Two derivatives of 5-amino­tetrazole: 5-amino-1-phenyl­tetrazole and 5-amino-1-(1-naphthyl)­tetrazole

In the mol­ecules of 5-amino-1-phenyl­tetrazole, C₇H₇N₅, (I), and 5-amino-1-(1-naphthyl)­tetrazole, C₁₁H₉N₅, (II), the tetrazole rings and aryl fragments are not coplanar; corresponding dihedral angles are 50.58 (5) and 45.19 (7)° for the two independent mol­ecules of (I), and 64.14 (5)° for (II). Intermolecular N—H...N hydrogen bonds between the amino groups and tetrazole N atoms are primarily responsible for formation of two-dimensional networks extending parallel to the bc plane in both compounds. The presence of the amino group has a distinct effect on the geometry of the tetrazole rings in each case.

S1. Comment

5-Amino-1-aryltetrazoles have attracted much attention because of their biological activity (Wittenberger, 1994; Schelenz, 2000, and references therein). Thus, 5-amino-1-phenyltetrazole, (I), reveals anti-inflammatory, muscle relaxation and central nervous system (CNS) depressant properties. Recently, algistatic activity of 5-amino-1-aryltetrazoles, including 5-amino-1-(1-naphthyl)tetrazole, (II), was reported (Schelenz, 2000; Katritzky et al., 2001). Although a large body of information concerned with synthesis techniques and biological activities of 5-amino-1-aryltetrazoles is available, no systematic investigations of their structures have been performed; only one compound, namely 1-(4-methoxyphenyl)-5-(phenylamino)tetrazole (Brigas et al., 2001), was found in the Cambridge Structural Database (CSD; Version 5.24, November 2002 release; Allen, 2002) in a search for 1-aryl-5-aminotetrazoles. However, structural information might be very important for understanding the mechanisms of biological activity of these compounds. We present here the structures of two examples of 1-aryl-5-aminotetrazoles, the above-mentioned compounds (I) and (II). The asymmetric unit of (I) consists of two independent molecules, which are denoted as A and B.

The tetrazole rings are planar to within 0.0024 (8) and 0.0014 (9) Å for molecules A and B, respectively, of (I), and 0.0026 (9) Å for (II). The tetrazole rings are not coplanar with the phenyl or naphthyl fragments in (I) and (II). The dihedral angles between the least-squares planes of the tetrazole and aryl systems in (I) are 50.58 (5) and 45.19 (7)° for A and B, respectively, and 64.14 (5)° in (II).

The molecule of (II) may exist in two forms, namely the s-trans-(N²)-conformer II and the s-cis-(N²)-conformer IIa, which are related by rotational isomerism. Density functional theory (DFT) calculations of the relative energies of conformers II and IIa in the gas phase, performed using the B3LYP model (Becke, 1993) and a standard 6–31 G^* basis set (Hehre et al., 1972) with the NWCHEM package (Harrison et al., 2002), showed that conformer IIa is more stable by 2.29 kJ mol⁻¹. However, it is conformer II which occurs in the crystal of (II). It seems probable that the magnitude of the crystal packing energy overlaps the energy difference for the s-trans-(N²)- and s-cis-(N²)-conformers of (II).

The N5 atoms of the amino groups in (I) and (II) display features of sp² hybridization. The angle sums around these atoms are ca 349° for both molecules in (I) and ca 360° in (II) (Tables 1 and 3). In (I), the amino atoms are located close to the adjacent tetrazole ring plane, with a maximum deviations of 0.25 (2) (for atom H5A in molecule A) and 0.26 (2) Å (for atom H5C in molecule B). In (II), the corresponding maximum deviation of 0.06 (2) Å occurs for atom H5A. Moreover, the C5—N5 bond lengths in (I) and (II) (Tables 1 and 3) are close to those for C═N double bonds.

The corresponding bond lengths and angles of the tetrazole rings of (I) and (II) are very similar (Tables 1 and 3). Comparison of the tetrazole-ring characteristics of (I) and (II) with those of 5-aminotetrazole (Bray & White, 1979) did not reveal any influence of the aryl substitutents on the ring geometry. Taking into account the results of the X-ray investigation for 1-phenyltetrazole (Matsunaga et al., 1999), it may be found that substitution of the H atom at ring atom C5 by the amino group in the molecule of (I) results in a shortening of the N2═N3 bond by 0.019 Å, but elongation of the N4═C5 and N1—N2 bonds by 0.027 and 0.020 Å, respectively. The N1—C5 and N3—N4 bond lengths are unaffected by this substitution.

