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The title structures, both C
10H
10N
4O, are substitutional isomers. The N—N bond lengths are longer and the C=N bond lengths are shorter by
ca 0.025 Å than the respective average values in the C=N—N=C group of asymmetric triazines; the assessed respective bond orders are 1.3 and 1.7. There are N—H
O and N—H
N hydrogen bonds in both structures, with 4-amino-3-methyl-6-phenyl-1,2,4-triazin-5(4
H)-one containing a rare bifurcated N—H
N,N hydrogen bond. The structures differ in their molecular stacking and the hydrogen-bonding patterns.
Supporting information
CCDC references: 645625; 645626
For both compounds, data collection: COLLECT (Nonius, 2000); cell refinement: HKL SCALEPACK (Otwinowski & Minor, 1997); data reduction: HKL DENZO (Otwinowski & Minor, 1997) and SCALEPACK; program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 2003); software used to prepare material for publication: SHELXL97.
(I) 4-amino-3-methyl-6-phenyl-1,2,4-triazin-5(4
H)-one
top
Crystal data top
C10H10N4O | Dx = 1.408 Mg m−3 |
Mr = 202.22 | Melting point: 442 K |
Orthorhombic, Pbca | Mo Kα radiation, λ = 0.71069 Å |
Hall symbol: -P 2ac 2ab | Cell parameters from 20449 reflections |
a = 9.5433 (2) Å | θ = 1–27.5° |
b = 9.1416 (2) Å | µ = 0.10 mm−1 |
c = 21.8652 (4) Å | T = 150 K |
V = 1907.54 (7) Å3 | Prism, colourless |
Z = 8 | 0.35 × 0.16 × 0.10 mm |
F(000) = 848 | |
Data collection top
Nonius KappaCCD diffractometer | 1816 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.015 |
Graphite monochromator | θmax = 27.5°, θmin = 3.6° |
Detector resolution: 9.091 pixels mm-1 | h = 0→12 |
ω scans | k = 0→11 |
4037 measured reflections | l = −28→28 |
2172 independent reflections | |
Refinement top
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.039 | H atoms treated by a mixture of independent and constrained refinement |
wR(F2) = 0.099 | w = 1/[σ2(Fo2) + (0.0473P)2 + 0.4343P] where P = (Fo2 + 2Fc2)/3 |
S = 1.07 | (Δ/σ)max < 0.001 |
2172 reflections | Δρmax = 0.19 e Å−3 |
146 parameters | Δρmin = −0.17 e Å−3 |
0 restraints | Extinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
31 constraints | Extinction coefficient: 0.010 (2) |
Primary atom site location: structure-invariant direct methods | |
Special details top
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes)
are estimated using the full covariance matrix. The cell e.s.d.'s are taken
into account individually in the estimation of e.s.d.'s in distances, angles
and torsion angles; correlations between e.s.d.'s in cell parameters are only
used when they are defined by crystal symmetry. An approximate (isotropic)
