Synthesis and structures of tris(2-pyridyl)aluminate sandwich compounds [{RAl(2-py')2}2M] (py' = 2-pyridyl, M = Ca, Mn, Fe).
García-Rodríguez, Raúl; Bullock, Thomas H.; McPartlin, Mary; Wright, Dominic S.; Dalton transactions (Cambridge, England : 2003) 43 (2014) 14045–14053; doi:10.1039/c4dt00951g

data_7032437
_publ_section_title
;
 Synthesis and structures of tris(2-pyridyl)aluminate sandwich compounds
 [{RAl(2-py')2}2M] (py' = 2-pyridyl, M = Ca, Mn, Fe).
;
_journal_issue                   37
_journal_name_full
'Dalton transactions (Cambridge, England : 2003)'
_journal_page_first              14045
_journal_page_last               14053
_journal_paper_doi               10.1039/c4dt00951g
_journal_volume                  43
_journal_year                    2014
_chemical_absolute_configuration
;
 The absolute structure was NOT determined. 1850 Friedel pairs were
 averaged for the refinement.  Without Friedel averaging, the Flack
 parameter is ambiguous (ca 0.45) and attempts to refine as a twin
 did not improve matters.  Not too surprising, considering the problems
 of poor data and disorder (see _refine_special_details).
;
_chemical_formula_moiety         'C40 H46 Al2 Cl Li Mn N6'
_chemical_formula_sum            'C40 H46 Al2 Cl Li Mn N6'
_chemical_formula_weight         762.12
_chemical_name_systematic
; 
 ? 
;
_space_group_IT_number           144
_symmetry_cell_setting           trigonal
_symmetry_space_group_name_Hall  'P 31'
_symmetry_space_group_name_H-M   'P 31'
_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                120.00
_cell_formula_units_Z            3
_cell_length_a                   12.457(2)
_cell_length_b                   12.457(2)
_cell_length_c                   22.235(4)
_cell_measurement_reflns_used    138880
_cell_measurement_temperature    180(2)
_cell_measurement_theta_max      25.35
_cell_measurement_theta_min      1.02
_cell_volume                     2988.1(9)
_computing_cell_refinement       'HKL Scalepack (Otwinowski & Minor 1997)'
_computing_data_collection       'Collect (Nonius B.V. 1998)'
_computing_data_reduction
;
 HKL Denzo and Scalepack (Otwinowski & Minor 1997)
;
_computing_publication_material  'SHELXL-97 (Sheldrick 1997)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick 1997)'
_computing_structure_solution    'SIR-92 (Altomare et al. 1994)'
_diffrn_ambient_temperature      180(2)
_diffrn_measured_fraction_theta_full 0.954
_diffrn_measured_fraction_theta_max 0.954
_diffrn_measurement_device_type  'Nonius Kappa CCD'
_diffrn_measurement_method       'Thin slice \w and \f scans'
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0738
_diffrn_reflns_av_sigmaI/netI    0.1357
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -14
_diffrn_reflns_limit_k_max       14
_diffrn_reflns_limit_k_min       -13
_diffrn_reflns_limit_l_max       24
_diffrn_reflns_limit_l_min       -26
_diffrn_reflns_number            10346
_diffrn_reflns_theta_full        25.37
_diffrn_reflns_theta_max         25.37
_diffrn_reflns_theta_min         3.75
_exptl_absorpt_coefficient_mu    0.478
_exptl_absorpt_correction_T_max  0.984
_exptl_absorpt_correction_T_min  0.888
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
multi-scan from symmetry-related measurements 
 Sortav (Blessing 1995)
;
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.271
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             1197
_exptl_crystal_size_max          0.12
_exptl_crystal_size_mid          0.10
_exptl_crystal_size_min          0.05
_refine_diff_density_max         0.507
_refine_diff_density_min         -0.411
_refine_diff_density_rms         0.060
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.13(4)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.979
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     192
_refine_ls_number_reflns         3476
_refine_ls_number_restraints     4
_refine_ls_restrained_S_all      0.978
_refine_ls_R_factor_all          0.1446
_refine_ls_R_factor_gt           0.0653
_refine_ls_shift/su_max          0.022
_refine_ls_shift/su_mean         0.001
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0800P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1468
_refine_ls_wR_factor_ref         0.1655
_reflns_number_gt                1825
_reflns_number_total             3476
_reflns_threshold_expression     >2sigma(I)
_cod_duplicate_entry             7031966
_cod_data_source_file            c4dt00951g2.cif
_cod_data_source_block           dw1443
_cod_original_sg_symbol_H-M      P3(1)
_cod_database_code               7032437