027 0.00138 -0.00034 AFIX 43 H21 2 0.401794 0.824768 0.734010 11.00000 -1.20000 AFIX 0 HKLF 4 REM chiba442m in P2(1)/c REM wR2 = 0.132807, GooF = S = 1.03126, Restrained GooF = 1.03126 for all data REM R1 = 0.052344 for 4364 Fo > 4sig(Fo) and 0.077636 for all 5820 data REM 190 parameters refined using 0 restraints END WGHT 0.0513 0.5514 REM Highest difference peak 0.365, deepest hole -0.222, 1-sigma level 0.056 Q1 1 0.4457 0.8307 0.6610 11.00000 0.05 0.36 Q2 1 0.8305 0.6019 0.6367 11.00000 0.05 0.36 Q3 1 0.7155 0.3997 0.6337 11.00000 0.05 0.36 Q4 1 0.3895 0.8833 0.5645 11.00000 0.05 0.35 Q5 1 0.6057 0.3232 0.6097 11.00000 0.05 0.35 ; _shelx_res_checksum 8289 loop_ _space_group_symop_operation_xyz 'x, y, z' '-x, y+1/2, -z+1/2' '-x, -y, -z' 'x, -y-1/2, z-1/2' loop_ _atom_site_type_symbol _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_U_iso_or_equiv _atom_site_adp_type _atom_site_calc_flag _atom_site_refinement_flags_adp _atom_site_refinement_flags_occupancy _atom_site_refinement_flags_posn _atom_site_occupancy _atom_site_disorder_assembly _atom_site_disorder_group C C1 0.80678(14) 0.41517(9) 0.64654(5) 0.01234(17) Uani d . . . 1 . . C C2 0.62883(14) 0.38856(10) 0.61768(5) 0.01423(18) Uani d . . . 1 . . H H2 0.555131 0.458203 0.601078 0.017 Uiso calc U . R 1 . . C C3 0.56155(15) 0.26443(10) 0.61335(5) 0.01609(19) Uani d . . . 1 . . H H3 0.442102 0.249406 0.59409 0.019 Uiso calc U . R 1 . . C C4 0.66805(15) 0.15911(10) 0.63722(5) 0.0165(2) Uani d . . . 1 . . H H4 0.620181 0.073542 0.634429 0.02 Uiso calc U . R 1 . . C C5 0.84054(15) 0.18060(10) 0.66439(5) 0.01513(19) Uani d . . . 1 . . H H5 0.912417 0.109088 0.679815 0.018 Uiso calc U . R 1 . . C C6 0.91452(14) 0.30768(10) 0.67004(5) 0.01346(18) Uani d . . . 1 . . C C7 1.09308(14) 0.32863(10) 0.69874(5) 0.01588(19) Uani d . . . 1 . . H H7 1.163472 0.257198 0.715155 0.019 Uiso calc U . R 1 . . C C8 1.16474(15) 0.45103(11) 0.70296(5) 0.0169(2) Uani d . . . 1 . . H H8 1.284874 0.464311 0.721997 0.02 Uiso calc U . R 1 . . C C9 1.06042(14) 0.55756(10) 0.67907(5) 0.01539(19) Uani d . . . 1 . . H H9 1.113315 0.641705 0.681483 0.018 Uiso calc U . R 1 . . C C10 0.88369(14) 0.54336(9) 0.65228(5) 0.01269(18) Uani d . . . 1 . . C C11 0.77766(14) 0.66114(9) 0.63109(5) 0.01363(18) Uani d . . . 1 . . C C12 0.87849(15) 0.75591(10) 0.58690(6) 0.0179(2) Uani d . . . 1 . . H H12A 0.808761 0.838439 0.585913 0.021 Uiso calc U . R 1 . . H H12B 1.001461 0.773761 0.607717 0.021 Uiso calc U . R 1 . . C C13 0.90555(16) 0.71213(12) 0.51572(6) 0.0220(2) Uani d . . . 1 . . H H13 0.988416 0.761222 0.489482 0.026 Uiso calc U . R 1 . . C C14 0.82483(18) 0.61196(13) 0.48648(6) 0.0247(2) Uani d . . . 