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Oxidation of tetra­hydro­di­spiro­benz­imidazole by m-chloro­per­benzoic acid did not produce di­spiro-2H-benz­imidazole, which is the product obtained by oxidation with MnO2. Instead, a mixture of two compounds was identified, namely dispiro[2H-benzimidazole-2,1′-cyclohexane-4′,2′′-[2H]benzimidazole] 1-oxide, C18H16N4O, (III), and di­spiro­[2H-benz­imid­azole-2,1′-cyclo­hexane-4′,2′′-[2H]­benz­imidazole] 1,1′′-di­oxide, C18H16N4O2, (IV). In (III), the mol­ecules are disordered about a twofold rotation axis and have 2/m site symmetry. In (IV), the crystals are triclinic and the mol­ecules occupy crystallographic inversion centers. Although the two compounds are very similar and are arranged in layers, they adopt completely different packing modes within the layers, viz. herring-bone in (III) and parallel mol­ecules in (IV). The mol­ecules within the layers are held together by C—H...O and C—H...N hydrogen bonds.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270102001099/oa1128sup1.cif
Contains datablocks III, IV, global

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270102001099/oa1128IIIsup2.hkl
Contains datablock III

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270102001099/oa1128IVsup3.hkl
Contains datablock IV

CCDC references: 183032; 183033

Comment top

We have attempted to prepare tetranitroxide (V) (see Scheme 1) by a procedure similar to that described by Keana et al. (1967, 1978). Following the guidelines of Davies et al. (1984) and Herbert et al. (1988), dispiro(2H-benzimidazole-2,1'-cyclohexane-4,2''-[2H]benzimidazole), (I), was prepared. Oxidation of (I) by MnO2 led to the dispiro-2H-benzimidazole (II) (Herbert et al., 1988) (see Scheme 2). Further oxidation by m-chloroperbenzoic acid (von Glahn et al., 1999) produced (E)- and (Z)-dispiro[2H-benzimidazole-2,1'-cyclohexane-4',2''-[2H]benzimidazole] 1,1''-dioxide, i.e. (IV) and (IV'), respectively (see Scheme 2). We carried out the oxidation of (I) by m-chloroperbenzoic acid, skipping the oxidation step with MnO2. Two major products were identified, namely dispiro[2H-benzimidazole-2,1'-cyclohexane-4', 2''-[2H]benzimidazole] 1-oxide, (III), and dispiro[2H-benzimidazole-2,1'-cyclohexane-4',2''-[2H]benzimidazole] 1,1''-dioxide, (IV). Although the chemical difference between the two compounds is small, the crystal structures are completely different. Monoxide (III) crystallizes in the orthorhombic space group Cmca, occupying the 2/m crystallographic site symmetry. This means that the O atom is equally disordered between two sites related by a twofold symmetry axis. The crystals of dioxide (IV) are triclinic and the molecule occupies a crystallographic inversion center. The packing of the molecules of (III) and (IV) in the unit cells are shown in Figs. 1 and 2, respectively. In both, the molecules form layers but the arrangement of molecules within the layer is different. While the molecules in (III) adopt a herring=bone packing motif, the molecules are parallel in (IV). The molecules within a layer are held together by short intermolecular O···H—C and N···H—C contacts. Only two such contacts that were observed in the crystal structure of (III) could be considered hydrogen bonds: O1···H4 2.205 (3) Å, O1···C4 3.110 (3) Å and O1···H4—C4 158.7 (2)°; N2···H3 2.605 (3) Å, N2···C3 3.510 Å and N2···H3—C3 159.3 (2)°. In (IV), there is only one hydrogen bond [O1···H2 2.470 (4) Å, O1···C2 3.327 (4) Å and O1···H2—C2 153.4 (3)°]. The packing of the layers is also very different. While the molecules between successive layers in (IV) are related by translation, those in (III) are related by a twofold rotation axis perpendicular to the benzimidazole portions of the molecules (see Figs. 3 and 4). A comparison of bond lengths and angles is given in Table 1. Also compared in Table 1 are the bond lengths of the relevant moiety in benzimidazole dioxide (VI) (Keller et al., 1977), benzimidazole (VII), and dihydrobenzimidazole (VIII) (Hazelton et al., 1995) (see Scheme 3). The localization of double bonds in the benzene ring is clearly observed in (III), (IV) and (VII), where the C2—C3 and C4—C5 bonds are significantly shorter than C1—C2, C3—C4, C5—C6 and C1—C6 (see notation in Fig. 1), while in (VI) and (VIII) these bonds are normal for aromatic compounds. Some bond lengths should be noted; the N1—O1 bond length is significantly shorter in monooxyl (III) [1.152 (3) Å] than in dioxyl (IV) [1.274 (3) Å], and (VI) [1.28 (2) and 1.34 (3) Å]. The experimental geometry at the nitroxide group in (III) is strongly affected by the disorder. The disordered moiety is an average between benzimidazole [such as (VI)] and benzimidazoleoxide [such as (VII)]. The position of atom N1 is an average between two sites. The distance between the theoretical positions of the two sites is only 0.12 Å and all attempts to refine these positions separately or by fixing them failed to provide more reliable geometry. The N1C1 and N2C6 bond lengths are chemically equivalent within each of the compounds (VI), (VII) and (VIII), and therefore the bond lengths are equal within each molecule either as localized double bonds in (VII) [1.30 (1) and 1.30 (1) Å], localized Nsp3—Csp2 single bonds in (VIII) [1.399 (7) and 1.403 (7) Å] or delocalized double bonds in (VII) [1.34 (3) and 1.33 (3) Å]. These bonds in (IV) are significantly different [N1C1 1.320 (3) Å and N2C6 1.307 (3) Å] because only one of the two N atoms is connected to the electronegative atom O1; therefore the later is compared to the equivalent bond in (VI), and the former should be compared with that in (VII). The N2 C6 bond in (IV) is not affected by the disorder and therefore the bond length of 1.303 (3) Å is similar to that found in (VII). The N1C1 bond length in (III) is somewhat longer [1.312 (3) Å] as a result of the disorder. The presence of (III) in the reaction bath might suggest that the oxidation takes place in two steps. In the first step, the monooxyl is formed and in the second step, the second N atom is oxidized.