DFT calculations on 1-phenyltetrazole and 5-amino-1-phenyltetrazole, 1-(1-naphthyl)tetrazole and 5-amino-1-(1-naphthyl)tetrazole showed that introducing a 5-amino group shortened N2═N3 by 0.008 Å in (I), by 0.008 Å in (II), elongated N4═C5 by 0.007 and 0.008 Å in (I) and (II), respectively, and elongated N1—N2 by 0.019 Å for (I) and 0.020 Å for (II), in agreement with the results of the structure determination.

To clarify whether this is a general effect, we examined the tetrazole-ring geometries of 1-R-5-amino- and 1-R-5H-tetrazoles where R is a substituted alkyl or aryl group, using the CSD. As can be seen from Table 5, amino substitution tends to shorten N2═N3 and elongate N1—N2 and N4═C5, while there is no marked trend for N1—C5 and N3—N4. These results and those obtained in the present work allow us to consider the geometric influence of the amino group on features of the tetrazole rings of 5-aminotetrazoles.

The elongation of the C5═N4 and the shortening of the C5—NH₂ bonds relative to `normal' C—N bond lengths, and the approximately trigonal planar geometry of the 5-amino N atoms in 5-aminotetrazoles agree with considerable bond conjugation in the H₂N—C5═N4 fragments. However, the mechanism whereby N1—N2 is elongated and N2═N3 shortened in 5-aminotetrazoles relative to 5H-tetrazoles is not clear and may be a topic of future investigations.

Both structures exhibit intermolecular N—H···N hydrogen bonds between the amino groups and atoms N3 and N4 of the tetrazole rings (Tables 2 and 4). These hydrogen bonds are responsible for the formation of polymeric two-dimensional networks parallel to the bc plane in (I) and (II). The networks are linked only by van der Waals interactions. The hydrogen-bonding motifs in (I) and (II) differ to some extent. In (I), each molecule A is hydrogen bonded to three neighbours, viz. one A and two B molecules, forming an eight-membered hydrogen-bonded ring by binding with molecule A (Fig. 3). Each molecule B is hydrogen bonded to four neighbours, viz. two A and two B molecules. All hydrogen bonds involving the amino groups of molecules B are bifurcated. In (II), each molecule is hydrogen bonded with three others, eight-membered hydrogen-bonded rings being formed by bonding with one of them (Fig. 4). In addition to the two-dimensional network, the structure also contains non-classical C8—H8···N2 interactions.

S2. Experimental

The title compounds, (I) and (II), were prepared from aniline and 1-naphthylamine, respectively, using the three-stage technique reported by Vorobiev et al. (2003). Single crystals of (I) and (II) suitable for analysis were grown by slow evaporation from a 2-propanol–acetonitrile solvent system (3:1) at room temperature.

S3. Refinement

H-atom positions were found from difference Fourier map and thereafter positional and U_iso parameters were refined freely.

Computing details

Data collection: R3m Software (Nicolet, 1980) for (I); R3m Sofrware (Nicolet, 1980) for (II). Cell refinement: R3m Software for (I); R3m Sofrware for (II). Data reduction: R3m Software for (I); R3m Sofrware 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: ORTEP-3 for Windows (Farrugia, 1997) and PLATON (Spek, 2003); software used to prepare material for publication: SHELXL97.

Figures

	Fig. 1. A view of the two independent molecules of (I), showing the atom-numbering scheme and ellipsoids at the 30% probability level.
	Fig. 2. A view of (II), showing the atom-numbering scheme and ellipsoids at the 30% probability level.
	Fig. 3. A fragment of the crystal structure of (I), showing the hydrogen-bonded two-dimensional network parallel to the bc plane. Dashed lines show N—H···N hydrogen bonds. Label `B' indicates molecules B (unlabelled molecules are A). For clarity, phenyl groups are represented by their bridgehead atoms.
	Fig. 4. A fragment of the crystal structure of (II), showing the hydrogen-bonded two-dimensional network parallel to the bc plane. Dashed lines indicate N—H···N hydrogen bonds. For clarity, naphthyl groups are represented by their bridgehead atoms.

