############################################################################## # # # This CIF contains the data in a paper accepted for publication in # # Acta Crystallographica Section E. It conforms to the requirements of # # Notes for Authors for Acta Crystallographica Section E, and has been # # peer reviewed under the auspices of the IUCr Commission on Journals. # # # # Full details of the Crystallographic Information File format # # are given in the paper "The Crystallographic Information File (CIF): # # a New Standard Archive File for Crystallography" by S. R. Hall, F. H. # # Allen and I. D. Brown [Acta Cryst. (1991), A47, 655-685]. # # # # The current version of the core CIF dictionary is obtainable from # # ftp://ftp.iucr.org/pub/cif_core.dic. # # # # Software is freely available for graphical display of the structure(s) # # in this CIF. For information consult the CIF software page # # http://www.iucr.org/resources/cif/software. # # # # This file may be used for bona fide research purposes within the # # scientific community so long as proper attribution is given to the journal # # article from which it was obtained. # # # ############################################################################## data_I _audit_creation_method SHELXL-97 _chemical_name_systematic ; 6-(4-Chlorophenyl)-7-phenyl-2,3-dihydro-1H-pyrrolizine-5-carbaldehyde ; _chemical_name_common ? _chemical_formula_moiety 'C20 H16 Cl N O' _chemical_formula_sum 'C20 H16 Cl N O' _chemical_formula_iupac 'C20 H16 Cl N O' _chemical_formula_weight 321.79 _chemical_melting_point ? _symmetry_cell_setting monoclinic _symmetry_space_group_name_H-M 'C 2/c' _symmetry_space_group_name_Hall '-C 2yc' loop_ _symmetry_equiv_pos_as_xyz 'x, y, z' '-x, y, -z+1/2' 'x+1/2, y+1/2, z' '-x+1/2, y+1/2, -z+1/2' '-x, -y, -z' 'x, -y, z-1/2' '-x+1/2, -y+1/2, -z' 'x+1/2, -y+1/2, z-1/2' _cell_length_a 21.1526(13) _cell_length_b 11.5723(9) _cell_length_c 17.1484(12) _cell_angle_alpha 90.00 _cell_angle_beta 130.843(4) _cell_angle_gamma 90.00 _cell_volume 3175.5(4) _cell_formula_units_Z 8 _cell_measurement_reflns_used 6848 _cell_measurement_theta_min 2.5 _cell_measurement_theta_max 29.7 _cell_measurement_temperature 193(2) _exptl_crystal_description plate _exptl_crystal_colour colourless _exptl_crystal_size_max 0.34 _exptl_crystal_size_mid 0.31 _exptl_crystal_size_min 0.05 _exptl_crystal_density_diffrn 1.346 _exptl_crystal_density_meas ? _exptl_crystal_density_method 'not measured' _exptl_crystal_F_000 1344 _exptl_absorpt_coefficient_mu 0.244 _exptl_absorpt_correction_type none _exptl_special_details ? _diffrn_ambient_temperature 193(2) _diffrn_radiation_type MoK\a _diffrn_radiation_wavelength 0.71073 _diffrn_radiation_monochromator graphite _diffrn_measurement_device_type 'Stoe IPDS 2T' _diffrn_measurement_device '2-circle goniometer' _diffrn_measurement_method 'rotation method' _diffrn_detector_area_resol_mean 6.67 _diffrn_reflns_number 9492 _diffrn_reflns_av_R_equivalents 0.0355 _diffrn_reflns_av_sigmaI/netI 0.0309 _diffrn_reflns_theta_min 2.55 _diffrn_reflns_theta_max 28.00 _diffrn_reflns_theta_full 28.00 _diffrn_measured_fraction_theta_max 0.993 _diffrn_measured_fraction_theta_full 0.993 _diffrn_reflns_limit_h_min -27 _diffrn_reflns_limit_h_max 27 _diffrn_reflns_limit_k_min -15 _diffrn_reflns_limit_k_max 13 _diffrn_reflns_limit_l_min -22 _diffrn_reflns_limit_l_max 16 _diffrn_standards_number ? _diffrn_standards_interval_count ? _diffrn_standards_interval_time ? _diffrn_standards_decay_% ? _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^ > \s(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. ; _reflns_number_total 3804 _reflns_number_gt 2633 _reflns_threshold_expression I>2\s(I) _refine_ls_structure_factor_coef Fsqd _refine_ls_matrix_type full _refine_ls_R_factor_all 0.0645 _refine_ls_R_factor_gt 0.0399 _refine_ls_wR_factor_ref 0.1171 _refine_ls_wR_factor_obs 0.1015 _refine_ls_goodness_of_fit_ref 1.024 _refine_ls_restrained_S_all 1.024 _refine_ls_number_reflns 3804 _refine_ls_number_parameters 208 _refine_ls_number_restraints 0 _refine_ls_hydrogen_treatment constr _refine_ls_weighting_scheme calc _refine_ls_weighting_details 'calc w=1/[\s^2^(Fo^2^)+(0.0654P)^2^+0.4776P] where P=(Fo^2^+2Fc^2^)/3' _atom_sites_solution_hydrogens geom _atom_sites_solution_primary direct _atom_sites_solution_secondary difmap _refine_ls_shift/su_max 0.001 _refine_ls_shift/su_mean 0.000 _refine_diff_density_max 0.180 _refine_diff_density_min -0.377 _refine_ls_extinction_method none _refine_ls_extinction_coef ? 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' 'N' 'N' 0.0061 0.0033 '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' 'Cl' 'Cl' 0.1484 0.1585 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' _computing_data_collection 'X-AREA (Stoe & Cie, 2010)' _computing_cell_refinement 'X-AREA (Stoe & Cie, 2010)' _computing_data_reduction 'X-RED (Stoe & Cie, 2010)' _computing_structure_solution 'SIR97 (Altomare et al., 1999)' _computing_structure_refinement 'SHELXL97 (Sheldrick, 2008)' _computing_molecular_graphics 'PLATON (Spek, 2009)' _computing_publication_material 'PLATON (Spek, 2009)' 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 _atom_site_occupancy _atom_site_symmetry_multiplicity _atom_site_disorder_assembly _atom_site_disorder_group C C1 0.62354(11) 0.11928(15) 0.31943(15) 0.0441(4) Uani d . 