9-(Carboxymethyl)-2,6-dichloropurine Ethyl Ester. An Intermediate for Peptidic Nucleic Acid Synthesis
Chan, D. M. C.; Schwalbe, C. H.; Sood, G.; Fraser, W.; Acta Crystallographica Section C 51 (1995) 2383–2386; doi:10.1107/S0108270195008705

data_2004107
_publ_section_title
;
 9-(Carboxymethyl)-2,6-dichloropurine Ethyl Ester. An Intermediate for
 Peptidic Nucleic Acid Synthesis
;
_journal_issue                   11
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              2383
_journal_page_last               2386
_journal_paper_doi               10.1107/S0108270195008705
_journal_volume                  51
_journal_year                    1995
_chemical_formula_sum            'C9 H8 Cl2 N4 O2'
_chemical_formula_weight         275.09
_chemical_melting_point          394.1(10)
_chemical_name_systematic
;
 9-(carboxymethyl)-2,6-dichloropurine ethyl ester
;
_space_group_IT_number           15
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-C 2yc'
_symmetry_space_group_name_H-M   'C 1 2/c 1'
_audit_creation_method           SHELXL
_cell_angle_alpha                90
_cell_angle_beta                 104.03(2)
_cell_angle_gamma                90
_cell_formula_units_Z            8
_cell_length_a                   25.5850(14)
_cell_length_b                   11.841(2)
_cell_length_c                   8.012(3)
_cell_measurement_reflns_used    25
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      14.2
_cell_measurement_theta_min      9.7
_cell_volume                     2354.8(10)
_computing_cell_refinement       'CAD-4 Software'
_computing_data_collection       'CAD-4 Software (Enraf-Nonius, 1989)'
_computing_data_reduction
;
DATREDXL (Brookhaven National Laboratory & Univ. of Birmingham, 1986)
;
_computing_molecular_graphics    'ORTEPII (Johnson, 1976)'
_computing_publication_material  SHELXL93
_computing_structure_refinement  'SHELXL93 (Sheldrick, 1993)'
_computing_structure_solution    'MULTAN80 (Main et al., 1980)'
_diffrn_ambient_temperature      293(2)
_diffrn_measurement_device       'Enraf-Nonius CAD-4'
_diffrn_measurement_method       \q/2\q
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'normal-focus sealed tube'
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.71069
_diffrn_reflns_av_R_equivalents  0.0271
_diffrn_reflns_av_sigmaI/netI    0.0447
_diffrn_reflns_limit_h_max       30
_diffrn_reflns_limit_h_min       -30
_diffrn_reflns_limit_k_max       14
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       9
_diffrn_reflns_limit_l_min       -1
_diffrn_reflns_number            2524
_diffrn_reflns_theta_max         24.95
_diffrn_reflns_theta_min         3.00
_diffrn_standards_decay_%        1
_diffrn_standards_interval_time  120
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    0.546
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            'very pale yellow'
_exptl_crystal_density_diffrn    1.552
_exptl_crystal_description       tabular
_exptl_crystal_F_000             1120
_exptl_crystal_size_max          0.5
_exptl_crystal_size_mid          0.5
_exptl_crystal_size_min          0.25
_refine_diff_density_max         0.267
_refine_diff_density_min         -0.207
_refine_ls_extinction_coef       0.0024(4)
_refine_ls_extinction_method     'SHELXL93 (Sheldrick, 1993)'
_refine_ls_goodness_of_fit_all   1.015
_refine_ls_goodness_of_fit_obs   1.048
_refine_ls_hydrogen_treatment    refall
_refine_ls_matrix_type           full
_refine_ls_number_parameters     187
_refine_ls_number_reflns         2054
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.018
_refine_ls_restrained_S_obs      1.048
_refine_ls_R_factor_all          0.0682
_refine_ls_R_factor_obs          0.0353
_refine_ls_shift/esd_max         -0.002
_refine_ls_shift/esd_mean        0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_scheme
;
calc w = 1/[\s^2^(F~o~^2^) + (0.0583P)^2^ + 0.5523P]
where P = (F~o~^2^ + 2F~c~^2^)/3
;
_refine_ls_wR_factor_all         0.1064
_refine_ls_wR_factor_obs         0.0906
_reflns_number_observed          1462
_reflns_number_total             2055
_reflns_observed_criterion       >2sigma(I)
_cod_data_source_file            cf1024.cif
_cod_data_source_block           gita
_cod_depositor_comments
;
 Changing the _atom_site_occupancy data item value from '.' to '1'
 for all fully occupied atom sites.

 Antanas Vaitkus,
 2017-02-10

The following automatic conversions were performed:

'_chemical_melting_point' value '120-122_C' was changed to
'394.1(10)' - it was converted from degrees Celsius(C) to Kelvins(K),
the average value was taken and precision was estimated.

Automatic conversion script
Id: cif_fix_values 1715 2011-07-08 13:25:40Z adriana 
;
_cod_original_sg_symbol_H-M      'C 2/c'
_cod_database_code               2004107