Strong through-space two-halide magnetic exchange of −234 K in (2,5-dimethylpyrazine)copper(ii) bromide
Butcher, Robert T.; Novoa, Juan J.; Ribas-Ariño, Jordi; Sandvik, Anders W.; Turnbull, Mark M.; Landee, Christopher P.; Wells, Brian M.; Awwadi, Firas F.; Chemical Communications  (2009) 1359–1361; doi:10.1039/b819894b

data_7111529
_publ_section_title
;
 Strong through-space two-halide magnetic exchange of &#x2212;234 K in
 (2,5-dimethylpyrazine)copper(ii) bromide
;
_journal_issue                   11
_journal_name_full               'Chemical Communications'
_journal_page_first              1359
_journal_page_last               1361
_journal_paper_doi               10.1039/b819894b
_journal_year                    2009
_chemical_formula_sum            'C6 H8 Br2 Cu N2'
_chemical_formula_weight         331.50
_chemical_name_common            'Dibromo(2,5-dimethylpyrazino)copper (ii)'
_chemical_name_systematic
;
Dibromo(2,5-dimethylpyrazino)copper (II)
;
_space_group_IT_number           12
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-C 2y'
_symmetry_space_group_name_H-M   'C 1 2/m 1'
_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                 109.428(8)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   9.0555(11)
_cell_length_b                   8.3909(10)
_cell_length_c                   6.6969(8)
_cell_measurement_temperature    295(2)
_cell_volume                     479.88(10)
_computing_cell_refinement       'Bruker XSCANS'
_computing_data_collection       'Bruker XSCANS'
_computing_data_reduction        'Bruker SHELXTL'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      295(2)
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_diffrn_measurement_device_type  'Bruker P4'
_diffrn_measurement_method       '\w 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  0.0324
_diffrn_reflns_av_sigmaI/netI    0.0331
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -1
_diffrn_reflns_limit_k_max       1
_diffrn_reflns_limit_k_min       -9
_diffrn_reflns_limit_l_max       7
_diffrn_reflns_limit_l_min       -7
_diffrn_reflns_number            616
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         25.00
_diffrn_reflns_theta_min         3.23
_diffrn_standards_interval_count 97
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    10.541
_exptl_absorpt_correction_T_max  0.9055
_exptl_absorpt_correction_T_min  0.5442
_exptl_absorpt_correction_type   empirical
_exptl_absorpt_process_details   'via psi-scans'
_exptl_crystal_colour            brown
_exptl_crystal_density_diffrn    2.294
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       rod
_exptl_crystal_F_000             314
_exptl_crystal_size_max          .35
_exptl_crystal_size_mid          .1
_exptl_crystal_size_min          .1
_refine_diff_density_max         0.376
_refine_diff_density_min         -0.459
_refine_diff_density_rms         0.097
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.079
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     34
_refine_ls_number_reflns         451
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.079
_refine_ls_R_factor_all          0.0325
_refine_ls_R_factor_gt           0.0261
_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^)+(0.0347P)^2^+0.0447P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0632
_refine_ls_wR_factor_ref         0.0663
_reflns_number_gt                391
_reflns_number_total             451
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b819894bsup1.cif
_cod_data_source_block           3
_cod_original_sg_symbol_H-M      C2/m
_cod_database_code               7111529