# Electronic Supplementary Material for CrystEngComm
# This journal is (c) The Royal Society of Chemistry 2009

data_global
_journal_name_full               CrystEngComm

_journal_coden_Cambridge         1350

_publ_contact_author_name        'Alvin Holder'
_publ_contact_author_email       ALVIN.HOLDER@USM.EDU

_publ_section_title              
;
A new and efficient synthetic route for the synthesis
of 3,6-dimethylpyrazine-2,5-dicarboxylic acid hydrate:- Its molecular
structure and unique supramolecular interactions
;
loop_
_publ_author_name
'A Holder'
'Shawna L Balof'
'L Moody'
'Varma Rambaran'
'Donald G. VanDerveer'

# Attachment 'Alvin_Holder_h4pyr_publ.cif'

data_h4pyr
_database_code_depnum_ccdc_archive 'CCDC 706305'

_audit_creation_method           SHELXL-97
_chemical_name_systematic        
;
?
;
_chemical_name_common            ?
_chemical_melting_point          ?
_chemical_formula_moiety         ?
_chemical_formula_sum            'C8 H12 N2 O6'
_chemical_formula_weight         232.20

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'

_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_H-M   P21/c

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

_cell_length_a                   5.559(3)
_cell_length_b                   10.957(5)
_cell_length_c                   8.429(6)
_cell_angle_alpha                90.00
_cell_angle_beta                 99.21(3)
_cell_angle_gamma                90.00
_cell_volume                     506.8(5)
_cell_formula_units_Z            2
_cell_measurement_temperature    153(2)
_cell_measurement_reflns_used    1748
_cell_measurement_theta_min      3.6658
_cell_measurement_theta_max      26.3607

_exptl_crystal_description       chip
_exptl_crystal_colour            colorless
_exptl_crystal_size_max          0.50
_exptl_crystal_size_mid          0.19
_exptl_crystal_size_min          0.17
_exptl_crystal_density_meas      ?
_exptl_crystal_density_diffrn    1.521
_exptl_crystal_density_method    'not measured'
_exptl_crystal_F_000             244
_exptl_absorpt_coefficient_mu    0.132
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_correction_T_min  0.9371
_exptl_absorpt_correction_T_max  0.9780
_exptl_absorpt_process_details   'Jacobson, R., (1998)'
_exptl_special_details           
;
?
;

_diffrn_ambient_temperature      153(2)
_diffrn_radiation_wavelength     0.71073
_diffrn_radiation_type           MoK\a
_diffrn_radiation_source         'Sealed Tube'
_diffrn_radiation_monochromator  'Graphite Monochromator'
_diffrn_radiation_detector       CCD
_diffrn_measurement_device       
;
Rigaku AFC8S Mercury CCD
;
_diffrn_detector_area_resol_mean 14.6306
_diffrn_measurement_method       omega
_diffrn_reflns_reduction_process 'Lp corrections applied'
_diffrn_measurement_details      
;
scan:
Number of images: 260
Slice: -40.0000 - 90.0000
Image width: 0.5000
Exp time: 15.0000
Rotation axis: Omega
Omega: 0.0000
Chi: 45.0000
Phi: 0.0000
XTD: 27.7652
2theta: -0.9459
scan:
Number of images: 220
Slice: -30.0000 - 80.0000
Image width: 0.5000
Exp time: 15.0000
Rotation axis: Omega
Omega: 0.0000
Chi: 45.0000
Phi: 90.0000
XTD: 27.7652
2theta: -0.9459

;
_diffrn_measurement_device_details 
;
AFC8: Eulerian 3 circle
;
_diffrn_standards_number         0
_diffrn_standards_interval_count 0
_diffrn_standards_interval_time  0
_diffrn_standards_decay_%        0
_diffrn_reflns_number            3106
_diffrn_reflns_av_R_equivalents  0.0581
_diffrn_reflns_av_sigmaI/netI    0.0452
_diffrn_reflns_limit_h_min       -6
_diffrn_reflns_limit_h_max       6
_diffrn_reflns_limit_k_min       -13
_diffrn_reflns_limit_k_max       13
_diffrn_reflns_limit_l_min       -10
_diffrn_reflns_limit_l_max       9
_diffrn_reflns_theta_min         4.15
_diffrn_reflns_theta_max         25.04
_reflns_number_total             883
_reflns_number_gt                766
_reflns_threshold_expression     >2sigma(I)

_computing_data_collection       'CrystalClear (Rigaku/MSC,2006)'
_computing_cell_refinement       'CrystalClear (Rigaku/MSC,2006)'
_computing_data_reduction        'CrystalClear (Rigaku/MSC,2006)'
_computing_structure_solution    'SHELXTL 6.10 (Sheldrick,2008)'
_computing_structure_refinement  'SHELXTL 6.10 (Sheldrick,2008)'
_computing_molecular_graphics    'SHELXTL 6.10 (Sheldrick,2008)'
_computing_publication_material  'SHELXTL 6.10 (Sheldrick,2008)'

