#------------------------------------------------------------------------------
#$Date: 2016-01-28 04:26:11 +0200 (Thu, 28 Jan 2016) $
#$Revision: 175183 $
#$URL: svn://www.crystallography.net/cod/cif/2/24/15/2241522.cif $
#------------------------------------------------------------------------------
#
# This file is available in the Crystallography Open Database (COD),
# http://www.crystallography.net/. The original data for this entry
# were provided by IUCr Journals, http://journals.iucr.org/.
#
# The file may be used within the scientific community so long as
# proper attribution is given to the journal article from which the
# data were obtained.
#
data_2241522
loop_
_publ_author_name
'Alfonso, Montserrat'
'Stoeckli-Evans, Helen'
_publ_section_title
;
 Dimethyl and diethyl esters of
 5,6-bis(pyridin-2-yl)pyrazine-2,3-dicarboxylic acid: a comparison
;
_journal_issue                   2
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              233
_journal_page_last               237
_journal_paper_doi               10.1107/S2056989016001080
_journal_volume                  72
_journal_year                    2016
_chemical_formula_iupac          'C20 H18 N4 O4'
_chemical_formula_moiety         'C20 H18 N4 O4'
_chemical_formula_sum            'C20 H18 N4 O4'
_chemical_formula_weight         378.38
_chemical_name_systematic
;
Diethyl 5,6-bis(pyridin-2-yl)pyrazine-2,3-dicarboxylate
;
_space_group_crystal_system      tetragonal
_space_group_IT_number           88
_space_group_name_Hall           '-I 4ad'
_space_group_name_H-M_alt        'I 41/a'
_symmetry_space_group_name_Hall  '-I 4ad'
_symmetry_space_group_name_H-M   'I 41/a :2'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-2014/6
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            8
_cell_length_a                   10.2295(6)
_cell_length_b                   10.2295(6)
_cell_length_c                   36.281(3)
_cell_measurement_reflns_used    5000
_cell_measurement_temperature    223(2)
_cell_measurement_theta_max      52.1
_cell_measurement_theta_min      3.3
_cell_volume                     3796.5(4)
_computing_cell_refinement
;
CELL in IPDS-I (Stoe & Cie, 2004)
;
_computing_data_collection
;
EXPOSE in IPDS-I (Stoe & Cie, 2004)
;
_computing_data_reduction
;
INTEGRATE in IPDS-I (Stoe & Cie, 2004)
;
_computing_molecular_graphics
;
PLATON  (Spek, 2009) and Mercury (Macrae et al.,  2008)
;
_computing_publication_material
;
SHELXL2014 (Sheldrick, 2015), PLATON (Spek, 2009) and
publCIF (Westrip, 2010)
;
_computing_structure_refinement
;
SHELXL2014 (Sheldrick, 2015)
;
_computing_structure_solution
;
SHELXS97 (Sheldrick, 2008)
;
_diffrn_ambient_temperature      223(2)
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 0.997
_diffrn_measurement_device       '1 circle goniometer'
_diffrn_measurement_device_type  'Stoe IPDS 1'
_diffrn_measurement_method       'φ rotation'
_diffrn_radiation_monochromator  'plane graphite'
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0425
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       12
_diffrn_reflns_limit_k_min       -12
_diffrn_reflns_limit_l_max       44
_diffrn_reflns_limit_l_min       -44
_diffrn_reflns_number            14760
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         25.947
_diffrn_reflns_theta_min         2.068
_exptl_absorpt_coefficient_mu    0.095
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.324
_exptl_crystal_description       block
_exptl_crystal_F_000             1584
_exptl_crystal_size_max          0.65
_exptl_crystal_size_mid          0.50
_exptl_crystal_size_min          0.50
_refine_diff_density_max         0.338
_refine_diff_density_min         -0.190
_refine_ls_extinction_coef       0.0049(10)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4^
_refine_ls_extinction_method
;
SHELXL2014 (Sheldrick, 2015)
;
_refine_ls_goodness_of_fit_ref   1.006
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     129
_refine_ls_number_reflns         1851
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.006
_refine_ls_R_factor_all          0.0793
_refine_ls_R_factor_gt           0.0492
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[σ²(Fo²)+(0.0925P)²] where P=(Fo²+2Fc²)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1358
_refine_ls_wR_factor_ref         0.1493
_reflns_number_gt                1153
_reflns_number_total             1851
_reflns_threshold_expression     'I > 2σ(I)'
_cod_data_source_file            gk2653sup1.cif
_cod_data_source_block           II
_cod_original_cell_volume        3796.5(5)
_cod_database_code               2241522
_shelx_space_group_comment
;
The symmetry employed for this shelxl refinement is uniquely defined
by the following loop, which should always be used as a source of
symmetry information in preference to the above space-group names.
