Cp2Zr(η2-benzocyclobutadiene)(PMe3), a Rare η2-Cyclobutadiene Complex
Ramakrishna, T. V. V.; Lushnikova, Svetlana; Sharp, Paul R.; Organometallics 21 (2002) 5685–; doi:10.1021/om020829h

data_4077172
_publ_section_title
;
 Cp2Zr(\h2-benzocyclobutadiene)(PMe3), a Rare \h2-Cyclobutadiene Complex
;
_journal_issue                   26
_journal_name_full               Organometallics
_journal_page_first              5685
_journal_paper_doi               10.1021/om020829h
_journal_volume                  21
_journal_year                    2002
_chemical_formula_sum            'C28 H34 N2 Zr'
_chemical_formula_weight         489.79
_chemical_name_systematic
;
  ?
;
_space_group_IT_number           19
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2ac 2ab'
_symmetry_space_group_name_H-M   'P 21 21 21'
_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                90.00
_cell_formula_units_Z            12
_cell_length_a                   8.8770(13)
_cell_length_b                   27.103(4)
_cell_length_c                   30.421(4)
_cell_measurement_temperature    173(2)
_cell_volume                     7319.1(18)
_computing_cell_refinement       'SMART (Bruker, 1998)'
_computing_data_collection       'SMART (Bruker, 1998)'
_computing_data_reduction        'SAINT (Bruker, 1998)'
_computing_molecular_graphics
;
  L. J. Barbour, X-Seed - Graphical Interface to
  SHELX-97 and POV-Ray, 1999
  ORTEP (Johnson, 1976), ORTEP 3 for Windows (L. J. Farrugia, 1997)
;
_computing_publication_material  'CIFTAB (Sheldrick, 1997)'
_computing_structure_refinement
;
  SHELXL-97 (Sheldrick, 1997), L. J. Barbour, X-Seed - Graphical Interface to
  SHELX-97 and POV-Ray, 1999
;
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      173(2)
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_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  0.0488
_diffrn_reflns_av_sigmaI/netI    0.0802
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       34
_diffrn_reflns_limit_k_min       -33
_diffrn_reflns_limit_l_max       38
_diffrn_reflns_limit_l_min       -31
_diffrn_reflns_number            46222
_diffrn_reflns_theta_full        27.11
_diffrn_reflns_theta_max         27.11
_diffrn_reflns_theta_min         1.01
_exptl_absorpt_coefficient_mu    0.468
_exptl_absorpt_correction_T_max  0.9547
_exptl_absorpt_correction_T_min  0.8171
_exptl_absorpt_correction_type   multi-scan
_exptl_crystal_colour            yellow
_exptl_crystal_density_diffrn    1.334
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plate
_exptl_crystal_F_000             3072
_exptl_crystal_size_max          0.45
_exptl_crystal_size_mid          0.20
_exptl_crystal_size_min          0.10
_refine_diff_density_max         2.773
_refine_diff_density_min         -5.274
_refine_diff_density_rms         0.309
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -0.01(8)
_refine_ls_extinction_coef       0.0137(10)
_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_ref   1.053
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     857
_refine_ls_number_reflns         16132
_refine_ls_number_restraints     18
_refine_ls_restrained_S_all      1.053
_refine_ls_R_factor_all          0.1456
_refine_ls_R_factor_gt           0.1007
_refine_ls_shift/su_max          0.029
_refine_ls_shift/su_mean         0.001
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.2000P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.2563
_refine_ls_wR_factor_ref         0.3004
_reflns_number_gt                10369
_reflns_number_total             16132
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            om020829h.cif
_cod_data_source_block           Compound_7
_cod_original_cell_volume        7318.9(18)
_cod_original_sg_symbol_H-M      P2(1)2(1)2(1)
_cod_database_code               4077172