data_General _audit_creation_date 'Mon Jul 18 20:24:24 2005' _audit_creation_method 'by teXsan' _audit_update_record ? #------------------------------------------------------------------------------ # PROCESSING SUMMARY (IUCr Office Use Only) _journal_date_recd_electronic ? _journal_date_from_coeditor ? _journal_date_accepted ? _journal_coeditor_code ? #------------------------------------------------------------------------------ # SUBMISSION DETAILS _publ_contact_author_name ' ENTER NAME' _publ_contact_author_address ; ENTER ADDRESS ; _publ_contact_author_email ' ENTER EMAIL ADDRESS ' _publ_contact_author_fax ' ENTER FAX NUMBER ' _publ_contact_author_phone ' ENTER PHONE NUMBER ' _publ_contact_letter ; ENTER TEXT OF LETTER ; _publ_requested_journal ' ENTER JOURNAL NAME HERE' _publ_requested_category ' CHOOSE FI FM FO CI CM CO or AD' _publ_requested_coeditor_name ? #------------------------------------------------------------------------------ # TITLE AND AUTHOR LIST _publ_section_title ; ENTER SECTION TITLE ; _publ_section_title_footnote ; ENTER FOOTNOTE TO TITLE OF PAPER ; loop_ _publ_author_name _publ_author_footnote _publ_author_address ' FIRST AUTHORS NAME ' ; FIRST AUTHORS FOOTNOTES ; ; FIRST AUTHORS ADDRESS ; _publ_section_synopsis ; ENTER SYNOPSIS ; #------------------------------------------------------------------------------ # TEXT _publ_section_abstract ; ENTER ABSTRACT ; _publ_section_comment ; ENTER TEXT ; _publ_section_acknowledgements ; ENTER ACKNOWLEDGEMENTS ; _publ_section_references ; ENTER OTHER REFERENCES Molecular Structure Corporation, Rigaku Corporation. (1999). teXsan. Single Crystal Structure Analysis Software. Version 1.10. MSC, 3200 Research Forest Drive, The Woodlands, TX 77381, USA. Rigaku, 3-9-12 Akishima, Tokyo, Japan. ; _publ_section_figure_captions ; ENTER FIGURE CAPTIONS ; _publ_section_exptl_prep ; ENTER COMPOUND PREPARATION DETAILS ; _publ_section_exptl_refinement ; ENTER SPECIAL DETAILS OF THE REFINEMENT ; #------------------------------------------------------------------------------ data_IPA_tAmyl_ #------------------------------------------------------------------------------ # CHEMICAL DATA _chemical_formula_sum 'C18 H32 N2 O4 ' _chemical_formula_moiety '?' _chemical_formula_weight 340.46 _chemical_melting_point ? #------------------------------------------------------------------------------ # CRYSTAL DATA _symmetry_cell_setting monoclinic _symmetry_space_group_name_H-M 'P 1 21/c 1' _symmetry_Int_Tables_number 14 loop_ _symmetry_equiv_pos_as_xyz x,y,z -x,1/2+y,1/2-z -x,-y,-z x,1/2-y,1/2+z _cell_length_a 17.870(3) _cell_length_b 6.2519(9) _cell_length_c 18.688(3) _cell_angle_alpha 90 _cell_angle_beta 111.01(1) _cell_angle_gamma 