# Supplementary Material (ESI) for Organic & Biomolecular Chemistry
# This journal is © The Royal Society of Chemistry 2005

data_global
_journal_name_full               Org.Biomol.Chem.

_journal_coden_Cambridge         0177

_publ_contact_author_name        'Christopher P. Morley'

_publ_contact_author_address     
;
Chemistry Department
University of Wales, Swansea
Swansea
SA2 8PP
U.K.
;
_publ_contact_author_phone       '01792 295747'
_publ_contact_author_fax         '01792 295273'
_publ_contact_author_email       C.P.Morley@swansea.ac.uk

_publ_section_title              
;
Tetramethylcyclopentadienylselenium derivatives
;
loop_
_publ_author_name
'C. Morley'
'M.Di Vaira'
'Susan Ford'
'Marco Hofmann'
'John L. Roberts'

#============================================================================

data_btmecpse
_database_code_depnum_ccdc_archive 'CCDC 279726'

_audit_creation_method           SHELXL-97
_chemical_name_systematic        
;
bis(1,2,3,4-tetramethylcyclopentadienyl)selenium
;
_chemical_name_common            
bis(1,2,3,4-tetramethylcyclopentadienyl)selenium
_chemical_melting_point          ?
_chemical_formula_moiety         'C18 H26 Se'
_chemical_formula_sum            'C18 H26 Se'
_chemical_formula_weight         321.35

loop_
_atom_type_symbol
_atom_type_description
_atom_type_scat_dispersion_real
_atom_type_scat_dispersion_imag
_atom_type_scat_source
C C 0.0181 0.0091 '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'
Se Se -0.7943 1.1372 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'

_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_H-M   Pna21

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'

_cell_length_a                   8.418(3)
_cell_length_b                   13.169(9)
_cell_length_c                   15.523(13)
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_volume                     1721(2)
_cell_formula_units_Z            4
_cell_measurement_temperature    293(2)
_cell_measurement_reflns_used    4000
_cell_measurement_theta_min      5.0
_cell_measurement_theta_max      50.0

_exptl_crystal_description       'irregular prism'
_exptl_crystal_colour            orange
_exptl_crystal_size_max          0.80
_exptl_crystal_size_mid          0.60
_exptl_crystal_size_min          0.50
_exptl_crystal_density_meas      ?
_exptl_crystal_density_diffrn    1.240
_exptl_crystal_density_method    'not measured'
_exptl_crystal_F_000             672
_exptl_absorpt_coefficient_mu    2.821
_exptl_absorpt_correction_type   none
_exptl_absorpt_correction_T_min  ?
_exptl_absorpt_correction_T_max  ?
_exptl_absorpt_process_details   ?

_exptl_special_details           
;
A correction for absorption with SADABS (Sheldrick, 1986) was
attempted, but it did not yield improvements
;

_diffrn_ambient_temperature      293(2)
_diffrn_radiation_wavelength     1.54180
_diffrn_radiation_type           CuK\a
_diffrn_radiation_source         'rotating anode'
_diffrn_radiation_monochromator  'Goebel mirrors'
_diffrn_measurement_device_type  'Siemens-Bruker diffractometer'
_diffrn_measurement_method       '\w scans'
_diffrn_detector_area_resol_mean ?
_diffrn_standards_number         0
_diffrn_standards_interval_count ?
_diffrn_standards_interval_time  ?
_diffrn_standards_decay_%        0
_diffrn_reflns_number            7697
_diffrn_reflns_av_R_equivalents  0.0400
_diffrn_reflns_av_sigmaI/netI    0.0244
_diffrn_reflns_limit_h_min       -8
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_k_min       -13
_diffrn_reflns_limit_k_max       13
_diffrn_reflns_limit_l_min       -10
_diffrn_reflns_limit_l_max       16
_diffrn_reflns_theta_min         4.40
_diffrn_reflns_theta_max         56.32
_diffrn_reflns_theta_full        56.32
_diffrn_measured_fraction_theta_max 0.979
_diffrn_measured_fraction_theta_full 0.979
_reflns_number_total             1735
_reflns_number_gt                1689
_reflns_threshold_expression     I>2sigma(I)

_computing_data_collection       'Bruker software'
_computing_cell_refinement       'Bruker software'
_computing_data_reduction        'Bruker software'
_computing_structure_solution    'SIR97 (Giacovazzo et al., 1999)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_molecular_graphics    'ORTEP-3 (Farrugia, 1997)'
_computing_publication_material  ?

