Dipotassium heptahydrogenhexamolybdochromate(III) octahydrate, the first heptaprotonated Anderson-type polyoxometalate
Lee, Uk; Acta Crystallographica Section E 63 (2007) i5–i7; doi:10.1107/S1600536806052883

data_2211745
_publ_section_title
;
 Dipotassium heptahydrogenhexamolybdochromate(III) octahydrate, the
 first heptaprotonated Anderson-type polyoxometalate
;
_journal_coeditor_code           BT2216
_journal_issue                   1
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              i5
_journal_page_last               i7
_journal_paper_doi               10.1107/S1600536806052883
_journal_volume                  63
_journal_year                    2007
_chemical_formula_iupac          'K2 [H7 Cr Mo6 O24], 8H2 O'
_chemical_formula_moiety         'K2, H7 Cr Mo6 O24, 8(H2 O)'
_chemical_formula_sum            'Cr H23 K2 Mo6 O32'
_chemical_formula_weight         1241.02
_chemical_name_systematic
;
Dipotassium heptahydrogenhexamolybdochromate(III) octahydrate
;
_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                99.3090(10)
_cell_angle_beta                 94.4650(10)
_cell_angle_gamma                99.2560(10)
_cell_formula_units_Z            2
_cell_length_a                   10.4733(6)
_cell_length_b                   10.8698(6)
_cell_length_c                   12.6540(7)
_cell_measurement_reflns_used    5418
_cell_measurement_temperature    173(2)
_cell_measurement_theta_max      28.27
_cell_measurement_theta_min      2.30
_cell_volume                     1395.08(14)
_computing_cell_refinement       'SAINT (Bruker, 1997)'
_computing_data_collection       'SMART (Bruker, 1997)'
_computing_data_reduction        SAINT
_computing_molecular_graphics
'ORTEP-3 (Farrugia, 1997) and DIAMOND (Brandenburg, 1998)'
_computing_publication_material  SHELXL97
_computing_structure_refinement  'SHELXL97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      173(2)
_diffrn_detector_area_resol_mean 10.00
_diffrn_measured_fraction_theta_full 0.981
_diffrn_measured_fraction_theta_max 0.981
_diffrn_measurement_device_type  'Bruker SMART CCD'
_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  0.0249
_diffrn_reflns_av_sigmaI/netI    0.0346
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       13
_diffrn_reflns_limit_k_min       -13
_diffrn_reflns_limit_l_max       15
_diffrn_reflns_limit_l_min       -15
_diffrn_reflns_number            10855
_diffrn_reflns_theta_full        26.00
_diffrn_reflns_theta_max         26.00
_diffrn_reflns_theta_min         1.93
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    3.403
_exptl_absorpt_correction_T_max  0.512
_exptl_absorpt_correction_T_min  0.380
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   '(SADABS; Sheldrick, 1999)'
_exptl_crystal_colour            purple
_exptl_crystal_density_diffrn    2.954
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             1186
_exptl_crystal_size_max          0.32
_exptl_crystal_size_mid          0.25
_exptl_crystal_size_min          0.20
_refine_diff_density_max         0.849
_refine_diff_density_min         -0.849
_refine_ls_extinction_coef       0.0065(2)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL97
_refine_ls_goodness_of_fit_ref   1.190
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     408
_refine_ls_number_reflns         5360
_refine_ls_number_restraints     19
_refine_ls_restrained_S_all      1.192
_refine_ls_R_factor_all          0.0302
_refine_ls_R_factor_gt           0.0289
_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^)+(0.0228P)^2^+4.6144P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0728
_refine_ls_wR_factor_ref         0.0735
_reflns_number_gt                5200
_reflns_number_total             5360
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            bt2216.cif
_cod_data_source_block           I
_cod_original_sg_symbol_Hall     -p_1
_cod_original_formula_sum        'H23 Cr K2 Mo6 O32'
_cod_database_code               2211745
_cod_database_fobs_code          2211745