# Copyright The Royal Society of Chemistry, 1999 # CCDC Number: 182/1213 data_rrt9813 _audit_creation_method 'manual editing of SHELXL template' _publ_contact_author_name 'Dr Rik R Tykwinski' _publ_contact_author_address ; Department of Chemistry University of Alberta Edmonton Alberta T6G 2G2 Canada ; _publ_contact_author_email rik.tykwinski@ualberta.ca _publ_contact_author_fax '+1 780 492 8231' _publ_contact_author_phone '+1 780 492 5307' _publ_contact_letter ; To: Cambridge Crystallographic Data Centre Please accept the following CIF data which are being submitted in support of an upcoming communication to be published in Chemical Communications (manuscript 9/00910H). Please forward any questions concerning this CIF to Bob McDonald (Bob.McDonald@ualberta.ca). ; _publ_requested_journal 'Chemical Communications' _publ_section_title ; Cyclic alkynes - electronic behaviour as a function of ring strain ; _publ_author_name 'Dr Rik R Tykwinski' _publ_author_address ; Department of Chemistry University of Alberta Edmonton Alberta T6G 2G2 Canada ; _chemical_formula_sum 'C20 H20' _chemical_formula_weight 260.36 loop_ _atom_type_symbol _atom_type_description _atom_type_scat_dispersion_real _atom_type_scat_dispersion_imag _atom_type_scat_source 'C' 'C' .0033 .0016 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' 'H' 'H' .0000 .0000 '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)/c loop_ _symmetry_equiv_pos_as_xyz 'x, y, z' '-x, y+1/2, -z+1/2' '-x, -y, -z' 'x, -y-1/2, z-1/2' _cell_length_a 9.2119(8) _cell_length_b 12.5305(12) _cell_length_c 14.5747(10) _cell_angle_alpha 90.00 _cell_angle_beta 107.744(7) _cell_angle_gamma 90.00 _cell_volume 1602.3(2) _cell_formula_units_Z 4 _cell_measurement_temperature 213(2) _cell_measurement_reflns_used 40 _cell_measurement_theta_min 10.54 _cell_measurement_theta_max 12.92 _exptl_crystal_description fragment _exptl_crystal_colour colorless _exptl_crystal_size_max 0.60 _exptl_crystal_size_mid 0.30 _exptl_crystal_size_min 0.23 _exptl_crystal_density_meas ? _exptl_crystal_density_diffrn 1.079 _exptl_crystal_density_method ? _exptl_crystal_F_000 560 _exptl_absorpt_coefficient_mu 0.061 _exptl_absorpt_correction_type none _exptl_absorpt_correction_T_min ? _exptl_absorpt_correction_T_max ? _exptl_special_details ; ? ; _diffrn_ambient_temperature 213(2) _diffrn_radiation_wavelength 0.71073 _diffrn_radiation_type MoKa _diffrn_radiation_source 'fine-focus rotating anode' _diffrn_radiation_monochromator graphite _diffrn_measurement_device 'Siemens P4' _diffrn_measurement_method '2\q/\w scans' _diffrn_standards_number 3 _diffrn_standards_interval_count 297 _diffrn_standards_interval_time ? _diffrn_standards_decay_% ? _diffrn_reflns_number 3000 _diffrn_reflns_av_R_equivalents 0.0455 _diffrn_reflns_av_sigmaI/netI 0.0614 _diffrn_reflns_limit_h_min 0 _diffrn_reflns_limit_h_max 10 _diffrn_reflns_limit_k_min 0 _diffrn_reflns_limit_k_max 14 _diffrn_reflns_limit_l_min -17 _diffrn_reflns_limit_l_max 16 _diffrn_reflns_theta_min 2.19 _diffrn_reflns_theta_max 25.00 _reflns_number_total 2814 _reflns_number_observed 1399 _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 0 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^)+( 0.0724P)^2^+0.7846P] 