_refine_special_details          
;
Refinement of F^2^ against ALL reflections. The weighted R-factor wR and
goodness of fit S are based on F^2^, conventional R-factors R are based
on F, with F set to zero for negative F^2^. The threshold expression of
F^2^ > 2sigma(F^2^) is used only for calculating R-factors(gt) etc. and is
not relevant to the choice of reflections for refinement. R-factors based
on F^2^ 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/[\s^2^(Fo^2^)+(0.0445P)^2^+0.3230P] where P=(Fo^2^+2Fc^2^)/3'
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_atom_sites_solution_hydrogens   geom
_refine_ls_hydrogen_treatment    mixed
_refine_ls_extinction_method     none
_refine_ls_extinction_coef       ?
_refine_ls_number_reflns         883
_refine_ls_number_parameters     81
_refine_ls_number_restraints     2
_refine_ls_R_factor_all          0.0536
_refine_ls_R_factor_gt           0.0439
_refine_ls_wR_factor_ref         0.1091
_refine_ls_wR_factor_gt          0.1018
_refine_ls_goodness_of_fit_ref   1.106
_refine_ls_restrained_S_all      1.105
_refine_ls_shift/su_max          0.001
_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
O1 O 0.2660(3) 0.51753(12) 0.08576(16) 0.0250(4) Uani 1 1 d . . .
H1 H 0.2260 0.5496 -0.0037 0.030 Uiso 1 1 calc R . .
O2 O 0.3663(3) 0.70916(12) 0.16026(17) 0.0270(4) Uani 1 1 d . . .
C1 C 0.3517(3) 0.60094(17) 0.1904(2) 0.0191(4) Uani 1 1 d . . .
C2 C 0.4317(3) 0.54920(16) 0.3557(2) 0.0181(4) Uani 1 1 d . . .
N3 N 0.2969(3) 0.45737(14) 0.39871(18) 0.0188(4) Uani 1 1 d . . .
C4 C 0.3616(3) 0.40624(16) 0.5436(2) 0.0187(5) Uani 1 1 d . . .
C5 C 0.2027(4) 0.30587(18) 0.5888(3) 0.0256(5) Uani 1 1 d . . .
H5A H 0.0474 0.3086 0.5201 0.038 Uiso 1 1 calc R . .
H5B H 0.1800 0.3161 0.6985 0.038 Uiso 1 1 calc R . .
H5C H 0.2788 0.2285 0.5767 0.038 Uiso 1 1 calc R . .
O3 O 0.8275(3) 0.41304(13) 0.20484(16) 0.0237(4) Uani 1 1 d D . .
H3A H 0.770(4) 0.3474(17) 0.243(3) 0.028 Uiso 1 1 d D . .
H3B H 0.971(3) 0.418(2) 0.258(3) 0.028 Uiso 1 1 d 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
O1 0.0327(8) 0.0230(7) 0.0171(7) 0.0013(5) -0.0025(6) -0.0044(6)
O2 0.0348(9) 0.0192(8) 0.0256(8) 0.0040(6) 0.0004(6) 0.0010(6)
C1 0.0154(10) 0.0216(10) 0.0206(10) 0.0019(7) 0.0035(7) 0.0004(7)
C2 0.0185(10) 0.0159(9) 0.0202(10) 0.0004(7) 0.0041(7) 0.0015(7)
N3 0.0192(8) 0.0181(8) 0.0191(9) 0.0006(6) 0.0030(6) 0.0012(6)
C4 0.0195(10) 0.0164(9) 0.0200(9) 0.0003(7) 0.0022(7) 0.0010(7)
C5 0.0227(11) 0.0259(11) 0.0265(11) 0.0036(8) -0.0014(8) -0.0063(8)
O3 0.0208(8) 0.0271(8) 0.0217(8) 0.0035(6) -0.0010(6) -0.0032(6)

_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
O1 C1 1.306(2) . ?
O1 H1 0.8299 . ?
O2 C1 1.218(2) . ?
C1 C2 1.504(3) . ?
C2 N3 1.339(2) . ?
C2 C4 1.403(3) 3_666 ?
N3 C4 1.339(3) . ?
C4 C2 1.403(3) 3_666 ?
C4 C5 1.498(3) . ?
C5 H5A 0.9599 . ?
C5 H5B 0.9599 . ?
C5 H5C 0.9599 . ?
O3 H3A 0.869(16) . ?
O3 H3B 0.851(17) . ?

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
C1 O1 H1 109.5 . . ?
O2 C1 O1 124.71(17) . . ?
O2 C1 C2 122.72(16) . . ?
O1 C1 C2 112.57(16) . . ?
N3 C2 C4 122.52(17) . 3_666 ?
N3 C2 C1 116.02(16) . . ?
C4 C2 C1 121.45(17) 3_666 . ?
C2 N3 C4 118.75(15) . . ?
N3 C4 C2 118.73(17) . 3_666 ?
N3 C4 C5 117.14(16) . . ?
C2 C4 C5 124.12(17) 3_666 . ?
C4 C5 H5A 109.5 . . ?
C4 C5 H5B 109.5 . . ?
H5A C5 H5B 109.5 . . ?
C4 C5 H5C 109.5 . . ?
H5A C5 H5C 109.5 . . ?
H5B C5 H5C 109.5 . . ?
H3A O3 H3B 103(2) . . ?

loop_
_geom_hbond_atom_site_label_D
_geom_hbond_atom_site_label_H
_geom_hbond_atom_site_label_A
_geom_hbond_distance_DH
_geom_hbond_distance_HA
_geom_hbond_distance_DA
_geom_hbond_angle_DHA
_geom_hbond_site_symmetry_A
O1 H1 O3 0.83 1.72 2.538(2) 166.9 3_665
O3 H3A O2 0.869(16) 1.932(17) 2.799(2) 176(2) 2_645
O3 H3B N3 0.851(17) 2.048(17) 2.890(2) 170(2) 1_655
O3 H3B O1 0.851(17) 2.60(2) 3.008(2) 110.7(19) 1_655

_diffrn_measured_fraction_theta_max 0.989
_diffrn_reflns_theta_full        25.04
_diffrn_measured_fraction_theta_full 0.989
_refine_diff_density_max         0.266
_refine_diff_density_min         -0.252
_refine_diff_density_rms         0.065