Isatin 3-semicarbazone and 1-methyl­isatin 3-semicarbazone

The two title semicarbazones, namely 2,3-dihydro-1H-indole-2,3-dione 3-semicarbazone, C₉H₈N₄O₂, (I), and 1-methyl-2,3-dihydro-1H-indole-2,3-dione 3-semicarbazone, C₁₀H₁₀N₄O₂, (II), show the same configuration, viz. Z around the imine C=N bond and E around the C(O)-NH₂ bond, stabilized by two intra­molecular hydrogen bonds. The presence of a methyl group on the isatin N atom determines the difference in the packing; in (I), the mol­ecules are linked into chains which lie in the crystallographic (102) plane and run perpendicular to the b axis, while in (II), the mol­ecules are arranged to form helices running parallel to a crystallographic screw axis in the a direction.

S1. Comment

Isatin derivatives are molecules that possess biological properties (Pandeya et al., 1999, and references therein). During the past few years, we have devoted our research to isatin derivatives and their metal complexes in order to study their biological activity (Rodríguez-Argüelles et al., 1999, 2004; Casas et al., 2000). In this framework, we report here the synthesis and solid state characterization of two semicarbazones, viz. isatin- and 1-methylisatin-3-semicarbazone, (I) and (II), respectively.

The configuration of (I) (Fig. 1) is Z with respect to the C2—N3 bond (with the configuration stabilized by an N2—H3···O2 intramolecular hydrogen bond; Table 2), while it is E with respect to the C1—N2 bond (stabilized by an N1—H2···N3 intramolecular hydrogen bond; Table 2). The same configurations have been found in uncomplexed isatin-3-thiosemicarbazone (Casas et al., 2000) and in isatinthiosemicarbazone ethyl or p-tolyl monosubstituted on the amine N atom (Bain et al., 1997; Revenko et al., 1994). The bond distances and angles are listed in Table 1 and are comparable to those reported in the literature for similar compounds (Allen, 2002). In the five-membered ring, the C2—C9 bond [1.505 (3) Å] is shorter than the corresponding bond in free isatin [1.555 (3) Å; Palenik et al., 1990]. This difference confirms the hypothesis that the bond lengthening of unsubstituted isatin is due to repulsion between the lone pair of the O atom in the cis position. The six- and five-membered rings are nearly planar [the dihedral angle between the mean planes of the two rings is 1.20 (6)°], and the dihedral angle between the mean planes of the isatin and semicarbazide groups is 5.42 (5)°. These molecules could take the keto–imine tautomeric form in solution, but in the crystal only the keto form is observed, as confirmed by the C9═O2 distance [1.230 (2) Å]. This form is stabilized by intermolecular hydrogen bondings (i) between amine atom N1 and atom O2 at (x − 1, −y + 1/2, z + 1/2) and (ii) between isatin atom N4 and atom O1 of the semicarbazide moiety at (x + 1, −y + 1/2, z − 1/2) (Table 2). This short hydrogen bond justifies the unusually long distance N4—H (1.04 Å). These two bonds link the molecules in chains lying in the crystallographic (102) plane and running perpendicular to the b axis (Fig. 2). Forces which can probably be interpreted as due to stacking interactions between the six-membered isatin rings of centrosymmetrical molecules (in the range 3.340–3.519 Å) hold the chains together to form a complex network in directions c and a.

Fig. 3 shows an ORTEPIII (Burnett & Johnson, 1996) view of (II). The molecular geometry is similar to that of the non-methylated compound (I). The configuration is Z around the C2—N3 bond, stabilized by an intramolecular N2—H3···O2 bond, and E with respect to the C1—N2 bond as a consequence of the intramolecular N1—H2···N3 bond (Table 3). Again, the C2—C9 bond [1.497 (3) Å] is shorter than that in free isatin. The dihedral angles between the mean planes of the two rings is 1.04 (9)°, and that between the mean planes of the isatin and semicarbazide groups is 1.61 (9)°. The whole molecule is therefore essentially planar. In the crystal packing (Fig. 4), which is different from (I), the presence of hydrogen bonds between atoms N1 and O1 of molecules related by a 2₁ axis (Table 3) gives rise to a helix running parallel to the crystallographic a axis. Weak interactions C—H···O between an aromatic isatin C atom, a methyl C atom and a carbonyl O atom are also present; details are in Table 3.