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 none _refine_ls_extinction_coef ? _refine_ls_number_reflns 2814 _refine_ls_number_parameters 185 _refine_ls_number_restraints 0 _refine_ls_R_factor_all 0.1618 _refine_ls_R_factor_obs 0.0762 _refine_ls_wR_factor_all 0.2012 _refine_ls_wR_factor_obs 0.1549 _refine_ls_goodness_of_fit_all 1.024 _refine_ls_goodness_of_fit_obs 1.149 _refine_ls_restrained_S_all 1.024 _refine_ls_restrained_S_obs 1.149 _refine_ls_shift/esd_max 0.004 _refine_ls_shift/esd_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_thermal_displace_type _atom_site_occupancy _atom_site_calc_flag _atom_site_refinement_flags _atom_site_disorder_group C1 C 0.2704(4) -0.0471(3) 0.2094(3) 0.0415(9) Uani 1 d . . C2 C 0.2510(4) -0.1611(3) 0.2044(3) 0.0458(10) Uani 1 d . . C3 C 0.2044(4) -0.2506(3) 0.1903(3) 0.0438(9) Uani 1 d . . C4 C 0.1240(4) -0.3445(3) 0.1658(3) 0.0448(10) Uani 1 d . . C5 C 0.0321(4) -0.4148(3) 0.1367(3) 0.0484(10) Uani 1 d . . C6 C -0.1091(4) -0.4696(3) 0.0942(3) 0.0451(10) Uani 1 d . . C7 C -0.2290(5) -0.3912(3) 0.0639(3) 0.0496(10) Uani 1 d . . C8 C -0.3019(5) -0.3113(3) 0.0476(3) 0.0546(11) Uani 1 d . . C9 C -0.3685(5) -0.2041(3) 0.0367(4) 0.0734(14) Uani 1 d . . H9A H -0.4220(5) -0.1927(3) 0.0846(4) 0.088 Uiso 1 calc R . H9B H -0.4421(5) -0.1962(3) -0.0276(4) 0.088 Uiso 1 calc R . C10 C -0.2388(6) -0.1208(4) 0.0510(4) 0.086(2) Uani 1 d . . H10A H -0.1525(6) -0.1442(4) 0.1053(4) 0.103 Uiso 1 calc R . H10B H -0.2049(6) -0.1220(4) -0.0066(4) 0.103 Uiso 1 calc R . C11 C -0.2722(5) -0.0137(4) 0.0680(4) 0.095(2) Uani 1 d . . H11A H -0.2989(5) -0.0123(4) 0.1282(4) 0.114 Uiso 1 calc R . H11B H -0.3637(5) 0.0073(4) 0.0163(4) 0.114 Uiso 1 calc R . C12 C -0.1544(4) 0.0704(3) 0.0751(3) 0.0664(13) Uani 1 d . . H12A H -0.1576(4) 0.0919(3) 0.0099(3) 0.080 Uiso 1 calc R . H12B H -0.1804(4) 0.1331(3) 0.1072(3) 0.080 Uiso 1 calc R . C13 C 0.0009(5) 0.0374(3) 0.1276(3) 0.0492(10) Uani 1 d . . C14 C 0.1259(5) 0.0070(3) 0.1662(3) 0.0451(10) Uani 1 d . . C15 C 0.4042(4) 0.0014(3) 0.2488(3) 0.0456(10) Uani 1 d . . C16 C 0.4197(5) 0.1199(3) 0.2486(3) 0.0642(13) Uani 1 d . . H16A H 0.4843(23) 0.1398(3) 0.2098(15) 0.077 Uiso 1 calc R . H16B H 0.4649(26) 0.1450(4) 0.3140(4) 0.077 Uiso 1 calc R . H16C H 0.3198(6) 0.1519(3) 0.2217(17) 0.077 Uiso 1 calc R . C17 C 0.5469(4) -0.0608(3) 0.2943(3) 0.0619(12) Uani 1 d . . H17A H 0.5768(15) -0.0518(15) 0.3636(3) 0.074 Uiso 1 calc R . H17B H 0.6276(8) -0.0350(13) 0.2701(13) 0.074 Uiso 1 calc R . H17C H 0.5286(9) -0.1358(4) 0.2784(14) 0.074 Uiso 1 calc R . C18 C -0.1258(4) -0.5758(3) 0.0857(3) 0.0467(10) Uani 1 d . . C19 C 0.0078(5) -0.6492(3) 0.1218(3) 0.0619(12) Uani 1 d . . H19A H 0.0159(16) -0.6943(13) 0.0695(5) 0.074 Uiso 1 calc R . H19B H -0.0062(13) -0.6935(13) 0.1731(11) 0.074 Uiso 1 calc R . H19C H 0.1003(6) -0.6075(3) 0.1463(15) 0.074 Uiso 1 calc R . C20 C -0.2781(4) -0.6261(3) 0.0419(3) 0.0555(11) Uani 1 d . . H20A H -0.3011(12) -0.6729(14) 0.0887(6) 0.067 Uiso 1 calc R . H20B H -0.2767(9) -0.6672(14) -0.0142(10) 0.067 Uiso 1 calc R . H20C H -0.3553(6) -0.5709(3) 0.0229(14) 0.067 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 C1 0.041(2) 0.040(2) 0.042(2) -0.005(2) 0.010(2) -0.009(2) C2 0.033(2) 