_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^ > 2sigma(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.
Non-hydrogen atoms were anisotropic. Methyl hydrogens riding with U linked
to Ueq of carrier atom. The allylic hydrogens were located from DF maps
and their parameters were refined. Restraints were imposed on values of
chemically equivalent bond distances.
;

_refine_ls_structure_factor_coef Fsqd
_refine_ls_matrix_type           full
_refine_ls_weighting_scheme      calc
_refine_ls_weighting_details     
'calc w=1/[\s^2^(Fo^2^)+(0.0450P)^2^+0.6064P] where P=(Fo^2^+2Fc^2^)/3'
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_atom_sites_solution_hydrogens   'geometric and DFmap'
_refine_ls_hydrogen_treatment    mixed
_refine_ls_extinction_method     SHELXL
_refine_ls_extinction_coef       0.0045(4)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.01(6)
_refine_ls_number_reflns         1735
_refine_ls_number_parameters     192
_refine_ls_number_restraints     18
_refine_ls_R_factor_all          0.0302
_refine_ls_R_factor_gt           0.0295
_refine_ls_wR_factor_ref         0.0748
_refine_ls_wR_factor_gt          0.0741
_refine_ls_goodness_of_fit_ref   1.064
_refine_ls_restrained_S_all      1.064
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_diff_density_max         0.222
_refine_diff_density_min         -0.328
_refine_diff_density_rms         0.050

