# Electronic Supplementary Material (ESI) for RSC Advances.
# This journal is © The Royal Society of Chemistry 2016

####################################################################### 
# 
# This file contains crystal structure data downloaded from the 
# Cambridge Structural Database (CSD) hosted by the Cambridge 
# Crystallographic Data Centre (CCDC).
# 
# Full information about CCDC data access policies and citation 
# guidelines are available at http://www.ccdc.cam.ac.uk/access/V1 
# 
# Audit and citation data items may have been added by the CCDC. 
# Please retain this information to preserve the provenance of 
# this file and to allow appropriate attribution of the data. 
# 
#######################################################################

data_Compound1
_database_code_depnum_ccdc_archive 'CCDC 1032260'
_audit_update_record             
;
2015-06-27 deposited with the CCDC.
2016-01-11 downloaded from the CCDC.
;

_audit_creation_method           SHELXL-97
_chemical_name_systematic        
;
 ?
;
_chemical_name_common            2,6-bis(pyridine-4-ylethynyl)pyrazine
_chemical_melting_point          ?
_chemical_formula_moiety         ?
_chemical_formula_sum            'C18 H10 N4'
_chemical_formula_weight         282.30

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'

_symmetry_cell_setting           Monoclinic
_symmetry_space_group_name_H-M   C2/c

loop_
_symmetry_equiv_pos_as_xyz
'x, y, z'
'-x, y, -z+1/2'
'x+1/2, y+1/2, z'
'-x+1/2, y+1/2, -z+1/2'
'-x, -y, -z'
'x, -y, z-1/2'
'-x+1/2, -y+1/2, -z'
'x+1/2, -y+1/2, z-1/2'

_cell_length_a                   22.8914(8)
_cell_length_b                   5.7531(2)
_cell_length_c                   23.2380(7)
_cell_angle_alpha                90.00
_cell_angle_beta                 113.464(4)
_cell_angle_gamma                90.00
_cell_volume                     2807.30(16)
_cell_formula_units_Z            8
_cell_measurement_temperature    296(2)
_cell_measurement_reflns_used    4277
_cell_measurement_theta_min      3.2
_cell_measurement_theta_max      30.5

_exptl_crystal_description       needle
_exptl_crystal_colour            colorless
_exptl_crystal_size_max          .2
_exptl_crystal_size_mid          .17
_exptl_crystal_size_min          0.15
_exptl_crystal_density_meas      ?
_exptl_crystal_density_diffrn    1.336
_exptl_crystal_density_method    'not measured'
_exptl_crystal_F_000             1168
_exptl_absorpt_coefficient_mu    0.083
_exptl_absorpt_correction_type   Multi-Scan
_exptl_absorpt_correction_T_min  0.6861
_exptl_absorpt_correction_T_max  0.7461
_exptl_absorpt_process_details   'SADABS Bruker, 2007)'

_exptl_special_details           
;
 ?
;

_diffrn_ambient_temperature      296(2)
_diffrn_radiation_wavelength     0.71073
_diffrn_radiation_type           MoK\a
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_monochromator  graphite
_diffrn_measurement_device_type  'Bruker SMART APEX CCD diffractometer'
_diffrn_measurement_method       'φ and ω scan'
_diffrn_detector_area_resol_mean ?
_diffrn_standards_number         ?
_diffrn_standards_interval_count ?
_diffrn_standards_interval_time  ?
_diffrn_standards_decay_%        ?
_diffrn_reflns_number            29111
_diffrn_reflns_av_R_equivalents  0.0386
_diffrn_reflns_av_sigmaI/netI    0.0275
_diffrn_reflns_limit_h_min       -32
_diffrn_reflns_limit_h_max       31
_diffrn_reflns_limit_k_min       -5
_diffrn_reflns_limit_k_max       8
_diffrn_reflns_limit_l_min       -33
_diffrn_reflns_limit_l_max       33
_diffrn_reflns_theta_min         3.22
_diffrn_reflns_theta_max         30.54
_reflns_number_total             4277
_reflns_number_gt                3110
_reflns_threshold_expression     >2sigma(I)

