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_7150358
_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         'C28 H53 N5 O5 Si2'
_chemical_formula_sum            'C28 H53 N5 O5 Si2'
_chemical_formula_weight         595.93
_chemical_name_common            2',3'-O-bis(triisopropylsilyl)-guanosine
_chemical_name_systematic
;
2',3'-O-bis(triisopropylsilyl)-guanosine
;
_space_group_IT_number           1
_symmetry_cell_setting           triclinic
_symmetry_space_group_name_Hall  'P 1'
_symmetry_space_group_name_H-M   'P 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                98.980(2)
_cell_angle_beta                 99.526(2)
_cell_angle_gamma                101.012(2)
_cell_formula_units_Z            2
_cell_length_a                   7.9550(2)
_cell_length_b                   12.3980(4)
_cell_length_c                   18.0350(4)
_cell_measurement_reflns_used    16949
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      73.37
_cell_measurement_theta_min      2.53
_cell_volume                     1689.22(8)
_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      100(2)
_diffrn_measured_fraction_theta_full 0.837
_diffrn_measured_fraction_theta_max 0.837
_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  0.030
_diffrn_reflns_av_sigmaI/netI    0.0205
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -7
_diffrn_reflns_limit_k_max       14
_diffrn_reflns_limit_k_min       -15
_diffrn_reflns_limit_l_max       17
_diffrn_reflns_limit_l_min       -22
_diffrn_reflns_number            16949
_diffrn_reflns_theta_full        73.37
_diffrn_reflns_theta_max         73.37
_diffrn_reflns_theta_min         2.53
_exptl_absorpt_coefficient_mu    1.288
_exptl_absorpt_correction_T_max  0.8667
_exptl_absorpt_correction_T_min  0.5394
_exptl_absorpt_correction_type   integration
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.172
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       needle
_exptl_crystal_F_000             648
_exptl_crystal_size_max          0.69
_exptl_crystal_size_mid          0.37
_exptl_crystal_size_min          0.13
_refine_diff_density_max         0.517
_refine_diff_density_min         -0.470
_refine_diff_density_rms         0.097
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.17(5)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.056
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     896
_refine_ls_number_reflns         7067
_refine_ls_number_restraints     248
_refine_ls_restrained_S_all      1.077
_refine_ls_R_factor_all          0.0883
_refine_ls_R_factor_gt           0.0857
_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^)+(0.1808P)^2^+2.2429P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.2408
_refine_ls_wR_factor_ref         0.2496
_reflns_number_gt                6934
_reflns_number_total             7067
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b315769e.txt
_cod_data_source_block           2b
_cod_original_sg_symbol_H-M      p1
_cod_database_code               7150358