#============================================================================== data_global #============================================================================== _publ_contact_author 'Harry L. Anderson' _publ_contact_author_email harry.anderson@chem.ox.ac.uk loop_ _publ_author_name _publ_author_address 'Scriven, Lorel M.' ; Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Oxford OX1 3TA. UK. ; 'Kaiser, Katharina' ; IBM Research-Zurich, S\"aumerstrasse 4, 8803 R\"uschlikon, Switzerland. ; 'Schulz, Fabian' ; IBM Research-Zurich, S\"aumerstrasse 4, 8803 R\"uschlikon, Switzerland. ; 'Sterling, Alistair J.' ; Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Oxford OX1 3TA. UK. ; 'Woltering, Steffen L.' ; Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Oxford OX1 3TA. UK. ; 'Gawel, Przemyslaw' ; Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Oxford OX1 3TA. UK. ; 'Christensen, Kirsten E.' ; Chemical Crystallography Department, Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA. UK. ; 'Anderson, Harry L.' ; Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Oxford OX1 3TA. UK. ; 'Gross, Leo.' ; IBM Research-Zurich, S\"aumerstrasse 4, 8803 R\"uschlikon, Switzerland. ; _publ_requested_journal 'Journal of American Chemical Society' _journal_volume '?' _journal_page_first '?' _journal_page_last '?' _journal_year '2020' _ccdc_journal_depnumber '?' _publ_section_title ; Synthesis of cyclo[18]carbon via debromination of C~18~Br~6~ ; _publ_section_abstract ; Cyclo[18]carbon (C~18~, a molecular carbon allotrope) can be synthesized by dehalogenation of a bromocyclocarbon precursor, C~18~Br~6~, in 50% yield, by atomic manipulation on a sodium chloride surface at 5 K, and imaged by high resolution atomic force microscopy (AFM). This method of generating C~18~ gives a higher yield and cleaner images than the method reported previously, elimination of CO from the cyclocarbon oxide, C~24~O~6~. The experimental images of C~18~ were compared with calculated images for four theoretical model geometries: D~9h~ polyyne, D~18h~ cumulene, D~9h~ cumulene and C~9h~ polyyne. The results fit well with the two polyyne models, but do not distinguish between D~9h~ and C~9h~ geometries: there is evidence for bond-length alternation, and some degree of bond-angle alternation cannot be excluded. ; #============================================================================== data_C18Br6 #============================================================================== _audit_creation_date "2020-04-14" _audit_creation_method 'CRYSTALS_ver_14.61_build_7491 ' _oxford_structure_analysis_title '7256-c Fdd2-cba' _chemical_name_systematic . _chemical_melting_point 'not measured' _diffrn_special_details ; The crystals of this compound quickly loose solvent and becomes amorphous. Several attempts at measuring these crystals were made. For one particular sample the solvent was