90 _cell_volume 1949.0(5) _cell_formula_units_Z 4 _cell_measurement_reflns_used 18301 _cell_measurement_theta_min 4.3 _cell_measurement_theta_max 68.4 _cell_measurement_temperature 213.2 #------------------------------------------------------------------------------ _exptl_crystal_description 'block' _exptl_crystal_colour 'colorless' _exptl_crystal_size_max 0.400 _exptl_crystal_size_mid 0.400 _exptl_crystal_size_min 0.200 _exptl_crystal_size_rad ? _exptl_crystal_density_diffrn 1.160 _exptl_crystal_density_meas ? _exptl_crystal_density_method 'not measured' _exptl_absorpt_coefficient_mu 0.658 _exptl_absorpt_correction_type integration _exptl_absorpt_process_details '(Higashi, 1999)' _exptl_absorpt_correction_T_min 0.793 _exptl_absorpt_correction_T_max 0.898 #------------------------------------------------------------------------------ # EXPERIMENTAL DATA _diffrn_radiation_type 'Cu K\a' _diffrn_radiation_wavelength 1.5419 _diffrn_measurement_device_type 'Rigaku RAXIS-RAPID Imaging Plate' _diffrn_measurement_method \w _diffrn_detector_area_resol_mean ? _diffrn_reflns_number 21302 _diffrn_reflns_av_R_equivalents 0.064 _diffrn_reflns_theta_max 68.25 _diffrn_measured_fraction_theta_max 0.9950 _diffrn_reflns_theta_full 68.25 _diffrn_measured_fraction_theta_full 0.9950 _diffrn_reflns_limit_h_min 0 _diffrn_reflns_limit_h_max 21 _diffrn_reflns_limit_k_min 0 _diffrn_reflns_limit_k_max 7 _diffrn_reflns_limit_l_min -22 _diffrn_reflns_limit_l_max 21 #------------------------------------------------------------------------------ # REFINEMENT DATA _refine_special_details ; Refinement using reflections with F^2^ > -10.0 sigma(F^2^). The weighted R-factor (wR) and goodness of fit (S) are based on F^2^. R-factor (gt) are based on F. The threshold expression of F^2^ > 2.0 sigma(F^2^) is used only for calculating R-factor (gt). ; _reflns_number_total 3558 _reflns_number_gt 2454 _reflns_threshold_expression F^2^>2.0\s(F^2^) _refine_ls_structure_factor_coef Fsqd _refine_ls_R_factor_gt 0.0527 _refine_ls_wR_factor_ref 0.1391 _refine_ls_hydrogen_treatment noref _refine_ls_number_reflns 3558 _refine_ls_number_parameters 217 _refine_ls_goodness_of_fit_ref 1.104 _refine_ls_weighting_scheme calc _refine_ls_weighting_details 'w = 1/[\s^2^(Fo^2^) + (0.05000(Max(Fo^2^,0) + 2Fc^2^)/3)^2^]' _refine_ls_shift/su_max 0.0002 _refine_diff_density_max 0.17 _refine_diff_density_min -0.23 _refine_ls_extinction_method none _refine_ls_extinction_coef ? _refine_ls_abs_structure_details ? _refine_ls_abs_structure_Flack ? loop_ _atom_type_symbol _atom_type_description _atom_type_scat_dispersion_real _atom_type_scat_dispersion_imag _atom_type_scat_source 'C' 'C' 0.018 0.009 ;International Tables for