In situ cyclodehydration of iminodiacetic acid into 2,5-diketopiperazine-1,4-diacetate in lanthanide-based coordination polymers
Kong, Xiang-Jian; Zhuang, Gui-Lin; Ren, Yan-Ping; Long, La-Sheng; Huang, Rong-Bin; Zheng, Lan-Sun; Dalton Transactions  (2009) 1707–1709; doi:10.1039/b819792j

data_7000684
_publ_section_title
;
 In situ cyclodehydration of iminodiacetic acid into
 2,5-diketopiperazine-1,4-diacetate in lanthanide-based coordination
 polymers
;
_journal_issue                   10
_journal_name_full               'Dalton Transactions'
_journal_page_first              1707
_journal_page_last               1709
_journal_paper_doi               10.1039/b819792j
_journal_year                    2009
_chemical_formula_sum            'C12 H12 Er2 N2 O16'
_chemical_formula_weight         774.76
_chemical_name_systematic
;
?
;
_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                95.676(4)
_cell_angle_beta                 110.170(3)
_cell_angle_gamma                93.544(4)
_cell_formula_units_Z            1
_cell_length_a                   6.6574(15)
_cell_length_b                   7.7517(18)
_cell_length_c                   9.066(2)
_cell_measurement_reflns_used    3441
_cell_measurement_temperature    298(2)
_cell_measurement_theta_max      28.342
_cell_measurement_theta_min      2.413
_cell_volume                     434.71(17)
_computing_cell_refinement       'SHELXTL-Plus (Sheldrick, 1990)'
_computing_data_collection       'SHELXTL-Plus (Sheldrick, 1990)'
_computing_data_reduction        'SHELXTL-Plus (Sheldrick, 1990)'
_computing_molecular_graphics    'SHELXTL V.5.0 (Sheldrick, 1997)'
_computing_publication_material  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      298(2)
_diffrn_measured_fraction_theta_full 0.968
_diffrn_measured_fraction_theta_max 0.968
_diffrn_measurement_device_type  'Bruker Smart Apex CCD area detector'
_diffrn_measurement_method       'phi and omega 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  0.0182
_diffrn_reflns_av_sigmaI/netI    0.0252
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       -8
_diffrn_reflns_limit_k_max       9
_diffrn_reflns_limit_k_min       -9
_diffrn_reflns_limit_l_max       10
_diffrn_reflns_limit_l_min       -11
_diffrn_reflns_number            3318
_diffrn_reflns_theta_full        26.00
_diffrn_reflns_theta_max         26.00
_diffrn_reflns_theta_min         2.41
_exptl_absorpt_coefficient_mu    9.685
_exptl_absorpt_correction_T_max  0.6980
_exptl_absorpt_correction_T_min  0.3442
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   '(SADABS; Bruker, 2001)'
_exptl_crystal_colour            pink
_exptl_crystal_density_diffrn    2.959
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    .
_exptl_crystal_description       block
_exptl_crystal_F_000             362
_exptl_crystal_size_max          0.14
_exptl_crystal_size_mid          0.12
_exptl_crystal_size_min          0.04
_refine_diff_density_max         0.879
_refine_diff_density_min         -1.322
_refine_diff_density_rms         0.142
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.119
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     145
_refine_ls_number_reflns         1656
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.119
_refine_ls_R_factor_all          0.0189
_refine_ls_R_factor_gt           0.0186
_refine_ls_shift/su_max          0.008
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0320P)^2^+0.0675P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0501
_refine_ls_wR_factor_ref         0.0504
_reflns_number_gt                1640
_reflns_number_total             1656
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b819792j.txt
_cod_data_source_block           complex_3
_cod_original_cell_volume        434.73(17)
_cod_original_sg_symbol_H-M      p-1
_cod_database_code               7000684