very slowly evaporated in the fridge. A small hexagonal plate crystal was seen and mounted. This particular sample did not seem to suffer from solvent loss in the same way as the others. The crystal was mounted using our in-house diffractometor and collected over the weekend. Unfortunately the crystal diffracted weakly and a hemisphere of data were collected to 1\%. ; _refine_special_details ; Data were carefully examined for symmetry, beam damage and other issues. The collected data were weak but would solve in Fdd2 using SHELXT. Due to the resolution of the data the data to parameter ratio is low, which is why a disordered model is not appropriate though the thermal ellipsoids clearly indicate that disorder is present in the structure. ; _cell_length_a 21.6885(16) _cell_length_b 13.647(4) _cell_length_c 12.5084(11) _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 3702(1) _symmetry_cell_setting 'orthorhombic' _symmetry_space_group_name_H-M 'F d d 2 ' _symmetry_space_group_name_Hall 'F 2 -2d' loop_ _symmetry_equiv_pos_as_xyz 'x,y,z' 'x,y+1/2,z+1/2' 'x+1/2,y,z+1/2' 'x+1/2,y+1/2,z' '-x,-y,z' '-x,-y+1/2,z+1/2' '-x+1/2,-y,z+1/2' '-x+1/2,-y+1/2,z' '-x+1/4,y+1/4,z+1/4' '-x+1/4,y+3/4,z+3/4' '-x+3/4,y+1/4,z+3/4' '-x+3/4,y+3/4,z+1/4' 'x+1/4,-y+1/4,z+1/4' 'x+1/4,-y+3/4,z+3/4' 'x+3/4,-y+1/4,z+3/4' 'x+3/4,-y+3/4,z+1/4' loop_ _atom_type_symbol _atom_type_scat_dispersion_real _atom_type_scat_dispersion_imag _atom_type_scat_Cromer_Mann_a1 _atom_type_scat_Cromer_Mann_b1 _atom_type_scat_Cromer_Mann_a2 _atom_type_scat_Cromer_Mann_b2 _atom_type_scat_Cromer_Mann_a3 _atom_type_scat_Cromer_Mann_b3 _atom_type_scat_Cromer_Mann_a4 _atom_type_scat_Cromer_Mann_b4 _atom_type_scat_Cromer_Mann_c _atom_type_scat_source C 0.0181 0.0091 2.3100 20.8439 1.0200 10.2075 1.5886 0.5687 0.8650 51.6512 0.2156 'International Tables Vol C 4.2.6.8 and 6.1.1.4' Br -0.6763 1.2805 17.1789 2.1723 5.2358 16.5796 5.6377 0.2609 3.9851 41.4328 2.9557 'International Tables Vol C 4.2.6.8 and 6.1.1.4' _cell_formula_units_Z 8 # Given Formula = C18 Br6 # Dc = 2.50 Fooo = 2544.00 Mu = 156.48 M = 695.62 # Found Formula = C18 Br6 # Dc = 2.50 FOOO = 2544.00 Mu = 156.48 M = 695.62 _chemical_formula_sum 'C18 Br6' _chemical_formula_moiety 'C18 Br6' _chemical_compound_source . _chemical_formula_weight 695.62 _cell_measurement_reflns_used 408 _cell_measurement_theta_min 5.20 _cell_measurement_theta_max 47.67 _cell_measurement_temperature 150 _exptl_crystal_description 'plate' _exptl_crystal_colour 'clear_intense_red' _exptl_crystal_size_min 0.01 _exptl_crystal_size_mid 0.04 _exptl_crystal_size_max 0.04 _exptl_crystal_density_diffrn 2.496 _exptl_crystal_density_meas 'not measured' _exptl_crystal_density_method 'not measured' # Non-dispersive F(000): _exptl_crystal_F_000 2544 _exptl_absorpt_coefficient_mu 15.648 # Sheldrick geometric approximatio 0.53 0.86 _exptl_absorpt_correction_type multi-scan _exptl_absorpt_process_details ; CrysAlisPro (Rigaku Oxford Diffraction, 2017) ; _exptl_absorpt_correction_T_min 0.27 _exptl_absorpt_correction_T_max 0.86 _diffrn_measurement_device_type 'Oxford Diffraction SuperNova' _diffrn_measurement_device 'Area' _diffrn_radiation_monochromator 'focussing mirrors' _diffrn_radiation_type 'Cu K\a' _diffrn_radiation_wavelength 1.54184 _diffrn_measurement_method \w # If a reference occurs more than once, delete the author # and date from subsequent references. _computing_data_collection 'SuperNova, (Oxford Diffraction, 2010)' _computing_cell_refinement ; CrysAlisPro (Rigaku Oxford Diffraction, 2017) ; _computing_data_reduction ; CrysAlisPro (Rigaku Oxford Diffraction, 2017) ; _computing_structure_solution 'SHELXT ' _computing_structure_refinement 'CRYSTALS (Betteridge et al., 2003)' _computing_publication_material 'CRYSTALS (Betteridge et al., 2003)' _computing_molecular_graphics 'CAMERON (Watkin et al., 1996)' _diffrn_standards_interval_time . _diffrn_standards_interval_count . _diffrn_standards_number 0 _diffrn_standards_decay_% . _diffrn_ambient_temperature 150 _diffrn_reflns_number 906 _diffrn_reflns_av_unetI/netI 0.099 _reflns_number_total 906 _diffrn_reflns_av_R_equivalents 0.1301 _diffrn_reflns_av_sigmaI/netI 0.1830 # Number of reflections without Friedels Law is 906 # Number of reflections with Friedels Law is 514 # Theoretical number of reflections is about 480 _diffrn_reflns_theta_min 5.212 _diffrn_reflns_theta_max 50.225 _diffrn_measured_fraction_theta_max 1.000 _diffrn_reflns_theta_full 50.225 _diffrn_measured_fraction_theta_full 1.000 _diffrn_reflns_limit_h_min 0 _diffrn_reflns_limit_h_max 21 _diffrn_reflns_limit_k_min 0 _diffrn_reflns_limit_k_max 13 _diffrn_reflns_limit_l_min -11 _diffrn_reflns_limit_l_max 12 _reflns_limit_h_min 0 _reflns_limit_h_max 21 _reflns_limit_k_min 0 _reflns_limit_k_max 13 _reflns_limit_l_min -11 _reflns_limit_l_max 12 _oxford_diffrn_Wilson_B_factor 7.04 _oxford_diffrn_Wilson_scale 550.43 _atom_sites_solution_primary other #heavy,direct,difmap,geom,iterative # _atom_sites_solution_secondary difmap _atom_sites_solution_hydrogens difmap _refine_diff_density_min -1.61 _refine_diff_density_max 2.87 # The current dictionary definitions do not cover the # situation where the reflections used for refinement were # selected by a user-defined sigma threshold # Explicitly named reflections are ALWAYS excluded from R&wR # The values actually used during refinement # These are labelled "all" for compatibility with PLATON _oxford_refine_reflns_threshold_expression_ref I>-10.0\s(I) _refine_ls_number_restraints 219 _refine_ls_number_parameters 110 _refine_ls_number_reflns 902 _oxford_refine_ls_R_factor_ref 0.2032 _refine_ls_R_factor_all 0.2032 _refine_ls_wR_factor_ref 0.3720 #Calculated the Oxford way _refine_ls_wR_factor_all 0.3720 _refine_ls_goodness_of_fit_ref 0.9687 _refine_ls_shift/su_max 0.0000615 _refine_ls_shift/su_mean 0.0000117 # Computed with no filters except I/sigma = -10 _oxford_reflns_number_all 902 _oxford_refine_ls_R_factor_all 0.2032 _oxford_refine_ls_wR_factor_all 0.3720 # Computed with no filters except I/sigma = +2 a la SHELX _reflns_threshold_expression I>2.0\s(I) _reflns_number_gt 460 _refine_ls_R_factor_gt 0.1297 _refine_ls_wR_factor_gt 0.2958 # For an explanation, see Cooper & Watkin, Acta Cryst. (2016). B72, 661-683 _oxford_Hooft_y -0.1(3) # for 169 Friedel pairs _oxford_Bijvoet_difference -0.1(2) # for 169 Friedel pairs # (Similar to the Parsons(q).) _oxford_refined_Flack_x 0.2(4) # for 392 Friedel pairs _refine_ls_abs_structure_Flack -0.1(2) _refine_ls_abs_structure_details ; Parsons, Flack & Wagner (2013), 169 Friedel Pairs ; # choose from: # rm (reference molecule of known chirality), # ad (anomolous dispersion - Flack), rmad (rm and ad), # syn (from synthesis), unk (unknown) or . (not applicable). _chemical_absolute_configuration 'ad' _refine_ls_structure_factor_coef Fsqd _refine_ls_matrix_type full _refine_ls_hydrogen_treatment noref #undef, noref, refall, # refxyz, refU, constr or mixed _refine_ls_weighting_scheme calc _refine_ls_weighting_details ; Method= Modified Sheldrick w=1/[\s^2^(F^2^) + ( 0.20P)^2^ + 0.00P] ,where P=(max(Fo^2^,0) + 2Fc^2^)/3 ; # Insert your own references if required - in alphabetical order _publ_section_references ; User-defined structure solution reference Betteridge, P.W., Carruthers, J.R., Cooper, R.I., Prout, K. & Watkin, D.J. (2003). J. Appl. Cryst. 36, 1487. Oxford Diffraction, (2010). Supernova User Manual. Parsons,S., Flack, H.D. and Wagner, T. Acta Cryst. (2013). B69, 249�259 Rigaku Oxford Diffraction (2017). CrysAlisPro. Watkin, D.J., Prout, C.K. & Pearce, L.J. (1996). CAMERON, Chemical Crystallography Laboratory, Oxford, UK. ; # Uequiv = arithmetic mean of Ui i.e. Ueqiv = (U1+U2+U3)/3 # Replace last . with number of unfound hydrogen atoms attached to an atom. # ..._refinement_flags_... # . no refinement constraints S special position constraint on site # G rigid group refinement of site R riding atom # D distance or angle restraint on site T thermal displacement constraints # U Uiso or Uij restraint (rigid bond) P partial occupancy constraint 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_occupancy _atom_site_adp_type _atom_site_refinement_flags_posn _atom_site_refinement_flags_adp _atom_site_refinement_flags_occupancy _atom_site_disorder_assembly _atom_site_disorder_group _atom_site_attached_hydrogens Br1 Br 0.4230(3) 0.4901(6) 0.9029(7) 0.1281 1.0000 Uani . U . . . . C2 C 0.469(2) 0.487(6) 0.776(5) 0.1174 1.0000 Uani . U . . . . C3 C 0.434(2) 0.498(6) 0.679(5) 0.1165 1.0000 Uani . U . . . . C4 C 0.408(2) 0.492(6) 0.595(4) 0.1150 1.0000 Uani . U . . . . C5 C 0.373(2) 0.498(7) 0.504(4) 0.1146 1.0000 Uani . U . . . . C6 C 0.349(3) 0.501(5) 0.416(4) 0.1189 1.0000 Uani . U . . . . C7 C 0.318(2) 0.496(6) 0.313(4) 0.1216 1.0000 Uani . U . . . . Br8 Br 0.2319(2) 0.5004(7) 0.3250(8) 0.1263 1.0000 Uani . U . . . . Br9 Br 0.3066(3) 0.5085(7) 0.0931(7) 0.1259 1.0000 Uani . U . . . . C10 C 0.351(3) 0.503(6) 0.225(4) 0.1199 1.0000 Uani . U . . . . C11 C 0.410(2) 0.506(6) 0.215(4) 0.1190 1.0000 Uani . U . . . . C12 C 0.465(2) 0.513(6) 0.214(4) 0.1169 1.0000 Uani . U . . . . 