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_symmetry_multiplicity
_atom_site_calc_flag
_atom_site_refinement_flags
_atom_site_disorder_assembly
_atom_site_disorder_group
Se Se 0.38443(3) -0.11871(2) 0.2098 0.0641(2) Uani 1 1 d . . .
C1 C 0.3287(3) 0.02686(18) 0.2124(4) 0.0459(7) Uani 1 1 d D . .
H1 H 0.215(4) 0.0291(19) 0.220(3) 0.045(9) Uiso 1 1 d . . .
C2 C 0.3988(8) 0.0804(6) 0.1367(4) 0.059(2) Uani 1 1 d D . .
C3 C 0.4908(9) 0.1579(5) 0.1611(5) 0.066(2) Uani 1 1 d D . .
C4 C 0.4905(9) 0.1548(4) 0.2560(5) 0.067(2) Uani 1 1 d D . .
C5 C 0.3937(7) 0.0837(7) 0.2884(4) 0.055(2) Uani 1 1 d D . .
C6 C 0.3562(13) 0.0577(9) 0.0452(5) 0.091(3) Uani 1 1 d D . .
H6A H 0.2495 0.0799 0.0342 0.137 Uiso 1 1 calc R . .
H6B H 0.3638 -0.0141 0.0353 0.137 Uiso 1 1 calc R . .
H6C H 0.4279 0.0927 0.0074 0.137 Uiso 1 1 calc R . .
C7 C 0.5799(12) 0.2338(8) 0.1066(8) 0.119(4) Uani 1 1 d D . .
H7A H 0.6913 0.2184 0.1078 0.178 Uiso 1 1 calc R . .
H7B H 0.5629 0.3009 0.1289 0.178 Uiso 1 1 calc R . .
H7C H 0.5421 0.2304 0.0483 0.178 Uiso 1 1 calc R . .
C8 C 0.5822(14) 0.2312(7) 0.3092(8) 0.114(4) Uani 1 1 d D . .
H8A H 0.5252 0.2943 0.3107 0.171 Uiso 1 1 calc R . .
H8B H 0.6849 0.2419 0.2838 0.171 Uiso 1 1 calc R . .
H8C H 0.5948 0.2058 0.3667 0.171 Uiso 1 1 calc R . .
C9 C 0.3490(14) 0.0553(9) 0.3785(4) 0.093(3) Uani 1 1 d D . .
H9A H 0.4094 -0.0029 0.3962 0.140 Uiso 1 1 calc R . .
H9B H 0.2378 0.0396 0.3808 0.140 Uiso 1 1 calc R . .
H9C H 0.3713 0.1111 0.4164 0.140 Uiso 1 1 calc R . .
C10 C 0.1682(3) -0.1789(2) 0.2121(5) 0.0532(8) Uani 1 1 d D . .
H10 H 0.185(4) -0.248(2) 0.196(3) 0.050(9) Uiso 1 1 d . . .
C11 C 0.0740(9) -0.1427(6) 0.2875(4) 0.0559(19) Uani 1 1 d D . .
C12 C -0.0489(7) -0.0901(6) 0.2562(4) 0.0586(18) Uani 1 1 d D . .
C13 C -0.0467(8) -0.0878(6) 0.1617(4) 0.063(2) Uani 1 1 d D . .
C14 C 0.0739(9) -0.1463(5) 0.1360(4) 0.059(2) Uani 1 1 d D . .
C15 C 0.1059(11) -0.1732(11) 0.3788(5) 0.091(3) Uani 1 1 d D . .
H15A H 0.2130 -0.1555 0.3938 0.136 Uiso 1 1 calc R . .
H15B H 0.0917 -0.2452 0.3848 0.136 Uiso 1 1 calc R . .
H15C H 0.0335 -0.1385 0.4164 0.136 Uiso 1 1 calc R . .
C16 C -0.1609(12) -0.0362(10) 0.3162(7) 0.127(4) Uani 1 1 d D . .
H16A H -0.2676 -0.0582 0.3051 0.190 Uiso 1 1 calc R . .
H16B H -0.1534 0.0358 0.3070 0.190 Uiso 1 1 calc R . .
H16C H -0.1331 -0.0516 0.3747 0.190 Uiso 1 1 calc R . .
C17 C -0.1780(10) -0.0340(6) 0.1142(7) 0.091(3) Uani 1 1 d D . .
H17A H -0.1961 0.0313 0.1401 0.137 Uiso 1 1 calc R . .
H17B H -0.2735 -0.0737 0.1174 0.137 Uiso 1 1 calc R . .
H17C H -0.1483 -0.0252 0.0550 0.137 Uiso 1 1 calc R . .
C18 C 0.1259(13) -0.1771(11) 0.0474(6) 0.113(4) Uani 1 1 d D . .
H18A H 0.0644 -0.2344 0.0287 0.169 Uiso 1 1 calc R . .
H18B H 0.2364 -0.1952 0.0486 0.169 Uiso 1 1 calc R . .
H18C H 0.1104 -0.1215 0.0083 0.169 Uiso 1 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
Se 0.0376(3) 0.0351(3) 0.1196(4) 0.0005(6) 0.0030(6) 0.00562(9)
C1 0.0349(15) 0.0356(14) 0.0670(19) -0.017(4) -0.001(3) 0.0013(10)
C2 0.056(6) 0.035(4) 0.086(6) -0.008(4) 0.009(3) 0.009(3)
C3 0.042(4) 0.056(5) 0.101(6) 0.017(4) 0.009(4) -0.001(4)
C4 0.052(4) 0.028(3) 0.119(6) -0.001(4) -0.019(4) -0.003(4)
C5 0.045(5) 0.057(5) 0.062(5) -0.017(4) -0.010(3) 0.003(3)
C6 0.121(8) 0.070(8) 0.083(6) -0.012(5) 0.029(5) -0.007(5)
C7 0.071(6) 0.099(8) 0.185(9) 0.063(7) 0.002(6) -0.037(6)
C8 0.118(8) 0.059(6) 0.166(9) -0.011(6) -0.059(7) -0.012(5)
C9 0.130(9) 0.094(9) 0.056(4) -0.007(5) -0.010(5) 0.008(6)
C10 0.0486(16) 0.0329(15) 0.078(2) 0.004(5) 0.015(4) -0.0030(11)
C11 0.053(5) 0.056(5) 0.058(5) 0.003(3) 0.002(4) -0.013(4)
C12 0.023(4) 0.059(4) 0.093(5) -0.001(4) 0.004(3) -0.002(3)
C13 0.076(6) 0.045(4) 0.068(4) 0.012(4) -0.024(4) -0.017(4)
C14 0.069(6) 0.042(4) 0.067(5) -0.008(4) -0.002(4) -0.021(4)
C15 0.085(5) 0.121(8) 0.066(5) 0.027(5) -0.012(3) -0.036(5)
C16 0.083(6) 0.171(10) 0.126(8) -0.013(7) 0.053(5) 0.000(6)
C17 0.062(5) 0.063(4) 0.149(7) 0.039(4) -0.024(4) -0.006(3)
C18 0.165(10) 0.094(8) 0.080(6) -0.038(6) 0.004(5) -0.041(6)