(I) 5-amino-1-phenyltetrazole

Crystal data

C7H7N5	F(000) = 672
Mr = 161.18	Dx = 1.386 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 25 reflections
a = 11.619 (3) Å	θ = 18.8–21.3°
b = 7.342 (2) Å	µ = 0.10 mm^−1
c = 18.124 (3) Å	T = 293 K
β = 92.202 (19)°	Rectangular prism, colourless
V = 1545.0 (6) Å^3	0.60 × 0.40 × 0.24 mm
Z = 8

Data collection

Nicolet R3m four-circle diffractometer	Rint = 0.030
Radiation source: fine-focus sealed tube	θmax = 30.1°, θmin = 1.8°
Graphite monochromator	h = 0→16
ω/2θ scans	k = 0→10
4745 measured reflections	l = −25→25
4542 independent reflections	3 standard reflections every 100 reflections
3154 reflections with I > 2σ(I)	intensity decay: none

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.047	All H-atom parameters refined
wR(F^2) = 0.145	w = 1/[σ^2(Fo^2) + (0.076P)^2 + 0.1138P] where P = (Fo^2 + 2Fc^2)/3
S = 1.05	(Δ/σ)max < 0.001
4542 reflections	Δρmax = 0.19 e Å^−3
274 parameters	Δρmin = −0.24 e Å^−3
0 restraints	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.211 (9)

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
N1A	0.25115 (8)	0.15732 (14)	0.41508 (5)	0.0485 (2)
N2A	0.18779 (10)	0.19257 (17)	0.47555 (6)	0.0642 (3)
N3A	0.25662 (12)	0.17375 (18)	0.53183 (6)	0.0689 (3)
N4A	0.36476 (10)	0.12655 (16)	0.51202 (5)	0.0603 (3)
C5A	0.35933 (10)	0.11594 (16)	0.43878 (6)	0.0477 (3)
N5A	0.44705 (9)	0.07523 (18)	0.39605 (5)	0.0578 (3)
H5A	0.5063 (14)	0.019 (2)	0.4188 (9)	0.076 (5)*
H5B	0.4318 (12)	0.036 (2)	0.3492 (8)	0.065 (4)*
C6A	0.20163 (9)	0.16779 (15)	0.34169 (6)	0.0453 (2)
C7A	0.25593 (10)	0.26893 (18)	0.28936 (6)	0.0515 (3)
H7A	0.3266 (13)	0.334 (2)	0.3036 (8)	0.066 (4)*
C8A	0.20924 (12)	0.2742 (2)	0.21782 (7)	0.0576 (3)
H8A	0.2479 (14)	0.343 (2)	0.1809 (10)	0.083 (5)*
C9A	0.11044 (13)	0.1806 (2)	0.19978 (8)	0.0663 (4)
H9A	0.0813 (16)	0.188 (3)	0.1485 (11)	0.093 (5)*
C10A	0.05484 (15)	0.0848 (2)	0.25294 (10)	0.0800 (5)
H10A	−0.018 (2)	0.019 (4)	0.2410 (12)	0.127 (7)*
C11A	0.10020 (12)	0.0772 (2)	0.32489 (8)	0.0660 (4)
H11A	0.0602 (15)	0.015 (3)	0.3657 (9)	0.085 (5)*
N1B	0.31763 (9)	0.83550 (14)	0.14261 (5)	0.0517 (3)
N2B	0.28885 (15)	0.70393 (18)	0.19183 (7)	0.0808 (4)
N3B	0.34968 (16)	0.7369 (2)	0.25096 (7)	0.0888 (5)
N4B	0.41771 (12)	0.8859 (2)	0.24375 (6)	0.0713 (4)
C5B	0.39637 (10)	0.94503 (19)	0.17552 (6)	0.0532 (3)
N5B	0.44640 (11)	1.0871 (2)	0.14375 (7)	0.0724 (4)
H5C	0.4107 (17)	1.137 (3)	0.1077 (11)	0.097 (6)*
