Understanding the NMR chemical shifts for 6-halopurines: role of structure, solvent and relativistic effects.
Standara, Stanislav; Malináková, Katerina; Marek, Radek; Marek, Jaromír; Hocek, Michal; Vaara, Juha; Straka, Michal; Physical chemistry chemical physics : PCCP 12 (2010) 5126–5139; doi:10.1039/b921383j

data_7212176
_publ_section_title
;
 Understanding the NMR chemical shifts for 6-halopurines: role of
 structure, solvent and relativistic effects.
;
_journal_issue                   19
_journal_name_full               'Physical chemistry chemical physics : PCCP'
_journal_page_first              5126
_journal_page_last               5139
_journal_paper_doi               10.1039/b921383j
_journal_volume                  12
_journal_year                    2010
_chemical_formula_moiety         'C12 H9 Cl N4'
_chemical_formula_sum            'C12 H9 Cl N4'
_chemical_formula_weight         244.68
_chemical_name_common            7-benzyl-6-chloropurine
_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   constr
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 111.317(11)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   14.7190(14)
_cell_length_b                   4.9706(4)
_cell_length_c                   15.8872(15)
_cell_measurement_reflns_used    3121
_cell_measurement_temperature    120(2)
_cell_measurement_theta_max      25.7165
_cell_measurement_theta_min      2.372
_cell_volume                     1082.82(19)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      120(2)
_diffrn_detector_area_resol_mean 8.3611
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_diffrn_measurement_device_type  'KUMA KM4 + CCD'
_diffrn_measurement_method       'rotation method, \w--scan'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'Enhance (Mo) X-ray Source'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.1018
_diffrn_reflns_av_sigmaI/netI    0.0552
_diffrn_reflns_limit_h_max       15
_diffrn_reflns_limit_h_min       -18
_diffrn_reflns_limit_k_max       6
_diffrn_reflns_limit_k_min       -6
_diffrn_reflns_limit_l_max       19
_diffrn_reflns_limit_l_min       -19
_diffrn_reflns_number            6502
_diffrn_reflns_theta_full        26.00
_diffrn_reflns_theta_max         26.00
_diffrn_reflns_theta_min         3.85
_exptl_absorpt_coefficient_mu    0.332
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.501
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             504
_exptl_crystal_size_max          0.55
_exptl_crystal_size_mid          0.30
_exptl_crystal_size_min          0.30
_refine_diff_density_max         0.381
_refine_diff_density_min         -0.327
_refine_diff_density_rms         0.082
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.039
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     154
_refine_ls_number_reflns         2118
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.039
_refine_ls_R_factor_all          0.0572
_refine_ls_R_factor_gt           0.0522
_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^)+(0.1000P)^2^+0.5000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1432
_refine_ls_wR_factor_ref         0.1509
_reflns_number_gt                1834
_reflns_number_total             2118
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b921383j.txt
_cod_data_source_block           Compound1a
_cod_depositor_comments
;
The following automatic conversions were performed:
'_atom_site_symetry_multiplicity' tag replaced with
'_atom_site_symmetry_multiplicity'.

Automatic conversion script
Id: cif_correct_tags 1440 2010-10-19 06:21:57Z saulius 
;
_cod_original_cell_volume        1082.82(17)
_cod_original_sg_symbol_H-M      'P 21/n '
_cod_database_code               7212176