_computing_data_collection       SMART
_computing_cell_refinement       'SMART, SAINT'
_computing_data_reduction        SAINT
_computing_structure_solution    'SHELXS-97 (Sheldrick, 2008)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_molecular_graphics    'Diamond (Brandenburg, 1999)'
_computing_publication_material  'SHELXTLCIF-97 (Sheldrick, 2008)'

_refine_special_details          
;
 Refinement of F² against ALL reflections.  The weighted R-factor wR and
 goodness of fit S are based on F², conventional R-factors R are based
 on F, with F set to zero for negative F². The threshold expression of
 F² > 2sigma(F²) is used only for calculating R-factors(gt) etc. and is
 not relevant to the choice of reflections for refinement.  R-factors based
 on F² are statistically about twice as large as those based on F, and R-
 factors based on ALL data will be even larger.
;

_refine_ls_structure_factor_coef Fsqd
_refine_ls_matrix_type           full
_refine_ls_weighting_scheme      calc
_refine_ls_weighting_details     
'calc w=1/[σ²(Fo²)+(0.0537P)²+0.7383P] where P=(Fo²+2Fc²)/3'
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_atom_sites_solution_hydrogens   geom
_refine_ls_hydrogen_treatment    constr
_refine_ls_extinction_method     SHELXL
_refine_ls_extinction_coef       0.0060(6)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4^
_refine_ls_number_reflns         4277
_refine_ls_number_parameters     200
_refine_ls_number_restraints     0
_refine_ls_R_factor_all          0.0626
_refine_ls_R_factor_gt           0.0431
_refine_ls_wR_factor_ref         0.1214
_refine_ls_wR_factor_gt          0.1097
_refine_ls_goodness_of_fit_ref   1.053
_refine_ls_restrained_S_all      1.053
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000

loop_
_atom_site_label
_atom_site_type_symbol
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_U_iso_or_equiv
_atom_site_adp_type
_atom_site_occupancy
_atom_site_symmetry_multiplicity
_atom_site_calc_flag
_atom_site_refinement_flags
_atom_site_disorder_assembly
_atom_site_disorder_group
C1 C 0.74338(6) 0.2232(2) 0.41161(6) 0.0525(3) Uani 1 1 d . . .
H1 H 0.7737 0.3391 0.4289 0.063 Uiso 1 1 calc R . .
C5 C 0.70314(6) -0.1270(2) 0.42002(6) 0.0524(3) Uani 1 1 d . . .
H5 H 0.7046 -0.2604 0.4432 0.063 Uiso 1 1 calc R . .
C4 C 0.65514(5) -0.1083(2) 0.36108(5) 0.0479(3) Uani 1 1 d . . .
H4 H 0.6254 -0.2269 0.3451 0.058 Uiso 1 1 calc R . .
C2 C 0.69725(5) 0.2596(2) 0.35228(5) 0.0447(3) Uani 1 1 d . . .
H2 H 0.6968 0.3955 0.3304 0.054 Uiso 1 1 calc R . .
C3 C 0.65169(5) 0.08904(19) 0.32596(5) 0.0371(2) Uani 1 1 d . . .
C6 C 0.60101(5) 0.1212(2) 0.26532(5) 0.0408(2) Uani 1 1 d . . .
C7 C 0.55818(5) 0.1510(2) 0.21572(5) 0.0421(3) Uani 1 1 d . . .
C8 C 0.50532(5) 0.20307(19) 0.15797(5) 0.0369(2) Uani 1 1 d . . .
C9 C 0.47287(5) 0.4123(2) 0.15181(5) 0.0449(3) Uani 1 1 d . . .
H9 H 0.4872 0.5179 0.1848 0.054 Uiso 1 1 calc R . .
C10 C 0.40510(5) 0.3120(2) 0.05456(5) 0.0447(3) Uani 1 1 d . . .
H10 H 0.3695 0.3424 0.0180 0.054 Uiso 1 1 calc R . .
C11 C 0.43843(5) 0.10554(19) 0.05899(5) 0.0384(2) Uani 1 1 d . . .
C12 C 0.41930(5) -0.0523(2) 0.00690(5) 0.0449(3) Uani 1 1 d . . .
C13 C 0.40093(5) -0.1733(2) -0.03837(5) 0.0447(3) Uani 1 1 d . . .
C14 C 0.37734(5) -0.32019(19) -0.09278(5) 0.0379(2) Uani 1 1 d . . .
C15 C 0.40771(5) -0.5252(2) -0.09610(6) 0.0449(3) Uani 1 1 d . . .
H15 H 0.4447 -0.5716 -0.0628 0.054 Uiso 1 1 calc R . .
C16 C 0.38222(6) -0.6586(2) -0.14945(6) 0.0526(3) Uani 1 1 d . . .
H16 H 0.4034 -0.7949 -0.1511 0.063 Uiso 1 1 calc R . .
C17 C 0.30047(6) -0.4087(2) -0.19507(5) 0.0505(3) Uani 1 1 d . . .
H17 H 0.2632 -0.3682 -0.2288 0.061 Uiso 1 1 calc R . .
C18 C 0.32256(5) -0.2618(2) -0.14435(5) 0.0445(3) Uani 1 1 d . . .
H18 H 0.3010 -0.1245 -0.1446 0.053 Uiso 1 1 calc R . .
N2 N 0.32936(5) -0.60590(19) -0.19882(5) 0.0554(3) Uani 1 1 d . . .
N1 N 0.74757(5) 0.0339(2) 0.44583(5) 0.0525(3) Uani 1 1 d . . .
N3 N 0.42232(5) 0.46663(18) 0.10061(5) 0.0489(3) Uani 1 1 d . . .
N4 N 0.48872(4) 0.04769(16) 0.11145(4) 0.0393(2) Uani 1 1 d . . .

