Preparation of stable AsBr4+ and I2As-PI3+ salts. Why didn't we succeed to prepare AsI4+ and As2X5+? A combined experimental and theoretical study.
Gonsior, Marcin; Krossing, Ingo; Dalton transactions (Cambridge, England : 2003)  (2005) 1203–1213; doi:10.1039/b417629d

data_7008137
_publ_section_title
;
 Preparation of stable AsBr4+ and I2As-PI3+ salts. Why didn't we
 succeed to prepare AsI4+ and As2X5+? A combined experimental and
 theoretical study.
;
_journal_issue                   7
_journal_name_full
'Dalton transactions (Cambridge, England : 2003)'
_journal_page_first              1203
_journal_page_last               1213
_journal_paper_doi               10.1039/b417629d
_journal_year                    2005
_chemical_formula_sum            'C16 Al As Br4 F36 O4'
_chemical_formula_weight         1361.70
_chemical_name_common            'AsBr4(+)(Al(OR)4)(-) (R = C(CF3)3)'
_chemical_name_systematic
;
AsBr4(+)[Al(OR)4](-) (R = C(CF3)3)
;
_space_group_IT_number           33
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2c -2n'
_symmetry_space_group_name_H-M   'P n a 21'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   19.062(4)
_cell_length_b                   13.874(3)
_cell_length_c                   13.588(3)
_cell_measurement_reflns_used    1987
_cell_measurement_temperature    200(2)
_cell_volume                     3593.6(13)
_computing_cell_refinement       'EXPOSE (STOE)'
_computing_data_collection       'EXPOSE (STOE)'
_computing_data_reduction        'INTEGRATE (STOE)'
_computing_molecular_graphics    RESVIEW
_computing_publication_material  RESVIEW
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      200(2)
_diffrn_measured_fraction_theta_full 0.942
_diffrn_measured_fraction_theta_max 0.942
_diffrn_measurement_device_type  'STOE IPDS'
_diffrn_measurement_method       'Image Plate Technique'
_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  0.0707
_diffrn_reflns_av_sigmaI/netI    0.0701
_diffrn_reflns_limit_h_max       21
_diffrn_reflns_limit_h_min       -21
_diffrn_reflns_limit_k_max       16
_diffrn_reflns_limit_k_min       -17
_diffrn_reflns_limit_l_max       16
_diffrn_reflns_limit_l_min       -16
_diffrn_reflns_number            22082
_diffrn_reflns_theta_full        25.94
_diffrn_reflns_theta_max         25.94
_diffrn_reflns_theta_min         2.35
_exptl_absorpt_coefficient_mu    5.634
_exptl_absorpt_correction_T_max  0.5391
_exptl_absorpt_correction_T_min  0.3910
_exptl_absorpt_correction_type   numerical
_exptl_crystal_colour            yellow
_exptl_crystal_density_diffrn    2.517
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             2552
_exptl_crystal_size_max          0.3
_exptl_crystal_size_mid          0.1
_exptl_crystal_size_min          0.1
_refine_diff_density_max         0.529
_refine_diff_density_min         -0.491
_refine_diff_density_rms         0.081
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.524(6)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.855
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     777
_refine_ls_number_reflns         6572
_refine_ls_number_restraints     334
_refine_ls_restrained_S_all      0.852
_refine_ls_R_factor_all          0.0925
_refine_ls_R_factor_gt           0.0394
_refine_ls_shift/su_max          0.046
_refine_ls_shift/su_mean         0.002
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0546P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0861
_refine_ls_wR_factor_ref         0.1022
_reflns_number_gt                3485
_reflns_number_total             6572
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b417629d.txt
_cod_data_source_block           pna21
_cod_original_cell_volume        3593.6(12)
_cod_original_sg_symbol_H-M      Pna2(1)
_cod_database_code               7008137