Experimental top

Compound (I) was synthesized according to the procedure of Herbert et al. (1988) (see Scheme 1). Monooxyl (III) and dioxyl (IV) were prepared by oxidation of (I) (0.29 g, 1 mmol) by dropwise addition over 20 min of an ether solution of m-chloroperbenzoic acid (MPCA; 0.95 g, 5.5 mmol) at 273 K. Overnight stirring produced a yellow solution which was washed with 5% Na2CO3, dried (K2CO3) and evaporated. After chromatography of the resulting solid over silica gel with CHCl3, two substances were isolated, monooxyl (III) [90 mg, 30%; MS (M++1): 305] and dioxyl (IV) [118 mg, 37%; MS: (M++1) 321].

Refinement top

The positions of all H atoms were located in a difference Fourier map and they were refined as riding on their attached atoms (C—H = 0.95 and 0.99 Å).

Computing details top

Data collection: COLLECT (Nonius, 1998) for (III); Philips PW1100/20 Software (Philips, 1973) for (IV). Cell refinement: DENZO-SMN (Otwinowski & Minor, 1997) for (III); Philips PW1100/20 Software for (IV). Data reduction: DENZO-SMN for (III); Philips PW1100/20 Software for (IV). Program(s) used to solve structure: SHELXS97 (Sheldrick, 1997a) for (III); SHELXS97 (Sheldrick, 1997) for (IV). Program(s) used to refine structure: SHELXL97 (Sheldrick, 1997b) for (III); SHELXL97 (Sheldrick, 1997) for (IV). Molecular graphics: ORTEP-3 for Windows (Farrugia, 1997) for (III); ORTEP-3 (Farrugia, 1997) for (IV).

