Secondary diphosphine and diphosphido ligands: synthesis, characterisation and group 1 coordination compounds.
Ritch, Jamie S.; Julienne, Delphine; Rybchinski, Shayne R.; Brockman, Kathryne S.; Johnson, Kevin R. D.; Hayes, Paul G.; Dalton transactions (Cambridge, England : 2003) 43 (2014) 267–276; doi:10.1039/c3dt51844b

data_7029229
_publ_section_title
;
 Secondary diphosphine and diphosphido ligands: synthesis,
 characterisation and group 1 coordination compounds.
;
_journal_issue                   1
_journal_name_full
'Dalton transactions (Cambridge, England : 2003)'
_journal_page_first              267
_journal_page_last               276
_journal_paper_doi               10.1039/c3dt51844b
_journal_volume                  43
_journal_year                    2014
_chemical_formula_moiety         'C16 H28 P2 Se2, 2(C5H12)'
_chemical_formula_sum            'C26 H52 P2 Se2'
_chemical_formula_weight         584.5643
_chemical_name_systematic
; 
 ? 
;
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2ybc'
_symmetry_space_group_name_H-M   'P 1 21/c 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                 90.930(6)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   9.2514(7)
_cell_length_b                   21.7558(18)
_cell_length_c                   12.7311(11)
_cell_measurement_reflns_used    7061
_cell_measurement_temperature    173(2)
_cell_measurement_theta_max      23.53
_cell_measurement_theta_min      2.40
_cell_volume                     2562.1(4)
_computing_cell_refinement       'Bruker SMART'
_computing_data_collection       'Bruker SMART'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      173(2)
_diffrn_measured_fraction_theta_full 0.983
_diffrn_measured_fraction_theta_max 0.983
_diffrn_measurement_device_type  'CCD area detector'
_diffrn_measurement_method       'phi and omega scans'
_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  0.0561
_diffrn_reflns_av_sigmaI/netI    0.0573
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       24
_diffrn_reflns_limit_k_min       -18
_diffrn_reflns_limit_l_max       15
_diffrn_reflns_limit_l_min       -12
_diffrn_reflns_number            29577
_diffrn_reflns_theta_full        25.03
_diffrn_reflns_theta_max         25.03
_diffrn_reflns_theta_min         2.86
_exptl_absorpt_coefficient_mu    3.004
_exptl_absorpt_correction_T_max  0.8333
_exptl_absorpt_correction_T_min  0.4144
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
'Blessing, R. H. (1995) Acta Cryst. A51, 33-38'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.515
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       rod
_exptl_crystal_F_000             1224
_exptl_crystal_size_max          0.36
_exptl_crystal_size_mid          0.16
_exptl_crystal_size_min          0.06
_platon_squeeze_details
;
The unit cell of the diselenide contained heavily disordered
solvent molecules (either of isoelectronic pentane or diethyl
ether) for which no suitable model could be found. The electron
density associated with these molecules was removed from the
reflection data using the program SQUEEZE (PLATON).  After this
treatment, two voids of ca. 411 A3 remained in the unit cell, each
originally containing 155 electrons and corresponding to ca.
two solvent molecules.

Accordingly, two solvent molecule (arbitrarily selected to be
pentane) are included in _chemical_formula_moiety (and _sum), and
calculations of Mr, density, and F(OOO) to more accurately reflect
the unit cell properties.
;
_refine_diff_density_max         0.647
_refine_diff_density_min         -0.366
_refine_diff_density_rms         0.076
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.006
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     195
_refine_ls_number_reflns         4432
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.006
_refine_ls_R_factor_all          0.0598
_refine_ls_R_factor_gt           0.0378
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0446P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0834
_refine_ls_wR_factor_ref         0.0886
_reflns_number_gt                3159
_reflns_number_total             4432
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c3dt51844b.txt
_cod_data_source_block           rac-4
_cod_depositor_comments
;
The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Monoclinic' changed to 'monoclinic'
according to
/usr/data/users/saulius/automatic-downloads/current/RSC/lib/dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.2 from 2011-04-26.

Automatic conversion script
Id: cif_fix_values 2281 2013-09-26 08:29:07Z andrius 
;
_cod_original_sg_symbol_H-M      P2(1)/c
_cod_database_code               7029229