2,2'-(Piperazine-1,4-diium-1,4-diyl)diacetate dihydrate
Shen, Li; Wang, Feng-Wu; Cheng, Ai-Bin; Yang, Song; Acta Crystallographica Section E 62 (2006) o2242–o2244; doi:10.1107/S1600536806013572

data_2209207
_publ_section_title
;
 2,2'-(Piperazine-1,4-diium-1,4-diyl)diacetate dihydrate
;
_journal_coeditor_code           HK2023
_journal_issue                   6
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              o2242
_journal_page_last               o2244
_journal_paper_doi               10.1107/S1600536806013572
_journal_volume                  62
_journal_year                    2006
_chemical_formula_iupac          'C8 H14 N2 O4 , 2H2 O'
_chemical_formula_moiety         'C8 H14 N2 O4 , 2H2 O'
_chemical_formula_sum            'C8 H18 N2 O6'
_chemical_formula_weight         238.24
_chemical_name_common            'N,N'-1,4-Piperazinediacetic acid'
_chemical_name_systematic
;
2,2'-(Piperazine-1,4-diium-1,4-diyl)diacetate dihydrate
;
_space_group_IT_number           61
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  '-P 2ac 2ab'
_symmetry_space_group_name_H-M   'P b c a'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL97
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   6.5060(13)
_cell_length_b                   11.344(2)
_cell_length_c                   14.587(3)
_cell_measurement_reflns_used    2965
_cell_measurement_temperature    296(2)
_cell_measurement_theta_max      27.31
_cell_measurement_theta_min      2.70
_cell_volume                     1076.6(4)
_computing_cell_refinement       SMART
_computing_data_collection       'SMART (Bruker, 2001)'
_computing_data_reduction        SAINT
_computing_molecular_graphics    'SHELXTL (Bruker, 2001)'
_computing_publication_material  SHELXTL
_computing_structure_refinement  'SHELXL97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      296(2)
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.999
_diffrn_measurement_device_type  'Bruker SMART APEX area-detector'
_diffrn_measurement_method       '\f and \w'
_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  0.0865
_diffrn_reflns_av_sigmaI/netI    0.0840
_diffrn_reflns_limit_h_max       0
_diffrn_reflns_limit_h_min       -8
_diffrn_reflns_limit_k_max       13
_diffrn_reflns_limit_k_min       -13
_diffrn_reflns_limit_l_max       0
_diffrn_reflns_limit_l_min       -17
_diffrn_reflns_number            2031
_diffrn_reflns_theta_full        26.00
_diffrn_reflns_theta_max         26.00
_diffrn_reflns_theta_min         2.79
_diffrn_standards_decay_%        0
_diffrn_standards_interval_count 0
_diffrn_standards_interval_time  0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.125
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.470
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             512
_exptl_crystal_size_max          0.28
_exptl_crystal_size_mid          0.24
_exptl_crystal_size_min          0.16
_refine_diff_density_max         0.173
_refine_diff_density_min         -0.210
_refine_ls_extinction_coef       0.047(5)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     'SHELXL97 (Sheldrick, 1997)'
_refine_ls_goodness_of_fit_ref   1.052
_refine_ls_hydrogen_treatment    refall
_refine_ls_matrix_type           full
_refine_ls_number_parameters     110
_refine_ls_number_reflns         1049
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.052
_refine_ls_R_factor_all          0.0655
_refine_ls_R_factor_gt           0.0428
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w = 1/[\s^2^(Fo^2^)+(0.0347P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0953
_refine_ls_wR_factor_ref         0.1069
_reflns_number_gt                762
_reflns_number_total             1049
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            hk2023.cif
_cod_data_source_block           I
_cod_database_code               2209207
_cod_database_fobs_code          2209207