_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
Se C1 1.974(3) . ?
Se C10 1.986(3) . ?
C1 C2 1.492(5) . ?
C1 C5 1.501(4) . ?
C1 H1 0.96(3) . ?
C2 C3 1.335(5) . ?
C2 C6 1.496(5) . ?
C3 C4 1.473(5) . ?
C3 C7 1.510(5) . ?
C4 C5 1.339(5) . ?
C4 C8 1.513(5) . ?
C5 C9 1.496(5) . ?
C6 H6A 0.9600 . ?
C6 H6B 0.9600 . ?
C6 H6C 0.9600 . ?
C7 H7A 0.9600 . ?
C7 H7B 0.9600 . ?
C7 H7C 0.9600 . ?
C8 H8A 0.9600 . ?
C8 H8B 0.9600 . ?
C8 H8C 0.9600 . ?
C9 H9A 0.9600 . ?
C9 H9B 0.9600 . ?
C9 H9C 0.9600 . ?
C10 C14 1.488(5) . ?
C10 C11 1.492(4) . ?
C10 H10 0.95(3) . ?
C11 C12 1.337(5) . ?
C11 C15 1.498(5) . ?
C12 C13 1.467(4) . ?
C12 C16 1.504(5) . ?
C13 C14 1.335(5) . ?
C13 C17 1.505(5) . ?
C14 C18 1.498(5) . ?
C15 H15A 0.9600 . ?
C15 H15B 0.9600 . ?
C15 H15C 0.9600 . ?
C16 H16A 0.9600 . ?
C16 H16B 0.9600 . ?
C16 H16C 0.9600 . ?
C17 H17A 0.9600 . ?
C17 H17B 0.9600 . ?
C17 H17C 0.9600 . ?
C18 H18A 0.9600 . ?
C18 H18B 0.9600 . ?
C18 H18C 0.9600 . ?

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
C1 Se C10 99.75(11) . . ?
C2 C1 C5 103.8(2) . . ?
C2 C1 Se 110.4(4) . . ?
C5 C1 Se 114.4(5) . . ?
C2 C1 H1 119(3) . . ?
C5 C1 H1 104(3) . . ?
Se C1 H1 105.6(15) . . ?
C3 C2 C1 111.6(5) . . ?
C3 C2 C6 124.1(7) . . ?
C1 C2 C6 123.9(6) . . ?
C2 C3 C4 105.1(6) . . ?
C2 C3 C7 129.4(8) . . ?
C4 C3 C7 125.5(8) . . ?
C5 C4 C3 113.4(6) . . ?
C5 C4 C8 124.7(9) . . ?
C3 C4 C8 121.7(8) . . ?
C4 C5 C9 132.8(7) . . ?
C4 C5 C1 106.0(4) . . ?
C9 C5 C1 121.3(6) . . ?
C2 C6 H6A 109.5 . . ?
C2 C6 H6B 109.5 . . ?
H6A C6 H6B 109.5 . . ?
C2 C6 H6C 109.5 . . ?
H6A C6 H6C 109.5 . . ?
H6B C6 H6C 109.5 . . ?
C3 C7 H7A 109.5 . . ?
C3 C7 H7B 109.5 . . ?
H7A C7 H7B 109.5 . . ?
C3 C7 H7C 109.5 . . ?
H7A C7 H7C 109.5 . . ?
H7B C7 H7C 109.5 . . ?
C4 C8 H8A 109.5 . . ?
C4 C8 H8B 109.5 . . ?
H8A C8 H8B 109.5 . . ?
C4 C8 H8C 109.5 . . ?
H8A C8 H8C 109.5 . . ?
H8B C8 H8C 109.5 . . ?
C5 C9 H9A 109.5 . . ?
C5 C9 H9B 109.5 . . ?
H9A C9 H9B 109.5 . . ?
C5 C9 H9C 109.5 . . ?
H9A C9 H9C 109.5 . . ?
H9B C9 H9C 109.5 . . ?
C14 C10 C11 104.3(2) . . ?
C14 C10 Se 111.1(5) . . ?
C11 C10 Se 112.0(5) . . ?
C14 C10 H10 99(2) . . ?
C11 C10 H10 126(2) . . ?
Se C10 H10 104.1(18) . . ?
C12 C11 C10 107.0(4) . . ?
C12 C11 C15 128.5(7) . . ?
C10 C11 C15 124.1(7) . . ?
C11 C12 C13 111.4(6) . . ?
C11 C12 C16 120.3(8) . . ?
C13 C12 C16 128.1(8) . . ?
C14 C13 C12 107.2(6) . . ?
C14 C13 C17 133.1(8) . . ?
C12 C13 C17 119.3(7) . . ?
C13 C14 C10 109.6(4) . . ?
C13 C14 C18 130.8(8) . . ?
C10 C14 C18 119.6(8) . . ?
C11 C15 H15A 109.5 . . ?
C11 C15 H15B 109.5 . . ?
H15A C15 H15B 109.5 . . ?
C11 C15 H15C 109.5 . . ?
H15A C15 H15C 109.5 . . ?
H15B C15 H15C 109.5 . . ?
C12 C16 H16A 109.5 . . ?
C12 C16 H16B 109.5 . . ?
H16A C16 H16B 109.5 . . ?
C12 C16 H16C 109.5 . . ?
H16A C16 H16C 109.5 . . ?
H16B C16 H16C 109.5 . . ?
C13 C17 H17A 109.5 . . ?
C13 C17 H17B 109.5 . . ?
H17A C17 H17B 109.5 . . ?
C13 C17 H17C 109.5 . . ?
H17A C17 H17C 109.5 . . ?
H17B C17 H17C 109.5 . . ?
C14 C18 H18A 109.5 . . ?
C14 C18 H18B 109.5 . . ?
H18A C18 H18B 109.5 . . ?
C14 C18 H18C 109.5 . . ?
H18A C18 H18C 109.5 . . ?
H18B C18 H18C 109.5 . . ?