H5D	0.4849 (18)	1.158 (3)	0.1751 (12)	0.106 (7)*
C6B	0.26717 (10)	0.83768 (15)	0.06961 (6)	0.0457 (3)
C7B	0.33647 (10)	0.86182 (18)	0.01017 (6)	0.0509 (3)
H7B	0.4171 (13)	0.874 (2)	0.0171 (8)	0.067 (4)*
C8B	0.28668 (13)	0.8637 (2)	−0.06055 (7)	0.0591 (3)
H8B	0.3376 (14)	0.881 (2)	−0.1026 (9)	0.077 (5)*
C9B	0.17024 (13)	0.8386 (2)	−0.07105 (8)	0.0675 (4)
H9B	0.1308 (15)	0.839 (2)	−0.1203 (10)	0.084 (5)*
C10B	0.10231 (13)	0.8107 (2)	−0.01182 (9)	0.0737 (4)
H10B	0.0208 (16)	0.789 (3)	−0.0180 (9)	0.091 (5)*
C11B	0.15003 (12)	0.8113 (2)	0.05934 (8)	0.0612 (3)
H11B	0.1088 (13)	0.789 (2)	0.1002 (8)	0.066 (4)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1A	0.0537 (5)	0.0566 (6)	0.0352 (4)	0.0009 (4)	0.0006 (4)	−0.0001 (4)
N2A	0.0718 (7)	0.0770 (8)	0.0446 (5)	0.0077 (6)	0.0122 (5)	0.0004 (5)
N3A	0.0895 (8)	0.0789 (8)	0.0385 (5)	0.0072 (7)	0.0060 (5)	−0.0012 (5)
N4A	0.0776 (7)	0.0688 (7)	0.0339 (5)	0.0010 (6)	−0.0051 (4)	−0.0022 (4)
C5A	0.0570 (6)	0.0509 (6)	0.0344 (5)	−0.0019 (5)	−0.0068 (4)	0.0002 (4)
N5A	0.0536 (6)	0.0819 (8)	0.0373 (5)	0.0065 (5)	−0.0070 (4)	−0.0014 (5)
C6A	0.0487 (5)	0.0471 (5)	0.0396 (5)	0.0043 (4)	−0.0033 (4)	0.0003 (4)
C7A	0.0530 (6)	0.0600 (7)	0.0412 (5)	−0.0023 (5)	−0.0015 (4)	0.0012 (5)
C8A	0.0676 (7)	0.0647 (8)	0.0404 (6)	0.0095 (6)	−0.0008 (5)	0.0050 (5)
C9A	0.0777 (9)	0.0654 (8)	0.0538 (7)	0.0088 (7)	−0.0240 (6)	0.0014 (6)
C10A	0.0749 (9)	0.0787 (10)	0.0833 (10)	−0.0182 (8)	−0.0356 (8)	0.0147 (8)
C11A	0.0620 (7)	0.0685 (8)	0.0662 (8)	−0.0123 (6)	−0.0137 (6)	0.0169 (7)
N1B	0.0636 (6)	0.0555 (6)	0.0357 (4)	0.0042 (4)	−0.0025 (4)	0.0047 (4)
N2B	0.1296 (12)	0.0660 (8)	0.0465 (6)	−0.0035 (8)	0.0004 (7)	0.0148 (5)
N3B	0.1412 (14)	0.0803 (9)	0.0439 (6)	0.0189 (9)	−0.0079 (7)	0.0137 (6)
N4B	0.0840 (8)	0.0917 (9)	0.0372 (5)	0.0244 (7)	−0.0118 (5)	0.0015 (5)
C5B	0.0514 (6)	0.0728 (8)	0.0349 (5)	0.0111 (5)	−0.0060 (4)	−0.0019 (5)
N5B	0.0680 (7)	0.1014 (10)	0.0466 (6)	−0.0245 (7)	−0.0146 (5)	0.0016 (6)
C6B	0.0515 (6)	0.0473 (6)	0.0380 (5)	0.0011 (4)	−0.0030 (4)	−0.0001 (4)
C7B	0.0484 (6)	0.0636 (7)	0.0404 (5)	0.0022 (5)	−0.0019 (4)	−0.0019 (5)
C8B	0.0690 (8)	0.0704 (8)	0.0376 (5)	−0.0011 (6)	−0.0018 (5)	−0.0024 (5)
C9B	0.0723 (8)	0.0799 (10)	0.0485 (7)	−0.0063 (7)	−0.0192 (6)	−0.0042 (6)
C10B	0.0554 (7)	0.0922 (11)	0.0721 (9)	−0.0155 (7)	−0.0159 (6)	−0.0035 (8)
C11B	0.0552 (7)	0.0740 (9)	0.0547 (7)	−0.0106 (6)	0.0043 (5)	−0.0004 (6)

