Azine-Hydrazone Tautomerism of Guanylhydrazones: Evidence for the Preference Toward the Azine Tautomer.
Chourasiya, Sumit S.; Kathuria, Deepika; Nikam, Sampada S.; Ramakrishnan, Ashok; Khullar, Sadhika; Mandal, Sanjay K.; Chakraborti, Asit K.; Bharatam, Prasad V.; The Journal of organic chemistry 81 (2016) 7574–7583; doi:10.1021/acs.joc.6b01258

data_4037013
_publ_section_title
;
 Azine-Hydrazone Tautomerism of Guanylhydrazones: Evidence for the
 Preference Toward the Azine Tautomer.
;
_journal_issue                   17
_journal_name_full               'The Journal of organic chemistry'
_journal_page_first              7574
_journal_page_last               7583
_journal_paper_doi               10.1021/acs.joc.6b01258
_journal_volume                  81
_journal_year                    2016
_chemical_formula_moiety         'C19 H23 N4 O3, Cl'
_chemical_formula_sum            'C19 H23 Cl N4 O3'
_chemical_formula_weight         390.86
_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
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   7.4460(13)
_cell_length_b                   11.786(2)
_cell_length_c                   21.591(4)
_cell_measurement_reflns_used    6847
_cell_measurement_temperature    296.(2)
_cell_measurement_theta_max      23.3389
_cell_measurement_theta_min      2.5586
_cell_volume                     1894.8(6)
_computing_cell_refinement       'SAINT V8.27B (Bruker AXS Inc., 2012)'
_computing_data_collection       'APEX2 (Bruker)'
_computing_data_reduction        'SAINT V8.27B (Bruker AXS Inc., 2012)'
_computing_molecular_graphics    'SHELXTL (Bruker AXS)'
_computing_publication_material  'SHELXTL (Bruker AXS)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      296.(2)
_diffrn_detector_area_resol_mean 8.3333
_diffrn_measured_fraction_theta_full 0.994
_diffrn_measured_fraction_theta_max 0.994
_diffrn_measurement_device_type  'Bruker Kappa APEX II'
_diffrn_measurement_method       'phi and omega scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0493
_diffrn_reflns_av_sigmaI/netI    0.0299
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       -8
_diffrn_reflns_limit_k_max       14
_diffrn_reflns_limit_k_min       -14
_diffrn_reflns_limit_l_max       25
_diffrn_reflns_limit_l_min       -22
_diffrn_reflns_number            19415
_diffrn_reflns_theta_full        25.17
_diffrn_reflns_theta_max         25.17
_diffrn_reflns_theta_min         1.89
_diffrn_source                   'sealed tube'
_diffrn_source_type              'fine focus'
_exptl_absorpt_coefficient_mu    0.229
_exptl_absorpt_correction_T_max  0.7452
_exptl_absorpt_correction_T_min  0.6612
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS V2012/1 (Bruker AXS Inc.)'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.370
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       rectangle
_exptl_crystal_F_000             824
_exptl_crystal_size_max          0.25
_exptl_crystal_size_mid          0.20
_exptl_crystal_size_min          0.16
_refine_diff_density_max         0.163
_refine_diff_density_min         -0.254
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -0.01(8)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.041
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     247
_refine_ls_number_reflns         3393
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.041
_refine_ls_R_factor_all          0.0417
_refine_ls_R_factor_gt           0.0370
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0695P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0981
_refine_ls_wR_factor_ref         0.1016
_reflns_number_gt                3053
_reflns_number_total             3393
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            jo6b01258_si_002.cif
_cod_data_source_block           14.HCl
_cod_database_code               4037013