S2. Experimental

The title compounds were obtained from isatin or 1-methylisatin and neutral semicarbazide (1:1 molar ratio) in an ethanol–water solution, following a similar procedure to that previously reported by Tomchin et al. (1973). The solids obtained by cooling were filtered, washed with ethanol 98% and dried under a vacuum. For isatin 3-semicarbazone H₂L¹·H₂O: yellow powder, solid, m.p. 564 K. Analysis found: C 48.8, H 4.4, N 25.0%; calculated for for C₉H₈N₄O₂·H₂O: C 48.7, H 4.5, N 25.2%. The yield was 54%. The solid was dissolved in ethyl acetate and after several days at room temperature the solution afforded crystals of (I) that were extremely small but suitable for X-ray diffraction studies and that did not contain the water molecule observed for the powder. For 1-methylisatin 3-semicarbazone HL²: yellow solid, m.p. 522 K 249° C. Analysis found: C 54.9, H 4.7, N 25.0%; calculated for C₁₀H₁₀N₄O₂: C 55.0, H 4.6, N 25.7%. Yield 57%. After several days at room temperature the solution afforded crystals of (II) that were suitable for X-ray diffraction studies.

S3. Refinement

In (I), all H atoms were located in a difference map, except aromatic atoms H4 and H7, which were calculated with standard geometries. In (II) all H atoms were visible in difference maps and subsequently allowed for as riding atoms with C—H 0.93 to 0.96 Å and N—H 0.86 Å with U_iso(H) = 1.2U_eq(C,N), or 1.5U_eq(C) for the methyl groups. In the absence of significant anomalous scattering i (II), the Flack parameter (Flack, 1983) was indeterminate (Flack & Bernardinelli, 2000), and the Friedel-equivalent reflections were merged prior to the final refinements.

Computing details

Data collection: local program (Belletti et al., 1988) for (I); SMART (Bruker, 1997) for (II). Cell refinement: local program (Belletti et al., 1988) for (I); SMART for (II). Data reduction: local program (Belletti et al., 1988) for (I); SAINT (Bruker, 1997) for (II). For both compounds, program(s) used to solve structure: SIR97 (Altomare et al., 1999); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPIII (Burnett & Johnson, 1996) and PLATON (Spek, 2003); software used to prepare material for publication: SHELXL97.

Figures

	Fig. 1. An ORTEPIII (Burnett & Johnson, 1996) view of the molecule of (I), with displacement ellipsoids drawn at the 50% probability level.
	Fig. 2. A packing diagram for (I), with hydrogen bonds indicated by dashed lines.
	Fig. 3. An ORTEPIII (Burnett & Johnson, 1996) view of the molecule of (II), with displacement ellipsoids drawn at the 50% probability level.
	Fig. 4. A packing diagram for (II), with hydrogen bonds indicated by dashed lines.

(I) 1H-indole-2,3-dione 3-semicarbazone

Crystal data

C9H8N4O2	F(000) = 424
Mr = 204.19	Dx = 1.483 Mg m^−3
Monoclinic, P21/c	Melting point: 291 K
Hall symbol: -P 2ybc	Cu Kα radiation, λ = 1.54178 Å
a = 5.554 (1) Å	Cell parameters from 20 reflections
b = 18.754 (3) Å	θ = 20–30°
c = 8.974 (2) Å	µ = 0.93 mm^−1
β = 101.84 (3)°	T = 298 K
V = 914.8 (3) Å^3	Prism, pale yellow
Z = 4	0.3 × 0.2 × 0.2 mm

Data collection

Siemens AED diffractometer	Rint = 0.032
Radiation source: fine-focus sealed tube	θmax = 62.5°, θmin = 2.2°
Graphite monochromator	h = −6→5
θ–2θ scans	k = 0→21
1438 measured reflections	l = 0→10
1354 independent reflections	1 standard reflections every 100 reflections
907 reflections with I > 2σ(I)	intensity decay: 1%

