Favoured conformations of methyl isopropyl, ethyl isopropyl, methyl <i>tert</i>-butyl, and ethyl <i>tert</i>-butyl 2-(triphenylphosphoranylidene)malonate
Castañeda, Fernando; Silva, Paul; Bunton, Clifford A.; Garland, María Teresa; Baggio, Ricardo; Acta Crystallographica Section C 64 (2008) o405–o410; doi:10.1107/S0108270108018246

data_2016657
_publ_section_title
;
 Favoured conformations of methyl isopropyl, ethyl isopropyl, methyl
 <i>tert</i>-butyl, and ethyl <i>tert</i>-butyl
 2-(triphenylphosphoranylidene)malonate
;
_journal_coeditor_code           AV3152
_journal_issue                   7
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              o405
_journal_page_last               o410
_journal_paper_doi               10.1107/S0108270108018246
_journal_volume                  64
_journal_year                    2008
_chemical_formula_iupac          'C26 H27 O4 P'
_chemical_formula_moiety         'C26 H27 O4 P'
_chemical_formula_sum            'C26 H27 O4 P'
_chemical_formula_weight         434.45
_chemical_name_systematic
;
ethyl isopropyl 2-(triphenylphosphoranyliden)malonate
;
_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           SHELXL97
_cell_angle_alpha                90.00
_cell_angle_beta                 96.342(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   12.5175(16)
_cell_length_b                   9.1555(12)
_cell_length_c                   20.351(3)
_cell_measurement_reflns_used    1773
_cell_measurement_temperature    140(5)
_cell_measurement_theta_max      18.82
_cell_measurement_theta_min      2.43
_cell_volume                     2318.0(5)
_computing_cell_refinement       'SAINT-NT (Bruker, 2001)'
_computing_data_collection       'SMART-NT (Bruker, 2001)'
_computing_data_reduction        'SAINT-NT (Bruker, 2001)'
_computing_molecular_graphics    'SHELXTL-NT (Sheldrick, 2008)'
_computing_publication_material
;
SHELXTL-NT (Sheldrick, 2008) and PLATON (Spek, 2003)
;
_computing_structure_refinement  'SHELXL97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      140(5)
_diffrn_measured_fraction_theta_full 1.00
_diffrn_measured_fraction_theta_max 0.931
_diffrn_measurement_device_type  'Bruker SMART CCD area-detector'
_diffrn_measurement_method       '\f and \w'
_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  0.0532
_diffrn_reflns_av_sigmaI/netI    0.0773
_diffrn_reflns_limit_h_max       16
_diffrn_reflns_limit_h_min       -16
_diffrn_reflns_limit_k_max       11
_diffrn_reflns_limit_k_min       -12
_diffrn_reflns_limit_l_max       26
_diffrn_reflns_limit_l_min       -26
_diffrn_reflns_number            19001
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         28.08
_diffrn_reflns_theta_min         2.01
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.148
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.245
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             920
_exptl_crystal_size_max          0.18
_exptl_crystal_size_mid          0.16
_exptl_crystal_size_min          0.16
_refine_diff_density_max         0.332
_refine_diff_density_min         -0.274
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.856
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     300
_refine_ls_number_reflns         5252
_refine_ls_number_restraints     7
_refine_ls_restrained_S_all      0.862
_refine_ls_R_factor_all          0.1048
_refine_ls_R_factor_gt           0.0565
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w = 1/[\s^2^(Fo^2^)+(0.0649P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1255
_refine_ls_wR_factor_ref         0.1396
_reflns_number_gt                2713
_reflns_number_total             5252
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            av3152.cif
_cod_data_source_block           Ib
_cod_original_sg_symbol_H-M      'P 21/c '
_cod_database_code               2016657
_cod_database_fobs_code          2016657