They are only intended as comments.
;
_shelx_estimated_absorpt_t_min   0.941
_shelx_estimated_absorpt_t_max   0.954
_shelxl_version_number           2014/6
loop_
_space_group_symop_operation_xyz
'x, y, z'
'-x+1/2, -y, z+1/2'
'-y+3/4, x+1/4, z+1/4'
'y+3/4, -x+3/4, z+3/4'
'x+1/2, y+1/2, z+1/2'
'-x+1, -y+1/2, z+1'
'-y+5/4, x+3/4, z+3/4'
'y+5/4, -x+5/4, z+5/4'
'-x, -y, -z'
'x-1/2, y, -z-1/2'
'y-3/4, -x-1/4, -z-1/4'
'-y-3/4, x-3/4, -z-3/4'
'-x+1/2, -y+1/2, -z+1/2'
'x, y+1/2, -z'
'y-1/4, -x+1/4, -z+1/4'
'-y-1/4, x-1/4, -z-1/4'
loop_
_atom_site_type_symbol
_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_occupancy
O O1 0.7424(2) 0.7559(3) 0.00480(5) 0.1009(9) Uani d 1
O O2 0.91015(17) 0.64422(18) -0.01674(4) 0.0693(5) Uani d 1
N N1 0.86590(16) 0.73125(18) 0.07318(4) 0.0478(5) Uani d 1
N N2 0.88149(17) 0.8399(2) 0.16340(5) 0.0583(6) Uani d 1
C C1 0.9332(2) 0.7371(2) 0.04156(5) 0.0473(5) Uani d 1
C C2 0.93113(19) 0.7446(2) 0.10488(5) 0.0450(5) Uani d 1
C C3 0.84753(19) 0.7504(2) 0.13824(5) 0.0452(5) Uani d 1
C C4 0.7388(2) 0.6719(2) 0.14134(5) 0.0466(5) Uani d 1
H H4 0.7174 0.6124 0.1225 0.056 Uiso calc 1
C C5 0.6613(2) 0.6817(2) 0.17249(5) 0.0503(5) Uani d 1
H H5 0.5874 0.6282 0.1755 0.060 Uiso calc 1
C C6 0.6952(2) 0.7712(2) 0.19868(6) 0.0569(6) Uani d 1
H H6 0.6448 0.7803 0.2202 0.068 Uiso calc 1
C C7 0.8042(2) 0.8481(3) 0.19322(6) 0.0637(7) Uani d 1
H H7 0.8256 0.9098 0.2114 0.076 Uiso calc 1
C C8 0.8508(2) 0.7155(3) 0.00796(5) 0.0558(6) Uani d 1
C C9 0.8402(3) 0.6183(4) -0.05106(7) 0.0978(11) Uani d 1
H H9A 0.7744 0.5501 -0.0471 0.117 Uiso calc 1
H H9B 0.7956 0.6977 -0.0594 0.117 Uiso calc 1
C C10 0.9335(4) 0.5760(3) -0.07867(8) 0.0965(11) Uani d 1
H H10A 0.8877 0.5552 -0.1013 0.145 Uiso calc 1
H H10B 0.9793 0.4990 -0.0699 0.145 Uiso calc 1
H H10C 0.9960 0.6455 -0.0833 0.145 Uiso calc 1
loop_
_atom_type_symbol
_atom_type_description
_atom_type_scat_dispersion_real
_atom_type_scat_dispersion_imag
_atom_type_scat_source
C C 0.0033 0.0016 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
H H 0.0000 0.0000 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
N N 0.0061 0.0033 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
O O 0.0106 0.0060 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
loop_
_geom_angle_atom_site_label_1
_geom_angle_atom_site_label_2
_geom_angle_atom_site_label_3
_geom_angle_site_symmetry_1
_geom_angle_site_symmetry_3
_geom_angle
C8 O2 C9 . . 117.3(2)
C2 N1 C1 . . 118.40(17)
C3 N2 C7 . . 116.06(19)
N1 C1 C1 . 6_664 120.88(11)
N1 C1 C8 . . 113.63(18)