1 1 . . H H1A 0.5719 0.0923 0.3037 0.053 Uiso calc R 1 1 . . H H1B 0.6721 0.0780 0.3810 0.053 Uiso calc R 1 1 . . C C2 0.61862(13) 0.10249(16) 0.22614(16) 0.0510(4) Uani d . 1 1 . . H H2A 0.6461 0.0294 0.2326 0.061 Uiso calc R 1 1 . . H H2B 0.5597 0.1007 0.1610 0.061 Uiso calc R 1 1 . . C C3 0.66451(11) 0.20673(16) 0.22833(15) 0.0451(4) Uani d . 1 1 . . H H3A 0.7241 0.1889 0.2663 0.054 Uiso calc R 1 1 . . H H3B 0.6379 0.2328 0.1578 0.054 Uiso calc R 1 1 . . N N4 0.65521(8) 0.29317(12) 0.28297(10) 0.0375(3) Uani d . 1 1 . . C C5 0.66339(10) 0.41119(14) 0.29645(12) 0.0369(3) Uani d . 1 1 . . C C6 0.64365(9) 0.43919(13) 0.35826(12) 0.0351(3) Uani d . 1 1 . . C C7 0.62553(9) 0.33471(14) 0.38334(12) 0.0349(3) Uani d . 1 1 . . C C7A 0.63337(9) 0.24695(14) 0.33439(12) 0.0367(3) Uani d . 1 1 . . C C8 0.69420(10) 0.48273(16) 0.25951(13) 0.0423(4) Uani d . 1 1 . . H H8 0.7003 0.5629 0.2748 0.051 Uiso calc R 1 1 . . O O9 0.71332(9) 0.44865(13) 0.20975(11) 0.0543(3) Uani d . 1 1 . . C C10 0.64265(9) 0.55686(14) 0.39052(12) 0.0349(3) Uani d . 1 1 . . C C11 0.60820(10) 0.64988(15) 0.32190(13) 0.0411(4) Uani d . 1 1 . . H H11 0.5853 0.6372 0.2530 0.049 Uiso calc R 1 1 . . C C12 0.60672(11) 0.75998(15) 0.35203(14) 0.0435(4) Uani d . 1 1 . . H H12 0.5839 0.8225 0.3047 0.052 Uiso calc R 1 1 . . C C13 0.63874(10) 0.77793(14) 0.45162(14) 0.0401(4) Uani d . 1 1 . . C C14 0.67412(10) 0.68840(14) 0.52186(13) 0.0387(3) Uani d . 1 1 . . H H14 0.6972 0.7020 0.5907 0.046 Uiso calc R 1 1 . . C C15 0.67564(9) 0.57881(14) 0.49104(12) 0.0361(3) Uani d . 1 1 . . H H15 0.6996 0.5171 0.5393 0.043 Uiso calc R 1 1 . . Cl Cl16 0.63185(3) 0.91463(4) 0.48838(4) 0.05391(15) Uani d . 1 1 . . C C17 0.59919(9) 0.31301(13) 0.44330(12) 0.0343(3) Uani d . 1 1 . . C C18 0.53753(10) 0.37916(15) 0.42983(14) 0.0408(4) Uani d . 1 1 . . H H18 0.5134 0.4426 0.3834 0.049 Uiso calc R 1 1 . . C C19 0.51117(11) 0.35325(16) 0.48348(15) 0.0460(4) Uani d . 1 1 . . H H19 0.4690 0.3988 0.4734 0.055 Uiso calc R 1 1 . . C C20 0.54598(11) 0.26142(17) 0.55167(14) 0.0483(4) Uani d . 1 1 . . H H20 0.5276 0.2435 0.5882 0.058 Uiso calc R 1 1 . . C C21 0.60775(12) 0.19570(17) 0.56642(14) 0.0486(4) Uani d . 1 1 . . H H21 0.6321 0.1328 0.6135 0.058 Uiso calc R 1 1 . . C C22 0.63404(11) 0.22143(15) 0.51282(13) 0.0416(4) Uani d . 