data_2008581
_journal_name_full  'Acta Crystallographica'
_journal_year  1999
_journal_volume  C55
_journal_page_first  1034
_journal_page_last  1037
_publ_section_title
;
Dimorphism of 2,3,5,6-tetraphenylpyrazine
;
loop_
_publ_author_name
  'Bartnik, Romuald'
  "Faure, Ren\'e"
  'Gebicki, Krzysztof'
_chemical_formula_moiety  'C28 H20 N2'
_chemical_formula_sum  'C28 H20 N2'
_chemical_formula_structural  'C28 H20 N2'
_chemical_formula_weight  384.48
_symmetry_cell_setting  'Monoclinic'
_symmetry_space_group_name_H-M  'P 21/c'
loop_
_symmetry_equiv_pos_as_xyz
  x,y,z
  -x,1/2+y,1/2-z
  -x,-y,-z
  x,1/2-y,1/2+z
_cell_length_a  15.210(2)
_cell_length_b  5.5390(6)
_cell_length_c  17.192(2)
_cell_angle_alpha  90
_cell_angle_beta  134.450(10)
_cell_angle_gamma  90
_cell_volume  1034.0(3)
_cell_formula_units_Z  2
_cell_measurement_temperature  291
_exptl_crystal_density_diffrn  1.235
_diffrn_ambient_temperature  291
_refine_ls_R_factor_obs  .060
_refine_ls_wR_factor_obs  .137
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_U_iso_or_equiv
_atom_site_thermal_displace_type
_atom_site_occupancy
  N1  .05755(6)  .4290(2)  .10303(6)  .0418(2) Uani 1.000
  C2  .12471(8)  .4901(2)  .08229(7)  .0391(2) Uani 1.000
  C3  -.06561(7)  .4383(2)  .02371(6)  .0403(2) Uani 1.000
  C21  .26004(7)  .4879(2)  .17938(6)  .0396(2) Uani 1.000
  C22  .33647(8)  .6721(3)  .20043(7)  .0456(3) Uani 1.000
  C23  .46106(8)  .6731(3)  .29672(8)  .0539(3) Uani 1.000
  C24  .50959(9)  .4900(3)  .37171(9)  .0544(3) Uani 1.000
  C25  .43460(10)
  .3044(3)  .35096(9)  .0563(3) Uani 1.000
  C26  .31113(8)  .3042(3)  .25631(8)  .0490(3) Uani 1.000
  C31  -.12985(7)  .3855(3)  .05835(6)  .0405(2) Uani 1.000
  C32  -.21683(8)  .5435(3)  .03429(7)  .0448(3) Uani 1.000
  C33  -.26866(9)  .5022(3)  .07444(8)  .0538(3) Uani 1.000
  C34  -.23504(8)  .3018(3)  .13810(7)  .0549(3) Uani 1.000
  C35  -.14907(9)  .1431(3)  .16248(8)  .0540(3) Uani 1.000
  C36  -.09555(8)  .1844(3)  .12353(8)  .0505(3) Uani 1.000
  H22  .303  .798  .149  .0500 Uiso 1.000
  H23  .513  .800  .311  .0500 Uiso 1.000
  H24  .594  .491  .438  .0500 Uiso 1.000
  H25  .468  .177  .402  .0500 Uiso 1.000
  H26  .260  .178  .243  .0500 Uiso 1.000
  H32  -.241  .681  -.010  .0500 Uiso 1.000
  H33  -.328  .612  .058  .0500 Uiso 1.000
  H34  -.272  .273  .165  .0500 Uiso 1.000
  H35  -.126  .006  .206  .0500 Uiso 1.000
  H36  -.035  .076  .142  .0500 Uiso 1.000
loop_
_atom_site_aniso_label
_atom_site_aniso_U_11
_atom_site_aniso_U_22
_atom_site_aniso_U_33
_atom_site_aniso_U_12
_atom_site_aniso_U_13
_atom_site_aniso_U_23
  N1  .0370(2)  .0536(6)  .0338(2)  .0001(3)  .02440(10)
  .0013(3)
  C2  .0378(2)  .0449(6)  .0344(2)  .0008(3)  .02520(10)
  .0008(3)
  C3  .0394(2)  .0469(6)  .0348(2)  .0006(3)  .02610(10)
  .0013(3)
  C21  .0366(2)  .0502(6)  .0326(2)  -.0001(3)  .0244(2)  -.0007(3)
  C22  .0458(3)  .0500(7)  .0372(3)  -.0017(4)  .0277(2)  .0017(3)
  C23  .0441(3)  .0641(9)  .0439(4)  -.0095(4)  .0273(2)  -.0058(4)
  C24  .0376(3)  .0730(10)
  .0407(3)  -.0001(4)  .0230(2)  .0001(4)
  C25  .0456(4)  .0660(9)  .0443(3)  .0073(5)  .0267(2)  .0133(4)
  C26  .0428(3)  .0567(7)  .0443(3)  .0018(4)  .0293(2)  .0070(4)
  C31  .0362(2)  .0524(6)  .0312(2)  -.0044(3)  .02300(10)
  -.0019(3)
  C32  .0453(3)  .0512(6)  .0419(3)  .0003(4)  .0320(2)  .0007(3)
  C33  .0541(3)  .0680(9)  .0507(3)  -.0023(4)  .0408(2)  -.0061(4)
  C34  .0580(3)  .0722(9)  .0484(3)  -.0146(4)  .0423(2)  -.0083(4)
  C35  .0561(3)  .0643(8)  .0426(3)  -.0087(4)  .0348(2)  .0033(4)
  C36  .0483(3)  .0579(8)  .0422(3)  .0018(4)  .0306(2)  .0075(3)
loop_
_geom_bond_atom_site_label_1
_geom_bond_atom_site_label_2
_geom_bond_site_symmetry_1
_geom_bond_site_symmetry_2
_geom_bond_distance
_geom_bond_publ_flag
  N1 C2 . . 1.340(2) no
  N1 C3 . . 1.3390(10)
  no
  C2 C21 . . 1.4870(10)
  no
  C2 C3 . 3_565 1.4120(10)
  no
  C3 C31 . . 1.487(2) no
  C21 C22 . . 1.391(2) no
  C21 C26 . . 1.396(2) no
  C22 C23 . . 1.3920(10)
  no
  C23 C24 . . 1.380(2) no
  C24 C25 . . 1.384(2) no
  C25 C26 . . 1.3770(10)
  no
  C31 C32 . . 1.386(2) no
  C31 C36 . . 1.396(2) no
  C32 C33 . . 1.383(2) no
  C33 C34 . . 1.381(2) no
  C34 C35 . . 1.375(2) no
  C35 C36 . . 1.388(2) no
  C22 H22 . .  .95 no
  C23 H23 . .  .95 no
  C24 H24 . .  .95 no
  C25 H25 . .  .95 no
  C26 H26 . .  .95 no
  C32 H32 . .  .95 no
  C33 H33 . .  .95 no
  C34 H34 . .  .95 no
  C35 H35 . .  .95 no
  C36 H36 . .  .95 no