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
_geom_torsion_site_symmetry_1
_geom_torsion_site_symmetry_2
_geom_torsion_site_symmetry_3
_geom_torsion_site_symmetry_4
_geom_torsion_publ_flag
C10 Se C1 C2 -123.3(4) . . . . ?
C10 Se C1 C5 120.0(4) . . . . ?
C5 C1 C2 C3 -0.4(5) . . . . ?
Se C1 C2 C3 -123.5(6) . . . . ?
C5 C1 C2 C6 -173.8(10) . . . . ?
Se C1 C2 C6 63.1(8) . . . . ?
C1 C2 C3 C4 2.7(10) . . . . ?
C6 C2 C3 C4 176.0(9) . . . . ?
C1 C2 C3 C7 -177.8(8) . . . . ?
C6 C2 C3 C7 -4.5(15) . . . . ?
C2 C3 C4 C5 -4.4(13) . . . . ?
C7 C3 C4 C5 176.0(7) . . . . ?
C2 C3 C4 C8 180.0(6) . . . . ?
C7 C3 C4 C8 0.5(17) . . . . ?
C3 C4 C5 C9 -176.9(10) . . . . ?
C8 C4 C5 C9 -1.5(16) . . . . ?
C3 C4 C5 C1 4.1(11) . . . . ?
C8 C4 C5 C1 179.5(7) . . . . ?
C2 C1 C5 C4 -2.3(5) . . . . ?
Se C1 C5 C4 118.2(6) . . . . ?
C2 C1 C5 C9 178.6(10) . . . . ?
Se C1 C5 C9 -60.9(9) . . . . ?
C1 Se C10 C14 60.5(4) . . . . ?
C1 Se C10 C11 -55.6(4) . . . . ?
C14 C10 C11 C12 -4.4(6) . . . . ?
Se C10 C11 C12 115.8(7) . . . . ?
C14 C10 C11 C15 168.9(10) . . . . ?
Se C10 C11 C15 -70.9(9) . . . . ?
C10 C11 C12 C13 0.4(12) . . . . ?
C15 C11 C12 C13 -172.5(9) . . . . ?
C10 C11 C12 C16 -175.3(7) . . . . ?
C15 C11 C12 C16 11.8(16) . . . . ?
C11 C12 C13 C14 4.3(15) . . . . ?
C16 C12 C13 C14 179.6(8) . . . . ?
C11 C12 C13 C17 178.6(5) . . . . ?
C16 C12 C13 C17 -6.2(19) . . . . ?
C12 C13 C14 C10 -7.1(12) . . . . ?
C17 C13 C14 C10 179.8(8) . . . . ?
C12 C13 C14 C18 175.6(9) . . . . ?
C17 C13 C14 C18 2.5(18) . . . . ?
C11 C10 C14 C13 7.3(5) . . . . ?
Se C10 C14 C13 -113.6(7) . . . . ?
C11 C10 C14 C18 -175.1(9) . . . . ?
Se C10 C14 C18 64.1(8) . . . . ?

