(15)N NMR Spectroscopy, X-ray and Neutron Diffraction, Quantum-Chemical Calculations, and UV/vis-Spectrophotometric Titrations as Complementary Techniques for the Analysis of Pyridine-Supported Bicyclic Guanidine Superbases.
Schwamm, Ryan J.; Vianello, Robert; Maršavelski, Aleksandra; García, M Ángeles; Claramunt, Rosa M.; Alkorta, Ibon; Saame, Jaan; Leito, Ivo; Fitchett, Christopher M.; Edwards, Alison J.; Coles, Martyn P.; The Journal of organic chemistry 81 (2016) 7612–7625; doi:10.1021/acs.joc.6b01330

data_4037038
_publ_section_title
;
 (15)N NMR Spectroscopy, X-ray and Neutron Diffraction, Quantum-Chemical
 Calculations, and UV/vis-Spectrophotometric Titrations as Complementary
 Techniques for the Analysis of Pyridine-Supported Bicyclic Guanidine
 Superbases.
;
_journal_issue                   17
_journal_name_full               'The Journal of organic chemistry'
_journal_page_first              7612
_journal_page_last               7625
_journal_paper_doi               10.1021/acs.joc.6b01330
_journal_volume                  81
_journal_year                    2016
_chemical_formula_moiety         'C24 H20 B, C12 H17 N4'
_chemical_formula_sum            'C36 H37 B N4'
_chemical_formula_weight         536.53
_space_group_IT_number           2
_space_group_name_Hall           '-P 1'
_space_group_name_H-M_alt        'P -1'
_symmetry_cell_setting           triclinic
_symmetry_space_group_name_H-M   'P -1'
_atom_sites_solution_hydrogens   difmap
_atom_sites_solution_primary     geom
_cell_angle_alpha                69.939(4)
_cell_angle_beta                 76.544(3)
_cell_angle_gamma                69.975(3)
_cell_formula_units_Z            2
_cell_length_a                   10.6291(3)
_cell_length_b                   11.8059(5)
_cell_length_c                   13.0252(5)
_cell_measurement_reflns_used    6699
_cell_measurement_temperature    120
_cell_measurement_theta_max      76
_cell_measurement_theta_min      4
_cell_volume                     1430.14(10)
_computing_cell_refinement       'LaueG (Piltz, 2011)'
_computing_data_collection       'MAATEL/ANSTO control program'
_computing_data_reduction
'argonne_boxes (Wilkinson et al., 1988) & LaueG (Piltz, 2011)'
_computing_molecular_graphics    'CAMERON (Watkin et al., 1996)'
_computing_publication_material  'CRYSTALS (Betteridge et al., 2003)'
_computing_structure_refinement  'CRYSTALS (Betteridge et al., 2003)'
_computing_structure_solution    'SHELXS 86 (Sheldrick, 1986)'
_diffrn_ambient_pressure         101
_diffrn_ambient_temperature      120
_diffrn_measured_fraction_theta_full 0.641
_diffrn_measured_fraction_theta_max 0.641
_diffrn_measurement_details      '16 images, exposure time   0 minutes'
_diffrn_measurement_device       'Laue image-plate diffractometer'
_diffrn_measurement_device_type  KOALA
_diffrn_measurement_method       Laue
_diffrn_radiation_probe          neutron
_diffrn_radiation_type           neutron
_diffrn_radiation_wavelength     0.85
_diffrn_reflns_av_R_equivalents  0.050
_diffrn_reflns_av_unetI/netI     0.1038
_diffrn_reflns_limit_h_max       15
_diffrn_reflns_limit_h_min       -14
_diffrn_reflns_limit_k_max       16
_diffrn_reflns_limit_k_min       -16
_diffrn_reflns_limit_l_max       17
_diffrn_reflns_limit_l_min       -18
_diffrn_reflns_number            26805
_diffrn_reflns_reduction_process 'LaueG (Piltz, 2011)'
_diffrn_reflns_resolution_max    1.43
_diffrn_reflns_theta_full        71.19
_diffrn_reflns_theta_max         71.28
_diffrn_reflns_theta_min         2.171
_diffrn_source                   'nuclear reactor'
_diffrn_source_details           'thermal neutrons, supermirror guides'
_diffrn_source_type              'OPAL reactor, ANSTO, Lucas Heights, Australia'
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.0
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.246
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plate
_exptl_crystal_F_000             290
_exptl_crystal_size_max          0.450
_exptl_crystal_size_mid          0.280
_exptl_crystal_size_min          0.120
_refine_diff_density_max         1.10
_refine_diff_density_min         -1.12
_refine_ls_extinction_method     None
_refine_ls_goodness_of_fit_ref   1.0894
_refine_ls_hydrogen_treatment    refall,
_refine_ls_matrix_type           full
_refine_ls_number_parameters     703
_refine_ls_number_reflns         3704
_refine_ls_number_restraints     0
_refine_ls_R_factor_all          0.1114
_refine_ls_R_factor_gt           0.0721
_refine_ls_shift/su_max          0.0001552
_refine_ls_shift/su_mean         0.0000213
_refine_ls_structure_factor_coef F
_refine_ls_weighting_details
;
 Method, part 1, Chebychev polynomial, (Watkin, 1994, Prince, 1982) 
 [weight] = 1.0/[A~0~*T~0~(x)+A~1~*T~1~(x) ... +A~n-1~]*T~n-1~(x)] 
 where A~i~ are the Chebychev coefficients listed below and x= Fcalc/Fmax 
 Method = Robust Weighting (Prince, 1982) 
 W = [weight] * [1-(deltaF/6*sigmaF)^2^]^2^ 
 A~i~ are: 
 14.4 -3.94 7.42 6.71 
;
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_all         0.0793
_refine_ls_wR_factor_gt          0.0531
_refine_ls_wR_factor_ref         0.0467
_reflns_number_gt                4119
_reflns_number_total             5587
_reflns_threshold_expression     >2sigma(I)
_oxford_diffrn_Wilson_B_factor   0.00
_oxford_diffrn_Wilson_scale      0.00
_oxford_refine_ls_r_factor_ref   0.0581
_oxford_refine_ls_scale          1.181(3)
_oxford_reflns_number_all        5579
_publcif_info_exptl_table_max_cols 4
_publcif_info_exptl_table_use_headnotes n
_cod_data_source_file            jo6b01330_si_002.cif
_cod_data_source_block           ajemodneut
_cod_original_sg_symbol_H-M      'P -1 '
_cod_original_formula_sum        'C36 H37 B1 N4'
_cod_database_code               4037038
_iucr_refine_instruction_details_constraints
;
BLOCK 
CONT SCALE 
CONT N    (    2 ,X'S,U'S)  UNTIL H    (   11 ) 
END                                                                             
;
_iucr_refine_instruction_details_restraints
;
NO 
REM   HREST   START (DO NOT REMOVE THIS LINE) 
REM   HREST   END (DO NOT REMOVE THIS LINE) 
END                                                                             
;