Geometric parameters (Å, º)

N1A—C5A	1.3473 (15)	N1B—C5B	1.3407 (16)
N1A—N2A	1.3681 (14)	N1B—N2B	1.3651 (15)
N1A—C6A	1.4309 (13)	N1B—C6B	1.4265 (14)
N2A—N3A	1.2793 (16)	N2B—N3B	1.2840 (18)
N3A—N4A	1.3647 (18)	N3B—N4B	1.359 (2)
N4A—C5A	1.3288 (13)	N4B—C5B	1.3248 (14)
C5A—N5A	1.3374 (16)	C5B—N5B	1.3351 (19)
N5A—H5A	0.890 (17)	N5B—H5C	0.84 (2)
N5A—H5B	0.906 (15)	N5B—H5D	0.88 (2)
C6A—C7A	1.3766 (16)	C6B—C11B	1.3802 (18)
C6A—C11A	1.3772 (18)	C6B—C7B	1.3809 (16)
C7A—C8A	1.3867 (16)	C7B—C8B	1.3859 (16)
C7A—H7A	0.976 (15)	C7B—H7B	0.945 (15)
C8A—C9A	1.367 (2)	C8B—C9B	1.371 (2)
C8A—H8A	0.964 (17)	C8B—H8B	0.992 (16)
C9A—C10A	1.374 (2)	C9B—C10B	1.372 (2)
C9A—H9A	0.978 (19)	C9B—H9B	0.987 (18)
C10A—C11A	1.389 (2)	C10B—C11B	1.384 (2)
C10A—H10A	0.99 (2)	C10B—H10B	0.963 (18)
C11A—H11A	0.999 (17)	C11B—H11B	0.912 (15)
C5A—N1A—N2A	108.15 (9)	C5B—N1B—N2B	108.29 (10)
C5A—N1A—C6A	130.19 (9)	C5B—N1B—C6B	130.93 (10)
N2A—N1A—C6A	121.66 (10)	N2B—N1B—C6B	120.77 (11)
N3A—N2A—N1A	106.21 (11)	N3B—N2B—N1B	105.72 (13)
N2A—N3A—N4A	111.80 (10)	N2B—N3B—N4B	112.04 (12)
C5A—N4A—N3A	105.60 (10)	C5B—N4B—N3B	105.36 (12)
N4A—C5A—N5A	125.71 (11)	N4B—C5B—N5B	126.12 (13)
N4A—C5A—N1A	108.25 (11)	N4B—C5B—N1B	108.59 (13)
N5A—C5A—N1A	126.03 (10)	N5B—C5B—N1B	125.27 (10)
C5A—N5A—H5A	115.4 (10)	C5B—N5B—H5C	117.5 (14)
C5A—N5A—H5B	119.1 (9)	C5B—N5B—H5D	113.7 (14)
H5A—N5A—H5B	114.0 (14)	H5C—N5B—H5D	118 (2)
C7A—C6A—C11A	121.28 (11)	C11B—C6B—C7B	120.96 (11)
C7A—C6A—N1A	119.40 (10)	C11B—C6B—N1B	119.44 (11)
C11A—C6A—N1A	119.32 (11)	C7B—C6B—N1B	119.59 (10)
C6A—C7A—C8A	119.08 (12)	C6B—C7B—C8B	119.18 (11)
C6A—C7A—H7A	119.0 (9)	C6B—C7B—H7B	120.9 (9)
C8A—C7A—H7A	121.9 (9)	C8B—C7B—H7B	119.9 (9)
C9A—C8A—C7A	120.29 (13)	C9B—C8B—C7B	120.10 (12)
C9A—C8A—H8A	120.5 (10)	C9B—C8B—H8B	121.7 (9)
C7A—C8A—H8A	119.2 (10)	C7B—C8B—H8B	118.2 (9)
C8A—C9A—C10A	120.19 (13)	C8B—C9B—C10B	120.38 (12)
C8A—C9A—H9A	117.1 (11)	C8B—C9B—H9B	123.1 (10)
C10A—C9A—H9A	122.7 (11)	C10B—C9B—H9B	116.5 (10)