1 1 . . H H22 0.6765 0.1759 0.5236 0.050 Uiso calc R 1 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 0.0489(9) 0.0362(9) 0.0538(10) 0.0032(7) 0.0364(8) -0.0003(7) C2 0.0619(11) 0.0429(10) 0.0578(11) -0.0025(8) 0.0434(10) -0.0094(8) C3 0.0520(9) 0.0457(9) 0.0490(9) -0.0016(7) 0.0379(8) -0.0100(8) N4 0.0421(7) 0.0388(7) 0.0386(7) 0.0002(5) 0.0294(6) -0.0017(6) C5 0.0390(7) 0.0386(8) 0.0354(8) -0.0016(6) 0.0254(7) -0.0023(6) C6 0.0361(7) 0.0365(8) 0.0337(7) 0.0008(6) 0.0232(6) -0.0010(6) C7 0.0355(7) 0.0354(8) 0.0354(7) 0.0023(6) 0.0239(6) 0.0016(6) C7A 0.0386(7) 0.0361(8) 0.0396(8) 0.0031(6) 0.0274(7) 0.0012(7) C8 0.0471(8) 0.0455(9) 0.0397(8) -0.0059(7) 0.0308(8) -0.0039(7) O9 0.0679(8) 0.0623(9) 0.0545(8) -0.0101(7) 0.0496(7) -0.0086(6) C10 0.0359(7) 0.0352(8) 0.0369(8) -0.0004(6) 0.0253(7) 0.0003(6) C11 0.0477(8) 0.0389(9) 0.0371(8) -0.0003(7) 0.0279(7) 0.0021(7) C12 0.0500(9) 0.0348(8) 0.0458(9) 0.0020(7) 0.0313(8) 0.0062(7) C13 0.0452(8) 0.0330(8) 0.0518(9) -0.0034(6) 0.0360(8) -0.0027(7) C14 0.0449(8) 0.0397(8) 0.0414(8) -0.0012(7) 0.0325(7) -0.0022(7) C15 0.0403(8) 0.0372(8) 0.0372(8) 0.0031(6) 0.0281(7) 0.0032(6) Cl16 0.0722(3) 0.0334(2) 0.0704(3) -0.00204(19) 0.0529(3) -0.0052(2) C17 0.0361(7) 0.0326(8) 0.0366(8) -0.0022(6) 0.0248(7) -0.0015(6) C18 0.0424(8) 0.0369(8) 0.0482(9) 0.0026(6) 0.0319(8) 0.0024(7) C19 0.0486(9) 0.0449(9) 0.0595(10) -0.0057(7) 0.0420(9) -0.0083(8) C20 0.0591(10) 0.0515(10) 0.0512(10) -0.0127(8) 0.0434(9) -0.0072(8) C21 0.0592(10) 0.0454(10) 0.0467(9) -0.0022(8) 0.0370(9) 0.0062(8) C22 0.0452(8) 0.0403(9) 0.0427(8) 0.0030(7) 0.0302(7) 0.0035(7) _geom_special_details ; All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes. ; 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 C7A . 1.491(2) ? C1 C2 . 1.546(3) ? C1 H1A . 0.9900 ? C1 H1B . 0.9900 ? C2 C3 . 1.533(3) ? C2 H2A . 0.9900 ? C2 H2B . 0.9900 ? C3 N4 . 1.469(2) ? C3 H3A . 0.9900 ? C3 H3B . 0.9900 ? N4 C7A . 1.345(2) ? N4 C5 . 1.377(2) ? C5 C6 . 1.408(2) ? C5 C8 . 1.432(2) ? C6 C7 . 1.417(2) ? C6 C10 . 1.475(2) ? C7 C7A . 1.395(2) ? C7 C17 . 1.476(2) ? C8 O9 . 1.224(2) ? C8 H8 . 0.9500 ? C10 C15 . 1.396(2) ? C10 C11 . 1.397(2) ? C11 C12 . 1.383(2) ? C11 H11 . 0.9500 ? C12 C13 . 1.380(3) ? C12 H12 . 0.9500 ? C13 C14 . 1.380(2) ? C13 Cl16 . 1.7440(17) ? C14 C15 . 1.382(2) ? C14 H14 . 0.9500 ? C15 H15 . 0.9500 ? C17 C22 . 1.392(2) ? C17 C18 . 1.395(2) ? C18 C19 . 1.385(2) ? C18 H18 . 0.9500 ? C19 C20 . 1.383(3) ? C19 H19 . 0.9500 ? C20 C21 . 