Crystallography (1992, Vol. C, Tables 4.2.6.8 and 6.1.1.1) ; 'H' 'H' 0.000 0.000 ;International Tables for Crystallography (1992, Vol. C, Table 6.1.1.2) ; 'O' 'O' 0.049 0.032 ;International Tables for Crystallography (1992, Vol. C, Tables 4.2.6.8 and 6.1.1.1) ; 'N' 'N' 0.031 0.018 ;International Tables for Crystallography (1992, Vol. C, Tables 4.2.6.8 and 6.1.1.1) ; #------------------------------------------------------------------------------ # ATOMIC COORDINATES AND DISPLACEMENT PARAMETERS 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_calc_flag _atom_site_refinement_flags _atom_site_disorder_assembly _atom_site_disorder_group O(1) O 0.59249(9) -0.0180(2) 0.31105(9) 0.0332(4) Uani 1.00 d . . . O(2) O 0.6566(1) -0.3227(3) 0.3537(1) 0.0433(5) Uani 1.00 d . . . O(3) O 0.93082(9) -0.0505(3) 0.66621(9) 0.0338(4) Uani 1.00 d . . . O(4) O 0.88804(10) -0.3487(3) 0.59853(10) 0.0381(5) Uani 1.00 d . . . N(1) N 0.5708(1) 0.1130(3) 0.7448(1) 0.0275(5) Uani 1.00 d . . . N(2) N 0.9960(1) -0.3483(3) 0.32030(10) 0.0248(4) Uani 1.00 d . . . C(1) C 0.6460(1) -0.1294(3) 0.3602(1) 0.0268(5) Uani 1.00 d . . . C(2) C 0.7000(1) -0.0196(3) 0.4326(1) 0.0245(5) Uani 1.00 d . . . C(3) C 0.7644(1) -0.1284(3) 0.4847(1) 0.0240(5) Uani 1.00 d . . . C(4) C 0.8140(1) -0.0311(3) 0.5526(1) 0.0229(5) Uani 1.00 d . . . C(5) C 0.8828(1) -0.1552(3) 0.6096(1) 0.0253(5) Uani 1.00 d . . . C(6) C 0.7971(1) 0.1778(3) 0.5676(1) 0.0272(6) Uani 1.00 d . . . C(7) C 0.7329(1) 0.2876(3) 0.5167(1) 0.0284(6) Uani 1.00 d . . . C(8) C 0.6848(1) 0.1911(3) 0.4492(1) 0.0277(6) Uani 1.00 d . . . C(9) C 0.5974(1) 0.1140(4) 0.6769(1) 0.0346(6) Uani 1.00 d . . . C(10) C 0.5474(2) 0.2797(5) 0.6208(2) 0.0514(8) Uani 1.00 d . . . C(11) C 0.6859(2) 0.1726(6) 0.7071(2) 0.0599(10) Uani 1.00 d . . . C(12) C 0.5827(2) -0.1128(4) 0.6441(2) 0.0448(8) Uani 1.00 d . . . C(13) C 0.6124(2) -0.1521(6) 0.5790(2) 0.072(1) Uani 1.00 d . . . C(14) C 0.9306(1) -0.3394(3) 0.3538(1) 0.0274(5) Uani 1.00 d . . . C(15) C 0.9669(2) -0.2433(5) 0.4333(1) 0.0442(8) Uani 1.00 d . . . C(16) C 0.8641(2) -0.1965(4) 0.3017(2) 0.0415(7) Uani 1.00 d . . . C(17) C 0.9025(1) -0.5715(4) 0.3545(1) 0.0328(6) Uani 1.00 d . . . C(18) C 0.8425(2) -0.6052(5) 0.3942(2) 0.0449(8) Uani 1.00 d . . . H(1) H 0.5787 0.2502 0.7686 0.0315 Uiso 1.00 calc . . . H(2) H 0.5155 0.0759 0.7293 0.0315 Uiso 1.00 calc . . . H(3) H 0.6014 0.0101 0.7817 0.0315 Uiso 1.00 calc . . . H(4) H 1.0389 -0.4369 0.3516 0.0290 Uiso 1.00 calc . . . H(5) H 0.9757 -0.4066 0.2699 0.0290 Uiso 1.00 calc . . . H(6) H 1.0162 -0.2086 0.3184 0.0290 Uiso 1.00 calc . . . H(7) H 0.7757 -0.2716 0.4743 0.0282 Uiso 1.00 calc . . . H(8) H 0.8313 0.2463 0.6135 0.0323 Uiso 1.00 calc . . . H(9) H 0.7218 0.4293 