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Two new polymorphic forms of 5-nitrofurazone (5-nitro-2-furaldehyde semicarbazone) have been synthesized and structurally characterized by single-crystal and powder X-ray diffraction methods, vibrational spectroscopy (FT–IR and temperature Raman), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and Hirshfeld surface analysis. The compound crystallizes in three different polymorphic forms P21/a (polymorph α), P21 (polymorph β) and P21/c (polymorph γ), the crystal structures of two of which (polymorphs β and γ) represent new structure determinations. The solid-state molecular organization in the three crystal forms is analyzed and discussed in terms of molecular conformation, crystal packing and hydrogen-bonded networks. All three crystals are formed from trans geometrical isomers, but the molecular conformation of the α-polymorph is syn–anti–anti–anti, while that of β- and γ-polymorphs is syn–anti–syn–syn. As a consequence of this the hydrogen-bond donor and acceptor sites of the molecules are oriented differently, which in turn results in different hydrogen-bond connectivity and packing patterns.
Supporting information
CCDC references: 1444950; 1444951
For both compounds, data collection: Oxford Diffraction (2010). CrysAlis CCD, Version 1.171.33.42; cell refinement: Oxford Diffraction (2010). CrysAlis RED, Version 1.171.33.42; data reduction: Oxford Diffraction (2010). CrysAlis RED, Version 1.171.33.42; program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL2014/7 (Sheldrick, 2015); molecular graphics: Brandenburg & Putz (2006). Diamond 3.0. Crystal and Molecular Structure Visualisation, University of Bonn, Germany; software used to prepare material for publication: SHELXL2014/7 (Sheldrick, 2015).
Crystal data top
C6H6N4O4 | F(000) = 204 |
Mr = 198.15 | Dx = 1.547 Mg m−3 Dm = 1.54 Mg m−3 Dm measured by floatation |
Monoclinic, P21 | Mo Kα radiation, λ = 0.71073 Å |
a = 4.1964 (3) Å | Cell parameters from 1345 reflections |
b = 7.0129 (5) Å | θ = 3.0–29.4° |
c = 14.4528 (10) Å | µ = 0.13 mm−1 |
β = 90.924 (7)° | T = 295 K |
V = 425.28 (5) Å3 | Parallelepiped, yellow |
Z = 2 | 0.24 × 0.22 × 0.16 mm |
Data collection top
KUMA KM-4 CCD diffractometer | 1893 independent reflections |
Radiation source: fine-focus sealed tube | 1386 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.020 |
Detector resolution: 1024x1024 with blocks 2x2 pixels mm-1 | θmax = 29.4°, θmin = 2.8° |
ω–scan | h = −5→5 |
Absorption correction: numerical Oxford Diffraction (2010). CrysAlis Red,