Figures top
[Figure 1] Fig. 1. The structure of a layer of (III) down the a axis (the c axis is pointing upwards) (ORTEP-3; Farrugia, 1997).
[Figure 2] Fig. 2. The structure of a layer of (IV) (the b axis is pointing upwards and the a axis is pointing to the right) (ORTEP-3; Farrugia, 1997).
[Figure 3] Fig. 3. Overlap diagram of (III) (ORTEP-3; Farrugia, 1997).
[Figure 4] Fig. 4. Overlap diagram of (IV) (ORTEP-3; Farrugia, 1997).
(III) Dispiro[2H-benzimidazole-2,1'-cyclohexane-4',2''- [2H]benzimidazole],1,-oxide top
Crystal data top
C18H16N4ODx = 1.395 Mg m3
Mr = 304.35Mo Kα radiation, λ = 0.71069 Å
Orthorhombic, CmcaCell parameters from 902 reflections
a = 6.774 (2) Åθ = 0.9–27.5°
b = 15.875 (3) ŵ = 0.09 mm1
c = 13.477 (3) ÅT = 150 K
V = 1449.3 (6) Å3Prism, orange–red
Z = 40.50 × 0.35 × 0.30 mm
F(000) = 640
Data collection top
Nonius KappaCCD
diffractometer
658 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.054
Graphite monochromatorθmax = 27.5°, θmin = 2.6°
ϕ and ω scansh = 08
3482 measured reflectionsk = 2020
902 independent reflectionsl = 1617
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.043H-atom parameters constrained
wR(F2) = 0.119 w = 1/[σ2(Fo2) + (0.0602P)2 + 0.5909P]
where P = (Fo2 + 2Fc2)/3
S = 1.02(Δ/σ)max < 0.001
902 reflectionsΔρmax = 0.22 e Å3
77 parametersΔρmin = 0.17 e Å3
0 restraintsExtinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methodsExtinction coefficient: 0.038 (5)
Crystal data top
C18H16N4OV = 1449.3 (6) Å3
Mr = 304.35Z = 4
Orthorhombic, CmcaMo Kα radiation
a = 6.774 (2) ŵ = 0.09 mm1
b = 15.875 (3) ÅT = 150 K
c = 13.477 (3) Å0.50 × 0.35 × 0.30 mm
Data collection top
Nonius KappaCCD
diffractometer
658 reflections with I > 2σ(I)
3482 measured reflectionsRint = 0.054
902 independent reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0430 restraints
wR(F2) = 0.119H-atom parameters constrained
S = 1.02Δρmax = 0.22 e Å3
902 reflectionsΔρmin = 0.17 e Å3
77 parameters
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
xyzUiso*/UeqOcc. (<1)
O10.00000.02025 (17)0.2498 (2)0.0400 (7)0.50
N10.00000.07428 (11)0.19275 (12)0.0355 (5)
N20.00000.14359 (11)0.03727 (12)0.0352 (5)
C10.00000.15606 (13)0.20659 (14)0.0326 (5)
C20.00000.20307 (13)0.29706 (14)0.0340 (5)
C30.00000.28779 (14)0.28967 (15)0.0372 (5)
C40.00000.33013 (14)0.19452 (16)0.0393 (6)
C50.00000.28830 (14)0.10753 (16)0.0398 (6)
C60.00000.19724 (12)0.11008 (14)0.0320 (5)
C70.00000.06067 (12)0.08329 (15)0.0343 (5)