C1 C1 C8 6_664 . 125.48(12)
N1 C2 C2 . 6_664 120.38(11)
N1 C2 C3 . . 114.72(17)
C2 C2 C3 6_664 . 124.88(11)
N2 C3 C4 . . 123.56(18)
N2 C3 C2 . . 115.71(18)
C4 C3 C2 . . 120.65(18)
C3 C4 C5 . . 119.1(2)
C3 C4 H4 . . 120.4
C5 C4 H4 . . 120.4
C6 C5 C4 . . 118.2(2)
C6 C5 H5 . . 120.9
C4 C5 H5 . . 120.9
C5 C6 C7 . . 119.20(19)
C5 C6 H6 . . 120.4
C7 C6 H6 . . 120.4
N2 C7 C6 . . 123.8(2)
N2 C7 H7 . . 118.1
C6 C7 H7 . . 118.1
O1 C8 O2 . . 124.2(2)
O1 C8 C1 . . 123.5(2)
O2 C8 C1 . . 112.27(19)
C10 C9 O2 . . 108.7(3)
C10 C9 H9A . . 109.9
O2 C9 H9A . . 109.9
C10 C9 H9B . . 109.9
O2 C9 H9B . . 109.9
H9A C9 H9B . . 108.3
C9 C10 H10A . . 109.5
C9 C10 H10B . . 109.5
H10A C10 H10B . . 109.5
C9 C10 H10C . . 109.5
H10A C10 H10C . . 109.5
H10B C10 H10C . . 109.5
loop_
_geom_bond_atom_site_label_1
_geom_bond_atom_site_label_2
_geom_bond_site_symmetry_2
_geom_bond_distance
O1 C8 . 1.189(3)
O2 C8 . 1.305(3)
O2 C9 . 1.460(3)
N1 C2 . 1.337(2)
N1 C1 . 1.339(2)
N2 C3 . 1.339(3)
N2 C7 . 1.343(3)
C1 C1 6_664 1.392(4)
C1 C8 . 1.499(3)
C2 C2 6_664 1.413(4)
C2 C3 . 1.483(3)
C3 C4 . 1.377(3)
C4 C5 . 1.384(3)
C4 H4 . 0.9400
C5 C6 . 1.364(3)
C5 H5 . 0.9400
C6 C7 . 1.379(3)
C6 H6 . 0.9400
C7 H7 . 0.9400
C9 C10 . 1.450(5)
C9 H9A . 0.9800
C9 H9B . 0.9800
C10 H10A . 0.9700
C10 H10B . 0.9700
C10 H10C . 0.9700
loop_
_geom_hbond_atom_site_label_D
_geom_hbond_atom_site_label_H
_geom_hbond_atom_site_label_A
_geom_hbond_site_symmetry_A
_geom_hbond_distance_DH
_geom_hbond_distance_HA
_geom_hbond_distance_DA
_geom_hbond_angle_DHA
C7 H7 O1 3_655 0.94 2.48 3.308(3) 147
C4 H4 Cg2 15_565 0.94 2.92 3.739(2) 147
C10 H10B Cg1 9_765 0.97 2.56 3.409(3) 146
C10 H10B Cg1 14_545 0.97 2.56 3.409(3) 146
loop_
_geom_torsion_atom_site_label_1
_geom_torsion_atom_site_label_2
_geom_torsion_atom_site_label_3
_geom_torsion_atom_site_label_4
_geom_torsion_site_symmetry_1
_geom_torsion_site_symmetry_4
_geom_torsion
C2 N1 C1 C1 . 6_664 -3.1(4)
C2 N1 C1 C8 . . 177.7(2)
C1 N1 C2 C2 . 6_664 -4.4(4)
C1 N1 C2 C3 . . 174.09(19)
C7 N2 C3 C4 . . 1.6(3)
C7 N2 C3 C2 . . 178.3(2)
N1 C2 C3 N2 . . -137.7(2)
C2 C2 C3 N2 6_664 . 40.8(4)
N1 C2 C3 C4 . . 39.1(3)
C2 C2 C3 C4 6_664 . -142.4(3)
N2 C3 C4 C5 . . -2.1(3)
C2 C3 C4 C5 . . -178.62(19)
C3 C4 C5 C6 . . 1.1(3)
C4 C5 C6 C7 . . 0.1(3)
C3 N2 C7 C6 . . -0.2(4)
C5 C6 C7 N2 . . -0.6(4)
C9 O2 C8 O1 . . 3.0(4)
C9 O2 C8 C1 . . -179.0(2)
N1 C1 C8 O1 . . 37.9(4)
C1 C1 C8 O1 6_664 . -141.2(3)
N1 C1 C8 O2 . . -140.1(2)
C1 C1 C8 O2 6_664 . 40.8(4)
C8 O2 C9 C10 . . 162.0(3)

_cod_database_fobs_code 2241522