C9A—C10A—C11A	120.49 (14)	C9B—C10B—C11B	120.44 (13)
C9A—C10A—H10A	121.1 (13)	C9B—C10B—H10B	121.8 (10)
C11A—C10A—H10A	118.5 (13)	C11B—C10B—H10B	117.8 (10)
C6A—C11A—C10A	118.61 (13)	C6B—C11B—C10B	118.93 (13)
C6A—C11A—H11A	118.3 (10)	C6B—C11B—H11B	117.5 (9)
C10A—C11A—H11A	122.9 (10)	C10B—C11B—H11B	123.5 (9)
C5A—N1A—N2A—N3A	0.47 (14)	C5B—N1B—N2B—N3B	−0.24 (16)
C6A—N1A—N2A—N3A	−179.27 (11)	C6B—N1B—N2B—N3B	178.71 (12)
N1A—N2A—N3A—N4A	−0.11 (15)	N1B—N2B—N3B—N4B	0.37 (18)
N2A—N3A—N4A—C5A	−0.28 (16)	N2B—N3B—N4B—C5B	−0.36 (18)
N3A—N4A—C5A—N5A	179.16 (13)	N3B—N4B—C5B—N5B	−178.35 (14)
N3A—N4A—C5A—N1A	0.56 (14)	N3B—N4B—C5B—N1B	0.18 (15)
N2A—N1A—C5A—N4A	−0.65 (14)	N2B—N1B—C5B—N4B	0.03 (15)
C6A—N1A—C5A—N4A	179.05 (11)	C6B—N1B—C5B—N4B	−178.78 (11)
N2A—N1A—C5A—N5A	−179.24 (13)	N2B—N1B—C5B—N5B	178.58 (14)
C6A—N1A—C5A—N5A	0.5 (2)	C6B—N1B—C5B—N5B	−0.2 (2)
C5A—N1A—C6A—C7A	−50.62 (17)	C5B—N1B—C6B—C11B	−136.16 (14)
N2A—N1A—C6A—C7A	129.05 (13)	N2B—N1B—C6B—C11B	45.15 (17)
C5A—N1A—C6A—C11A	129.70 (15)	C5B—N1B—C6B—C7B	45.35 (18)
N2A—N1A—C6A—C11A	−50.63 (16)	N2B—N1B—C6B—C7B	−133.34 (13)
C11A—C6A—C7A—C8A	−2.17 (19)	C11B—C6B—C7B—C8B	1.52 (19)
N1A—C6A—C7A—C8A	178.16 (11)	N1B—C6B—C7B—C8B	179.99 (11)
C6A—C7A—C8A—C9A	0.21 (19)	C6B—C7B—C8B—C9B	−1.1 (2)
C7A—C8A—C9A—C10A	1.9 (2)	C7B—C8B—C9B—C10B	−0.3 (2)
C8A—C9A—C10A—C11A	−2.1 (3)	C8B—C9B—C10B—C11B	1.4 (3)
C7A—C6A—C11A—C10A	2.0 (2)	C7B—C6B—C11B—C10B	−0.5 (2)
N1A—C6A—C11A—C10A	−178.35 (13)	N1B—C6B—C11B—C10B	−178.93 (13)
C9A—C10A—C11A—C6A	0.2 (3)	C9B—C10B—C11B—C6B	−1.0 (2)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N5A—H5A···N4A^i	0.89 (2)	2.194 (18)	3.0777 (17)	172 (12)
N5A—H5B···N4B^ii	0.91 (2)	2.209 (16)	3.0975 (16)	166.7 (13)
N5B—H5C···N4A^iii	0.84 (2)	2.50 (2)	3.2935 (19)	157 (2)
N5B—H5C···N3A^iii	0.84 (2)	2.62 (2)	3.423 (2)	161 (2)
N5B—H5D···N4B^iv	0.88 (2)	2.47 (2)	3.3493 (19)	173 (2)
N5B—H5D···N3B^iv	0.88 (2)	2.37 (2)	3.181 (2)	153 (2)