treatment of cell e.s.d.'s is used for estimating e.s.d.'s 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 >
σ(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 | |
N1 | 0.52246 (10) | 0.33863 (11) | 0.55975 (4) | 0.0303 (2) | |
N2 | 0.51372 (11) | 0.30930 (11) | 0.49829 (5) | 0.0327 (3) | |
N4 | 0.73621 (10) | 0.41068 (10) | 0.48514 (4) | 0.0273 (2) | |
N14 | 0.84248 (11) | 0.45224 (13) | 0.44339 (5) | 0.0349 (3) | |
O15 | 0.85921 (9) | 0.50747 (12) | 0.56381 (4) | 0.0450 (3) | |
C3 | 0.61899 (12) | 0.34511 (12) | 0.46302 (5) | 0.0284 (3) | |
C5 | 0.75262 (12) | 0.44546 (13) | 0.54638 (5) | 0.0291 (3) | |
C6 | 0.63274 (11) | 0.40094 (12) | 0.58377 (5) | 0.0262 (3) | |
C7 | 0.63123 (12) | 0.42502 (12) | 0.65095 (5) | 0.0275 (3) | |
C8 | 0.54034 (14) | 0.34282 (14) | 0.68712 (6) | 0.0352 (3) | |
C9 | 0.53178 (15) | 0.36659 (15) | 0.74954 (6) | 0.0408 (3) | |
C10 | 0.61393 (15) | 0.47204 (15) | 0.77706 (6) | 0.0402 (3) | |
C11 | 0.70411 (15) | 0.55361 (16) | 0.74189 (6) | 0.0425 (3) | |
C12 | 0.71363 (13) | 0.53109 (14) | 0.67920 (6) | 0.0369 (3) | |
C13 | 0.61174 (14) | 0.31096 (15) | 0.39650 (5) | 0.0370 (3) | |
H8 | 0.4848 | 0.2712 | 0.6691 | 0.042* | |
H9 | 0.4703 | 0.3112 | 0.7731 | 0.049* | |
H10 | 0.6083 | 0.4877 | 0.8190 | 0.048* | |
H11 | 0.7595 | 0.6248 | 0.7603 | 0.051* | |
H12 | 0.7753 | 0.5871 | 0.6560 | 0.044* | |
H13A | 0.5229 | 0.2668 | 0.3873 | 0.056* | |
H13B | 0.6857 | 0.2445 | 0.3859 | 0.056* | |
H13C | 0.6219 | 0.3996 | 0.3734 | 0.056* | |
H141 | 0.9004 (18) | 0.5183 (19) | 0.4663 (8) | 0.058 (5)* | |
H142 | 0.8956 (17) | 0.368 (2) | 0.4380 (7) | 0.059 (5)* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
N1 | 0.0316 (5) | 0.0341 (5) | 0.0251 (5) | −0.0042 (4) | −0.0005 (4) | 0.0008 (4) |
N2 | 0.0361 (6) | 0.0369 (6) | 0.0253 (5) | −0.0059 (4) | −0.0011 (4) | 0.0003 (4) |
N4 | 0.0271 (5) | 0.0289 (5) | 0.0257 (5) | 0.0035 (4) | 0.0036 (4) | 0.0044 (4) |
N14 | 0.0302 (6) | 0.0431 (6) | 0.0315 (5) | 0.0040 (5) | 0.0086 (4) | 0.0095 (5) |
O15 | 0.0326 (5) | 0.0613 (6) | 0.0411 (5) | −0.0158 (4) | 0.0057 (4) | −0.0105 (4) |
C3 | 0.0324 (6) | 0.0255 (5) | 0.0273 (6) | 0.0040 (5) | −0.0013 (5) | 0.0026 (4) |
C5 | 0.0290 (6) | 0.0285 (6) | 0.0300 (6) | −0.0003 (5) | 0.0014 (5) | −0.0004 (5) |
C6 | 0.0264 (6) | 0.0241 (5) | 0.0280 (6) | 0.0020 (4) | 0.0005 (4) | 0.0013 (4) |
C7 | 0.0264 (6) | 0.0287 (6) | 0.0273 (6) | 0.0057 (5) | −0.0012 (4) | 0.0004 (4) |
C8 | 0.0413 (7) | 0.0350 (6) | 0.0292 (6) | −0.0027 (5) | 0.0002 (5) | 0.0011 (5) |
C9 | 0.0530 (8) | 0.0409 (7) | 0.0286 (6) | 0.0009 (6) | 0.0053 (6) | 0.0044 (5) |
C10 | 0.0539 (8) | 0.0411 (7) | 0.0257 (6) | 0.0116 (6) | −0.0027 (6) | −0.0020 (5) |