0.5279 0.0325 Uiso 1.00 calc . . . H(10) H 0.6404 0.2690 0.4140 0.0316 Uiso 1.00 calc . . . H(11) H 0.5544 0.4174 0.6441 0.0620 Uiso 1.00 calc . . . H(12) H 0.5617 0.2852 0.5767 0.0620 Uiso 1.00 calc . . . H(13) H 0.4912 0.2430 0.6049 0.0620 Uiso 1.00 calc . . . H(14) H 0.7164 0.0666 0.7438 0.0720 Uiso 1.00 calc . . . H(15) H 0.7064 0.1761 0.6664 0.0720 Uiso 1.00 calc . . . H(16) H 0.6949 0.3077 0.7321 0.0720 Uiso 1.00 calc . . . H(17) H 0.6076 -0.2122 0.6842 0.0545 Uiso 1.00 calc . . . H(18) H 0.5255 -0.1402 0.6254 0.0545 Uiso 1.00 calc . . . H(19) H 0.6010 -0.2960 0.5607 0.0875 Uiso 1.00 calc . . . H(20) H 0.5871 -0.0568 0.5377 0.0875 Uiso 1.00 calc . . . H(21) H 0.6689 -0.1307 0.5965 0.0875 Uiso 1.00 calc . . . H(22) H 1.0101 -0.3342 0.4645 0.0531 Uiso 1.00 calc . . . H(23) H 0.9878 -0.1062 0.4308 0.0531 Uiso 1.00 calc . . . H(24) H 0.9279 -0.2354 0.4567 0.0531 Uiso 1.00 calc . . . H(25) H 0.8849 -0.0565 0.2997 0.0500 Uiso 1.00 calc . . . H(26) H 0.8444 -0.2538 0.2507 0.0500 Uiso 1.00 calc . . . H(27) H 0.8214 -0.1872 0.3201 0.0500 Uiso 1.00 calc . . . H(28) H 0.8777 -0.6189 0.3019 0.0399 Uiso 1.00 calc . . . H(29) H 0.9480 -0.6597 0.3786 0.0399 Uiso 1.00 calc . . . H(30) H 0.8660 -0.5620 0.4467 0.0569 Uiso 1.00 calc . . . H(31) H 0.7956 -0.5204 0.3701 0.0569 Uiso 1.00 calc . . . H(32) H 0.8272 -0.7513 0.3924 0.0569 Uiso 1.00 calc . . . 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 O(1) 0.0270(8) 0.0319(9) 0.0280(9) -0.0010(7) -0.0056(7) 0.0059(7) O(2) 0.044(1) 0.0292(9) 0.037(1) 0.0045(7) -0.0105(8) -0.0077(7) O(3) 0.0369(9) 0.0314(8) 0.0213(8) -0.0088(7) -0.0038(7) 0.0026(7) O(4) 0.0366(9) 0.0283(9) 0.0340(10) 0.0081(7) -0.0060(7) -0.0013(7) N(1) 0.0266(9) 0.0270(9) 0.0226(10) 0.0008(7) 0.0011(8) 0.0016(7) N(2) 0.0259(9) 0.0253(9) 0.0184(9) 0.0019(7) 0.0019(7) 0.0007(7) C(1) 0.025(1) 0.029(1) 0.021(1) -0.0010(9) 0.0027(9) 0.0027(9) C(2) 0.024(1) 0.025(1) 0.022(1) -0.0034(8) 0.0065(9) 0.0005(8) C(3) 0.026(1) 0.0213(10) 0.022(1) -0.0025(8) 0.0060(9) -0.0006(8) C(4) 0.023(1) 0.024(1) 0.021(1) -0.0038(8) 0.0056(9) 0.0017(8) C(5) 0.027(1) 0.027(1) 0.019(1) -0.0050(9) 0.0042(9) 0.0017(9) C(6) 0.030(1) 0.027(1) 0.023(1) -0.0021(9) 0.0072(9) -0.0022(9) C(7) 0.032(1) 0.020(1) 0.032(1) 0.0032(9) 0.0108(10) 0.0003(9) C(8) 0.027(1) 0.026(1) 0.028(1) 0.0072(9) 0.0073(10) 0.0051(9) C(9) 0.038(1) 0.039(1) 0.026(1) -0.003(1) 0.010(1) 0.001(1) C(10) 0.069(2) 0.047(2) 0.035(2) -0.007(1) 0.015(1) 0.010(1) C(11) 0.039(2) 0.092(2) 0.049(2) -0.006(2) 0.016(1) -0.001(2) C(12) 0.062(2) 0.036(1) 0.042(2) 0.000(1) 0.025(1) -0.003(1) C(13) 0.102(3) 0.065(2) 0.066(2) -0.025(2) 0.051(2) -0.023(2) C(14) 0.028(1) 0.029(1) 0.023(1) -0.0034(9) 0.0061(9) -0.0025(9) C(15) 0.054(2) 