1 . . H H14A 0.740882 0.560025 0.510759 0.03 Uiso calc U . R 1 . . H H14B 0.850553 0.591635 0.441105 0.03 Uiso calc U . R 1 . . C C15 0.60784(14) 0.68271(10) 0.65483(5) 0.01413(18) Uani d . . . 1 . . H H15 0.563674 0.62126 0.686158 0.017 Uiso calc U . R 1 . . C C16 0.48233(14) 0.79087(9) 0.63779(5) 0.01362(18) Uani d . . . 1 . . C C17 0.45040(15) 0.83128(10) 0.57135(5) 0.0170(2) Uani d . . . 1 . . H H17 0.511988 0.788852 0.535896 0.02 Uiso calc U . R 1 . . C C18 0.32959(15) 0.93279(10) 0.55673(5) 0.0174(2) Uani d . . . 1 . . H H18 0.309992 0.959541 0.511491 0.021 Uiso calc U . R 1 . . C C19 0.23749(15) 0.99522(10) 0.60792(6) 0.0172(2) Uani d . . . 1 . . H H19 0.156301 1.065292 0.597905 0.021 Uiso calc U . R 1 . . C C20 0.26492(15) 0.95445(10) 0.67406(5) 0.0165(2) Uani d . . . 1 . . H H20 0.20124 0.996263 0.70921 0.02 Uiso calc U . R 1 . . C C21 0.38526(14) 0.85267(10) 0.68882(5) 0.01446(18) Uani d . . . 1 . . H H21 0.401794 0.824768 0.73401 0.017 Uiso calc U . R 1 . . loop_ _atom_site_aniso_label _atom_site_aniso_U_11 _atom_site_aniso_U_22 _atom_site_aniso_U_33 _atom_site_aniso_U_12 _atom_site_aniso_U_13 _atom_site_aniso_U_23 C1 0.0126(4) 0.0138(4) 0.0106(4) 0.0006(3) 0.0009(3) 0.0002(3) C2 0.0138(4) 0.0148(4) 0.0140(4) 0.0012(3) -0.0011(3) 0.0004(3) C3 0.0146(4) 0.0164(4) 0.0172(4) -0.0007(3) -0.0012(4) -0.0007(4) C4 0.0187(5) 0.0128(4) 0.0181(5) -0.0010(3) 0.0015(4) -0.0009(4) C5 0.0169(5) 0.0135(4) 0.0150(4) 0.0030(3) 0.0019(4) 0.0015(3) C6 0.0137(4) 0.0153(4) 0.0114(4) 0.0017(3) 0.0014(3) 0.0004(3) C7 0.0139(4) 0.0192(5) 0.0145(4) 0.0033(3) -0.0003(4) 0.0015(4) C8 0.0121(4) 0.0225(5) 0.0162(4) 0.0009(4) -0.0010(4) -0.0010(4) C9 0.0144(4) 0.0169(4) 0.0149(4) -0.0013(3) 0.0007(4) -0.0009(4) C10 0.0132(4) 0.0143(4) 0.0106(4) -0.0002(3) 0.0013(3) 0.0000(3) C11 0.0154(4) 0.0128(4) 0.0127(4) -0.0008(3) -0.0006(3) -0.0006(3) C12 0.0175(5) 0.0154(4) 0.0207(5) -0.0016(4) 0.0014(4) 0.0042(4) C13 0.0195(5) 0.0275(6) 0.0194(5) 0.0045(4) 0.0055(4) 0.0091(4) C14 0.0284(6) 0.0318(6) 0.0141(5) 0.0082(5) 0.0038(4) 0.0024(4) C15 0.0166(4) 0.0131(4) 0.0128(4) 0.0002(3) 0.0014(3) 0.0004(3) C16 0.0139(4) 0.0123(4) 0.0147(4) -0.0008(3) 0.0012(3) -0.0002(3) C17 0.0185(5) 0.0187(5) 0.0138(4) 0.0015(4) 0.0022(4) -0.0009(4) C18 0.0182(5) 0.0192(5) 0.0149(4) 0.0009(4) 0.0005(4) 0.0032(4) C19 0.0153(4) 0.0157(4) 0.0208(5) 0.0013(3) 0.0012(4) 0.0025(4) C20 0.0157(4) 0.0158(4) 0.0181(5) 0.0019(3) 0.0036(4) -0.0007(4) C21 0.0148(4) 0.0152(4) 0.0134(4) -0.0003(3) 0.0014(3) 0.0003(3) 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' loop_ _geom_angle_atom_site_label_1 _geom_angle_atom_site_label_2 _geom_angle_atom_site_label_3 _geom_angle_site_symmetry_1 _geom_angle_site_symmetry_3 _geom_angle _geom_angle_publ_flag C2 C1 C6 . . 