C11 | 0.0473 (8) | 0.0460 (8) | 0.0343 (7) | −0.0002 (6) | −0.0064 (6) | −0.0093 (6) |
C12 | 0.0364 (7) | 0.0407 (7) | 0.0335 (6) | −0.0035 (6) | 0.0000 (5) | −0.0039 (5) |
C13 | 0.0447 (7) | 0.0398 (7) | 0.0265 (6) | 0.0039 (6) | −0.0006 (5) | −0.0004 (5) |
Geometric parameters (Å, º) top
N1—C6 | 1.3069 (14) | C13—H13B | 0.9600 |
N1—N2 | 1.3729 (13) | C13—H13C | 0.9600 |
O15—C5 | 1.2254 (14) | C7—C12 | 1.3929 (17) |
N4—C3 | 1.3582 (15) | C7—C8 | 1.3937 (17) |
N4—C5 | 1.3850 (14) | C8—C9 | 1.3844 (18) |
N4—N14 | 1.4163 (13) | C8—H8 | 0.9300 |
C5—C6 | 1.4638 (16) | C9—C10 | 1.3806 (19) |
C6—C7 | 1.4854 (15) | C9—H9 | 0.9300 |
N2—C3 | 1.3081 (15) | C10—C11 | 1.3741 (19) |
N14—H141 | 0.960 (18) | C10—H10 | 0.9300 |
N14—H142 | 0.928 (19) | C11—C12 | 1.3891 (17) |
C3—C13 | 1.4893 (16) | C11—H11 | 0.9300 |
C13—H13A | 0.9600 | C12—H12 | 0.9300 |
| | | |
C6—N1—N2 | 121.83 (9) | H13A—C13—H13C | 109.5 |
C3—N4—C5 | 122.59 (9) | H13B—C13—H13C | 109.5 |
C3—N4—N14 | 118.60 (9) | C12—C7—C8 | 118.37 (11) |
C5—N4—N14 | 118.72 (10) | C12—C7—C6 | 122.42 (11) |
O15—C5—N4 | 120.05 (10) | C8—C7—C6 | 119.16 (10) |
O15—C5—C6 | 127.13 (11) | C9—C8—C7 | 120.76 (12) |
N4—C5—C6 | 112.82 (10) | C9—C8—H8 | 119.6 |
N1—C6—C5 | 121.74 (10) | C7—C8—H8 | 119.6 |
N1—C6—C7 | 117.01 (10) | C10—C9—C8 | 120.38 (12) |
C5—C6—C7 | 121.25 (10) | C10—C9—H9 | 119.8 |
C3—N2—N1 | 118.78 (10) | C8—C9—H9 | 119.8 |
N4—N14—H141 | 104.1 (10) | C11—C10—C9 | 119.38 (12) |
N4—N14—H142 | 104.6 (10) | C11—C10—H10 | 120.3 |
H141—N14—H142 | 105.8 (14) | C9—C10—H10 | 120.3 |
N2—C3—N4 | 122.22 (10) | C10—C11—C12 | 120.86 (12) |
N2—C3—C13 | 119.18 (11) | C10—C11—H11 | 119.6 |
N4—C3—C13 | 118.59 (10) | C12—C11—H11 | 119.6 |
C3—C13—H13A | 109.5 | C11—C12—C7 | 120.25 (12) |
C3—C13—H13B | 109.5 | C11—C12—H12 | 119.9 |
H13A—C13—H13B | 109.5 | C7—C12—H12 | 119.9 |
C3—C13—H13C | 109.5 | | |
| | | |
N1—C6—C7—C8 | 20.31 (15) | C5—C6—C7—C8 | −159.76 (11) |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N14—H141···O15 | 0.960 (18) | 2.169 (17) | 2.6856 (14) | 112.3 (12) |
N14—H141···O15i | 0.960 (18) | 2.398 (17) | 2.8749 (13) | 110.2 (12) |
N14—H142···N1ii | 0.928 (19) | 2.245 (19) | 3.1663 (15) | 171.3 (14) |
N14—H142···N2ii | 0.928 (19) | 2.418 (18) | 3.1643 (15) | 137.4 (13) |
C12—H12···O15 | 0.93 | 2.29 | 2.8883 (16) | 122 |
Symmetry codes: (i) −x+2, −y+1, −z+1; (ii) x+1/2, −y+1/2, −z+1. |
(II) 4-amino-6-methyl-3-phenyl-1,2,4-triazin-5(4
H)-one
top
Crystal data top
C10H10N4O | F(000) = 424 |
Mr = 202.22 | Dx = 1.458 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ybc | Cell parameters from 7789 reflections |
a = 11.6164 (3) Å | θ = 1.0–27.5° |
b = 7.1361 (2) Å | µ = 0.10 mm−1 |
c = 12.0604 (3) Å | T = 150 K |