0.049(2) 0.050(2) -0.003(2) 0.004(2) -0.003(2) C3 0.034(2) 0.045(2) 0.049(2) -0.003(2) 0.007(2) 0.001(2) C4 0.039(2) 0.041(2) 0.053(2) -0.001(2) 0.011(2) 0.001(2) C5 0.043(2) 0.041(2) 0.059(3) -0.005(2) 0.012(2) -0.006(2) C6 0.039(2) 0.047(2) 0.048(2) -0.007(2) 0.011(2) -0.010(2) C7 0.044(2) 0.051(3) 0.051(3) -0.006(2) 0.010(2) -0.012(2) C8 0.042(2) 0.049(3) 0.068(3) 0.000(2) 0.009(2) -0.016(2) C9 0.059(3) 0.050(3) 0.101(4) 0.013(3) 0.009(3) -0.004(2) C10 0.072(4) 0.052(3) 0.122(4) -0.007(3) 0.011(3) -0.006(3) C11 0.052(3) 0.074(4) 0.142(5) 0.009(3) 0.007(3) 0.004(3) C12 0.053(3) 0.051(3) 0.081(3) -0.005(2) -0.001(2) 0.002(2) C13 0.046(2) 0.041(2) 0.056(3) -0.004(2) 0.009(2) -0.001(2) C14 0.045(2) 0.038(2) 0.050(2) -0.006(2) 0.010(2) -0.006(2) C15 0.045(2) 0.045(2) 0.044(2) -0.007(2) 0.010(2) -0.007(2) C16 0.064(3) 0.053(3) 0.070(3) -0.005(2) 0.013(2) -0.016(2) C17 0.041(2) 0.071(3) 0.066(3) -0.003(2) 0.005(2) -0.010(2) C18 0.044(2) 0.047(2) 0.051(2) -0.007(2) 0.017(2) -0.011(2) C19 0.050(3) 0.051(3) 0.081(3) -0.007(2) 0.014(2) -0.011(2) C20 0.051(3) 0.055(3) 0.058(3) -0.008(2) 0.013(2) -0.018(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 C1 C15 1.337(5) . ? C1 C2 1.439(5) . ? C1 C14 1.455(5) . ? C2 C3 1.196(5) . ? C3 C4 1.378(5) . ? C4 C5 1.207(5) . ? C5 C6 1.433(5) . ? C6 C18 1.341(5) . ? C6 C7 1.444(6) . ? C7 C8 1.188(5) . ? C8 C9 1.465(6) . ? C9 C10 1.552(6) . ? C10 C11 1.416(6) . ? C11 C12 1.494(6) . ? C12 C13 1.461(6) . ? C13 C14 1.180(5) . ? C15 C16 1.492(5) . ? C15 C17 1.497(5) . ? C18 C20 1.492(5) . ? C18 C19 1.498(5) . ? 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 C15 C1 C2 123.9(3) . . ? C15 C1 C14 125.2(3) . . ? C2 C1 C14 110.9(3) . . ? C3 C2 C1 166.5(4) . . ? C2 C3 C4 169.0(4) . . ? C5 C4 C3 168.3(4) . . ? C4 C5 C6 161.6(4) . . ? C18 C6 C5 125.4(4) . . ? C18 C6 C7 126.3(3) . . ? C5 C6 C7 108.4(3) . . ? C8 C7 C6 165.4(4) . . ? C7 C8 C9 170.5(4) . . ? C8 C9 C10 108.8(4) . . ? C11 C10 C9 117.4(4) . . ? C10 C11 C12 119.2(4) . . ? C13 C12 C11 114.3(4) . . ? C14 C13 C12 176.6(5) . . ? C13 C14 C1 171.0(4) . . ? C1 C15 C16 121.8(4) . . ? C1 C15 C17 121.6(3) . . ? C16 C15 C17 116.6(3) . . ? C6 C18 C20 121.7(4) . . ? C6 C18 C19 121.2(3) . . ? C20 C18 C19 117.1(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 C15 C1 C2 C3 -177.2(16) . . . . ? C14 C1 C2 C3 2.8(19) . . . . ? C1 C2 C3 C4 -2.2(37) . . . . ? C2 C3 C4 C5 3.6(38) . . . . ? C3 C4 C5 C6 -6.4(32) . . . . ? C4 C5 C6 C18 -179.7(12) . . . . ? C4 C5 C6 C7 -0.7(15) . . . . ? C18 C6 C7 C8 177.7(16) . . . . ? C5 C6 C7 C8 -1.3(19) . . . . ? C6 C7 C8 C9 -6.6(43) . . . . ? C7 C8 C9 C10 23.3(30) . . . . ? C8 C9 C10 C11 -164.1(5) . . . . ? C9 C10 C11 C12 -175.7(5) . . . . ? C10 C11 C12 C13 -40.1(7) . . . . ? C11 C12 C13 C14 65.2(74) . . . . ? C12 C13 C14 C1 -40.7(92) . . . . ? C15 C1 C14 C13 173.8(26) . . . . ? C2 C1 C14 C13 -6.3(29) . . . . ? C2 C1 C15 C16 177.4(4) . . . . ? C14 C1 C15 C16 -2.6(6) . . . . ? C2 C1 C15 C17 -1.7(6) . . . . ? C14 C1 C15 C17 178.2(4) . . . . ? C5 C6 C18 C20 178.8(4) . . . . ? C7 C6 C18 C20 0.0(6) . . . . ? C5 C6 C18 C19 0.1(6) . . . . ? C7 C6 C18 C19 -178.8(4) . . . . ? _refine_diff_density_max .421 _refine_diff_density_min -.217 _refine_diff_density_rms .076