High-pressure polymorphism in pyridine
Giordano, Nico; Beavers, Christine M.; Campbell, Branton J.; Eigner, Václav; Gregoryanz, Eugene; Marshall, Willliam G.; Peña-Álvarez, Miriam; Teat, Simon J.; Vennari, Cara E.; Parsons, Simon; IUCrJ 7 (2020) 58–70; doi:10.1107/S2052252519015616

data_1556893
_publ_section_title
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 High-pressure polymorphism in pyridine
;
_journal_coeditor_code           LQ5025SUP1
_journal_issue                   1
_journal_name_full               IUCrJ
_journal_page_first              58
_journal_page_last               70
_journal_paper_doi               10.1107/S2052252519015616
_journal_volume                  7
_journal_year                    2020
_chemical_formula_moiety         'C5 H5 N'
_chemical_formula_sum            'C5 H5 N'
_chemical_formula_weight         79.10
_chemical_name_systematic        'Pyridine II'
_space_group_crystal_system      orthorhombic
_space_group_IT_number           19
_space_group_name_Hall           'P 2ac 2ab'
_space_group_name_H-M_alt        'P 21 21 21'
_atom_sites_solution_hydrogens   geom
_audit_creation_date             2017-11-13
_audit_creation_method
;
Olex2 1.2
(compiled 2017.08.10 svn.r3458 for OlexSys, GUI svn.r5381)
;
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   5.392(3)
_cell_length_b                   6.806(3)
_cell_length_c                   11.261(5)
_cell_measurement_reflns_used    925
_cell_measurement_temperature    293
_cell_measurement_theta_max      17.84
_cell_measurement_theta_min      2.44
_cell_volume                     413.3(3)
_computing_cell_refinement       'SAINT v8.34A (Bruker, 2013)'
_computing_data_collection       'SAINT V8.38A Bruker-AXS, Madison WI'
_computing_data_reduction        'SAINT v8.34A (Bruker, 2013)'
_computing_molecular_graphics    'Olex2 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 (Dolomanov et al., 2009)'
_computing_structure_refinement  'XL (Sheldrick, 2008)'
_computing_structure_solution    'XT (Sheldrick, 2015)'
_diffrn_ambient_temperature      293.0
_diffrn_detector_area_resol_mean 10.42
_diffrn_measured_fraction_theta_full 0.517
_diffrn_measured_fraction_theta_max 0.508
_diffrn_measurement_device_type  'Perkin-Elmer a-Si Detector'
_diffrn_measurement_method       '\f shuterless scans'
_diffrn_radiation_monochromator  'silicon 111'
_diffrn_radiation_type           synchrotron
_diffrn_radiation_wavelength     0.49594
_diffrn_reflns_av_R_equivalents  0.0330
_diffrn_reflns_av_unetI/netI     0.0431
_diffrn_reflns_Laue_measured_fraction_full 0.517
_diffrn_reflns_Laue_measured_fraction_max 0.508
_diffrn_reflns_limit_h_max       3
_diffrn_reflns_limit_h_min       -3
_diffrn_reflns_limit_k_max       8
_diffrn_reflns_limit_k_min       -8
_diffrn_reflns_limit_l_max       14
_diffrn_reflns_limit_l_min       -14
_diffrn_reflns_number            1324
_diffrn_reflns_point_group_measured_fraction_full 0.495
_diffrn_reflns_point_group_measured_fraction_max 0.484
_diffrn_reflns_theta_full        17.311
_diffrn_reflns_theta_max         18.069
_diffrn_reflns_theta_min         2.524
_diffrn_source
;
Advanced Light Source, station 12.2.2
;
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.042
_exptl_absorpt_correction_T_max  0.7442
_exptl_absorpt_correction_T_min  0.4840
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
SADABS-2014/4 (Bruker,2014/4) was used for absorption correction.
wR2(int) was 0.1139 before and 0.0421 after correction.
The Ratio of minimum to maximum transmission is 0.6504.
The \l/2 correction factor is Not present.
;
_exptl_crystal_colour            colourless
_exptl_crystal_colour_primary    colourless
_exptl_crystal_density_diffrn    1.271
_exptl_crystal_description       irregular
_exptl_crystal_F_000             168
_exptl_crystal_recrystallization_method
;
Crystallized in-situ from pyridine (H5) directly. No hydrostatic medium. 
Pressure was cycled until 1.1 GPa was reached. The pressure dropped 
slightly at the end of data collection. Sample was not heat treated.
;
_exptl_crystal_size_max          0.26
_exptl_crystal_size_mid          0.26
_exptl_crystal_size_min          0.1
_refine_diff_density_max         0.043
_refine_diff_density_min         -0.048
_refine_diff_density_rms         0.013
_refine_ls_abs_structure_details
;
 Flack x determined using 85 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   10.0(10)
_refine_ls_extinction_coef       1.8(4)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     'SHELXL-2014/7 (Sheldrick 2014'
_refine_ls_goodness_of_fit_ref   0.882
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     56
_refine_ls_number_reflns         411
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.882
_refine_ls_R_factor_all          0.0400
_refine_ls_R_factor_gt           0.0290
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0349P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0583
_refine_ls_wR_factor_ref         0.0602
_reflns_Friedel_coverage         0.545
_reflns_Friedel_fraction_full    0.457
_reflns_Friedel_fraction_max     0.445
_reflns_number_gt                291
_reflns_number_total             411
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            lq5025.cif
_cod_data_source_block           pyridine2_final
_cod_original_cell_volume        413.2(3)
_cod_database_code               1556893
_shelx_shelxl_version_number     2014/7
_shelx_estimated_absorpt_t_max   0.996
_shelx_estimated_absorpt_t_min   0.989
_olex2_refinement_description
;
1. Fixed Uiso
 At 1.2 times of:
  All C(H) groups
2.a Aromatic/amide H refined with riding coordinates:
 C2(H2), C3(H3), C4(H4), C5(H5), C6(H6)
;
_shelx_res_checksum              81337
_shelx_hkl_checksum              3274
_olex2_submission_special_instructions 'No special instructions were received'