Symmetry codes: (i) −x+1, −y, −z+1; (ii) x, y−1, z; (iii) x, −y+3/2, z−1/2; (iv) −x+1, y+1/2, −z+1/2.

(II) 5-amino-1-(1-naphthyl)tetrazole

Crystal data

C11H9N5	F(000) = 440
Mr = 211.23	Dx = 1.341 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 25 reflections
a = 12.176 (5) Å	θ = 17.8–21.0°
b = 7.3611 (18) Å	µ = 0.09 mm^−1
c = 11.699 (3) Å	T = 293 K
β = 93.85 (3)°	Rectangular prism, colourless
V = 1046.2 (6) Å^3	0.56 × 0.44 × 0.12 mm
Z = 4

Data collection

Nicolet R3m four-circle diffractometer	Rint = 0.016
Radiation source: fine-focus sealed tube	θmax = 30.1°, θmin = 1.7°
Graphite monochromator	h = −17→17
ω/2θ scans	k = −10→0
3326 measured reflections	l = 0→16
3078 independent reflections	3 standard reflections every 100 reflections
2055 reflections with I > 2σ(I)	intensity decay: none

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)] = 0.062	Hydrogen site location: difference Fourier map
wR(F^2) = 0.207	All H-atom parameters refined
S = 1.03	w = 1/[σ^2(Fo^2) + (0.1428P)^2] where P = (Fo^2 + 2Fc^2)/3
3078 reflections	(Δ/σ)max < 0.001
181 parameters	Δρmax = 0.37 e Å^−3
0 restraints	Δρmin = −0.24 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
N1	0.33859 (10)	0.13716 (17)	0.41718 (9)	0.0456 (3)
N2	0.33242 (12)	0.04963 (19)	0.51949 (11)	0.0545 (4)
N3	0.39166 (12)	0.1420 (2)	0.59291 (11)	0.0558 (4)
N4	0.43910 (11)	0.28837 (19)	0.54460 (10)	0.0517 (3)
N5	0.43099 (15)	0.4005 (2)	0.35409 (12)	0.0682 (5)
H5A	0.4104 (15)	0.385 (3)	0.2850 (17)	0.052 (5)*
H5B	0.4753 (15)	0.493 (3)	0.3762 (18)	0.064 (5)*
C5	0.40500 (12)	0.2831 (2)	0.43444 (11)	0.0461 (3)
C6	0.28715 (11)	0.06631 (19)	0.31331 (12)	0.0436 (3)
C7	0.31843 (15)	−0.0993 (2)	0.27559 (16)	0.0578 (4)
H7	0.374 (2)	−0.165 (4)	0.318 (2)	0.102 (8)*
C8	0.27055 (18)	−0.1688 (3)	0.17235 (19)	0.0719 (6)
H8	0.292 (2)	−0.282 (4)	0.147 (2)	0.092 (8)*
C9	0.19499 (16)	−0.0705 (3)	0.10866 (17)	0.0687 (5)
H9	0.1602 (18)	−0.101 (3)	0.030 (2)	0.078 (7)*
C10	0.15941 (12)	0.1006 (2)	0.14625 (13)	0.0538 (4)
C11	0.07670 (15)	0.2033 (4)	0.08406 (17)	0.0727 (6)
H11	0.0442 (19)	0.160 (3)	0.011 (2)	0.082 (7)*
C12	0.03957 (18)	0.3618 (4)	0.1245 (2)	0.0819 (7)
H12	−0.023 (2)	0.426 (4)	0.081 (3)	0.098 (7)*
C13	0.08561 (18)	0.4317 (3)	0.2271 (2)	0.0754 (6)
H13	0.069 (2)	0.539 (4)	0.249 (3)	0.105 (9)*
C14	0.16689 (15)	0.3408 (2)	0.29027 (16)	0.0567 (4)
H14	0.1982 (16)	0.384 (3)	0.3629 (18)	0.064 (6)*
C15	0.20520 (11)	0.1717 (2)	0.25190 (11)	0.0437 (3)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1	0.0574 (7)	0.0411 (6)	0.0374 (6)	−0.0051 (5)	−0.0034 (5)	0.0021 (4)
N2	0.0727 (8)	0.0475 (7)	0.0428 (6)	−0.0025 (6)	0.0002 (6)	0.0097 (5)
N3	0.0714 (8)	0.0557 (7)	0.0393 (6)	0.0011 (6)	−0.0035 (6)	0.0063 (5)
N4	0.0644 (7)	0.0538 (8)	0.0358 (6)	−0.0053 (6)	−0.0054 (5)	0.0002 (5)
N5	0.0942 (11)	0.0729 (10)	0.0357 (6)	−0.0397 (9)	−0.0093 (7)	0.0043 (6)
C5	0.0556 (7)	0.0455 (7)	0.0365 (6)	−0.0067 (6)	−0.0031 (5)	−0.0017 (5)
C6	0.0495 (7)	0.0384 (6)	0.0423 (6)	−0.0040 (5)	−0.0005 (5)	−0.0034 (5)
C7	0.0615 (9)	0.0408 (8)	0.0701 (10)	0.0027 (6)	−0.0031 (8)	−0.0084 (7)
C8	0.0809 (12)	0.0537 (10)	0.0808 (13)	−0.0060 (9)	0.0026 (10)	−0.0279 (9)
C9	0.0702 (10)	0.0732 (12)	0.0616 (10)	−0.0215 (9)	−0.0022 (8)	−0.0226 (9)
C10	0.0485 (7)	0.0666 (10)	0.0455 (7)	−0.0113 (7)	−0.0018 (6)	−0.0003 (7)
C11	0.0551 (9)	0.1079 (18)	0.0533 (9)	−0.0088 (10)	−0.0092 (7)	0.0171 (10)
C12	0.0649 (11)	0.1036 (18)	0.0766 (13)	0.0154 (11)	−0.0006 (10)	0.0355 (13)
C13	0.0744 (11)	0.0676 (12)	0.0856 (14)	0.0231 (10)	0.0163 (10)	0.0201 (10)
C14	0.0632 (9)	0.0523 (9)	0.0554 (9)	0.0089 (7)	0.0107 (7)	0.0023 (7)
C15	0.0460 (6)	0.0444 (7)	0.0406 (6)	−0.0029 (5)	0.0030 (5)	0.0014 (5)

Geometric parameters (Å, º)