1.385(3) ? C20 H20 . 0.9500 ? C21 C22 . 1.383(3) ? C21 H21 . 0.9500 ? C22 H22 . 0.9500 ? 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 C7A C1 C2 . . 102.13(15) ? C7A C1 H1A . . 111.3 ? C2 C1 H1A . . 111.3 ? C7A C1 H1B . . 111.3 ? C2 C1 H1B . . 111.3 ? H1A C1 H1B . . 109.2 ? C3 C2 C1 . . 105.23(14) ? C3 C2 H2A . . 110.7 ? C1 C2 H2A . . 110.7 ? C3 C2 H2B . . 110.7 ? C1 C2 H2B . . 110.7 ? H2A C2 H2B . . 108.8 ? N4 C3 C2 . . 101.81(13) ? N4 C3 H3A . . 111.4 ? C2 C3 H3A . . 111.4 ? N4 C3 H3B . . 111.4 ? C2 C3 H3B . . 111.4 ? H3A C3 H3B . . 109.3 ? C7A N4 C5 . . 110.10(14) ? C7A N4 C3 . . 113.20(14) ? C5 N4 C3 . . 136.70(15) ? N4 C5 C6 . . 106.74(14) ? N4 C5 C8 . . 122.86(15) ? C6 C5 C8 . . 130.15(16) ? C5 C6 C7 . . 107.71(14) ? C5 C6 C10 . . 125.36(15) ? C7 C6 C10 . . 126.92(14) ? C7A C7 C6 . . 106.05(14) ? C7A C7 C17 . . 122.87(14) ? C6 C7 C17 . . 131.02(14) ? N4 C7A C7 . . 109.39(14) ? N4 C7A C1 . . 110.50(14) ? C7 C7A C1 . . 140.10(16) ? O9 C8 C5 . . 125.12(17) ? O9 C8 H8 . . 117.4 ? C5 C8 H8 . . 117.4 ? C15 C10 C11 . . 117.63(15) ? C15 C10 C6 . . 120.84(14) ? C11 C10 C6 . . 121.52(15) ? C12 C11 C10 . . 121.46(16) ? C12 C11 H11 . . 119.3 ? C10 C11 H11 . . 119.3 ? C13 C12 C11 . . 119.22(16) ? C13 C12 H12 . . 120.4 ? C11 C12 H12 . . 120.4 ? C12 C13 C14 . . 120.94(16) ? C12 C13 Cl16 . . 119.62(14) ? C14 C13 Cl16 . . 119.42(13) ? C13 C14 C15 . . 119.33(15) ? C13 C14 H14 . . 120.3 ? C15 C14 H14 . . 120.3 ? C14 C15 C10 . . 121.41(15) ? C14 C15 H15 . . 119.3 ? C10 C15 H15 . . 119.3 ? C22 C17 C18 . . 118.26(15) ? C22 C17 C7 . . 119.75(14) ? C18 C17 C7 . . 121.94(15) ? C19 C18 C17 . . 120.67(16) ? C19 C18 H18 . . 119.7 ? C17 C18 H18 . . 119.7 ? C20 C19 C18 . . 120.32(16) ? C20 C19 H19 . . 119.8 ? C18 C19 H19 . . 119.8 ? C19 C20 C21 . . 119.58(16) ? C19 C20 H20 . . 120.2 ? C21 C20 H20 . . 120.2 ? C22 C21 C20 . . 120.13(17) ? C22 C21 H21 . . 119.9 ? C20 C21 H21 . . 119.9 ? C21 C22 C17 . . 121.02(16) ? C21 C22 H22 . . 119.5 ? C17 C22 H22 . . 119.5 ? 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_site_symmetry_1 _geom_torsion_site_symmetry_2 _geom_torsion_site_symmetry_3 _geom_torsion_site_symmetry_4 _geom_torsion _geom_torsion_publ_flag C7A C1 C2 C3 . . . . 25.15(18) ? C1 C2 C3 N4 . . . . -25.45(18) ? C2 C3 N4 C7A . . . . 16.96(19) ? C2 C3 N4 C5 . . . . -163.46(18) ? C7A N4 C5 C6 . . . . -1.26(18) ? C3 N4 C5 C6 . . . . 179.14(17) ? C7A N4 C5 C8 . . . . 173.57(15) ? C3 N4 C5 C8 . . . . -6.0(3) ? N4 C5 C6 C7 . . . . 1.41(17) ? C8 C5 C6 C7 . . . . -172.90(16) ? N4 C5 C6 C10 . . . . -178.77(14) ? C8 C5 C6 C10 . . . . 