loop_
_atom_site_aniso_label
_atom_site_aniso_U_11
_atom_site_aniso_U_22
_atom_site_aniso_U_33
_atom_site_aniso_U_23
_atom_site_aniso_U_13
_atom_site_aniso_U_12
C1 0.0451(6) 0.0549(7) 0.0420(6) -0.0049(5) 0.0010(5) -0.0079(5)
C5 0.0564(7) 0.0522(7) 0.0401(6) 0.0108(5) 0.0104(5) 0.0025(6)
C4 0.0442(6) 0.0476(6) 0.0432(6) 0.0018(5) 0.0081(5) -0.0076(5)
C2 0.0428(6) 0.0458(6) 0.0375(6) 0.0028(5) 0.0075(5) -0.0038(5)
C3 0.0318(5) 0.0454(6) 0.0292(5) -0.0021(4) 0.0070(4) 0.0025(4)
C6 0.0352(5) 0.0484(6) 0.0340(5) -0.0023(4) 0.0087(4) 0.0005(4)
C7 0.0363(5) 0.0522(6) 0.0336(5) -0.0026(5) 0.0093(4) 0.0011(5)
C8 0.0327(5) 0.0469(6) 0.0283(5) -0.0001(4) 0.0091(4) 0.0000(4)
C9 0.0467(6) 0.0496(6) 0.0336(5) -0.0062(5) 0.0111(5) 0.0036(5)
C10 0.0419(6) 0.0524(6) 0.0307(5) 0.0014(5) 0.0050(4) 0.0066(5)
C11 0.0377(5) 0.0450(6) 0.0282(5) -0.0006(4) 0.0085(4) -0.0005(4)
C12 0.0456(6) 0.0494(6) 0.0323(5) -0.0007(5) 0.0076(5) 0.0013(5)
C13 0.0471(6) 0.0470(6) 0.0351(5) -0.0019(5) 0.0111(5) -0.0004(5)
C14 0.0403(5) 0.0402(5) 0.0312(5) -0.0017(4) 0.0121(4) -0.0032(4)
C15 0.0399(5) 0.0459(6) 0.0425(6) 0.0011(5) 0.0097(5) 0.0045(5)
C16 0.0526(7) 0.0439(6) 0.0584(8) -0.0100(6) 0.0189(6) 0.0040(5)
C17 0.0451(6) 0.0583(7) 0.0363(6) -0.0024(5) 0.0038(5) 0.0015(5)
C18 0.0452(6) 0.0433(6) 0.0401(6) 0.0000(5) 0.0117(5) 0.0072(5)
N2 0.0543(6) 0.0558(6) 0.0483(6) -0.0158(5) 0.0122(5) -0.0039(5)
N1 0.0499(6) 0.0595(6) 0.0346(5) 0.0022(4) 0.0026(4) 0.0041(5)
N3 0.0505(6) 0.0501(6) 0.0394(5) -0.0009(4) 0.0107(4) 0.0120(4)
N4 0.0358(4) 0.0453(5) 0.0310(4) -0.0015(4) 0.0071(3) 0.0027(4)