N1—C5	1.3513 (19)	C8—H8	0.93 (3)
N1—N2	1.3658 (17)	C9—C10	1.411 (3)
N1—C6	1.4278 (17)	C9—H9	1.02 (2)
N2—N3	1.2796 (19)	C10—C11	1.420 (3)
N3—N4	1.3628 (19)	C10—C15	1.421 (2)
N4—C5	1.3277 (17)	C11—C12	1.348 (4)
N5—C5	1.3309 (19)	C11—H11	0.97 (2)
N5—H5A	0.84 (2)	C12—C13	1.389 (4)
N5—H5B	0.90 (2)	C12—H12	1.01 (3)
C6—C7	1.359 (2)	C13—C14	1.369 (3)
C6—C15	1.420 (2)	C13—H13	0.86 (3)
C7—C8	1.402 (3)	C14—C15	1.413 (2)
C7—H7	0.95 (3)	C14—H14	0.96 (2)
C8—C9	1.354 (3)
C5—N1—N2	108.15 (12)	C8—C9—C10	121.12 (16)
C5—N1—C6	129.89 (12)	C8—C9—H9	127.6 (13)
N2—N1—C6	121.79 (12)	C10—C9—H9	111.2 (13)
N3—N2—N1	106.01 (12)	C9—C10—C11	122.50 (17)
N2—N3—N4	112.17 (12)	C9—C10—C15	119.25 (15)
C5—N4—N3	105.40 (12)	C11—C10—C15	118.22 (18)
C5—N5—H5A	121.6 (13)	C12—C11—C10	121.57 (19)
C5—N5—H5B	117.2 (13)	C12—C11—H11	117.9 (15)
H5A—N5—H5B	121.0 (19)	C10—C11—H11	120.5 (15)
N4—C5—N5	126.35 (14)	C11—C12—C13	119.91 (18)
N4—C5—N1	108.27 (13)	C11—C12—H12	119.5 (16)
N5—C5—N1	125.38 (13)	C13—C12—H12	120.5 (16)
C7—C6—C15	121.87 (14)	C14—C13—C12	121.4 (2)
C7—C6—N1	119.17 (13)	C14—C13—H13	118 (2)
C15—C6—N1	118.96 (13)	C12—C13—H13	120 (2)
C6—C7—C8	119.83 (16)	C13—C14—C15	120.08 (18)
C6—C7—H7	119.5 (18)	C13—C14—H14	122.9 (12)
C8—C7—H7	120.6 (18)	C15—C14—H14	117.0 (12)
C9—C8—C7	120.46 (18)	C14—C15—C6	123.78 (13)
C9—C8—H8	119.7 (17)	C14—C15—C10	118.82 (14)
C7—C8—H8	119.8 (17)	C6—C15—C10	117.40 (14)
C5—N1—N2—N3	0.68 (17)	C8—C9—C10—C11	−177.06 (18)
C6—N1—N2—N3	176.35 (13)	C8—C9—C10—C15	1.0 (3)
N1—N2—N3—N4	−0.65 (18)	C9—C10—C11—C12	176.30 (18)
N2—N3—N4—C5	0.37 (18)	C15—C10—C11—C12	−1.8 (3)
N3—N4—C5—N5	179.97 (17)	C10—C11—C12—C13	2.7 (3)
N3—N4—C5—N1	0.08 (17)	C11—C12—C13—C14	−1.5 (3)
N2—N1—C5—N4	−0.47 (17)	C12—C13—C14—C15	−0.4 (3)
C6—N1—C5—N4	−175.67 (14)	C13—C14—C15—C6	−178.40 (16)
N2—N1—C5—N5	179.64 (17)	C13—C14—C15—C10	1.2 (2)
C6—N1—C5—N5	4.4 (3)	C7—C6—C15—C14	177.25 (15)
C5—N1—C6—C7	113.83 (19)	N1—C6—C15—C14	−3.2 (2)
N2—N1—C6—C7	−60.8 (2)	C7—C6—C15—C10	−2.4 (2)
C5—N1—C6—C15	−65.7 (2)	N1—C6—C15—C10	177.18 (12)
N2—N1—C6—C15	119.63 (16)	C9—C10—C15—C14	−178.32 (15)
C15—C6—C7—C8	1.1 (3)	C11—C10—C15—C14	−0.1 (2)
N1—C6—C7—C8	−178.49 (16)	C9—C10—C15—C6	1.3 (2)
C6—C7—C8—C9	1.4 (3)	C11—C10—C15—C6	179.50 (14)
C7—C8—C9—C10	−2.4 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N5—H5A···N3^i	0.84 (2)	2.25 (2)	3.077 (2)	168 (2)
N5—H5B···N4^ii	0.90 (2)	2.10 (2)	2.983 (2)	169 (2)
C8—H8···N2^iii	0.93 (3)	2.54 (3)	3.436 (2)	163 (2)

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