Version 1.171.33.42 | k = −7→9 |
Tmin = 0.974, Tmax = 0.984 | l = −19→19 |
5895 measured reflections | |
Refinement top
Refinement on F2 | Hydrogen site location: mixed |
Least-squares matrix: full | H atoms treated by a mixture of independent and constrained refinement |
R[F2 > 2σ(F2)] = 0.032 | w = 1/[σ2(Fo2) + (0.027P)2] where P = (Fo2 + 2Fc2)/3 |
wR(F2) = 0.059 | (Δ/σ)max < 0.001 |
S = 1.00 | Δρmax = 0.10 e Å−3 |
1893 reflections | Δρmin = −0.10 e Å−3 |
136 parameters | Absolute structure: Flack x determined using 449 quotients [(I+)-(I-)]/[(I+)+(I-)]
(Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259). |
1 restraint | Absolute structure parameter: −0.1 (1) |
Special details top
Geometry. 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. |
Refinement. 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. |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
O1 | 0.4383 (3) | 0.3386 (2) | 0.22542 (8) | 0.0459 (3) | |
C1 | 0.6066 (5) | 0.3173 (4) | 0.14708 (13) | 0.0459 (5) | |
C2 | 0.5733 (5) | 0.1441 (4) | 0.10957 (14) | 0.0566 (6) | |
H2 | 0.6671 | 0.0992 | 0.0559 | 0.068* | |
C3 | 0.3674 (5) | 0.0438 (4) | 0.16786 (14) | 0.0542 (6) | |
H3 | 0.2976 | −0.0812 | 0.1605 | 0.065* | |
C4 | 0.2904 (4) | 0.1661 (3) | 0.23720 (12) | 0.0412 (5) | |
N1 | 0.7921 (5) | 0.4765 (3) | 0.12053 (13) | 0.0609 (5) | |
O2 | 0.9453 (4) | 0.4585 (3) | 0.04943 (11) | 0.0849 (6) | |
O3 | 0.7958 (5) | 0.6193 (3) | 0.16871 (13) | 0.0914 (6) | |
C5 | 0.0920 (4) | 0.1536 (3) | 0.31757 (12) | 0.0411 (5) | |
H5 | 0.0562 | 0.2599 | 0.3544 | 0.049* | |
N2 | −0.0334 (3) | −0.0075 (2) | 0.33688 (10) | 0.0415 (4) | |
N3 | −0.2195 (4) | −0.0118 (2) | 0.41303 (11) | 0.0432 (4) | |
H1 | −0.276 (5) | 0.095 (3) | 0.4419 (14) | 0.052* | |
C6 | −0.3527 (5) | −0.1777 (3) | 0.44125 (12) | 0.0433 (5) | |
O4 | −0.5107 (4) | −0.17866 (19) | 0.51261 (9) | 0.0526 (4) | |
N4 | −0.3018 (6) | −0.3317 (3) | 0.39040 (16) | 0.0697 (6) | |
H41 | −0.207 (6) | −0.327 (4) | 0.3380 (17) | 0.084* | |
H42 | −0.387 (6) | −0.439 (4) | 0.4090 (17) | 0.084* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
O1 | 0.0465 (7) | 0.0500 (9) | 0.0415 (7) | 0.0037 (7) | 0.0135 (6) | 0.0046 (7) |
C1 | 0.0392 (10) | 0.0605 (13) | 0.0384 (10) | 0.0064 (12) | 0.0114 (9) | 0.0094 (12) |
C2 | 0.0458 (11) | 0.0825 (18) | 0.0419 (11) | 0.0076 (13) | 0.0105 (10) | −0.0077 (14) |
C3 | 0.0510 (12) | 0.0594 (14) | 0.0525 (12) | 0.0008 (11) | 0.0090 (11) | −0.0110 (11) |
C4 | 0.0364 (9) | 0.0448 (12) | 0.0423 (11) | 0.0035 (10) | 0.0014 (9) | 0.0011 (11) |
