Alkynyl and Phosphonyl Substituted Nucleobases: A Case of Thermally Induced Conformational Polymorphism
Kumara Swamy, K. C.; Allu, Srinivasarao; Srinivas, Venu; Balaraman, E.; Kumar, K. V. P. Pavan; Crystal Growth & Design 11 (2011) 2302–; doi:10.1021/cg101737x

data_4500587
_publ_section_title
;
 Alkynyl and Phosphonyl Substituted Nucleobases: A Case of Thermally
 Induced Conformational Polymorphism
;
_journal_issue                   6
_journal_name_full               'Crystal Growth &amp; Design'
_journal_page_first              2302
_journal_paper_doi               10.1021/cg101737x
_journal_volume                  11
_journal_year                    2011
_chemical_formula_sum            'C11 H13 N5'
_chemical_formula_weight         215.26
_space_group_IT_number           2
_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                101.27(1)
_cell_angle_beta                 96.38(1)
_cell_angle_gamma                100.33(1)
_cell_formula_units_Z            4
_cell_length_a                   8.271(1)
_cell_length_b                   11.522(1)
_cell_length_c                   12.058(1)
_cell_measurement_temperature    200(2)
_cell_volume                     1095.9(2)
_computing_cell_refinement       'CrysAlisPro, Oxford Diffraction Ltd'
_computing_data_collection       'CrysAlisPro, Oxford Diffraction Ltd'
_computing_data_reduction        'CrysAlisPro, Oxford Diffraction Ltd'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      200(2)
_diffrn_measured_fraction_theta_full 0.990
_diffrn_measured_fraction_theta_max 0.990
_diffrn_measurement_device_type  'Xcalibur, Eos, Gemini'
_diffrn_measurement_method       '\w scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0578
_diffrn_reflns_av_sigmaI/netI    0.0939
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_k_max       12
_diffrn_reflns_limit_k_min       -12
_diffrn_reflns_limit_l_max       13
_diffrn_reflns_limit_l_min       -10
_diffrn_reflns_number            7649
_diffrn_reflns_theta_full        23.35
_diffrn_reflns_theta_max         23.35
_diffrn_reflns_theta_min         2.80
_diffrn_standards_decay_%        none
_diffrn_standards_interval_count 'not applicable'
_diffrn_standards_interval_time  'not applicable'
_diffrn_standards_number         'not applicable'
_exptl_absorpt_coefficient_mu    0.085
_exptl_absorpt_correction_T_max  0.9899
_exptl_absorpt_correction_T_min  0.9799
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'CrysAlisPro, Oxford Diffraction Ltd'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.305
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       blocks
_exptl_crystal_F_000             456
_exptl_crystal_size_max          0.24
_exptl_crystal_size_mid          0.18
_exptl_crystal_size_min          0.12
_refine_diff_density_max         0.388
_refine_diff_density_min         -0.343
_refine_diff_density_rms         0.092
_refine_ls_extinction_coef       0.014(6)
_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   1.122
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     290
_refine_ls_number_reflns         3155
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.122
_refine_ls_R_factor_all          0.1230
_refine_ls_R_factor_gt           0.0862
_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^)+(0.1428P)^2^+1.9335P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.2802
_refine_ls_wR_factor_ref         0.2915
_reflns_number_gt                1965
_reflns_number_total             3155
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            cg101737x_si_002.cif
_cod_data_source_block           compd8'
_cod_original_sg_symbol_H-M      P-1
_cod_database_code               4500587