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 Br1 0.061(3) 0.265(8) 0.058(3) 0.000(5) -0.000(2) -0.008(5) C2 0.062(8) 0.23(2) 0.057(5) 0.001(8) -0.001(2) -0.008(19) C3 0.061(12) 0.23(2) 0.059(4) 0.009(13) 0.000(6) -0.008(18) C4 0.060(13) 0.23(2) 0.057(10) 0.018(15) 0.002(9) -0.011(17) C5 0.055(12) 0.24(2) 0.052(8) 0.022(17) 0.007(8) -0.011(18) C6 0.059(7) 0.25(2) 0.052(5) 0.019(16) 0.006(7) -0.007(18) C7 0.060(3) 0.251(19) 0.054(4) 0.021(15) 0.003(4) -0.000(17) Br8 0.060(3) 0.268(8) 0.051(3) -0.001(4) 0.004(2) 0.004(6) Br9 0.066(3) 0.260(7) 0.052(3) 0.004(5) -0.000(2) 0.000(6) C10 0.060(4) 0.25(2) 0.052(5) 0.018(15) 0.003(3) 0.008(19) C11 0.060(5) 0.24(2) 0.052(12) 0.014(14) 0.004(4) 0.01(2) C12 0.060(5) 0.24(3) 0.047(16) 0.005(8) -0.002(7) 0.01(2) _refine_ls_extinction_method 'None' _oxford_refine_ls_scale 0.04987(7) loop_ _geom_bond_atom_site_label_1 _geom_bond_site_symmetry_1 _geom_bond_atom_site_label_2 _geom_bond_site_symmetry_2 _geom_bond_distance _geom_bond_publ_flag Br1 . C2 . 1.87(6) yes C2 . C2 5_665 1.38(10) yes C2 . C3 . 1.45(8) yes C3 . C4 . 1.19(7) yes C4 . C5 . 1.37(7) yes C5 . C6 . 1.21(7) yes C6 . C7 . 1.47(8) yes C7 . Br8 . 1.87(4) yes C7 . C10 . 1.32(7) yes Br9 . C10 . 1.91(5) yes C10 . C11 . 1.29(7) yes C11 . C12 . 1.19(6) yes C12 . C12 5_665 1.55(11) yes loop_ _geom_angle_atom_site_label_1 _geom_angle_site_symmetry_1 _geom_angle_atom_site_label_2 _geom_angle_site_symmetry_2 _geom_angle_atom_site_label_3 _geom_angle_site_symmetry_3 _geom_angle _geom_angle_publ_flag Br1 . C2 . C2 5_665 121(2) yes Br1 . C2 . C3 . 115(4) yes C2 5_665 C2 . C3 . 119(4) yes C2 . C3 . C4 . 169(9) yes C3 . C4 . C5 . 171(9) yes C4 . C5 . C6 . 171(6) yes C5 . C6 . C7 . 175(7) yes C6 . C7 . Br8 . 113(4) yes C6 . C7 . C10 . 119(4) yes Br8 . C7 . C10 . 128(4) yes Br9 . C10 . C7 . 116(4) yes Br9 . C10 . C11 . 115(4) yes C7 . C10 . C11 . 129(5) yes C10 . C11 . C12 . 174(8) yes C12 5_665 C12 . C11 . 162(11) yes _iucr_refine_instructions_details ; # # Punched on 14/04/20 at 11:01:23 # #LIST 12 BLOCK SCALE X'S U'S CONT ENANTIO END # # Punched on 14/04/20 at 11:01:23 # #LIST 16 NO REM HREST START (DO NOT REMOVE THIS LINE) REM HREST END (DO NOT REMOVE THIS LINE) REM DELU START (DO NOT REMOVE THIS LINE) VIBR .0, 0.00100 = BR(1) TO C(2) VIBR .0, 0.00100 = C(2) TO C(2,2,1,1,1) VIBR .0, 0.00100 = C(2) TO C(3) VIBR .0, 0.00300 = C(2,2,1,1,1) TO BR(1) VIBR .0, 0.00300 = C(3) TO BR(1) VIBR .0, 0.00300 = C(3) TO C(2,2,1,1,1) VIBR .0, 0.00100 = C(3) TO C(4) VIBR .0, 0.00300 = C(4) TO C(2) VIBR .0, 