########################################################
# END of CIF
########################################################

data_tricyse
_database_code_depnum_ccdc_archive 'CCDC 279727'

_audit_creation_method           SHELXL-97
_chemical_name_systematic        
;
1,4,5,6,7,10,11,12-octamethyltricyclo[7.3.0.0]-
2,8-diselenadodeca-3,5,9,11-tetraene
;
_chemical_name_common            
;
1,4,5,6,7,10,11,12-octamethyltricyclo(7.3.0.0)-2,8-
diselenadodeca-3,5,9,11-tetraene
;
_chemical_melting_point          ?
_chemical_formula_moiety         'C9 H12 Se'
_chemical_formula_sum            'C9 H12 Se'
_chemical_formula_weight         199.15

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'
Se Se -0.0929 2.2259 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'

_symmetry_cell_setting           triclinic
_symmetry_space_group_name_H-M   P-1

loop_
_symmetry_equiv_pos_as_xyz
'x, y, z'
'-x, -y, -z'

_cell_length_a                   7.325(2)
_cell_length_b                   8.283(3)
_cell_length_c                   8.758(3)
_cell_angle_alpha                62.64(3)
_cell_angle_beta                 84.18(3)
_cell_angle_gamma                67.59(3)
_cell_volume                     434.5(2)
_cell_formula_units_Z            2
_cell_measurement_temperature    293(2)
_cell_measurement_reflns_used    25
_cell_measurement_theta_min      12.0
_cell_measurement_theta_max      14.0

_exptl_crystal_description       prism
_exptl_crystal_colour            orange
_exptl_crystal_size_max          0.60
_exptl_crystal_size_mid          0.50
_exptl_crystal_size_min          0.30
_exptl_crystal_density_meas      ?
_exptl_crystal_density_diffrn    1.522
_exptl_crystal_density_method    'not measured'
_exptl_crystal_F_000             200
_exptl_absorpt_coefficient_mu    4.244
_exptl_absorpt_correction_type   psi-scans
_exptl_absorpt_correction_T_min  0.739
_exptl_absorpt_correction_T_max  0.995
_exptl_absorpt_process_details   ?

_exptl_special_details           
;
?
;

_diffrn_ambient_temperature      293(2)
_diffrn_radiation_wavelength     0.71069
_diffrn_radiation_type           MoK\a
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_monochromator  graphite
_diffrn_measurement_device_type  'Nonius CAD4 diffractometer'
_diffrn_measurement_method       '\w scans'
_diffrn_detector_area_resol_mean ?
_diffrn_standards_number         2
_diffrn_standards_interval_count 300
_diffrn_standards_interval_time  ?
_diffrn_standards_decay_%        0
_diffrn_reflns_number            2339
_diffrn_reflns_av_R_equivalents  0.0298
_diffrn_reflns_av_sigmaI/netI    0.0499
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_k_min       -9
_diffrn_reflns_limit_k_max       10
_diffrn_reflns_limit_l_min       -1
_diffrn_reflns_limit_l_max       11
_diffrn_reflns_theta_min         2.63
_diffrn_reflns_theta_max         27.98
_diffrn_reflns_theta_full        27.98
_diffrn_measured_fraction_theta_max 0.993
_diffrn_measured_fraction_theta_full 0.993
_reflns_number_total             2074
_reflns_number_gt                1564
_reflns_threshold_expression     I>2sigma(I)

_computing_data_collection       'Nonius software'
_computing_cell_refinement       'Nonius software'
_computing_data_reduction        'Nonius software'
_computing_structure_solution    'SIR97 (Giacovazzo et al., 1999)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_molecular_graphics    'ORTEP-3 (Farrugia, 1997)'
_computing_publication_material  ?

_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^ > 2sigma(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.
Non-hydrogen atoms were anisotropic. Hydrogens isotropic with U linked to
Ueq of the respective C atom. H atom coordinates were refined, with
geometrical restraints for H atoms of one methyl group.
;

