Evidence for the Cyclic CN2 Carbene in Solution.
Hanzlová, Eva; Navrátil, Rafael; Cejka, Jan; Böhm, Stanislav; Martin°u, Tomáš; Organic letters 16 (2014) 852–855; doi:10.1021/ol4036243

data_1513496
_publ_section_title
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 Evidence for the Cyclic CN2 Carbene in Solution.
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_journal_issue                   3
_journal_name_full               'Organic letters'
_journal_page_first              852
_journal_page_last               855
_journal_paper_doi               10.1021/ol4036243
_journal_volume                  16
_journal_year                    2014
_chemical_formula_moiety         'C9 H8 Br1 N3 O1'
_chemical_formula_sum            'C9 H8 Br N3 O'
_chemical_formula_weight         254.09
_space_group_IT_number           15
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-C 2yc'
_symmetry_space_group_name_H-M   'C 1 2/c 1'
_atom_sites_solution_hydrogens   difmap
_atom_sites_solution_primary     direct
_cell_angle_alpha                90
_cell_angle_beta                 108.1180(13)
_cell_angle_gamma                90
_cell_formula_units_Z            16
_cell_length_a                   17.9017(2)
_cell_length_b                   12.61697(13)
_cell_length_c                   19.0856(2)
_cell_measurement_reflns_used    11780
_cell_measurement_temperature    180
_cell_measurement_theta_max      77
_cell_measurement_theta_min      4
_cell_volume                     4097.04(8)
_computing_cell_refinement       'CrysAlis, (Oxford Diffraction, 2002)'
_computing_data_collection       'Xcalibur, (Oxford Diffraction, 2002)'
_computing_data_reduction        'CrysAlis, (Oxford Diffraction, 2002)'
_computing_molecular_graphics    'CAMERON (Watkin et al., 1996)'
_computing_publication_material  'CRYSTALS (Betteridge et al., 2003)'
_computing_structure_refinement  'CRYSTALS (Betteridge et al., 2003)'
_computing_structure_solution    'SIR92 (Altomare et al., 1994)'
_diffrn_ambient_temperature      180
_diffrn_measured_fraction_theta_full 0.997
_diffrn_measured_fraction_theta_max 0.979
_diffrn_measurement_device       Area
_diffrn_measurement_device_type  'Oxford Diffraction XCALIBUR'
_diffrn_measurement_method       \w
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_type           'Cu K\a'
_diffrn_radiation_wavelength     1.54184
_diffrn_reflns_av_R_equivalents  0.022
_diffrn_reflns_limit_h_max       22
_diffrn_reflns_limit_h_min       -21
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -15
_diffrn_reflns_limit_l_max       14
_diffrn_reflns_limit_l_min       -23
_diffrn_reflns_number            14642
_diffrn_reflns_theta_full        70.946
_diffrn_reflns_theta_max         77.115
_diffrn_reflns_theta_min         4.363
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    5.248
_exptl_absorpt_correction_T_max  0.73
_exptl_absorpt_correction_T_min  0.11
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'CrysAlis, (Oxford Diffraction, 2002)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.648
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       needle
_exptl_crystal_F_000             2016
_exptl_crystal_size_max          0.600
_exptl_crystal_size_mid          0.230
_exptl_crystal_size_min          0.060
_refine_diff_density_max         0.40
_refine_diff_density_min         -0.38
_refine_ls_extinction_coef       51(2)
_refine_ls_extinction_method     'Larson (1970), Equation 22'
_refine_ls_goodness_of_fit_ref   0.9989
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     372
_refine_ls_number_reflns         4237
_refine_ls_number_restraints     115
_refine_ls_R_factor_all          0.0305
_refine_ls_R_factor_gt           0.0284
_refine_ls_shift/su_max          0.0003360
_refine_ls_shift/su_mean         0.0000387
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
;
 Method, part 1, Chebychev polynomial, (Watkin, 1994, Prince, 1982) 
 [weight] = 1.0/[A~0~*T~0~(x)+A~1~*T~1~(x) ... +A~n-1~]*T~n-1~(x)] 
 where A~i~ are the Chebychev coefficients listed below and x= Fcalc/Fmax 
 Method = Robust Weighting (Prince, 1982) 
 W = [weight] * [1-(deltaF/6*sigmaF)^2^]^2^ 
 A~i~ are: 
 0.246E+04 0.417E+04 0.270E+04 0.123E+04 318. 
;
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_all         0.0805
_refine_ls_wR_factor_gt          0.0787
_refine_ls_wR_factor_ref         0.0805
_reflns_limit_h_max              21
_reflns_limit_h_min              -22
_reflns_limit_k_max              15
_reflns_limit_k_min              0
_reflns_limit_l_max              23
_reflns_limit_l_min              0
_reflns_number_gt                3947
_reflns_number_total             4237
_reflns_threshold_expression     I>2.0\s(I)
_oxford_diffrn_Wilson_B_factor   3.58
_oxford_diffrn_Wilson_scale      0.17
_oxford_refine_ls_r_factor_ref   0.0305
_oxford_refine_ls_scale          2.68(3)
_oxford_reflns_number_all        4237
_oxford_reflns_threshold_expression_ref I>-10.0\s(I)
_cod_data_source_file            ol4036243_si_002.cif
_cod_data_source_block           1
_cod_original_cell_volume        4097.04(9)
_cod_original_sg_symbol_H-M      'C 1 2/c 1 '
_cod_original_formula_sum        'C9 H8 Br1 N3 O1'
_cod_database_code               1513496
_iucr_refine_instruction_details_constraints
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BLOCK 
CONT SCALE 
CONT C    (    3 ,X'S,U'S)  UNTIL BR   (  241 ) 
CONT H    (   71 ,X'S,U[ISO])  UNTIL H    (  341 ) 
CONT EXTPARAM 
END                                                                             
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_iucr_refine_instruction_details_restraints
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NO 
REM   HREST   START (DO NOT REMOVE THIS LINE) 
REM   HREST   END (DO NOT REMOVE THIS LINE) 
REM   SHIFTLIMIT   START (DO NOT REMOVE THIS LINE) 
REM   SHIFTLIMIT   END (DO NOT REMOVE THIS LINE) 
DELU 0.010000 C(3) PART(0001) PART(0002) 
DELU 0.010000 C(23) PART(0003) PART(0004) 
SIMU 0.010000 C(3) PART(0001) PART(0002) 
SIMU 0.010000 C(23) PART(0003) PART(0004) 
DISTANCE 1.460000 , 0.010000 = C(3) TO N(21) 
DISTANCE 1.460000 , 0.010000 = C(23) TO N(221) 
DISTANCE 1.460000 , 0.010000 = C(23) TO N(210) 
END

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