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_2016656
_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          'C25 H25 O4 P'
_chemical_formula_moiety         'C25 H25 O4 P'
_chemical_formula_sum            'C25 H25 O4 P'
_chemical_formula_weight         420.42
_chemical_name_systematic
;
methyl isopropyl 2-(triphenylphosphoranyliden)malonate
;
_space_group_IT_number           2
_symmetry_cell_setting           triclinic
_symmetry_space_group_name_Hall  '-P 1'
_symmetry_space_group_name_H-M   'P -1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL97
_cell_angle_alpha                100.573(2)
_cell_angle_beta                 94.878(2)
_cell_angle_gamma                102.446(3)
_cell_formula_units_Z            2
_cell_length_a                   9.8033(6)
_cell_length_b                   10.4492(7)
_cell_length_c                   11.2169(7)
_cell_measurement_reflns_used    1718
_cell_measurement_temperature    273(2)
_cell_measurement_theta_max      21.88
_cell_measurement_theta_min      2.46
_cell_volume                     1093.64(12)
_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      273(2)
_diffrn_measured_fraction_theta_full 0.993
_diffrn_measured_fraction_theta_max 0.904
_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  0.0249
_diffrn_reflns_av_sigmaI/netI    0.0480
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       13
_diffrn_reflns_limit_k_min       -13
_diffrn_reflns_limit_l_max       14
_diffrn_reflns_limit_l_min       -14
_diffrn_reflns_number            9176
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         27.76
_diffrn_reflns_theta_min         1.86
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.154
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.277
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             444
_exptl_crystal_size_max          0.20
_exptl_crystal_size_mid          0.17
_exptl_crystal_size_min          0.14
_refine_diff_density_max         0.273
_refine_diff_density_min         -0.169
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.014
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     282
_refine_ls_number_reflns         4675
_refine_ls_number_restraints     2
_refine_ls_restrained_S_all      1.014
_refine_ls_R_factor_all          0.0820
_refine_ls_R_factor_gt           0.0523
_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^)+(0.0646P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1181
_refine_ls_wR_factor_ref         0.1338
_reflns_number_gt                3133
_reflns_number_total             4675
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            av3152.cif
_cod_data_source_block           Ia
_cod_database_code               2016656
_cod_database_fobs_code          2016656