0.053(2) 0.026(1) -0.011(1) 0.016(1) -0.010(1) C(16) 0.040(1) 0.038(1) 0.046(2) 0.008(1) 0.013(1) 0.004(1) C(17) 0.029(1) 0.028(1) 0.041(1) -0.0016(9) 0.012(1) 0.000(1) C(18) 0.041(1) 0.051(2) 0.047(2) -0.002(1) 0.020(1) 0.006(1) #------------------------------------------------------------------------------ _computing_data_collection 'PROCESS-AUTO' _computing_cell_refinement 'PROCESS-AUTO' _computing_data_reduction 'teXsan Ver. 1.10' _computing_structure_solution SIR92 _computing_structure_refinement 'teXsan Ver. 1.10' _computing_publication_material 'teXsan Ver. 1.10' _computing_molecular_graphics ? #------------------------------------------------------------------------------ _geom_special_details ; ? ; loop_ _geom_bond_atom_site_label_1 _geom_bond_atom_site_label_2 _geom_bond_distance _geom_bond_site_symmetry_1 _geom_bond_site_symmetry_2 _geom_bond_publ_flag O(1) C(1) 1.270(3) . . yes O(2) C(1) 1.236(3) . . yes O(3) C(5) 1.278(3) . . yes O(4) C(5) 1.237(3) . . yes N(1) C(9) 1.506(3) . . yes N(2) C(14) 1.511(3) . . yes C(1) C(2) 1.515(3) . . yes C(2) C(3) 1.390(3) . . yes C(2) C(8) 1.403(3) . . yes C(3) C(4) 1.399(3) . . yes C(4) C(5) 1.519(3) . . yes C(4) C(6) 1.392(3) . . yes C(6) C(7) 1.383(3) . . yes C(7) C(8) 1.384(3) . . yes C(9) C(10) 1.516(4) . . yes C(9) C(11) 1.521(4) . . yes C(9) C(12) 1.531(3) . . yes C(12) C(13) 1.510(4) . . yes C(14) C(15) 1.515(3) . . yes C(14) C(16) 1.526(3) . . yes C(14) C(17) 1.537(3) . . yes C(17) C(18) 1.522(3) . . yes #------------------------------------------------------------------------------ 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_2 _geom_angle_site_symmetry_3 _geom_angle_publ_flag O(1) C(1) O(2) 124.6(2) . 1_555 1_555 yes O(1) C(1) C(2) 118.1(2) . 1_555 1_555 yes O(2) C(1) C(2) 117.3(2) . 1_555 1_555 yes C(1) C(2) C(3) 120.4(2) . 1_555 1_555 yes C(1) C(2) C(8) 120.7(2) . 1_555 1_555 yes C(3) C(2) C(8) 118.8(2) . 1_555 1_555 yes C(2) C(3) C(4) 121.3(2) . 1_555 1_555 yes C(3) C(4) C(5) 120.3(2) . 1_555 1_555 yes C(3) C(4) C(6) 118.6(2) . 1_555 1_555 yes C(5) C(4) C(6) 121.1(2) . 1_555 1_555 yes O(3) C(5) O(4) 124.8(2) . 1_555 1_555 yes O(3) C(5) C(4) 117.0(2) . 1_555 1_555 yes O(4) C(5) C(4) 118.2(2) . 1_555 1_555 yes C(4) C(6) C(7) 120.9(2) . 1_555 1_555 yes C(6) C(7) C(8) 120.1(2) . 1_555 1_555 yes C(2) C(8) C(7) 120.3(2) . 1_555 1_555 yes N(1) C(9) C(10) 107.5(2) . 1_555 1_555 yes N(1) C(9) C(11) 106.8(2) . 1_555 1_555 yes N(1) C(9) C(12) 105.9(2) . 1_555 1_555 yes C(10) C(9) C(11) 111.6(2) . 1_555 1_555 yes C(10) C(9) C(12) 112.4(2) . 1_555 1_555 yes C(11) C(9) C(12) 112.2(2) . 1_555 1_555 yes C(9) C(12) C(13) 114.5(2) . 1_555 1_555 yes N(2) C(14) C(15) 107.3(2) . 1_555 1_555 yes N(2) C(14) C(16) 107.3(2) . 