A three-dimensional hydrogen-bonded framework in piperazine‒3,4-dihydroxy-3-cyclobutene-1,2-dione‒water (1/1/2)
MacLean, Elizabeth J.; Wheatley, Paul S.; Ferguson, George; Glidewell, Christopher; Lough, Alan J.; Acta Crystallographica Section C 55 (1999) 1896–1899; doi:10.1107/S0108270199009531

data_2009198
_publ_section_title
;
 A three-dimensional hydrogen-bonded framework in
 piperazine--3,4-dihydroxy-3-cyclobutene-1,2-dione--water (1/1/2)
;
_journal_issue                   11
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              1896
_journal_page_last               1899
_journal_paper_doi               10.1107/S0108270199009531
_journal_volume                  55
_journal_year                    1999
_chemical_formula_moiety         'C4 H12 N2 2+ , C4 O4 2- , 2H2 O'
_chemical_formula_sum            'C8 H16 N2 O6'
_chemical_formula_weight         236.23
_chemical_name_common            'Piperazinium squarate dihydrate'
_chemical_name_systematic
;
Piperazine--3,4-dihydroxy-3-butenedione--water (1/1/2)
;
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2yn'
_symmetry_space_group_name_H-M   'P 1 21/n 1'
_cell_angle_alpha                90.00
_cell_angle_beta                 109.294(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   8.3393(8)
_cell_length_b                   6.9360(7)
_cell_length_c                   9.5034(9)
_cell_measurement_reflns_used    4549
_cell_measurement_temperature    150(2)
_cell_measurement_theta_max      29.47
_cell_measurement_theta_min      3.60
_cell_volume                     518.82(9)
_computing_cell_refinement       SMART
_computing_data_collection       'SMART (Siemens, 1996)'
_computing_data_reduction        'SAINT (Siemens, 1996)'
_computing_molecular_graphics
'ORTEPII (Johnson, 1976) and PLATON (Spek, 1999)'
_computing_publication_material  'SHELXL97 and PRPKAPPA (Ferguson, 1999)'
_computing_structure_refinement  'SHELXL97 (Sheldrick, 1997a)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 1997b)'
_diffrn_ambient_temperature      150(2)
_diffrn_measured_fraction_theta_full 0.966
_diffrn_measured_fraction_theta_max 0.908
_diffrn_measurement_device_type  'Siemens SMART CCD'
_diffrn_measurement_method       '\w rotation with narrow frames'
_diffrn_radiation_source         'synchrotron radiation'
_diffrn_radiation_type           synchrotron
_diffrn_radiation_wavelength     0.68910
_diffrn_reflns_av_R_equivalents  0.036
_diffrn_reflns_av_sigmaI/netI    0.032
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       9
_diffrn_reflns_limit_k_min       -9
_diffrn_reflns_limit_l_max       12
_diffrn_reflns_limit_l_min       -13
_diffrn_reflns_number            4403
_diffrn_reflns_theta_full        26.61
_diffrn_reflns_theta_max         29.51
_diffrn_reflns_theta_min         2.74
_diffrn_standards_decay_%        negligible
_exptl_absorpt_coefficient_mu    0.130
_exptl_absorpt_correction_T_max  1.000
_exptl_absorpt_correction_T_min  1.000
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.512
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plate
_exptl_crystal_F_000             252
_exptl_crystal_size_max          0.15
_exptl_crystal_size_mid          0.10
_exptl_crystal_size_min          0.08
_refine_diff_density_max         0.500
_refine_diff_density_min         -0.270
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.069
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     81
_refine_ls_number_reflns         1438
_refine_ls_number_restraints     2
_refine_ls_restrained_S_all      1.068
_refine_ls_R_factor_all          0.049
_refine_ls_R_factor_gt           0.043
_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^)+(0.0695P)^2^+0.1456P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_ref         0.115
_reflns_number_gt                1340
_reflns_number_total             1438
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            sk1317.cif
_cod_data_source_block           1b
_cod_original_sg_symbol_H-M      'P 21/n'
_cod_database_code               2009198