The influence of the trimethylsilyl group: helical self-assembly of syn-7-trimethylsilyl-5-norbornene-endo-2,3-dicarboxylic acid
Shahina Begum, Noor; Girija, C. R.; Nagendrappa, Gopalpur; CrystEngComm 6 (2004) 116–; doi:10.1039/b403631j

data_7204867
_publ_section_title
;
 The influence of the trimethylsilyl group: helical self-assembly of
 syn-7-trimethylsilyl-5-norbornene-endo-2,3-dicarboxylic acid
;
_journal_issue                   24
_journal_name_full               CrystEngComm
_journal_page_first              116
_journal_paper_doi               10.1039/b403631j
_journal_volume                  6
_journal_year                    2004
_chemical_formula_sum            'C12 H18 O4 Si'
_chemical_formula_weight         254.35
_chemical_name_common
'syn-7-trimethyl-silyl-5 Norbornene-2,3-endo -dicarboxylic acid'
_space_group_IT_number           33
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2c -2n'
_symmetry_space_group_name_H-M   'P n a 21'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   22.5962(5)
_cell_length_b                   8.1506(2)
_cell_length_c                   7.69640(10)
_cell_measurement_temperature    293(2)
_cell_volume                     1417.47(5)
_computing_cell_refinement       'Siemens SMART'
_computing_data_collection       'Siemens SMART'
_computing_data_reduction        'Siemens SAINT'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.994
_diffrn_measured_fraction_theta_max 0.994
_diffrn_measurement_device_type  'Siemens SMART CCD area detector'
_diffrn_measurement_method       ' \W scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0608
_diffrn_reflns_av_sigmaI/netI    0.0514
_diffrn_reflns_limit_h_max       24
_diffrn_reflns_limit_h_min       -23
_diffrn_reflns_limit_k_max       7
_diffrn_reflns_limit_k_min       -9
_diffrn_reflns_limit_l_max       8
_diffrn_reflns_limit_l_min       -8
_diffrn_reflns_number            5612
_diffrn_reflns_theta_full        23.25
_diffrn_reflns_theta_max         23.25
_diffrn_reflns_theta_min         1.80
_exptl_absorpt_coefficient_mu    0.166
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.192
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    .
_exptl_crystal_description       prism
_exptl_crystal_F_000             544
_exptl_crystal_size_max          0.30
_exptl_crystal_size_mid          0.25
_exptl_crystal_size_min          0.10
_refine_diff_density_max         0.185
_refine_diff_density_min         -0.191
_refine_diff_density_rms         0.037
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -0.41(19)
_refine_ls_extinction_coef       0.015(3)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_ref   0.890
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     157
_refine_ls_number_reflns         2007
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      0.889
_refine_ls_R_factor_all          0.0410
_refine_ls_R_factor_gt           0.0383
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0893P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1103
_refine_ls_wR_factor_ref         0.1133
_reflns_number_gt                1866
_reflns_number_total             2007
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b403631j.txt
_cod_data_source_block           gir1
_cod_original_sg_symbol_H-M      Pna21
_cod_database_code               7204867