C80.1861 (2)0.01152 (10)0.05516 (10)0.0371 (4)
H20.00000.17580.35980.045 (7)*
H30.00000.32060.34860.046 (7)*
H40.00000.39000.19340.052 (7)*
H50.00000.31780.04620.046 (7)*
H810.30410.04600.07030.046 (4)*
H820.19350.04060.09540.043 (4)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0594 (19)0.0318 (15)0.0290 (14)0.0000.0000.0079 (14)
N10.0363 (10)0.0402 (10)0.0301 (9)0.0000.0000.0075 (8)
N20.0376 (10)0.0384 (10)0.0296 (9)0.0000.0000.0055 (7)
C10.0282 (10)0.0408 (11)0.0288 (10)0.0000.0000.0062 (8)
C20.0328 (11)0.0414 (12)0.0279 (10)0.0000.0000.0069 (9)
C30.0356 (12)0.0436 (12)0.0325 (11)0.0000.0000.0116 (9)
C40.0384 (12)0.0362 (12)0.0432 (12)0.0000.0000.0056 (9)
C50.0451 (13)0.0387 (12)0.0356 (11)0.0000.0000.0017 (9)
C60.0325 (11)0.0351 (11)0.0284 (10)0.0000.0000.0046 (8)
C70.0353 (11)0.0343 (11)0.0334 (11)0.0000.0000.0104 (8)
C80.0318 (8)0.0404 (9)0.0392 (9)0.0005 (6)0.0021 (6)0.0123 (6)
Geometric parameters (Å, º) top
O1—N11.152 (3)C3—H30.9500
N1—C11.312 (3)C4—C51.348 (3)
N1—C71.491 (3)C4—H40.9500
N2—C61.299 (2)C5—C61.446 (3)
N2—C71.455 (3)C5—H50.9500
C1—C21.430 (3)C7—C8i1.5303 (18)
C1—C61.456 (3)C7—C81.5303 (18)
C2—C31.349 (3)C8—C8ii1.531 (3)
C2—H20.9500C8—H810.9900
C3—C41.448 (3)C8—H820.9900
O1—N1—C1130.0 (2)C4—C5—H5120.9
O1—N1—C7123.5 (2)C6—C5—H5120.9
C1—N1—C7106.51 (16)N2—C6—C5129.59 (19)
C6—N2—C7105.73 (16)N2—C6—C1112.36 (18)
N1—C1—C2129.65 (19)C5—C6—C1118.05 (17)
N1—C1—C6108.51 (16)N2—C7—N1106.89 (15)
C2—C1—C6121.84 (19)N2—C7—C8i110.83 (12)
C3—C2—C1117.24 (19)N1—C7—C8i108.60 (11)
C3—C2—H2121.4N2—C7—C8110.83 (12)
C1—C2—H2121.4N1—C7—C8108.60 (11)
C2—C3—C4121.90 (19)C8i—C7—C8110.94 (16)
C2—C3—H3119.1C8ii—C8—C7111.24 (12)
C4—C3—H3119.1C8ii—C8—H81109.4
C5—C4—C3122.8 (2)C7—C8—H81109.4
C5—C4—H4118.6C8ii—C8—H82109.4
C3—C4—H4118.6C7—C8—H82109.4
C4—C5—C6118.2 (2)H81—C8—H82108.0
O1—N1—C1—C20.0N1—C1—C6—C5180.0
C7—N1—C1—C2180.0C2—C1—C6—C50.0
O1—N1—C1—C6180.0C6—N2—C7—N10.0
C7—N1—C1—C60.0C6—N2—C7—C8i118.18 (12)
N1—C1—C2—C3180.0C6—N2—C7—C8118.18 (12)
C6—C1—C2—C30.0O1—N1—C7—N2180.0
C1—C2—C3—C40.0C1—N1—C7—N20.0
C2—C3—C4—C50.0O1—N1—C7—C8i60.37 (11)
C3—C4—C5—C60.0C1—N1—C7—C8i119.63 (11)
C7—N2—C6—C5180.0O1—N1—C7—C860.37 (11)
C7—N2—C6—C10.0C1—N1—C7—C8119.63 (11)
C4—C5—C6—N2180.0N2—C7—C8—C8ii67.98 (18)
C4—C5—C6—C10.0N1—C7—C8—C8ii174.88 (14)
N1—C1—C6—N20.0C8i—C7—C8—C8ii55.6 (2)
C2—C1—C6—N2180.0
Symmetry codes: (i) x, y, z; (ii) x, y, z.
(IV) dispiro [2H-benzimidazole-2,1'-cyclohexane-4',2''-[2H]benzimidazole], 1,1''-dioxide top
Crystal data top