β = 112.8259 (15)° | Prism, colourless |
V = 921.46 (4) Å3 | 0.25 × 0.17 × 0.08 mm |
Z = 4 | |
Data collection top
Nonius KappaCCD diffractometer | 1803 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.016 |
Graphite monochromator | θmax = 27.5°, θmin = 3.4° |
Detector resolution: 9.091 pixels mm-1 | h = 0→15 |
ω scans | k = 0→9 |
3998 measured reflections | l = −15→14 |
2108 independent reflections | |
Refinement top
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.038 | H atoms treated by a mixture of independent and constrained refinement |
wR(F2) = 0.099 | w = 1/[σ2(Fo2) + (0.0484P)2 + 0.2548P] where P = (Fo2 + 2Fc2)/3 |
S = 1.05 | (Δ/σ)max < 0.001 |
2108 reflections | Δρmax = 0.24 e Å−3 |
146 parameters | Δρmin = −0.23 e Å−3 |
0 restraints | Extinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
31 constraints | Extinction coefficient: 0.017 (5) |
Primary atom site location: structure-invariant direct methods | |
Special details top
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes)
are estimated using the full covariance matrix. The cell e.s.d.'s are taken
into account individually in the estimation of e.s.d.'s in distances, angles
and torsion angles; correlations between e.s.d.'s in cell parameters are only
used when they are defined by crystal symmetry. An approximate (isotropic)
treatment of cell e.s.d.'s is used for estimating e.s.d.'s 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 >
σ(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 | |
N1 | 0.70297 (8) | 0.04829 (13) | 0.18989 (8) | 0.0205 (2) | |
N2 | 0.57868 (8) | 0.05598 (13) | 0.17105 (8) | 0.0184 (2) | |
C3 | 0.54461 (9) | 0.11683 (15) | 0.25635 (9) | 0.0165 (2) | |
N4 | 0.62961 (8) | 0.17043 (12) | 0.36646 (8) | 0.0168 (2) | |
N14 | 0.59296 (9) | 0.23283 (14) | 0.45932 (8) | 0.0202 (2) | |
H141 | 0.6650 (15) | 0.283 (2) | 0.5147 (14) | 0.035 (4)* | |
H142 | 0.5383 (14) | 0.330 (2) | 0.4286 (13) | 0.031 (4)* | |
C5 | 0.75730 (10) | 0.15325 (15) | 0.39549 (9) | 0.0190 (3) | |
O15 | 0.83305 (7) | 0.19110 (12) | 0.49680 (7) | 0.0267 (2) | |
C6 | 0.78722 (10) | 0.09301 (16) | 0.29451 (10) | 0.0198 (3) | |
C13 | 0.92131 (10) | 0.08633 (18) | 0.31095 (11) | 0.0280 (3) | |
H133 | 0.9658 | 0.0020 | 0.3754 | 0.042* | |
H132 | 0.9569 | 0.2094 | 0.3300 | 0.042* | |
H131 | 0.9275 | 0.0433 | 0.2380 | 0.042* | |
C7 | 0.40765 (10) | 0.12484 (15) | 0.22530 (9) | 0.0175 (2) | |
C8 | 0.33239 (11) | 0.18077 (16) | 0.10838 (10) | 0.0214 (3) | |
H8 | 0.3687 | 0.2210 | 0.0561 | 0.026* | |
C9 | 0.20355 (11) | 0.17613 (17) | 0.07057 (11) | 0.0270 (3) | |
H9 | 0.1537 | 0.2139 | −0.0071 | 0.032* | |
C10 | 0.14854 (11) | 0.11585 (17) | 0.14742 (11) | 0.0276 (3) | |