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full with fixed elements per cycle	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.034	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.092	H-atom parameters not refined
S = 0.93	w = 1/[σ^2(Fo^2) + (0.0504P)^2] where P = (Fo^2 + 2Fc^2)/3
1354 reflections	(Δ/σ)max = 0.013
136 parameters	Δρmax = 0.17 e Å^−3
0 restraints	Δρmin = −0.15 e Å^−3

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq
H1	0.3141	0.2126	0.6025	0.089*
H2	0.4634	0.1467	0.5359	0.050*
H3	0.7810	0.2502	0.3417	0.074*
H4	0.7642	−0.0136	0.3698	0.050*
H5	0.9503	−0.1173	0.2932	0.065*
H6	1.2606	−0.1078	0.1552	0.065*
H7	1.3827	0.0068	0.0898	0.050*
H8	1.3034	0.1560	0.0924	0.092*
O1	0.5024 (3)	0.30826 (7)	0.48589 (18)	0.0571 (5)
O2	1.0307 (3)	0.24314 (7)	0.21098 (17)	0.0516 (4)
N1	0.4202 (4)	0.19444 (9)	0.5468 (2)	0.0540 (5)
N2	0.6855 (3)	0.21900 (8)	0.3862 (2)	0.0455 (5)
N3	0.7266 (3)	0.14809 (8)	0.37596 (19)	0.0431 (5)
N4	1.1815 (3)	0.13399 (8)	0.1535 (2)	0.0465 (5)
C1	0.5303 (4)	0.24379 (11)	0.4767 (2)	0.0440 (5)
C2	0.8857 (4)	0.12954 (10)	0.2964 (2)	0.0392 (5)
C3	0.9602 (4)	0.05687 (10)	0.2719 (2)	0.0402 (5)
C4	0.8875 (5)	−0.00943 (11)	0.3137 (3)	0.0522 (6)
C5	1.0005 (5)	−0.06931 (11)	0.2705 (3)	0.0602 (7)
C6	1.1839 (5)	−0.06316 (11)	0.1876 (3)	0.0597 (7)
C7	1.2581 (4)	0.00260 (12)	0.1448 (3)	0.0550 (6)
C8	1.1426 (4)	0.06185 (10)	0.1863 (2)	0.0436 (5)
C9	1.0355 (4)	0.17762 (10)	0.2165 (2)	0.0411 (5)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0673 (11)	0.0379 (9)	0.0789 (12)	0.0021 (7)	0.0445 (9)	−0.0033 (8)
O2	0.0578 (10)	0.0352 (8)	0.0694 (11)	−0.0025 (7)	0.0307 (8)	0.0010 (7)
N1	0.0657 (13)	0.0401 (10)	0.0683 (13)	−0.0008 (9)	0.0421 (11)	−0.0014 (9)
N2	0.0527 (11)	0.0352 (9)	0.0578 (12)	0.0010 (8)	0.0329 (10)	−0.0018 (8)
N3	0.0466 (11)	0.0368 (10)	0.0503 (11)	0.0022 (8)	0.0202 (9)	−0.0009 (8)
N4	0.0494 (11)	0.0390 (10)	0.0590 (12)	−0.0006 (8)	0.0295 (10)	0.0005 (9)
C1	0.0457 (12)	0.0399 (13)	0.0518 (14)	0.0012 (10)	0.0230 (11)	−0.0023 (10)
C2	0.0389 (12)	0.0378 (11)	0.0448 (12)	−0.0024 (9)	0.0177 (10)	−0.0002 (10)
C3	0.0417 (12)	0.0352 (10)	0.0462 (12)	−0.0007 (10)	0.0152 (10)	−0.0004 (10)
C4	0.0596 (15)	0.0424 (13)	0.0595 (15)	−0.0030 (11)	0.0237 (12)	0.0035 (11)
C5	0.0778 (19)	0.0351 (12)	0.0708 (17)	0.0010 (11)	0.0223 (15)	0.0006 (11)
C6	0.0736 (17)	0.0393 (13)	0.0683 (17)	0.0136 (12)	0.0198 (15)	−0.0060 (12)
C7	0.0561 (15)	0.0513 (14)	0.0640 (16)	0.0108 (11)	0.0271 (13)	−0.0040 (12)
C8	0.0445 (13)	0.0411 (12)	0.0482 (13)	0.0014 (10)	0.0163 (11)	−0.0025 (10)
C9	0.0405 (12)	0.0378 (12)	0.0488 (13)	−0.0023 (9)	0.0181 (11)	−0.0009 (10)