_geom_special_details            
;
 All esds (except the esd in the dihedral angle between two l.s. planes)
 are estimated using the full covariance matrix.  The cell esds are taken
 into account individually in the estimation of esds in distances, angles
 and torsion angles; correlations between esds in cell parameters are only
 used when they are defined by crystal symmetry.  An approximate (isotropic)
 treatment of cell esds is used for estimating esds involving l.s. planes.
;

loop_
_geom_bond_atom_site_label_1
_geom_bond_atom_site_label_2
_geom_bond_distance
_geom_bond_site_symmetry_2
_geom_bond_publ_flag
C1 N1 1.3290(17) . ?
C1 C2 1.3785(15) . ?
C5 N1 1.3287(16) . ?
C5 C4 1.3772(16) . ?
C4 C3 1.3819(16) . ?
C2 C3 1.3843(15) . ?
C3 C6 1.4365(14) . ?
C6 C7 1.1913(14) . ?
C7 C8 1.4361(14) . ?
C8 N4 1.3360(13) . ?
C8 C9 1.3917(16) . ?
C9 N3 1.3250(14) . ?
C10 N3 1.3252(14) . ?
C10 C11 1.3933(15) . ?
C11 N4 1.3433(13) . ?
C11 C12 1.4349(15) . ?
C12 C13 1.1900(15) . ?
C13 C14 1.4355(15) . ?
C14 C15 1.3865(16) . ?
C14 C18 1.3874(15) . ?
C15 C16 1.3751(17) . ?
C16 N2 1.3293(16) . ?
C17 N2 1.3335(16) . ?
C17 C18 1.3727(16) . ?

loop_
_geom_angle_atom_site_label_1
_geom_angle_atom_site_label_2
_geom_angle_atom_site_label_3
_geom_angle
_geom_angle_site_symmetry_1
_geom_angle_site_symmetry_3
_geom_angle_publ_flag
N1 C1 C2 124.54(11) . . ?
N1 C5 C4 123.96(11) . . ?
C5 C4 C3 119.14(11) . . ?
C1 C2 C3 118.46(11) . . ?
C4 C3 C2 117.73(10) . . ?
C4 C3 C6 121.26(10) . . ?
C2 C3 C6 120.95(10) . . ?
C7 C6 C3 178.37(12) . . ?
C6 C7 C8 175.49(12) . . ?
N4 C8 C9 121.83(9) . . ?
N4 C8 C7 118.61(10) . . ?
C9 C8 C7 119.56(10) . . ?
N3 C9 C8 122.40(10) . . ?
N3 C10 C11 122.31(10) . . ?
N4 C11 C10 121.63(9) . . ?
N4 C11 C12 118.17(10) . . ?
C10 C11 C12 120.19(9) . . ?
C13 C12 C11 176.08(13) . . ?
C12 C13 C14 178.61(13) . . ?
C15 C14 C18 117.30(10) . . ?
C15 C14 C13 121.91(10) . . ?
C18 C14 C13 120.79(10) . . ?
C16 C15 C14 118.88(11) . . ?
N2 C16 C15 124.35(11) . . ?
N2 C17 C18 123.86(11) . . ?
C17 C18 C14 119.32(11) . . ?
C16 N2 C17 116.27(10) . . ?
C5 N1 C1 116.16(10) . . ?
C9 N3 C10 116.07(10) . . ?
C8 N4 C11 115.68(9) . . ?

_diffrn_measured_fraction_theta_max 0.996
_diffrn_reflns_theta_full        30.54
_diffrn_measured_fraction_theta_full 0.996
_refine_diff_density_max         0.228
_refine_diff_density_min         -0.166
_refine_diff_density_rms         0.041