H10 | 0.0620 | 0.1136 | 0.1215 | 0.033* | |
C11 | 0.22278 (11) | 0.05873 (17) | 0.26330 (11) | 0.0255 (3) | |
H11 | 0.1858 | 0.0171 | 0.3148 | 0.031* | |
C12 | 0.35242 (10) | 0.06347 (15) | 0.30276 (10) | 0.0205 (3) | |
H12 | 0.4020 | 0.0258 | 0.3806 | 0.025* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
N1 | 0.0180 (5) | 0.0226 (5) | 0.0212 (5) | 0.0007 (4) | 0.0079 (4) | 0.0018 (4) |
N2 | 0.0173 (5) | 0.0210 (5) | 0.0167 (4) | −0.0003 (4) | 0.0065 (4) | 0.0005 (3) |
C3 | 0.0187 (5) | 0.0144 (5) | 0.0146 (5) | −0.0006 (4) | 0.0045 (4) | 0.0016 (4) |
N4 | 0.0174 (5) | 0.0177 (5) | 0.0145 (4) | 0.0010 (3) | 0.0051 (4) | 0.0006 (3) |
N14 | 0.0224 (5) | 0.0233 (5) | 0.0139 (4) | 0.0017 (4) | 0.0061 (4) | −0.0016 (4) |
C5 | 0.0183 (5) | 0.0172 (5) | 0.0182 (5) | 0.0012 (4) | 0.0034 (4) | 0.0024 (4) |
O15 | 0.0211 (4) | 0.0319 (5) | 0.0202 (4) | 0.0008 (3) | 0.0005 (3) | −0.0025 (3) |
C6 | 0.0189 (5) | 0.0189 (5) | 0.0211 (5) | 0.0008 (4) | 0.0071 (4) | 0.0031 (4) |
C13 | 0.0196 (6) | 0.0352 (7) | 0.0291 (6) | 0.0003 (5) | 0.0093 (5) | 0.0008 (5) |
C7 | 0.0182 (5) | 0.0147 (5) | 0.0192 (5) | −0.0002 (4) | 0.0067 (4) | −0.0016 (4) |
C8 | 0.0215 (6) | 0.0217 (6) | 0.0195 (5) | 0.0008 (4) | 0.0062 (4) | 0.0007 (4) |
C9 | 0.0214 (6) | 0.0281 (6) | 0.0244 (6) | 0.0030 (5) | 0.0012 (5) | −0.0001 (5) |
C10 | 0.0171 (5) | 0.0275 (6) | 0.0360 (7) | −0.0006 (5) | 0.0080 (5) | −0.0051 (5) |
C11 | 0.0246 (6) | 0.0239 (6) | 0.0319 (6) | −0.0041 (5) | 0.0152 (5) | −0.0036 (5) |
C12 | 0.0219 (6) | 0.0188 (6) | 0.0204 (5) | −0.0010 (4) | 0.0078 (4) | −0.0013 (4) |
Geometric parameters (Å, º) top
N1—C6 | 1.3013 (14) | C13—H132 | 0.9600 |
N1—N2 | 1.3729 (12) | C13—H131 | 0.9600 |
N2—C3 | 1.3112 (13) | C7—C12 | 1.3933 (15) |
C3—N4 | 1.3666 (13) | C7—C8 | 1.3984 (15) |
C3—C7 | 1.4874 (14) | C8—C9 | 1.3855 (17) |
N4—C5 | 1.3910 (14) | C8—H8 | 0.9300 |
N4—N14 | 1.4155 (12) | C9—C10 | 1.3826 (18) |
N14—H141 | 0.917 (16) | C9—H9 | 0.9300 |
N14—H142 | 0.917 (15) | C10—C11 | 1.3886 (17) |
C5—O15 | 1.2271 (13) | C10—H10 | 0.9300 |
C5—C6 | 1.4551 (15) | C11—C12 | 1.3926 (16) |
C6—C13 | 1.4927 (15) | C11—H11 | 0.9300 |
C13—H133 | 0.9600 | C12—H12 | 0.9300 |
| | | |
C6—N1—N2 | 119.85 (9) | H133—C13—H131 | 109.5 |
C3—N2—N1 | 120.10 (9) | H132—C13—H131 | 109.5 |
N2—C3—N4 | 122.06 (9) | C12—C7—C8 | 119.70 (10) |
N2—C3—C7 | 115.73 (9) | C12—C7—C3 | 123.02 (9) |
N4—C3—C7 | 122.21 (9) | C8—C7—C3 | 117.00 (9) |
C3—N4—C5 | 121.19 (9) | C9—C8—C7 | 119.86 (10) |
C3—N4—N14 | 122.08 (9) | C9—C8—H8 | 120.1 |
C5—N4—N14 | 116.57 (8) | C7—C8—H8 | 120.1 |
N4—N14—H141 | 103.3 (9) | C10—C9—C8 | 120.53 (11) |
N4—N14—H142 | 107.0 (9) | C10—C9—H9 | 119.7 |