6.9(3) ? C5 C6 C7 C7A . . . . -1.06(17) ? C10 C6 C7 C7A . . . . 179.13(14) ? C5 C6 C7 C17 . . . . -178.20(15) ? C10 C6 C7 C17 . . . . 2.0(3) ? C5 N4 C7A C7 . . . . 0.60(18) ? C3 N4 C7A C7 . . . . -179.70(13) ? C5 N4 C7A C1 . . . . 179.45(13) ? C3 N4 C7A C1 . . . . -0.85(19) ? C6 C7 C7A N4 . . . . 0.30(17) ? C17 C7 C7A N4 . . . . 177.73(14) ? C6 C7 C7A C1 . . . . -178.0(2) ? C17 C7 C7A C1 . . . . -0.6(3) ? C2 C1 C7A N4 . . . . -15.54(18) ? C2 C1 C7A C7 . . . . 162.8(2) ? N4 C5 C8 O9 . . . . 2.8(3) ? C6 C5 C8 O9 . . . . 176.32(17) ? C5 C6 C10 C15 . . . . -137.95(16) ? C7 C6 C10 C15 . . . . 41.8(2) ? C5 C6 C10 C11 . . . . 42.7(2) ? C7 C6 C10 C11 . . . . -137.55(17) ? C15 C10 C11 C12 . . . . 0.1(2) ? C6 C10 C11 C12 . . . . 179.48(15) ? C10 C11 C12 C13 . . . . -1.1(3) ? C11 C12 C13 C14 . . . . 1.8(3) ? C11 C12 C13 Cl16 . . . . -176.36(13) ? C12 C13 C14 C15 . . . . -1.5(2) ? Cl16 C13 C14 C15 . . . . 176.68(12) ? C13 C14 C15 C10 . . . . 0.4(2) ? C11 C10 C15 C14 . . . . 0.2(2) ? C6 C10 C15 C14 . . . . -179.16(14) ? C7A C7 C17 C22 . . . . 45.3(2) ? C6 C7 C17 C22 . . . . -137.98(18) ? C7A C7 C17 C18 . . . . -132.22(17) ? C6 C7 C17 C18 . . . . 44.5(2) ? C22 C17 C18 C19 . . . . -0.7(2) ? C7 C17 C18 C19 . . . . 176.81(15) ? C17 C18 C19 C20 . . . . 0.3(3) ? C18 C19 C20 C21 . . . . 0.3(3) ? C19 C20 C21 C22 . . . . -0.4(3) ? C20 C21 C22 C17 . . . . -0.1(3) ? C18 C17 C22 C21 . . . . 0.7(3) ? C7 C17 C22 C21 . . . . -176.92(16) ? data_global _journal_date_recd_electronic 2011-08-01 _journal_date_accepted 2011-08-03 _journal_name_full 'Acta Crystallographica, Section E' _journal_year 2011 _journal_volume 67 _journal_issue 9 _journal_page_first o2292 _journal_page_last o2292 _journal_paper_category QO _journal_coeditor_code BT5600 _publ_contact_author_name 'Stefan Laufer' _publ_contact_author_address ; Eberhard-Karls-University T\"ubingen Auf der Morgenstelle 8 72076 T\"ubingen Germany ; _publ_contact_author_email 'stefan.laufer@uni-tuebingen.de' _publ_contact_author_fax '+49 7071 295037' _publ_contact_author_phone '+49 7071 2972459' _publ_section_title ; 6-(4-Chlorophenyl)-7-phenyl-2,3-dihydro-1H-pyrrolizine-5-carbaldehyde ; loop_ _publ_author_name _publ_author_address 'Keck, Peter R. W. E. F.' ; Eberhard-Karls-University T\"ubingen Auf der Morgenstelle 8 72076 T\"ubingen Germany ; 'Schollmeyer, Dieter' ; University Mainz Institut of Organic Chemistry Duesbergweg 10-14 55099 Mainz Germany ; 'Laufer, Stefan' ; Eberhard-Karls-University T\"ubingen Auf der Morgenstelle 8 72076 T\"ubingen Germany ;