0.00100 = C(4) TO C(5) VIBR .0, 0.00300 = C(5) TO C(3) VIBR .0, 0.00100 = C(5) TO C(6) VIBR .0, 0.00300 = C(6) TO C(4) VIBR .0, 0.00100 = C(6) TO C(7) VIBR .0, 0.00300 = C(7) TO C(5) VIBR .0, 0.00100 = C(7) TO BR(8) VIBR .0, 0.00100 = C(7) TO C(10) VIBR .0, 0.00300 = BR(8) TO C(6) VIBR .0, 0.00300 = C(10) TO C(6) VIBR .0, 0.00300 = C(10) TO BR(8) VIBR .0, 0.00100 = BR(9) TO C(10) VIBR .0, 0.00100 = C(10) TO C(11) VIBR .0, 0.00300 = C(7) TO BR(9) VIBR .0, 0.00300 = C(11) TO BR(9) VIBR .0, 0.00300 = C(11) TO C(7) VIBR .0, 0.00100 = C(11) TO C(12) VIBR .0, 0.00300 = C(12) TO C(10) VIBR .0, 0.00100 = C(12) TO C(12,2,1,1,1) VIBR .0, 0.00300 = C(11) TO C(12,2,1,1,1) REM DELU END (DO NOT REMOVE THIS LINE) REM THERMSIM START (DO NOT REMOVE THIS LINE) U(IJ) .0, 0.04000 = BR(1) TO C(2) U(IJ) .0, 0.02000 = C(2) TO C(2,2,1,1,1) U(IJ) .0, 0.02000 = C(2) TO C(3) U(IJ) .0, 0.02000 = C(3) TO C(4) U(IJ) .0, 0.02000 = C(4) TO C(5) U(IJ) .0, 0.02000 = C(5) TO C(6) U(IJ) .0, 0.02000 = C(6) TO C(7) U(IJ) .0, 0.04000 = C(7) TO BR(8) U(IJ) .0, 0.02000 = C(7) TO C(10) U(IJ) .0, 0.04000 = BR(9) TO C(10) U(IJ) .0, 0.02000 = C(10) TO C(11) U(IJ) .0, 0.02000 = C(11) TO C(12) U(IJ) .0, 0.02000 = C(12) TO C(12,2,1,1,1) REM THERMSIM END (DO NOT REMOVE THIS LINE) REM SHIFTLIMIT START (DO NOT REMOVE THIS LINE) LIMIT 0.20000000 U[ISO] LIMIT 0.20000000 X LIMIT 0.20000000 Y LIMIT 0.20000000 Z LIMIT 0.20000000 U[11] LIMIT 0.20000000 U[22] LIMIT 0.20000000 U[33] LIMIT 0.20000000 U[12] LIMIT 0.20000000 U[13] LIMIT 0.20000000 U[23] LIMIT 0.20000000 OCC REM SHIFTLIMIT END (DO NOT REMOVE THIS LINE) END ; # Manually omitted reflections loop_ _oxford_refln_omitted_index_h _oxford_refln_omitted_index_k _oxford_refln_omitted_index_l _oxford_refln_omitted_flag _oxford_refln_omitted_details 0 4 0 x . 2 10 4 x . 0 8 0 x . 0 12 0 x . # start Validation Reply Form _vrf_THETM01_I ; PROBLEM: The value of sine(theta_max)/wavelength is less than 0.550 RESPONSE: The best crystal obtained were small and did not diffract to high angle. The emphasis was on collecting as intense data as possible. Data were collected to 1\%A. ; _vrf_PLAT084_I ; PROBLEM: High wR2 Value (i.e. > 0.25) RESPONSE: Data were carefully examined to determine space group and any potential twinning. Reflections were broad along certain directions but no obvious indications of twinning were observed. ; _vrf_PLAT090_I ; PROBLEM: Poor Data / Parameter Ratio (Zmax > 18) RESPONSE: Due to size of crystal and diffraction intensity data were only collected to 1\%A which gives rise to a poor data to parameter ratio. ; _vrf_PLAT250_I ; PROBLEM: Large U3/U1 Ratio for Average U(i,j) Tensor RESPONSE: Due to the poor data to parameter ratio it is not reasonable to model the disorder for this compound. Initial attemps were made to check if the disorder could easily be resolved. ; # end Validation Reply Form

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