C18H16N4O2Z = 1
Mr = 320.34F(000) = 168
Triclinic, P1Dx = 1.411 Mg m3
a = 5.416 (2) ÅMo Kα radiation, λ = 0.71069 Å
b = 7.290 (2) ÅCell parameters from 25 reflections
c = 10.426 (3) Åθ = 3.1–12.2°
α = 104.39 (3)°µ = 0.10 mm1
β = 104.15 (3)°T = 293 K
γ = 98.41 (3)°Plate, yellow
V = 377.1 (2) Å30.4 × 0.3 × 0.25 mm
Data collection top
Philips PW1100
diffractometer
Rint = 0.036
Radiation source: fine-focus sealed tubeθmax = 25.0°, θmin = 2.1°
Graphite monochromatorh = 66
ω/2θ scansk = 88
1422 measured reflectionsl = 012
1339 independent reflections3 standard reflections every 120 min
885 reflections with I > 2σ(I) intensity decay: 7.3%
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.053Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.139H-atom parameters constrained
S = 1.06 w = 1/[σ2(Fo2) + (0.0567P)2 + 0.0683P]
where P = (Fo2 + 2Fc2)/3
1339 reflections(Δ/σ)max < 0.001
117 parametersΔρmax = 0.20 e Å3
0 restraintsΔρmin = 0.18 e Å3
Crystal data top
C18H16N4O2γ = 98.41 (3)°
Mr = 320.34V = 377.1 (2) Å3
Triclinic, P1Z = 1
a = 5.416 (2) ÅMo Kα radiation
b = 7.290 (2) ŵ = 0.10 mm1
c = 10.426 (3) ÅT = 293 K
α = 104.39 (3)°0.4 × 0.3 × 0.25 mm
β = 104.15 (3)°
Data collection top
Philips PW1100
diffractometer
Rint = 0.036
1422 measured reflections3 standard reflections every 120 min
1339 independent reflections intensity decay: 7.3%
885 reflections with I > 2σ(I)
Refinement top
R[F2 > 2σ(F2)] = 0.0530 restraints
wR(F2) = 0.139H-atom parameters constrained
S = 1.06Δρmax = 0.20 e Å3
1339 reflectionsΔρmin = 0.18 e Å3
117 parameters
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
xyzUiso*/Ueq
O10.0836 (4)0.7268 (3)0.3112 (2)0.0567 (6)
N10.0766 (4)0.7937 (3)0.2539 (2)0.0381 (6)
N20.2981 (4)0.8060 (3)0.0879 (2)0.0372 (6)
C10.2504 (5)0.9603 (4)0.2994 (3)0.0362 (6)
C20.3161 (6)1.1149 (4)0.4242 (3)0.0449 (7)
C30.5157 (6)1.2607 (4)0.4436 (3)0.0517 (8)
C40.6519 (6)1.2672 (4)0.3419 (3)0.0521 (8)
C50.5908 (6)1.1253 (4)0.2206 (3)0.0470 (8)
C60.3842 (5)0.9614 (4)0.1951 (3)0.0360 (6)
C70.0962 (5)0.6816 (4)0.1158 (3)0.0338 (6)
C80.1671 (5)0.6423 (4)0.0080 (3)0.0399 (7)
C90.1757 (5)0.4932 (4)0.1304 (3)0.0389 (7)
H20.22491.11480.48900.066 (10)*
H30.56841.36160.52590.046 (8)*
H40.78731.37340.36030.045 (8)*
H50.68001.13350.15570.058 (9)*
H810.30260.58520.04140.054 (8)*
H820.20260.76430.00470.051 (8)*
H910.35120.52390.19290.033 (6)*
H920.05920.42800.17050.044 (8)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0637 (14)0.0596 (13)0.0520 (13)0.0013 (10)0.0365 (11)0.0136 (10)