Geometric parameters (Å, º)

O1—C1	1.224 (2)	C2—C3	1.454 (3)
O2—C9	1.230 (2)	C2—C9	1.505 (3)
N1—C1	1.336 (3)	C3—C4	1.383 (3)
N1—H1	0.9135	C3—C8	1.395 (3)
N1—H2	0.9378	C4—C5	1.380 (3)
N2—N3	1.356 (2)	C4—H4	0.933
N2—C1	1.380 (3)	C5—C6	1.384 (4)
N2—H3	0.9327	C5—H5	0.976
N3—C2	1.293 (3)	C6—C7	1.380 (3)
N4—C9	1.355 (3)	C6—H6	1.009
N4—C8	1.411 (2)	C7—C8	1.372 (3)
N4—H8	1.0396	C7—H7	0.932
C1—N1—H1	114.10	C5—C4—C3	118.7 (2)
C1—N1—H2	117.46	C5—C4—H4	120.7
H1—N1—H2	128.4	C3—C4—H4	120.6
N3—N2—C1	120.29 (16)	C4—C5—C6	120.7 (2)
N3—N2—H3	117.89	C4—C5—H5	121.7
C1—N2—H3	121.27	C6—C5—H5	117.5
C2—N3—N2	116.44 (17)	C7—C6—C5	121.3 (2)
C9—N4—C8	111.21 (17)	C7—C6—H6	119.6
C9—N4—H8	119.41	C5—C6—H6	119.1
C8—N4—H8	129.37	C8—C7—C6	117.7 (2)
O1—C1—N1	125.19 (19)	C8—C7—H7	120.9
O1—C1—N2	118.37 (18)	C6—C7—H7	121.3
N1—C1—N2	116.44 (17)	C7—C8—C3	121.9 (2)
N3—C2—C3	125.72 (19)	C7—C8—N4	128.3 (2)
N3—C2—C9	127.54 (19)	C3—C8—N4	109.80 (18)
C3—C2—C9	106.70 (17)	O2—C9—N4	126.61 (19)
C4—C3—C8	119.7 (2)	O2—C9—C2	127.49 (19)
C4—C3—C2	133.9 (2)	N4—C9—C2	105.89 (17)
C8—C3—C2	106.38 (18)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···O2^i	0.91	2.18	3.087 (3)	173
N1—H2···N3	0.94	2.25	2.659 (3)	106
N2—H3···O2	0.93	2.00	2.755 (2)	137
N4—H8···O1^ii	1.04	1.74	2.777 (2)	178
C6—H6···O1^iii	1.01	2.55	3.520 (3)	161

Symmetry codes: (i) x−1, −y+1/2, z+1/2; (ii) x+1, −y+1/2, z−1/2; (iii) −x+2, y−1/2, −z+1/2.

(II) 1-methylindole-2,3-dione 3-semicarbazone

Crystal data

C10H10N4O2	Dx = 1.434 Mg m^−3
Mr = 218.22	Melting point: 249 K
Orthorhombic, P212121	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 3118 reflections
a = 3.984 (2) Å	θ = 2.1–25.0°
b = 20.930 (6) Å	µ = 0.11 mm^−1
c = 12.122 (2) Å	T = 298 K
V = 1010.8 (6) Å^3	Prism, yellow
Z = 4	0.4 × 0.3 × 0.2 mm
F(000) = 456

