Self-complementary purines by quadruple hydrogen bonding
Martin, Alisha M.; Butler, Roslyn S.; Ghiviriga, Ion; Giessert, Rachel E.; Abboud, Khalil A.; Castellano, Ronald K.; Chemical Communications (Cambridge, United Kingdom)  (2006) 4413–4415; doi:10.1039/b610239e

data_7101505
_publ_section_title
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 Self-complementary purines by quadruple hydrogen bonding
;
_journal_coden_ASTM              CHCOFS
_journal_issue                   42
_journal_name_full
;
 Chemical Communications (Cambridge, United Kingdom)
;
_journal_page_first              4413
_journal_page_last               4415
_journal_paper_doi               10.1039/b610239e
_journal_year                    2006
_chemical_formula_sum            'C21 H21 N7 O'
_chemical_formula_weight         387.45
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2yn'
_symmetry_space_group_name_H-M   'P 1 21/n 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                 106.8620(10)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   9.0629(6)
_cell_length_b                   19.8629(13)
_cell_length_c                   11.3182(7)
_cell_measurement_reflns_used    75
_cell_measurement_temperature    173(2)
_cell_measurement_theta_max      28.0
_cell_measurement_theta_min      2.0
_cell_volume                     1949.9(2)
_computing_cell_refinement       'Bruker SMART & SAINT (Bruker 1998)'
_computing_data_collection       'Bruker SMART (Bruker 1998)'
_computing_data_reduction        'Bruker SHELXTL (Bruker 2000)'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'Bruker SHELXTL'
_computing_structure_solution    'Bruker SHELXTL'
_diffrn_ambient_temperature      173(2)
_diffrn_measured_fraction_theta_full 0.985
_diffrn_measured_fraction_theta_max 0.985
_diffrn_measurement_device_type  'SMART CCD area detector'
_diffrn_measurement_method       '\w scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'normal-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0337
_diffrn_reflns_av_sigmaI/netI    0.0326
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       20
_diffrn_reflns_limit_k_min       -25
_diffrn_reflns_limit_l_max       14
_diffrn_reflns_limit_l_min       -14
_diffrn_reflns_number            12603
_diffrn_reflns_theta_full        27.49
_diffrn_reflns_theta_max         27.49
_diffrn_reflns_theta_min         2.05
_diffrn_standards_decay_%        0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.087
_exptl_absorpt_correction_T_max  0.9943
_exptl_absorpt_correction_T_min  0.9800
_exptl_absorpt_correction_type   integration
_exptl_absorpt_process_details
'based on measured indexed crystal faces, SHELXTL (Bruker 1998)'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.320
_exptl_crystal_density_meas      0
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       needles
_exptl_crystal_F_000             816
_exptl_crystal_size_max          0.19
_exptl_crystal_size_mid          0.18
_exptl_crystal_size_min          0.17
_refine_diff_density_max         0.185
_refine_diff_density_min         -0.176
_refine_diff_density_rms         0.033
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.063
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     272
_refine_ls_number_reflns         4406
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.063
_refine_ls_R_factor_all          0.0572
_refine_ls_R_factor_gt           0.0374
_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^)+(0.0543P)^2^+0.0585P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0966
_refine_ls_wR_factor_ref         0.1038
_reflns_number_gt                3194
_reflns_number_total             4406
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            b610239e.txt
_cod_depositor_comments
;
The following automatic conversions were performed:
'_symmetry_cell_setting' value 'Monoclinic' changed to 'monoclinic'
according to '/home/saulius/struct/CIF-dictionaries/cif_core.dic'
dictionary named 'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_enum 1527 2010-12-29 10:47:43Z saulius 
;
_cod_original_sg_symbol_H-M      P2(1)/n
_cod_database_code               7101505