data_2011968
_journal_name_full  'Acta Crystallographica, Section C'
_journal_year  2001
_journal_volume  57
_journal_page_first  621
_journal_page_last  624
_publ_section_title
;
Linear hydrogen-bonded molecular tapes in the co-crystals of squaric
acid with 4,4'-dipyridylacetylene or 1,2-bis(4-pyridyl)ethylene
;
loop_
_publ_author_name
  'Zaman, Md. Badruz'
  'Tomura, Masaaki'
  'Yamashita, Yoshiro'
_chemical_formula_moiety  'C12 H10 N2 2+ , 2C4 H O4 -'
_chemical_formula_sum  'C20 H12 N2 O8'
_chemical_formula_weight  408.32
_symmetry_cell_setting  triclinic
_symmetry_space_group_name_H-M  'P -1'
loop_
_symmetry_equiv_pos_as_xyz
  'x, y, z'
  '-x, -y, -z'
_cell_length_a  10.221(2)
_cell_length_b  12.325(3)
_cell_length_c  3.7951(9)
_cell_angle_alpha  97.24(2)
_cell_angle_beta  98.49(2)
_cell_angle_gamma  67.649(18)
_cell_volume  436.06(18)
_cell_formula_units_Z  1
_cell_measurement_temperature  296(2)
_exptl_crystal_density_diffrn  1.555
_diffrn_ambient_temperature  296(2)
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_U_iso_or_equiv
_atom_site_adp_type
_atom_site_calc_flag
_atom_site_refinement_flags
_atom_site_occupancy
_atom_site_disorder_assembly
_atom_site_disorder_group
_atom_site_type_symbol
  O1  .9256(2)  .38326(19) 1.0550(6)  .0452(7) Uani d . 1 . . O
  O2  .6546(3)  .3847(2)  .5077(7)  .0551(8) Uani d . 1 . . O
  O3  .8044(3)  .10255(19)  .3353(7)  .0478(7) Uani d . 1 . . O
  O4 1.0818(3)  .1085(2)  .8942(7)  .0496(7) Uani d . 1 . . O
  N1  .7316(3)  .5944(2) 1.1723(8)  .0372(7) Uani d . 1 . . N
  C1  .8936(3)  .3058(3)  .8556(9)  .0329(8) Uani d . 1 . . C
  C2  .7664(4)  .3084(3)  .6062(9)  .0351(8) Uani d . 1 . . C
  C3  .8394(4)  .1777(3)  .5309(9)  .0327(8) Uani d . 1 . . C
  C4  .9582(3)  .1831(3)  .7728(9)  .0336(8) Uani d . 1 . . C
  C5  .5947(4)  .8266(3) 1.3525(8)  .0332(8) Uani d . 1 . . C
  C6  .7366(4)  .7706(3) 1.4741(9)  .0380(9) Uani d . 1 . . C
  C7  .8026(4)  .6535(3) 1.3795(10)  .0394(9) Uani d . 1 . . C
  C8  .5953(4)  .6450(3) 1.0499(10)  .0375(9) Uani d . 1 . . C
  C9  .5222(4)  .7626(3) 1.1356(9)  .0365(9) Uani d . 1 . . C
  C10  .5250(4)  .9495(3) 1.4534(10)  .0426(9) Uani d . 1 . . C
  H1  .793(4)  .516(3) 1.091(10)  .060(12) Uiso d . 1 . . H
  H4 1.106(5)  .025(4)  .763(12)  .095(16) Uiso d . 1 . . H
  H6  .786(4)  .813(3) 1.626(10)  .052(11) Uiso d . 1 . . H
  H7  .895(4)  .613(3) 1.459(9)  .046(10) Uiso d . 1 . . H
  H8  .556(4)  .598(3)  .903(10)  .058(12) Uiso d . 1 . . H
  H9  .429(4)  .796(3) 1.042(8)  .033(9) Uiso d . 1 . . H
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
  O1  .0378(14)  .0289(12)  .0567(16)  -.0074(11)  -.0074(12)  -.0100(11)
  O2  .0385(15)  .0344(14)  .0732(19)  -.0013(12)  -.0146(13)  -.0014(13)
  O3  .0415(15)  .0302(13)  .0610(16)  -.0109(11)  -.0091(13)  -.0104(12)
  O4  .0408(15)  .0273(13)  .0613(17)  -.0032(11)  -.0178(12)  -.0086(11)
  N1  .0377(17)  .0283(16)  .0403(17)  -.0100(13)  .0000(14)  -.0041(13)
  C1  .0291(18)  .0252(17)  .039(2)  -.0063(14)  .0002(16)  -.0007(14)
  C2  .0331(19)  .0326(18)  .0366(19)  -.0112(15)  .0030(16)  -.0048(15)
  C3  .0365(18)  .0274(17)  .0327(18)  -.0124(14)  .0003(15)  -.0010(14)
  C4  .0328(19)  .0265(17)  .0365(19)  -.0096(14)  -.0019(15)  -.0048(14)
  C5  .040(2)  .0249(17)  .0331(19)  -.0101(15)  .0097(16)  -.0029(14)
  C6  .037(2)  .039(2)  .039(2)  -.0183(18)  -.0007(17)  -.0038(16)
  C7  .024(2)  .038(2)  .045(2)  -.0036(15)  -.0056(16)  -.0010(16)
  C8  .036(2)  .0330(18)  .041(2)  -.0151(16)  -.0041(17)  -.0052(16)
  C9  .032(2)  .0357(19)  .038(2)  -.0111(16)  -.0024(16)  .0014(16)
  C10  .052(2)  .0318(18)  .041(2)  -.0119(17)  .0043(18)  .0035(16)
loop_
_geom_bond_atom_site_label_1
_geom_bond_atom_site_label_2
_geom_bond_site_symmetry_2
_geom_bond_distance
_geom_bond_publ_flag
  O1 C1 . 1.255(4) yes
  O2 C2 . 1.215(4) yes
  O3 C3 . 1.240(4) yes
  O4 C4 . 1.306(4) yes
  O4 H4 . 1.04(5) no
  N1 C7 . 1.328(4) yes
  N1 C8 . 1.329(4) yes
  N1 H1 .  .98(4) no
  C1 C4 . 1.415(4) yes
  C1 C2 . 1.483(5) yes
  C2 C3 . 1.505(5) yes
  C3 C4 . 1.427(5) yes
  C5 C6 . 1.383(4) yes
  C5 C9 . 1.397(4) yes
  C5 C10 . 1.436(5) yes
  C6 C7 . 1.367(5) yes
  C6 H6 .  .95(4) no
  C7 H7 .  .91(3) no
  C8 C9 . 1.377(5) yes
  C8 H8 .  .92(4) no
  C9 H9 .  .92(3) no
  C10 C10 2_678 1.181(6) yes