Data collection

Bruker SMART 1000 diffractometer	910 independent reflections
Radiation source: fine-focus sealed tube	782 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.038
Detector resolution: 8.192 pixels mm^-1	θmax = 23.3°, θmin = 1.9°
ω scans	h = −4→4
Absorption correction: multi-scan (SADABS; Bruker, 1999)	k = −23→23
Tmin = 0.939, Tmax = 0.980	l = −13→13
9231 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.028	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.077	H-atom parameters constrained
S = 1.02	w = 1/[σ^2(Fo^2) + (0.0557P)^2] where P = (Fo^2 + 2Fc^2)/3
910 reflections	(Δ/σ)max < 0.001
146 parameters	Δρmax = 0.10 e Å^−3
0 restraints	Δρmin = −0.12 e Å^−3

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq
O1	0.7991 (6)	0.16810 (8)	0.98208 (13)	0.0716 (6)
O2	1.1174 (5)	0.03955 (8)	0.71768 (13)	0.0646 (6)
N1	0.5444 (6)	0.23666 (11)	0.86358 (17)	0.0652 (7)
H1	0.4848	0.2629	0.9146	0.078*
H2	0.4941	0.2445	0.7959	0.078*
N2	0.8028 (7)	0.14554 (10)	0.80117 (14)	0.0589 (6)
H3	0.9091	0.1105	0.8133	0.071*
N3	0.7246 (6)	0.16223 (9)	0.69678 (14)	0.0488 (5)
N4	1.0444 (5)	0.03808 (9)	0.52878 (15)	0.0486 (5)
C1	0.7134 (7)	0.18433 (11)	0.8892 (2)	0.0550 (7)
C2	0.8210 (6)	0.12407 (10)	0.61916 (18)	0.0435 (6)
C3	0.7599 (6)	0.13253 (10)	0.50235 (17)	0.0422 (6)
C4	0.6054 (7)	0.17950 (11)	0.44031 (19)	0.0484 (6)
H4	0.5100	0.2150	0.4741	0.058*
C5	0.5958 (7)	0.17263 (13)	0.3271 (2)	0.0569 (7)
H5	0.4943	0.2040	0.2842	0.068*
C6	0.7346 (7)	0.11983 (12)	0.2768 (2)	0.0602 (7)
H6	0.7241	0.1163	0.2004	0.072*
C7	0.8886 (7)	0.07211 (12)	0.33672 (18)	0.0545 (7)
H7	0.9812	0.0365	0.3023	0.065*
C8	0.8998 (6)	0.07924 (10)	0.44936 (18)	0.0427 (6)
C9	1.0115 (7)	0.06289 (11)	0.63179 (19)	0.0481 (6)
C10	1.2050 (8)	−0.02279 (10)	0.5055 (2)	0.0622 (8)
H10A	1.3533	−0.0181	0.4436	0.093*
H10B	1.0369	−0.0542	0.4887	0.093*
H10C	1.3311	−0.0363	0.5688	0.093*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.1081 (17)	0.0666 (11)	0.0401 (10)	−0.0106 (13)	−0.0094 (10)	−0.0006 (8)
O2	0.0830 (14)	0.0571 (10)	0.0537 (10)	0.0084 (11)	−0.0110 (10)	0.0082 (8)
N1	0.0911 (19)	0.0614 (13)	0.0432 (12)	0.0067 (14)	0.0079 (12)	−0.0058 (10)
N2	0.0807 (17)	0.0510 (11)	0.0450 (12)	0.0046 (13)	−0.0035 (12)	−0.0043 (9)
N3	0.0595 (13)	0.0498 (11)	0.0370 (11)	−0.0035 (11)	−0.0023 (10)	−0.0037 (9)
N4	0.0529 (13)	0.0404 (10)	0.0526 (11)	0.0022 (11)	0.0012 (11)	−0.0051 (9)
C1	0.0713 (19)	0.0505 (14)	0.0432 (15)	−0.0132 (15)	0.0050 (16)	−0.0035 (12)
C2	0.0478 (15)	0.0404 (12)	0.0423 (13)	−0.0051 (12)	0.0022 (12)	−0.0019 (10)
C3	0.0410 (14)	0.0405 (11)	0.0451 (13)	−0.0053 (12)	0.0000 (12)	−0.0019 (9)
C4	0.0453 (14)	0.0458 (13)	0.0540 (15)	−0.0004 (12)	−0.0003 (13)	−0.0006 (11)
C5	0.0554 (17)	0.0622 (16)	0.0530 (15)	−0.0035 (15)	−0.0089 (14)	0.0101 (12)
C6	0.0649 (18)	0.0719 (17)	0.0437 (14)	−0.0091 (17)	−0.0025 (15)	−0.0022 (13)
C7	0.0583 (17)	0.0559 (14)	0.0492 (14)	−0.0049 (16)	0.0046 (13)	−0.0108 (12)
C8	0.0404 (14)	0.0412 (12)	0.0465 (13)	−0.0049 (12)	0.0020 (12)	−0.0015 (10)
C9	0.0501 (15)	0.0440 (13)	0.0500 (14)	−0.0050 (12)	−0.0015 (13)	0.0030 (11)
C10	0.0656 (19)	0.0429 (14)	0.0781 (18)	0.0068 (16)	0.0051 (17)	−0.0040 (12)