N10.0409 (13)0.0416 (13)0.0351 (12)0.0062 (10)0.0198 (11)0.0104 (10)
N20.0371 (12)0.0403 (13)0.0360 (12)0.0063 (10)0.0140 (10)0.0124 (10)
C10.0406 (15)0.0363 (15)0.0325 (14)0.0104 (12)0.0103 (12)0.0112 (11)
C20.0604 (19)0.0427 (17)0.0342 (16)0.0166 (15)0.0159 (14)0.0107 (13)
C30.074 (2)0.0330 (16)0.0382 (17)0.0129 (15)0.0049 (15)0.0045 (13)
C40.0565 (19)0.0384 (17)0.0560 (19)0.0009 (14)0.0084 (16)0.0177 (15)
C50.0501 (18)0.0441 (17)0.0474 (18)0.0015 (14)0.0173 (15)0.0170 (14)
C60.0412 (15)0.0391 (15)0.0313 (14)0.0119 (12)0.0110 (12)0.0147 (12)
C70.0345 (14)0.0338 (14)0.0310 (14)0.0054 (11)0.0123 (11)0.0048 (11)
C80.0355 (15)0.0388 (16)0.0441 (16)0.0106 (12)0.0114 (13)0.0088 (12)
C90.0358 (15)0.0433 (16)0.0343 (15)0.0069 (12)0.0060 (12)0.0111 (12)
Geometric parameters (Å, º) top
O1—N11.273 (3)C4—H40.9300
N1—C11.322 (3)C5—C61.434 (4)
N1—C71.505 (3)C5—H50.9300
N2—C61.308 (3)C7—C81.522 (4)
N2—C71.449 (3)C7—C91.530 (4)
C1—C21.420 (4)C8—C9i1.518 (3)
C1—C61.447 (4)C8—H810.9700
C2—C31.337 (4)C8—H820.9700
C2—H20.9300C9—C8i1.518 (3)
C3—C41.438 (4)C9—H910.9700
C3—H30.9300C9—H920.9700
C4—C51.351 (4)
O1—N1—C1129.2 (2)N2—C6—C1113.6 (2)
O1—N1—C7122.3 (2)C5—C6—C1118.1 (2)
C1—N1—C7108.5 (2)N2—C7—N1105.13 (19)
C6—N2—C7106.3 (2)N2—C7—C8112.0 (2)
N1—C1—C2131.2 (3)N1—C7—C8108.63 (19)
N1—C1—C6106.4 (2)N2—C7—C9111.1 (2)
C2—C1—C6122.4 (3)N1—C7—C9107.9 (2)
C3—C2—C1116.6 (3)C8—C7—C9111.7 (2)
C3—C2—H2121.7C9i—C8—C7112.1 (2)
C1—C2—H2121.7C9i—C8—H81109.2
C2—C3—C4122.5 (3)C7—C8—H81109.2
C2—C3—H3118.8C9i—C8—H82109.2
C4—C3—H3118.8C7—C8—H82109.2
C5—C4—C3122.6 (3)H81—C8—H82107.9
C5—C4—H4118.7C8i—C9—C7112.0 (2)
C3—C4—H4118.7C8i—C9—H91109.2
C4—C5—C6117.8 (3)C7—C9—H91109.2
C4—C5—H5121.1C8i—C9—H92109.2
C6—C5—H5121.1C7—C9—H92109.2
N2—C6—C5128.3 (2)H91—C9—H92107.9
O1—N1—C1—C20.6 (5)C2—C1—C6—C50.3 (4)
C7—N1—C1—C2178.3 (3)C6—N2—C7—N11.5 (3)
O1—N1—C1—C6178.9 (3)C6—N2—C7—C8119.3 (2)
C7—N1—C1—C60.1 (3)C6—N2—C7—C9115.0 (2)
N1—C1—C2—C3175.8 (3)O1—N1—C7—N2179.9 (2)
C6—C1—C2—C32.3 (4)C1—N1—C7—N21.0 (3)
C1—C2—C3—C42.7 (4)O1—N1—C7—C860.1 (3)
C2—C3—C4—C51.1 (5)C1—N1—C7—C8121.0 (2)
C3—C4—C5—C61.0 (4)O1—N1—C7—C961.2 (3)
C7—N2—C6—C5177.5 (3)C1—N1—C7—C9117.7 (2)
C7—N2—C6—C11.6 (3)N2—C7—C8—C9i72.0 (3)
C4—C5—C6—N2177.8 (3)N1—C7—C8—C9i172.3 (2)
C4—C5—C6—C11.3 (4)C9—C7—C8—C9i53.4 (3)
N1—C1—C6—N21.0 (3)N2—C7—C9—C8i72.6 (3)
C2—C1—C6—N2179.5 (2)N1—C7—C9—C8i172.7 (2)
N1—C1—C6—C5178.2 (2)C8—C7—C9—C8i53.3 (3)
Symmetry code: (i) x, y+1, z.

