Molecular Structures, Vibrational Spectroscopy, and Normal-Mode Analysis of M2(C\τbCR)4(PMe3)4 Dimetallatetraynes. Observation of Strongly Mixed Metal-Metal and Metal-Ligand Vibrational Modes
Kevin D. John; Vincent M. Miskowski; Michael A. Vance; Richard F. Dallinger; Louis C. Wang; Steven J. Geib; Michael D. Hopkins; Inorganic Chemistry 37 (1998) 6858–6873; doi:10.1021/ic980866u

data_4323260
_publ_section_title
;
 Molecular Structures, Vibrational Spectroscopy, and Normal-Mode Analysis
 of M2(C\\tbCR)4(PMe3)4 Dimetallatetraynes. Observation of Strongly Mixed
 Metal-Metal and Metal-Ligand Vibrational Modes
;
_journal_name_full               'Inorganic Chemistry'
_journal_page_first              6858
_journal_page_last               6873
_journal_paper_doi               10.1021/ic980866u
_journal_volume                  37
_journal_year                    1998
_chemical_formula_sum            'C32 H72 Mo2 P4 Si4'
_chemical_formula_weight         885.02
_chemical_name_systematic
; 
 ? 
;
_space_group_IT_number           62
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  '-P 2ac 2n'
_symmetry_space_group_name_H-M   'P n m a'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   19.550(5)
_cell_length_b                   18.346(5)
_cell_length_c                   14.473(3)
_cell_measurement_reflns_used    25
_cell_measurement_temperature    208(2)
_cell_measurement_theta_max      12.5
_cell_measurement_theta_min      10
_cell_volume                     5191(2)
_computing_data_collection       'Siemens P3/PC'
_computing_structure_refinement  'SHELXL-93 (Sheldrick, 1993)'
_computing_structure_solution    'SHELXS-86 (Sheldrick, 1990)'
_diffrn_ambient_temperature      208(2)
_diffrn_measurement_device       'Siemens P3'
_diffrn_measurement_method       '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  0.0000
_diffrn_reflns_av_sigmaI/netI    0.0481
_diffrn_reflns_limit_h_max       22
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       0
_diffrn_reflns_limit_k_min       -20
_diffrn_reflns_limit_l_max       16
_diffrn_reflns_limit_l_min       0
_diffrn_reflns_number            4217
_diffrn_reflns_theta_max         24.00
_diffrn_reflns_theta_min         1.75
_diffrn_standards_decay_%        <1%
_diffrn_standards_interval_count 200
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    0.716
_exptl_absorpt_correction_type   psi-scan
_exptl_crystal_colour            'azure blue'
_exptl_crystal_density_diffrn    1.132
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    N/A
_exptl_crystal_F_000             1856
_exptl_crystal_size_max          0.46
_exptl_crystal_size_mid          0.39
_exptl_crystal_size_min          0.21
_refine_diff_density_max         0.658
_refine_diff_density_min         -0.292
_refine_diff_density_rms         0.060
_refine_ls_extinction_coef       0.00000(6)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_all   1.011
_refine_ls_goodness_of_fit_obs   1.046
_refine_ls_matrix_type           full
_refine_ls_number_parameters     231
_refine_ls_number_reflns         4215
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.131
_refine_ls_restrained_S_obs      1.046
_refine_ls_R_factor_all          0.0774
_refine_ls_R_factor_obs          0.0444
_refine_ls_shift/esd_max         -4.924
_refine_ls_shift/esd_mean        0.022
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0448P)^2^+2.8903P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_all         0.1187
_refine_ls_wR_factor_obs         0.0913
_reflns_number_observed          2975
_reflns_number_total             4217
_reflns_observed_criterion       >2sigma(I)
_cod_data_source_file            ic980866u_3.cif
_cod_data_source_block           Mo2(CCSiMe3)4(PMe3)4
_cod_depositor_comments
;
The following automatic conversions were performed:

'_exptl_crystal_density_meas' value 'N/A' was changed to '?' - the
value is perceived as not measured.

Automatic conversion script
Id: cif_fix_values 3008 2015-01-20 13:52:24Z robertas 

The following automatic conversions were performed:

'_refine_ls_weighting_scheme' value 'calc
w=1/[\s^2^(Fo^2^)+(0.0448P)^2^+2.8903P] where P=(Fo^2^+2Fc^2^)/3' was
changed to 'calc'. New tag '_refine_ls_weighting_details' was
created. The value of the new tag was set to
'w=1/[\s^2^(Fo^2^)+(0.0448P)^2^+2.8903P] where P=(Fo^2^+2Fc^2^)/3'.

Automatic conversion script
Id: cif_fix_values 3143 2015-03-26 13:38:13Z robertas 
;
_cod_original_cell_volume        5191.0(23)
_cod_database_code               4323260