Geometric parameters (Å, º)

O1—C1	1.225 (3)	C3—C4	1.382 (3)
O2—C9	1.225 (3)	C3—C8	1.403 (3)
N1—C1	1.323 (3)	C4—C5	1.381 (3)
N1—H1	0.86	C4—H4	0.93
N1—H2	0.86	C5—C6	1.378 (4)
N2—N3	1.349 (3)	C5—H5	0.93
N2—C1	1.387 (3)	C6—C7	1.379 (4)
N2—H3	0.86	C6—H6	0.93
N3—C2	1.293 (3)	C7—C8	1.374 (3)
N4—C9	1.359 (3)	C7—H7	0.93
N4—C8	1.414 (3)	C10—H10A	0.96
N4—C10	1.453 (3)	C10—H10B	0.96
C2—C3	1.448 (3)	C10—H10C	0.96
C2—C9	1.496 (3)
C1—N1—H1	120.0	C6—C5—C4	120.8 (2)
C1—N1—H2	120.0	C6—C5—H5	119.6
H1—N1—H2	120.0	C4—C5—H5	119.6
N3—N2—C1	120.7 (2)	C5—C6—C7	121.8 (2)
N3—N2—H3	119.7	C5—C6—H6	119.1
C1—N2—H3	119.7	C7—C6—H6	119.1
C2—N3—N2	117.0 (2)	C8—C7—C6	117.3 (2)
C9—N4—C8	110.70 (18)	C8—C7—H7	121.3
C9—N4—C10	123.8 (2)	C6—C7—H7	121.3
C8—N4—C10	125.53 (19)	C7—C8—C3	121.9 (2)
O1—C1—N1	126.0 (2)	C7—C8—N4	128.6 (2)
O1—C1—N2	118.2 (2)	C3—C8—N4	109.54 (19)
N1—C1—N2	115.8 (2)	O2—C9—N4	126.5 (2)
N3—C2—C3	125.9 (2)	O2—C9—C2	127.1 (2)
N3—C2—C9	127.2 (2)	N4—C9—C2	106.37 (19)
C3—C2—C9	106.87 (19)	N4—C10—H10A	109.5
C4—C3—C8	119.6 (2)	N4—C10—H10B	109.5
C4—C3—C2	134.0 (2)	H10A—C10—H10B	109.5
C8—C3—C2	106.49 (19)	N4—C10—H10C	109.5
C5—C4—C3	118.6 (2)	H10A—C10—H10C	109.5
C5—C4—H4	120.7	H10B—C10—H10C	109.5
C3—C4—H4	120.7

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···O1^i	0.86	2.05	2.903 (3)	171
N1—H2···N3	0.86	2.29	2.652 (3)	105
N2—H3···O2	0.86	2.06	2.742 (3)	136
C7—H7···O2^ii	0.93	2.48	3.379 (4)	163
C10—H10C···O2	0.96	2.55	2.905 (3)	102

Symmetry codes: (i) x−1/2, −y+1/2, −z+2; (ii) −x+5/2, −y, z−1/2.