Zwitterionic niobium and tantalum complexes with bidentate aminophenol scaffolds: Synthesis, structural characterization and use in the ring opening polymerization of lactides
Roymuhury, Sagnik Kumar; Chakraborty, Debashis; V, Ramkumar; RSC Adv.  (2016) –; doi:10.1039/C6RA09789H

data_7225087
_publ_section_title
;
 Zwitterionic niobium and tantalum complexes with bidentate aminophenol
 scaffolds: Synthesis, structural characterization and use in the ring
 opening polymerization of lactides
;
_journal_name_full               'RSC Adv.'
_journal_paper_doi               10.1039/C6RA09789H
_journal_year                    2016
_chemical_formula_moiety         'C23 H41 Cl3 N Nb O4'
_chemical_formula_sum            'C23 H41 Cl3 N Nb O4'
_chemical_formula_weight         594.83
_chemical_name_systematic        2a
_chemical_properties_physical    Air-sensitive,Moisture-sensitive
_space_group_crystal_system      orthorhombic
_space_group_IT_number           33
_space_group_name_Hall           'P 2c -2n'
_space_group_name_H-M_alt        'P n a 21'
_symmetry_space_group_name_Hall  'P 2c -2n'
_symmetry_space_group_name_H-M   'P n a 21'
_atom_sites_solution_hydrogens   geom
_audit_creation_method           SHELXL-2014/7
_audit_update_record
;
2016-04-09 deposited with the CCDC.
2016-05-02 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   18.0256(14)
_cell_length_b                   15.4212(11)
_cell_length_c                   10.3922(6)
_cell_measurement_reflns_used    4398
_cell_measurement_temperature    298(2)
_cell_measurement_theta_max      24.28
_cell_measurement_theta_min      2.26
_cell_volume                     2888.8(3)
_computing_cell_refinement       'Bruker SAINT'
_computing_data_collection       'Bruker APEX2'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-2014/7 (Sheldrick, 2014)'
_computing_structure_solution    'SHELXS-97 (Sheldrick 2008)'
_diffrn_ambient_temperature      298(2)
_diffrn_measured_fraction_theta_full 0.997
_diffrn_measured_fraction_theta_max 0.997
_diffrn_measurement_device_type  'Bruker APEX-II CCD'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0306
_diffrn_reflns_av_unetI/netI     0.0391
_diffrn_reflns_Laue_measured_fraction_full 0.997
_diffrn_reflns_Laue_measured_fraction_max 0.997
_diffrn_reflns_limit_h_max       16
_diffrn_reflns_limit_h_min       -20
_diffrn_reflns_limit_k_max       17
_diffrn_reflns_limit_k_min       -14
_diffrn_reflns_limit_l_max       8
_diffrn_reflns_limit_l_min       -12
_diffrn_reflns_number            10273
_diffrn_reflns_point_group_measured_fraction_full 0.793
_diffrn_reflns_point_group_measured_fraction_max 0.793
_diffrn_reflns_theta_full        24.383
_diffrn_reflns_theta_max         24.383
_diffrn_reflns_theta_min         2.260
_exptl_absorpt_coefficient_mu    0.721
_exptl_absorpt_correction_T_max  0.930
_exptl_absorpt_correction_T_min  0.841
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS V2014/5(Bruker AXS.Inc)'
_exptl_crystal_colour            yellow
_exptl_crystal_density_diffrn    1.368
_exptl_crystal_description       rectangular
_exptl_crystal_F_000             1240
_exptl_crystal_size_max          0.25
_exptl_crystal_size_mid          0.20
_exptl_crystal_size_min          0.10
_refine_diff_density_max         0.276
_refine_diff_density_min         -0.306
_refine_diff_density_rms         0.050
_refine_ls_abs_structure_details
; 
 Flack x determined using 1011 quotients [(I+)-(I-)]/[(I+)+(I-)] 
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259). 
;
_refine_ls_abs_structure_Flack   0.00(3)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.031
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     356
_refine_ls_number_reflns         3754
_refine_ls_number_restraints     163
_refine_ls_restrained_S_all      1.048
_refine_ls_R_factor_all          0.0412
_refine_ls_R_factor_gt           0.0334
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0371P)^2^+1.0789P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0737
_refine_ls_wR_factor_ref         0.0778
_reflns_Friedel_coverage         0.498
_reflns_Friedel_fraction_full    0.562
_reflns_Friedel_fraction_max     0.562
_reflns_number_gt                3307
_reflns_number_total             3754
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            c6ra09789h2.cif
_cod_data_source_block           2a
_cod_database_code               7225087
_shelx_shelxl_version_number     2014/7
_shelx_res_checksum              81158