Effects of alkyl chain length and anion size on thermal and structural properties for 1-alkyl-3-methylimidazolium hexafluorocomplex salts (C(x)MImAF(6), x = 14, 16 and 18; A = P, As, Sb, Nb and Ta).
Xu, Fei; Matsumoto, Kazuhiko; Hagiwara, Rika; Dalton transactions (Cambridge, England : 2003) 41 (2012) 3494–3502; doi:10.1039/c2dt11693f

data_7018302
_publ_section_title
;
 Effects of alkyl chain length and anion size on thermal and structural
 properties for 1-alkyl-3-methylimidazolium hexafluorocomplex salts
 (C(x)MImAF(6), x = 14, 16 and 18; A = P, As, Sb, Nb and Ta).
;
_journal_issue                   12
_journal_name_full
'Dalton transactions (Cambridge, England : 2003)'
_journal_page_first              3494
_journal_page_last               3502
_journal_paper_doi               10.1039/c2dt11693f
_journal_volume                  41
_journal_year                    2012
_chemical_formula_moiety
;
(C22 N2 H43 +), (As F6 -)
;
_chemical_formula_sum            'C22 H43 As F6 N2'
_chemical_formula_weight         524.50
_chemical_melting_point          351.1
_chemical_name_common            C18MImAsF6
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2yab'
_symmetry_space_group_name_H-M   'P 1 21/a 1'
_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                 94.400(3)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   9.5645(13)
_cell_length_b                   9.8620(15)
_cell_length_c                   28.969(4)
_cell_measurement_reflns_used    7481
_cell_measurement_temperature    298
_cell_measurement_theta_max      54.90
_cell_measurement_theta_min      6.03
_cell_volume                     2724.5(7)
_computing_cell_refinement       'RAPID AUTO 2.40 (Rigaku 2006)'
_computing_data_collection       'Rigaku R-AXIS Rapid-II'
_computing_data_reduction        'RAPID AUTO 2.40 (Rigaku 2006)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SIR92 (Altmare et al., 1994)'
_diffrn_ambient_temperature      298
_diffrn_measured_fraction_theta_full 0.996
_diffrn_measured_fraction_theta_max 0.996
_diffrn_measurement_device_type  'Rigaku R-AXIS RapidII'
_diffrn_measurement_method       'imaging plate'
_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  0.0546
_diffrn_reflns_av_sigmaI/netI    0.0761
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       11
_diffrn_reflns_limit_k_min       -11
_diffrn_reflns_limit_l_max       34
_diffrn_reflns_limit_l_min       -34
_diffrn_reflns_number            20574
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         25.00
_diffrn_reflns_theta_min         3.02
_exptl_absorpt_coefficient_mu    1.299
_exptl_absorpt_correction_T_max  1.0000
_exptl_absorpt_correction_T_min  0.4746
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'RAPID AUTO 2.40 (Rigaku 2006)'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.279
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       platelet
_exptl_crystal_F_000             1104
_exptl_crystal_size_max          0.70
_exptl_crystal_size_mid          0.20
_exptl_crystal_size_min          0.05
_refine_diff_density_max         0.867
_refine_diff_density_min         -0.670
_refine_diff_density_rms         0.087
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.080
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     301
_refine_ls_number_reflns         4779
_refine_ls_number_restraints     99
_refine_ls_restrained_S_all      1.269
_refine_ls_R_factor_all          0.1466
_refine_ls_R_factor_gt           0.0886
_refine_ls_shift/su_max          0.007
_refine_ls_shift/su_mean         0.001
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.2000P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.2720
_refine_ls_wR_factor_ref         0.3324
_reflns_number_gt                2370
_reflns_number_total             4779
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c2dt11693f.txt
_cod_data_source_block           C18MImAsF6-25oC
_cod_original_sg_symbol_H-M      P21/a
_cod_database_code               7018302