N1 | 0.0581 (11) | 0.0729 (14) | 0.0521 (11) | 0.0063 (11) | 0.0154 (10) | 0.0172 (11) |
O2 | 0.0801 (11) | 0.1127 (16) | 0.0629 (10) | 0.0028 (11) | 0.0343 (9) | 0.0236 (10) |
O3 | 0.1134 (14) | 0.0678 (13) | 0.0942 (13) | −0.0168 (11) | 0.0420 (12) | 0.0029 (12) |
C5 | 0.0405 (9) | 0.0437 (13) | 0.0394 (10) | 0.0038 (11) | 0.0062 (9) | 0.0016 (11) |
N2 | 0.0402 (9) | 0.0436 (11) | 0.0408 (9) | 0.0056 (8) | 0.0088 (8) | 0.0027 (8) |
N3 | 0.0507 (9) | 0.0359 (11) | 0.0435 (9) | 0.0037 (9) | 0.0149 (8) | −0.0014 (8) |
C6 | 0.0542 (11) | 0.0338 (10) | 0.0422 (11) | 0.0051 (11) | 0.0080 (9) | 0.0031 (11) |
O4 | 0.0757 (9) | 0.0357 (8) | 0.0471 (7) | −0.0004 (9) | 0.0224 (7) | 0.0025 (7) |
N4 | 0.1099 (17) | 0.0356 (11) | 0.0650 (12) | −0.0034 (11) | 0.0421 (12) | −0.0020 (10) |
Geometric parameters (Å, º) top
O1—C1 | 1.352 (2) | N1—O2 | 1.228 (2) |
O1—C4 | 1.372 (3) | C5—N2 | 1.278 (3) |
C1—C2 | 1.336 (3) | C5—H5 | 0.9300 |
C1—N1 | 1.418 (3) | N2—N3 | 1.360 (2) |
C2—C3 | 1.405 (3) | N3—C6 | 1.357 (3) |
C2—H2 | 0.9300 | N3—H1 | 0.89 (2) |
C3—C4 | 1.362 (3) | C6—O4 | 1.235 (2) |
C3—H3 | 0.9300 | C6—N4 | 1.326 (3) |
C4—C5 | 1.443 (2) | N4—H41 | 0.86 (2) |
N1—O3 | 1.220 (3) | N4—H42 | 0.88 (3) |
| | | |
C1—O1—C4 | 104.45 (18) | O2—N1—C1 | 116.3 (2) |
C2—C1—O1 | 112.82 (19) | N2—C5—C4 | 118.33 (18) |
C2—C1—N1 | 131.31 (19) | N2—C5—H5 | 120.8 |
O1—C1—N1 | 115.8 (2) | C4—C5—H5 | 120.8 |
C1—C2—C3 | 105.82 (19) | C5—N2—N3 | 116.11 (16) |
C1—C2—H2 | 127.1 | C6—N3—N2 | 120.47 (17) |
C3—C2—H2 | 127.1 | C6—N3—H1 | 117.7 (14) |
C4—C3—C2 | 106.4 (2) | N2—N3—H1 | 121.5 (14) |
C4—C3—H3 | 126.8 | O4—C6—N4 | 123.5 (2) |
C2—C3—H3 | 126.8 | O4—C6—N3 | 119.02 (19) |
C3—C4—O1 | 110.54 (17) | N4—C6—N3 | 117.47 (16) |
C3—C4—C5 | 134.5 (2) | C6—N4—H41 | 123 (2) |
O1—C4—C5 | 114.95 (16) | C6—N4—H42 | 117.5 (17) |
O3—N1—O2 | 124.1 (2) | H41—N4—H42 | 120 (3) |
O3—N1—C1 | 119.61 (18) | | |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N3—H1···O4i | 0.89 (2) | 1.94 (2) | 2.817 (2) | 166.6 (19) |
N4—H41···O3ii | 0.86 (2) | 2.48 (2) | 3.255 (3) | 151 (2) |
N4—H42···O4iii | 0.88 (3) | 2.07 (3) | 2.922 (2) | 162 (2) |
Symmetry codes: (i) −x−1, y+1/2, −z+1; (ii) x−1, y−1, z; (iii) −x−1, y−1/2, −z+1. |
Crystal data top
C6H6N4O4 | F(000) = 408 |
Mr = 198.15 | Dx = 1.592 Mg m−3 Dm = 1.59 Mg m−3 Dm measured by floatation |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
a = 13.5703 (6) Å | Cell parameters from 1345 reflections |
b = 7.8254 (3) Å | θ = 3.0–29.4° |
c = 7.9677 (4) Å | µ = 0.14 mm−1 |
