Use of an adjustable soft segment as an effective molecular design for crystal engineering of hydrogen-bonded tape motifs.
Takasawa, Ryoichi; Yoshikawa, Isao; Araki, Koji; Organic & biomolecular chemistry 2 (2004) 1125–1132; doi:10.1039/b315769e

data_7150353
_publ_section_title
;
 Use of an adjustable soft segment as an effective molecular design for
 crystal engineering of hydrogen-bonded tape motifs.
;
_journal_issue                   8
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              1125
_journal_page_last               1132
_journal_paper_doi               10.1039/b315769e
_journal_volume                  2
_journal_year                    2004
_chemical_formula_moiety         'C22 H41 N5 O4 Si2'
_chemical_formula_sum            'C22 H41 N5 O4 Si2'
_chemical_formula_weight         495.78
_chemical_name_common
2'-deoxy-3',5'-O-bis(tert-butyldimethylsilyl)-guanosine
_chemical_name_systematic
;
2'-deoxy-3',5'-O-bis(tert-butyldimethylsilyl)-guanosine
;
_space_group_IT_number           5
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  'C 2y'
_symmetry_space_group_name_H-M   'C 1 2 1'
_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                 101.0920(10)
_cell_angle_gamma                90.00
_cell_formula_units_Z            8
_cell_length_a                   31.5910(6)
_cell_length_b                   10.8750(2)
_cell_length_c                   17.0050(2)
_cell_measurement_reflns_used    25256
_cell_measurement_temperature    200(2)
_cell_measurement_theta_max      73.14
_cell_measurement_theta_min      2.65
_cell_volume                     5732.97(17)
_computing_cell_refinement       Scalepack
_computing_data_collection       'MacScience Xpress'
_computing_data_reduction        'Denzo and Scalepack'
_computing_molecular_graphics    maXus
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      200(2)
_diffrn_measured_fraction_theta_full 0.938
_diffrn_measured_fraction_theta_max 0.938
_diffrn_measurement_device_type  'MacScience DIPLabo'
_diffrn_measurement_method       IP
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54184
_diffrn_reflns_av_R_equivalents  0.038
_diffrn_reflns_av_sigmaI/netI    0.0162
_diffrn_reflns_limit_h_max       38
_diffrn_reflns_limit_h_min       -39
_diffrn_reflns_limit_k_max       13
_diffrn_reflns_limit_k_min       -13
_diffrn_reflns_limit_l_max       20
_diffrn_reflns_limit_l_min       -20
_diffrn_reflns_number            25256
_diffrn_reflns_theta_full        73.14
_diffrn_reflns_theta_max         73.14
_diffrn_reflns_theta_min         2.65
_exptl_absorpt_coefficient_mu    1.399
_exptl_absorpt_correction_T_max  0.8022
_exptl_absorpt_correction_T_min  0.5458
_exptl_absorpt_correction_type   integration
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.149
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plate-like
_exptl_crystal_F_000             2144
_exptl_crystal_size_max          0.82
_exptl_crystal_size_mid          0.31
_exptl_crystal_size_min          0.17
_refine_diff_density_max         0.689
_refine_diff_density_min         -0.299
_refine_diff_density_rms         0.081
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.22(4)
_refine_ls_extinction_coef       0.0026(2)
_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   1.034
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     652
_refine_ls_number_reflns         10061
_refine_ls_number_restraints     571
_refine_ls_restrained_S_all      1.103
_refine_ls_R_factor_all          0.0776
_refine_ls_R_factor_gt           0.0768
_refine_ls_shift/su_max          0.002
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.1544P)^2^+3.9891P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.2123
_refine_ls_wR_factor_ref         0.2138
_reflns_number_gt                9874
_reflns_number_total             10061
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b315769e.txt
_cod_data_source_block           3c
_cod_original_sg_symbol_H-M      C2
_cod_database_code               7150353