Experimental details

(III)(IV)
Crystal data
Chemical formulaC18H16N4OC18H16N4O2
Mr304.35320.34
Crystal system, space groupOrthorhombic, CmcaTriclinic, P1
Temperature (K)150293
a, b, c (Å)6.774 (2), 15.875 (3), 13.477 (3)5.416 (2), 7.290 (2), 10.426 (3)
α, β, γ (°)90, 90.00 (3), 90104.39 (3), 104.15 (3), 98.41 (3)
V3)1449.3 (6)377.1 (2)
Z41
Radiation typeMo KαMo Kα
µ (mm1)0.090.10
Crystal size (mm)0.50 × 0.35 × 0.300.4 × 0.3 × 0.25
Data collection
DiffractometerNonius KappaCCD
diffractometer
Philips PW1100
diffractometer
Absorption correction
No. of measured, independent and
observed [I > 2σ(I)] reflections
3482, 902, 658 1422, 1339, 885
Rint0.0540.036
(sin θ/λ)max1)0.6490.595
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.043, 0.119, 1.02 0.053, 0.139, 1.06
No. of reflections9021339
No. of parameters77117
H-atom treatmentH-atom parameters constrainedH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.22, 0.170.20, 0.18

Computer programs: COLLECT (Nonius, 1998), Philips PW1100/20 Software (Philips, 1973), DENZO-SMN (Otwinowski & Minor, 1997), Philips PW1100/20 Software, DENZO-SMN, SHELXS97 (Sheldrick, 1997a), SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997b), SHELXL97 (Sheldrick, 1997), ORTEP-3 for Windows (Farrugia, 1997), ORTEP-3 (Farrugia, 1997).

Comparison of bond lengths (Å) for (III), (IV), (VI), (VII), (VIII). and bond angles (°) for (III) and (IV). top
(III)(IV)(VI)(VII)(VIII)
O1—N11.152 (3)1.273 (3)1.28 (2)/1.34 (3)
N1—C11.312 (3)1.322 (3)1.34 (3)1.30 (1)1.399 (7)
N1—C71.491 (3)1.505 (3)1.54 (3)1.506 (8)1.491 (7)
N2—C61.299 (2)1.308 (3)1.33 (3)1.30 (1)1.403 (7)
N2—C71.455 (3)1.449 (3)1.52 (3)1.48 (1)1.480 (8)
C1—C21.430 (3)1.420 (4)1.42 (3)1.463 (9)1.383 (7)
C1—C61.456 (3)1.447 (4)1.41 (3)1.48 (1)1.375 (7)
C2—C31.349 (3)1.337 (4)1.41 (4)1.36 (1)1.402 (7)
C3—C41.448 (3)1.438 (4)1.41 (4)1.51 (2)1.389 (9)
C4—C51.348 (3)1.351 (4)1.40 (4)1.36 (1)1.402 (9)
C5—C61.446 (3)1.434 (4)1.45 (4)1.43 (2)1.363 (8)
C7—C81.530 (2)1.522 (4)
C7—C8*1.530 (2)1.530 (4)
C8—C8*1.531 (3)1.518 (3)
O1—N1—C1130.0 (2)129.2 (2)
O1—N1—C7123.5 (2)122.3 (2)
C1—N1—C7106.5 (2)108.5 (2)
C6—N2—C7105.7 (2)106.3 (2)
N1—C1—C2129.6 (2)131.2 (3)
N1—C1—C6108.5 (2)106.4 (2)
C2—C1—C6121.8 (2)122.4 (3)
C3—C2—C1117.2 (2)116.6 (3)
C2—C3—C4121.9 (2)122.5 (3)
C5—C4—C3122.8 (2)122.6 (3)
C4—C5—C6118.2 (2)117.8 (3)
N2—C6—C5129.6 (2)128.3 (2)
N2—C6—C1112.4 (2)113.6 (2)
C5—C6—C1118.0 (2)118.1 (2)
N2—C7—N1106.9 (2)105.1 (2)
N2—C7—C8110.8 (1)112.0 (2)
N1—C7—C8109.0 (1)108.6 (2)
N2—C7—C8*110.8 (1)111.1 (2)
N1—C7—C8*108.6 (1)107.9 (2)
C8—C7—C8*110.9 (2)111.7 (2)
C8*—C8—C7111.2 (1)112.1 (2)
C8—C8*—C7111.2 (1)112.0 (2)
Notes: atoms marked with an asterisk are related by either twofold symmetry [in (III)] or by an inversion center [in (IV)].
 

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