117.61(9) ? C2 C1 C10 . . 123.60(9) ? C6 C1 C10 . . 118.77(9) ? C3 C2 C1 . . 121.41(9) ? C3 C2 H2 . . 119.3 ? C1 C2 H2 . . 119.3 ? C2 C3 C4 . . 120.59(10) ? C2 C3 H3 . . 119.7 ? C4 C3 H3 . . 119.7 ? C5 C4 C3 . . 119.71(9) ? C5 C4 H4 . . 120.1 ? C3 C4 H4 . . 120.1 ? C4 C5 C6 . . 121.34(9) ? C4 C5 H5 . . 119.3 ? C6 C5 H5 . . 119.3 ? C7 C6 C5 . . 120.74(9) ? C7 C6 C1 . . 119.93(9) ? C5 C6 C1 . . 119.33(9) ? C8 C7 C6 . . 120.43(9) ? C8 C7 H7 . . 119.8 ? C6 C7 H7 . . 119.8 ? C7 C8 C9 . . 120.05(10) ? C7 C8 H8 . . 120.0 ? C9 C8 H8 . . 120.0 ? C10 C9 C8 . . 122.06(10) ? C10 C9 H9 . . 119.0 ? C8 C9 H9 . . 119.0 ? C9 C10 C1 . . 118.73(9) ? C9 C10 C11 . . 119.17(9) ? C1 C10 C11 . . 122.09(9) ? C15 C11 C10 . . 120.19(9) ? C15 C11 C12 . . 123.55(9) ? C10 C11 C12 . . 116.09(9) ? C13 C12 C11 . . 115.32(9) ? C13 C12 H12A . . 108.4 ? C11 C12 H12A . . 108.4 ? C13 C12 H12B . . 108.4 ? C11 C12 H12B . . 108.4 ? H12A C12 H12B . . 107.5 ? C14 C13 C12 . . 125.94(11) ? C14 C13 H13 . . 117.0 ? C12 C13 H13 . . 117.0 ? C13 C14 H14A . . 120.0 ? C13 C14 H14B . . 120.0 ? H14A C14 H14B . . 120.0 ? C11 C15 C16 . . 127.39(9) ? C11 C15 H15 . . 116.3 ? C16 C15 H15 . . 116.3 ? C21 C16 C17 . . 118.31(9) ? C21 C16 C15 . . 119.58(9) ? C17 C16 C15 . . 122.06(9) ? C18 C17 C16 . . 120.77(10) ? C18 C17 H17 . . 119.6 ? C16 C17 H17 . . 119.6 ? C19 C18 C17 . . 120.33(10) ? C19 C18 H18 . . 119.8 ? C17 C18 H18 . . 119.8 ? C18 C19 C20 . . 119.56(10) ? C18 C19 H19 . . 120.2 ? C20 C19 H19 . . 120.2 ? C21 C20 C19 . . 120.23(10) ? C21 C20 H20 . . 119.9 ? C19 C20 H20 . . 119.9 ? C20 C21 C16 . . 120.75(9) ? C20 C21 H21 . . 119.6 ? C16 C21 H21 . . 119.6 ? loop_ _geom_bond_atom_site_label_1 _geom_bond_atom_site_label_2 _geom_bond_site_symmetry_2 _geom_bond_distance _geom_bond_publ_flag C1 C2 . 1.4243(14) ? C1 C6 . 1.4289(14) ? C1 C10 . 1.4391(14) ? C2 C3 . 1.3728(14) ? C2 H2 . 0.95 ? C3 C4 . 1.4089(15) ? C3 H3 . 0.95 ? C4 C5 . 1.3667(15) ? C4 H4 . 0.95 ? C5 C6 . 1.4203(14) ? C5 H5 . 0.95 ? C6 C7 . 1.4170(15) ? C7 C8 . 1.3677(15) ? C7 H7 . 0.95 ? C8 C9 . 1.4103(15) ? C8 H8 . 0.95 ? C9 C10 . 1.3817(14) ? C9 H9 . 0.95 ? C10 C11 . 1.4933(14) ? C11 C15 . 1.3438(14) ? C11 C12 . 1.5137(14) ? C12 C13 . 1.5048(16) ? C12 H12A . 0.99 ? C12 H12B . 0.99 ? C13 C14 . 1.3169(18) ? C13 H13 . 0.95 ? C14 H14A . 0.95 ? C14 H14B . 0.95 ? C15 C16 . 1.4737(14) ? C15 H15 . 0.95 ? C16 C21 . 1.4013(14) ? C16 C17 . 1.4017(14) ? C17 C18 . 1.3910(15) ? C17 H17 . 0.95 ? C18 C19 . 1.3884(15) ? C18 H18 . 0.95 ? C19 C20 . 1.3928(15) ? C19 H19 . 0.95 ? C20 C21 . 1.3915(14) ? C20 H20 . 0.95 ? C21 H21 . 0.95 ?