_refine_ls_structure_factor_coef Fsqd
_refine_ls_matrix_type           full
_refine_ls_weighting_scheme      calc
_refine_ls_weighting_details     
'calc w=1/[\s^2^(Fo^2^)+(0.0410P)^2^+0.8354P] 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    mixed
_refine_ls_extinction_method     SHELXL
_refine_ls_extinction_coef       0.006(4)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_number_reflns         2074
_refine_ls_number_parameters     133
_refine_ls_number_restraints     3
_refine_ls_R_factor_all          0.0760
_refine_ls_R_factor_gt           0.0489
_refine_ls_wR_factor_ref         0.1201
_refine_ls_wR_factor_gt          0.1120
_refine_ls_goodness_of_fit_ref   1.154
_refine_ls_restrained_S_all      1.153
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_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_adp_type
_atom_site_occupancy
_atom_site_symmetry_multiplicity
_atom_site_calc_flag
_atom_site_refinement_flags
_atom_site_disorder_assembly
_atom_site_disorder_group
Se Se 0.11404(9) 0.02342(8) -0.20491(7) 0.0469(2) Uani 1 1 d . . .
C1 C -0.1663(7) 0.1742(6) -0.1790(6) 0.0349(11) Uani 1 1 d . . .
C2 C -0.2178(7) 0.3829(7) -0.3188(6) 0.0362(11) Uani 1 1 d . . .
C3 C -0.2540(7) 0.5000(7) -0.2461(6) 0.0379(11) Uani 1 1 d . . .
C4 C -0.2189(7) 0.3824(7) -0.0558(6) 0.0343(10) Uani 1 1 d . . .
C5 C -0.1660(7) 0.1940(7) -0.0177(6) 0.0350(11) Uani 1 1 d . . .
C6 C -0.3018(11) 0.0764(10) -0.1866(9) 0.0557(15) Uani 1 1 d . . .
H6A H -0.260(10) -0.049(10) -0.099(9) 0.066(11) Uiso 1 1 d . . .
H6B H -0.305(10) 0.077(9) -0.295(9) 0.066(11) Uiso 1 1 d . . .
H6C H -0.424(11) 0.146(10) -0.165(8) 0.066(11) Uiso 1 1 d . . .
C7 C -0.2283(10) 0.4330(9) -0.5063(7) 0.0493(14) Uani 1 1 d D . .
H7A H -0.110(7) 0.374(9) -0.546(9) 0.079(13) Uiso 1 1 d D . .
H7B H -0.277(10) 0.570(5) -0.577(8) 0.079(13) Uiso 1 1 d D . .
H7C H -0.306(9) 0.384(10) -0.539(9) 0.079(13) Uiso 1 1 d D . .
C8 C -0.3203(11) 0.7217(9) -0.3349(9) 0.0581(16) Uani 1 1 d . . .
H8A H -0.429(11) 0.769(10) -0.277(9) 0.077(12) Uiso 1 1 d . . .
H8B H -0.349(10) 0.776(10) -0.459(9) 0.077(12) Uiso 1 1 d . . .
H8C H -0.195(11) 0.748(10) -0.301(9) 0.077(12) Uiso 1 1 d . . .
C9 C -0.2417(10) 0.4698(10) 0.0642(9) 0.0504(14) Uani 1 1 d . . .
H9A H -0.197(9) 0.367(9) 0.174(9) 0.061(11) Uiso 1 1 d . . .
H9B H -0.364(10) 0.531(9) 0.074(8) 0.061(11) Uiso 1 1 d . . .
H9C H -0.174(9) 0.562(9) 0.031(8) 0.061(11) Uiso 1 1 d . . .

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
Se 0.0491(4) 0.0428(3) 0.0283(3) -0.0126(2) 0.0103(2) -0.0034(2)
C1 0.042(3) 0.027(2) 0.029(2) -0.0126(18) 0.0031(19) -0.006(2)
C2 0.038(3) 0.035(2) 0.031(2) -0.012(2) -0.0006(19) -0.011(2)
C3 0.037(3) 0.033(2) 0.040(3) -0.014(2) 0.003(2) -0.013(2)
C4 0.031(2) 0.036(3) 0.038(2) -0.021(2) 0.0040(19) -0.0094(19)
C5 0.035(3) 0.035(2) 0.027(2) -0.0138(19) 0.0032(18) -0.006(2)
C6 0.066(4) 0.052(4) 0.056(4) -0.024(3) 0.001(3) -0.029(3)
C7 0.060(4) 0.044(3) 0.031(3) -0.013(2) -0.002(2) -0.011(3)
C8 0.066(4) 0.038(3) 0.059(4) -0.017(3) 0.010(3) -0.015(3)
C9 0.048(3) 0.055(4) 0.058(4) -0.039(3) 0.010(3) -0.014(3)

_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
Se C5 1.894(5) 2 ?
Se C1 2.010(5) . ?
C1 C5 1.496(6) . ?
C1 C2 1.510(6) . ?
C1 C6 1.524(8) . ?
C2 C3 1.324(7) . ?
C2 C7 1.499(7) . ?
C3 C4 1.482(7) . ?
C3 C8 1.515(7) . ?
C4 C5 1.335(7) . ?
C4 C9 1.492(7) . ?
C5 Se 1.894(5) 2 ?
C6 H6A 0.91(7) . ?
C6 H6B 0.95(7) . ?
C6 H6C 0.92(7) . ?
C7 H7A 0.94(3) . ?
C7 H7B 0.94(3) . ?
C7 H7C 0.94(3) . ?
C8 H8A 0.95(7) . ?
C8 H8B 0.97(7) . ?
C8 H8C 1.12(7) . ?
C9 H9A 0.93(6) . ?
C9 H9B 0.86(7) . ?
C9 H9C 0.99(7) . ?