β = 102.260 (4)° | T = 295 K |
V = 826.82 (6) Å3 | Parallelepiped, orange |
Z = 4 | 0.31 × 0.27 × 0.22 mm |
Data collection top
KUMA KM-4 with CCD detector diffractometer | 2127 independent reflections |
Radiation source: fine-focus sealed tube | 1614 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.015 |
Detector resolution: 1024x1024 with blocks 2x2 pixels mm-1 | θmax = 29.4°, θmin = 3.0° |
ω–scan | h = −18→17 |
Absorption correction: numerical Oxford Diffraction (2010). CrysAlis Red,
Version 1.171.33.42 | k = −10→10 |
Tmin = 0.961, Tmax = 0.976 | l = −10→10 |
11142 measured reflections | |
Refinement top
Refinement on F2 | 0 restraints |
Least-squares matrix: full | Hydrogen site location: mixed |
R[F2 > 2σ(F2)] = 0.029 | H atoms treated by a mixture of independent and constrained refinement |
wR(F2) = 0.081 | w = 1/[σ2(Fo2) + (0.0523P)2 + 0.0108P] where P = (Fo2 + 2Fc2)/3 |
S = 1.00 | (Δ/σ)max = 0.001 |
2127 reflections | Δρmax = 0.13 e Å−3 |
136 parameters | Δρmin = −0.17 e Å−3 |
Special details top
Geometry. 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. |
Refinement. 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. |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
O1 | 0.23439 (4) | 0.16292 (7) | 0.51987 (7) | 0.03382 (16) | |
C1 | 0.15329 (6) | 0.13258 (11) | 0.58773 (11) | 0.0340 (2) | |
C2 | 0.10884 (7) | 0.27700 (12) | 0.62574 (12) | 0.0413 (2) | |
H2 | 0.0519 | 0.2863 | 0.6727 | 0.050* | |
C3 | 0.16699 (7) | 0.41115 (12) | 0.57904 (12) | 0.0405 (2) | |
H3 | 0.1561 | 0.5276 | 0.5899 | 0.049* | |
C4 | 0.24227 (6) | 0.33758 (11) | 0.51490 (10) | 0.03248 (19) | |
N1 | 0.12908 (6) | −0.04135 (10) | 0.60652 (10) | 0.0428 (2) | |
O2 | 0.05919 (6) | −0.07059 (11) | 0.67792 (10) | 0.0605 (2) | |
O3 | 0.17783 (7) | −0.15180 (9) | 0.55223 (12) | 0.0687 (3) | |
C5 | 0.32308 (6) | 0.39903 (10) | 0.44028 (11) | 0.0338 (2) | |
H5 | 0.3657 | 0.3223 | 0.4018 | 0.041* | |
N2 | 0.33598 (5) | 0.56055 (9) | 0.42712 (9) | 0.03357 (18) | |
N3 | 0.41281 (6) | 0.60742 (9) | 0.35253 (9) | 0.03636 (19) | |
H3N | 0.4528 (8) | 0.5333 (14) | 0.3129 (13) | 0.044* | |
C6 | 0.43657 (7) | 0.77623 (11) | 0.34068 (11) | 0.0361 (2) | |
O4 | 0.51014 (6) | 0.81353 (9) | 0.28090 (10) | 0.0538 (2) | |
N4 | 0.37769 (7) | 0.88891 (11) | 0.39663 (13) | 0.0512 (2) | |
H41 | 0.3235 (10) | 0.8565 (15) | 0.4398 (15) | 0.061* | |
H42 | 0.3926 (9) | 0.9933 (17) | 0.3896 (15) | 0.061* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
O1 | 0.0349 (3) | 0.0241 (3) | 0.0465 (3) | −0.0035 (2) | 0.0178 (3) | 0.0008 (2) |