1_555 1_555 yes N(2) C(14) C(17) 105.8(2) . 1_555 1_555 yes C(15) C(14) C(16) 110.8(2) . 1_555 1_555 yes C(15) C(14) C(17) 113.1(2) . 1_555 1_555 yes C(16) C(14) C(17) 112.1(2) . 1_555 1_555 yes C(14) C(17) C(18) 115.1(2) . 1_555 1_555 yes #------------------------------------------------------------------------------ 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 O(1) C(1) C(2) C(3) -173.7(2) 1_555 1_555 1_555 1_555 yes O(1) C(1) C(2) C(8) 8.1(3) 1_555 1_555 1_555 1_555 yes O(2) C(1) C(2) C(3) 7.2(3) 1_555 1_555 1_555 1_555 yes O(2) C(1) C(2) C(8) -171.0(2) 1_555 1_555 1_555 1_555 yes O(3) C(5) C(4) C(3) 172.7(2) 1_555 1_555 1_555 1_555 yes O(3) C(5) C(4) C(6) -9.7(3) 1_555 1_555 1_555 1_555 yes O(4) C(5) C(4) C(3) -7.8(3) 1_555 1_555 1_555 1_555 yes O(4) C(5) C(4) C(6) 169.9(2) 1_555 1_555 1_555 1_555 yes N(1) C(9) C(12) C(13) -174.8(3) 1_555 1_555 1_555 1_555 yes N(2) C(14) C(17) C(18) 173.6(2) 1_555 1_555 1_555 1_555 yes C(1) C(2) C(3) C(4) -178.7(2) 1_555 1_555 1_555 1_555 yes C(1) C(2) C(8) C(7) 177.8(2) 1_555 1_555 1_555 1_555 yes C(2) C(3) C(4) C(5) 178.4(2) 1_555 1_555 1_555 1_555 yes C(2) C(3) C(4) C(6) 0.7(3) 1_555 1_555 1_555 1_555 yes C(2) C(8) C(7) C(6) 1.0(3) 1_555 1_555 1_555 1_555 yes C(3) C(2) C(8) C(7) -0.4(3) 1_555 1_555 1_555 1_555 yes C(3) C(4) C(6) C(7) -0.2(3) 1_555 1_555 1_555 1_555 yes C(4) C(3) C(2) C(8) -0.4(3) 1_555 1_555 1_555 1_555 yes C(4) C(6) C(7) C(8) -0.7(3) 1_555 1_555 1_555 1_555 yes C(5) C(4) C(6) C(7) -177.8(2) 1_555 1_555 1_555 1_555 yes C(10) C(9) C(12) C(13) 68.1(3) 1_555 1_555 1_555 1_555 yes C(11) C(9) C(12) C(13) -58.7(3) 1_555 1_555 1_555 1_555 yes C(15) C(14) C(17) C(18) 56.4(3) 1_555 1_555 1_555 1_555 yes C(16) C(14) C(17) C(18) -69.7(3) 1_555 1_555 1_555 1_555 yes #------------------------------------------------------------------------------ loop_ _geom_contact_atom_site_label_1 _geom_contact_atom_site_label_2 _geom_contact_distance _geom_contact_site_symmetry_1 _geom_contact_site_symmetry_2 _geom_contact_publ_flag O(1) N(1) 2.784(2) . 4_554 ? O(1) N(1) 2.788(2) . 3_656 ? O(1) C(9) 3.532(3) . 3_656 ? O(1) C(9) 3.582(3) . 4_554 ? O(1) C(10) 3.583(3) . 3_656 ? O(2) N(1) 2.747(2) . 4_544 ? O(2) C(8) 3.469(3) . 1_545 ? O(2) C(9) 3.584(3) . 4_544 ? O(2) C(18) 3.596(3) . . ? O(3) N(2) 2.765(2) . 4_545 ? O(3) N(2) 2.785(2) . 3_756 ? O(3) C(16) 3.536(3) . 4_545 ? O(3) C(15) 3.550(3) . 3_756 ? O(3) C(14) 3.574(3) . 4_545 ? O(3) C(14) 3.589(3) . 3_756 ? O(4) N(2) 2.816(2) . 3_746 ? O(4) C(6) 3.326(3) . 1_545 ? O(4) C(7) 3.487(3) . 1_545 ? O(4) C(17) 3.560(3) . 3_746 ? C(7) C(18) 3.569(3) . 1_565 ? C(8) C(18) 3.563(3) . 1_565 ? #------------------------------------------------------------------------------