H141—N14—H142 | 107.0 (13) | C8—C9—H9 | 119.7 |
O15—C5—N4 | 120.93 (10) | C9—C10—C11 | 119.86 (11) |
O15—C5—C6 | 125.91 (10) | C9—C10—H10 | 120.1 |
N4—C5—C6 | 113.14 (9) | C11—C10—H10 | 120.1 |
N1—C6—C5 | 123.37 (10) | C10—C11—C12 | 120.26 (11) |
N1—C6—C13 | 118.33 (10) | C10—C11—H11 | 119.9 |
C5—C6—C13 | 118.29 (10) | C12—C11—H11 | 119.9 |
C6—C13—H133 | 109.5 | C11—C12—C7 | 119.78 (10) |
C6—C13—H132 | 109.5 | C11—C12—H12 | 120.1 |
H133—C13—H132 | 109.5 | C7—C12—H12 | 120.1 |
C6—C13—H131 | 109.5 | | |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N14—H141···O15 | 0.917 (16) | 2.148 (15) | 2.6633 (13) | 114.6 (12) |
N14—H141···N1i | 0.917 (16) | 2.321 (15) | 3.0081 (13) | 131.5 (12) |
N14—H142···N2ii | 0.917 (15) | 2.149 (15) | 3.0550 (13) | 169.3 (12) |
C12—H12···N14 | 0.93 | 2.52 | 2.9564 (16) | 109 |
Symmetry codes: (i) x, −y+1/2, z+1/2; (ii) −x+1, y+1/2, −z+1/2. |
Table 3. Selected bond lengths (Å) in (I), (II) and (III) topBond | (I) | Bond | (II) | Bond | (III) |
C6—C7 | 1.4854 (15) | C3—C7 | 1.4874 (14) | – | – |
C6—N1 | 1.3069 (14) | C3—N2 | 1.3112 (13) | C1—N2 | 1.315 (7) |
N1—N2 | 1.3729 (13) | N1—N2 | 1.3729 (12) | N1—N2 | 1.358 (7) |
N2—C3 | 1.3081 (15) | N1—C6 | 1.3013 (14) | N1—C3 | 1.303 (7) |
C3—N4 | 1.3582 (15) | C3—N4 | 1.3666 (13) | C1—N3 | 1.376 (7) |
N4—C5 | 1.3850 (14) | N4—C5 | 1.3910 (14) | C2—N3 | 1.381 (6) |
C5—C6 | 1.4638 (16) | C5—C6 | 1.4551 (15) | C2—C3 | 1.504 (7) |
C3—C13 | 1.4893 (16) | C6—C13 | 1.4927 (15) | C3—C5 | 1.488 (7) |
N4—N14 | 1.4163 (13) | N4—N14 | 1.4155 (12) | N3—N4 | 1.397 (6) |
C5—O15 | 1.2254 (14) | C5—O15 | 1.2270 (13) | C2—O1 | 1.203 (7) |
Table 4. The representative structures containing the motif C—N—N—C with
varying order of C—N and N—N bonds
and with the corresponding bond lengths (Å). The structures contained no
disorder and are not flagged with errors. topREFCODE | C—N bond length | Bond order | N—N bond length | Bond order |
AZBENC01a | 1.443 | 1 | 1.251 | 2 |
AZOBEN12b | 1.430 | 1 | 1.256 | 2 |
| 1.430 | 1 | 1.249 | 2 |
AZOBEN13c | 1.431 | 1 | 1.256 | 2 |
| 1.431 | 1 | 1.249 | 2 |
BZAZIN11d | 1.269 | 2 | 1.413 | 1 |
PYRDNA01e | 1.336 | 1.5 | – | – |
TRIZIN01f | 1.317 | .5 | – | – |
(a) cis-Azobenzene (Mostad & Römming, 1971);
(b) trans-azobenzene (Harada & Ogawa, 2004);
(c) trans-azobenzene (Harada & Ogawa, 2004);
(d) benzalazine (Burke-Laing & Laing, 1976);
(e) pyridine (Mootz & Wussow, 1981), average values
from four independent molecules (the average C—C bond length
corresponding to the bond order 1.5 is 1.379 Å);
(f) s-triazine (Coppens, 1967).
(a), (d), (f) were determined at room temperature, (e) at 153 K, and
(b), (c) at 90 K. |
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