C1 | 0.0336 (4) | 0.0312 (4) | 0.0402 (4) | −0.0067 (3) | 0.0145 (4) | 0.0015 (3) |
C2 | 0.0396 (5) | 0.0407 (5) | 0.0493 (5) | −0.0024 (4) | 0.0224 (4) | −0.0020 (4) |
C3 | 0.0452 (5) | 0.0290 (4) | 0.0518 (5) | −0.0019 (4) | 0.0206 (4) | −0.0026 (4) |
C4 | 0.0365 (4) | 0.0244 (4) | 0.0379 (4) | −0.0041 (3) | 0.0110 (3) | 0.0006 (3) |
N1 | 0.0426 (4) | 0.0357 (4) | 0.0527 (5) | −0.0115 (3) | 0.0160 (4) | 0.0039 (3) |
O2 | 0.0564 (5) | 0.0596 (5) | 0.0735 (5) | −0.0212 (4) | 0.0314 (4) | 0.0094 (4) |
O3 | 0.0774 (6) | 0.0284 (4) | 0.1119 (7) | −0.0068 (3) | 0.0466 (5) | −0.0026 (4) |
C5 | 0.0361 (4) | 0.0262 (4) | 0.0429 (5) | −0.0022 (3) | 0.0165 (4) | 0.0003 (3) |
N2 | 0.0354 (4) | 0.0277 (3) | 0.0418 (4) | −0.0034 (3) | 0.0176 (3) | 0.0006 (3) |
N3 | 0.0420 (4) | 0.0228 (3) | 0.0524 (4) | −0.0014 (3) | 0.0284 (4) | −0.0009 (3) |
C6 | 0.0378 (5) | 0.0258 (4) | 0.0470 (5) | −0.0018 (3) | 0.0145 (4) | 0.0058 (3) |
O4 | 0.0472 (4) | 0.0351 (4) | 0.0885 (5) | −0.0040 (3) | 0.0356 (4) | 0.0141 (3) |
N4 | 0.0582 (6) | 0.0235 (4) | 0.0803 (6) | 0.0016 (4) | 0.0335 (5) | −0.0002 (4) |
Geometric parameters (Å, º) top
O1—C1 | 1.3464 (10) | N1—O2 | 1.2266 (11) |
O1—C4 | 1.3722 (10) | C5—N2 | 1.2834 (11) |
C1—C2 | 1.3455 (13) | C5—H5 | 0.9300 |
C1—N1 | 1.4155 (11) | N2—N3 | 1.3557 (10) |
C2—C3 | 1.4099 (13) | N3—C6 | 1.3678 (11) |
C2—H2 | 0.9300 | N3—H3N | 0.896 (12) |
C3—C4 | 1.3631 (13) | C6—O4 | 1.2291 (11) |
C3—H3 | 0.9300 | C6—N4 | 1.3289 (12) |
C4—C5 | 1.4367 (12) | N4—H41 | 0.911 (13) |
N1—O3 | 1.2221 (11) | N4—H42 | 0.846 (13) |
| | | |
C1—O1—C4 | 105.22 (6) | O2—N1—C1 | 116.62 (9) |
C2—C1—O1 | 112.71 (7) | N2—C5—C4 | 119.52 (8) |
C2—C1—N1 | 131.20 (8) | N2—C5—H5 | 120.2 |
O1—C1—N1 | 116.10 (8) | C4—C5—H5 | 120.2 |
C1—C2—C3 | 105.26 (8) | C5—N2—N3 | 115.67 (7) |
C1—C2—H2 | 127.4 | N2—N3—C6 | 120.41 (7) |
C3—C2—H2 | 127.4 | N2—N3—H3N | 124.0 (7) |
C4—C3—C2 | 106.89 (8) | C6—N3—H3N | 115.6 (7) |
C4—C3—H3 | 126.6 | O4—C6—N4 | 124.62 (8) |
C2—C3—H3 | 126.6 | O4—C6—N3 | 118.62 (8) |
C3—C4—O1 | 109.92 (7) | N4—C6—N3 | 116.76 (8) |
C3—C4—C5 | 135.44 (9) | C6—N4—H41 | 122.2 (8) |
O1—C4—C5 | 114.60 (7) | C6—N4—H42 | 116.7 (9) |
O3—N1—O2 | 124.21 (8) | H41—N4—H42 | 121.2 (12) |
O3—N1—C1 | 119.17 (8) | | |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N3—H3N···O4i | 0.896 (12) | 1.982 (12) | 2.8258 (10) | 156.3 (10) |
N4—H41···O3ii | 0.911 (13) | 2.338 (13) | 3.2283 (13) | 165.4 (11) |
Symmetry codes: (i) −x+1, y−1/2, −z+1/2; (ii) x, y+1, z. |
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