Phenylene–2,5-dimethylpyrazine co-oligomers: synthesis by Suzuki couplings, X-ray structures of neutral and diprotonated teraryl species and efficient blue emission
Figen Türksoy; Gregory Hughes; Andrei S. Batsanov; Martin R. Bryce; J. Mater. Chem. 13 (2003) 1554–1557; doi:10.1039/b303472k

data_7204647
_publ_section_title
;
 Phenylene--2,5-dimethylpyrazine co-oligomers: synthesis by Suzuki
 couplings, X-ray structures of neutral and diprotonated teraryl
 species and efficient blue emission
;
_journal_issue                   7
_journal_name_full               'J. Mater. Chem.'
_journal_page_first              1554
_journal_page_last               1557
_journal_paper_doi               10.1039/b303472k
_journal_volume                  13
_journal_year                    2003
_chemical_formula_moiety         'C20 H20 N2 O2'
_chemical_formula_sum            'C20 H20 N2 O2'
_chemical_formula_weight         320.38
_chemical_melting_point          507(2)
_chemical_name_systematic
; 
2,5-bis(2-methoxyphenyl)-3,6-dimethylpyrazine   
;
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2yn'
_symmetry_space_group_name_H-M   'P 1 21/n 1'
_atom_sites_solution_hydrogens   difmap
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 102.53(1)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   8.692(1)
_cell_length_b                   7.562(1)
_cell_length_c                   13.034(3)
_cell_measurement_reflns_used    598
_cell_measurement_temperature    120(2)
_cell_measurement_theta_max      29.76
_cell_measurement_theta_min      10.32
_cell_volume                     836.3(2)
_computing_cell_refinement       'SMART version 5.625 (Bruker, 2001)'
_computing_data_collection       'SMART version 5.625 (Bruker, 2001)'
_computing_data_reduction        'SAINT version 6.02A (Bruker, 2001)'
_computing_molecular_graphics    'SHELXTL version 6.12 (Bruker, 2001)'
_computing_publication_material  'SHELXTL version 6.12 (Bruker, 2001)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      120(2)
_diffrn_detector_area_resol_mean 8
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_device_type  'SMART 6K CCD area detector'
_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  0.0510
_diffrn_reflns_av_sigmaI/netI    0.0322
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       9
_diffrn_reflns_limit_k_min       -9
_diffrn_reflns_limit_l_max       16
_diffrn_reflns_limit_l_min       -16
_diffrn_reflns_number            8427
_diffrn_reflns_theta_full        26.00
_diffrn_reflns_theta_max         26.00
_diffrn_reflns_theta_min         2.58
_diffrn_standards_decay_%        0
_exptl_absorpt_coefficient_mu    0.083
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.272
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    .
_exptl_crystal_description       plate
_exptl_crystal_F_000             340
_exptl_crystal_size_max          0.44
_exptl_crystal_size_mid          0.27
_exptl_crystal_size_min          0.05
_refine_diff_density_max         0.260
_refine_diff_density_min         -0.193
_refine_diff_density_rms         0.048
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.074
_refine_ls_hydrogen_treatment    refall
_refine_ls_matrix_type           full
_refine_ls_number_parameters     149
_refine_ls_number_reflns         1648
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.074
_refine_ls_R_factor_all          0.0604
_refine_ls_R_factor_gt           0.0480
_refine_ls_shift/su_max          0.003
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0917P)^2^+0.0794P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1360
_refine_ls_wR_factor_ref         0.1466
_reflns_number_gt                1276
_reflns_number_total             1648
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            b303472k.txt
_cod_data_source_block           (2)
_cod_depositor_comments
;
The following automatic conversions were performed:
'_symmetry_cell_setting' value 'Monoclinic' changed to 'monoclinic'
according to '/home/adriana/struct/CIF-dictionaries/cif_core.dic'
dictionary named 'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_enum 1555 2011-01-17 13:19:09Z saulius 

The following automatic conversions were performed:

'_chemical_melting_point' value '232--236 C' was changed to '507(2)'
- it was converted from degrees Celsius(C) to Kelvins(K), the average
value was taken and precision was estimated.

Automatic conversion script
Id: cif_fix_values 1569 2011-02-09 13:29:24Z adriana 
;
_cod_original_sg_symbol_H-M      P2(1)/n
_cod_database_code               7204647