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
C5 Se C1 97.0(2) 2 . ?
C5 C1 C2 102.6(4) . . ?
C5 C1 C6 115.0(5) . . ?
C2 C1 C6 114.5(5) . . ?
C5 C1 Se 108.0(3) . . ?
C2 C1 Se 106.2(3) . . ?
C6 C1 Se 109.9(4) . . ?
C3 C2 C7 129.5(5) . . ?
C3 C2 C1 109.0(4) . . ?
C7 C2 C1 121.4(4) . . ?
C2 C3 C4 110.0(4) . . ?
C2 C3 C8 127.8(5) . . ?
C4 C3 C8 122.2(5) . . ?
C5 C4 C3 107.9(4) . . ?
C5 C4 C9 128.6(5) . . ?
C3 C4 C9 123.5(5) . . ?
C4 C5 C1 110.3(4) . . ?
C4 C5 Se 127.2(4) . 2 ?
C1 C5 Se 122.3(3) . 2 ?
C1 C6 H6A 109(4) . . ?
C1 C6 H6B 112(4) . . ?
H6A C6 H6B 111(6) . . ?
C1 C6 H6C 105(4) . . ?
H6A C6 H6C 108(6) . . ?
H6B C6 H6C 112(6) . . ?
C2 C7 H7A 116(4) . . ?
C2 C7 H7B 111(4) . . ?
H7A C7 H7B 109(6) . . ?
C2 C7 H7C 116(4) . . ?
H7A C7 H7C 96(6) . . ?
H7B C7 H7C 107(6) . . ?
C3 C8 H8A 106(4) . . ?
C3 C8 H8B 111(4) . . ?
H8A C8 H8B 115(6) . . ?
C3 C8 H8C 104(4) . . ?
H8A C8 H8C 106(6) . . ?
H8B C8 H8C 113(5) . . ?
C4 C9 H9A 107(4) . . ?
C4 C9 H9B 113(4) . . ?
H9A C9 H9B 103(6) . . ?
C4 C9 H9C 113(4) . . ?
H9A C9 H9C 112(5) . . ?
H9B C9 H9C 107(6) . . ?

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
C5 Se C1 C5 52.7(4) 2 . . . ?
C5 Se C1 C2 162.2(3) 2 . . . ?
C5 Se C1 C6 -73.5(4) 2 . . . ?
C5 C1 C2 C3 -3.9(5) . . . . ?
C6 C1 C2 C3 121.5(5) . . . . ?
Se C1 C2 C3 -117.1(4) . . . . ?
C5 C1 C2 C7 177.9(5) . . . . ?
C6 C1 C2 C7 -56.8(7) . . . . ?
Se C1 C2 C7 64.7(6) . . . . ?
C7 C2 C3 C4 -178.6(5) . . . . ?
C1 C2 C3 C4 3.4(6) . . . . ?
C7 C2 C3 C8 1.1(10) . . . . ?
C1 C2 C3 C8 -177.0(5) . . . . ?
C2 C3 C4 C5 -1.5(6) . . . . ?
C8 C3 C4 C5 178.9(5) . . . . ?
C2 C3 C4 C9 178.5(5) . . . . ?
C8 C3 C4 C9 -1.2(8) . . . . ?
C3 C4 C5 C1 -1.1(6) . . . . ?
C9 C4 C5 C1 178.9(5) . . . . ?
C3 C4 C5 Se -176.9(4) . . . 2 ?
C9 C4 C5 Se 3.2(8) . . . 2 ?
C2 C1 C5 C4 3.0(5) . . . . ?
C6 C1 C5 C4 -122.0(5) . . . . ?
Se C1 C5 C4 114.9(4) . . . . ?
C2 C1 C5 Se 179.0(3) . . . 2 ?
C6 C1 C5 Se 54.0(6) . . . 2 ?
Se C1 C5 Se -69.1(4) . . . 2 ?

_refine_diff_density_max         0.617
_refine_diff_density_min         -0.420
_refine_diff_density_rms         0.104

########################################################
# END of CIF
########################################################