Bis(5-phenyltetrazol-2-yl)methane

In the title compound, alternatively named 5,5′-diphenyl-2,2′-methyleneditetrazole, C₁₅H₁₂N₈, the dihedral angles between the tetrazole and benzene rings in the two 5-phenyl­tetrazole fragments are 2.45 (6) and 10.01 (9)°. There is weak intermolecular C—H...N hydrogen bonding involving the H atoms of the methyl­ene groups, which is responsible for the formation of two-membered aggregates. C—H...π interactions in the crystal structure are discussed.

S1. Comment

In recent years, binuclear tetrazoles have been of great interest, owing to their potential effectiveness as chelating agents and also due to their potential for use as starting materials for the synthesis of some organometallic structures with important physical properties (Saalfrank et al., 1995, 1996; Lyakhov et al., 2001, and references therein). Of special interest are tetrazole compounds with activated methylene groups, which are very promising in fine organic synthesis (Dashkovskaya et al., 1990; Brekhov et al., 1992). In the light of this interest, we have prepared the title compound, (I), and present its crystal structure here. \sch

The molecule of (I) (Fig. 1) contains two 5-phenyltetrazole fragments, denoted A and B. The geometrical parameters of the tetrazole rings of the 5-phenyltetrazole fragments in the molecule of (I) are very similar (Table 1); corresponding bond distances and angles of the rings fall within the 3σ range. The tetrazole ring geometry is typical for 2,5-substituted tetrazoles (Cambridge Structural Database; Version 5.22 of October 2001; Allen & Kennard, 1993), with the following main features. The tetrazole rings are planar, to within 0.0016 (7) and 0.0027 (7) Å for fragments A and B, respectively. The N3—N4 bond is the shortest in the ring, while the N4—C5 bond is essentially larger than N1—C5. All the bond distances of the tetrazole rings, with the exception of N4—C5, lie within the narrow range of 1.3127 (16)–1.3333 (14) Å (fragment A) and 1.3131 (16)–1.3287 (13) Å (fragment B). This is indicative of more aromatic character of the ring in 2,5-substituted tetrazoles in comparison with 1-, 5- and 1,5-substituted tetrazoles.

The benzene rings in (I) are planar to within 0.0038 (11) and 0.0030 (9) Å for 5-phenyltetrazole fragments A and B, respectively. The bond distances and angles are consistent with those observed previously for the ring (Cambridge Structural Database; Version 5.22 of October 2001; Allen & Kennard, 1993).

The benzene and tetrazole rings in (I) were found to be non-coplanar in the 5-phenyltetrazole fragments, the dihedral angles between the rings being 2.45 (6) and 10.01 (9)° for fragments A and B, respectively.

With regard to the packing structure, the following features may be noted (Spek, 1999). There are no classical hydrogen bonds in the structure of (I), but weak intermolecular C1—H1B···N3Bⁱ hydrogen bonds may be revealed [Table 2; symmetry code: (i) -x, 1 - y, -z]. These bonds are responsible for the formation of two-membered aggregates (Fig. 2).

Two types of intermolecular C—H···π interactions may be detected in the structure of (I) (Fig. 3 and Table 2). The first type corresponds to the interactions between atom H10A of one molecule and the B tetrazole π-ring of a second molecule at (1 - x, -y, -z). These interactions are characterized by the angle C10A—H10A···CgTz = 141.6 (12)° and the distance H10A···CgTz = 3.116 (16) Å (CgTz denotes the centroid of the tetrazole ring). These interactions form two-membered entities, as shown in Fig. 3.

Atom H9B of one molecule and the B benzene π-ring of another molecule at (-1/2 - x, y - 1/2, -1/2 - z) are involved in C—H···π interactions of the second type. These interactions are characterized by the angle C9B—H9B···CgBz = 140.1 (13)° and the distance H9B···CgBz = 2.877 (16) Å (CgBz denotes the centroid of the benzene ring). These interactions form chains extended along the b axis and link together the two-membered entities mentioned above, to form layers which are connected by C—H···N hydrogen bonds (Figs. 2 and 3).

As can be seen from Fig. 3, the crystal structure of (I) is also an object for investigations of π_benzene···π_tetrazole stacking interactions.

S2. Experimental

To prepare the title compound, a solution of 5-phenyltetrazole (0.06 mol), diiodomethane (0.03 mol) and triethylamine (0.06 mol) in dimethylformamide (50 ml) was agitated at 373 K for 20 h. The solution was cooled to room temperature and flushed with water (1 l). The oil which formed was left to crystallize for several hours. The precipitate was filtered, washed with water and vacuum dried. Crystals of (I) suitable for single-crystal X-ray analysis were grown by slow evaporation from an ethyl acetate solution (yield 59%; m.p. 463–465 K, decomposition, uncorrected). Spectroscopic analysis: ¹H NMR (100 MHz, d₆-DMSO, δ, p.p.m.): 7.50–7.68 (m, 6H, C₆H₅), 7.88 (s, 2H, CH₂), 8.0–8.21 (m, 4H, C₆H₅).

S3. Refinement

H-atom positions were found from the difference Fourier map and all associated parameters were refined freely [C—H = 0.95 (2)–1.01 (2) Å].

Computing details

Data collection: R3m Software (Nicolet, 1980); cell refinement: R3m Software; data reduction: R3m Software; 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, 1999); software used to prepare material for publication: SHELXL97.

Figures

	Fig. 1. A view of the molecular structure of (I), showing the labelling scheme for the two fragments. Displacement ellipsoids are drawn at the 50% probability level and H atoms are shown as spheres of arbitrary radii.
	Fig. 2. The crystal structure of (I) viewed along the b axis. Dashed lines indicate C—H···N hydrogen bonding.
	Fig. 3. The C—H···π interactions in the structure of (I), viewed along the direction close to [001].

Bis(5-phenyltetrazol-2-yl)methane

Crystal data

C15H12N8	F(000) = 632
Mr = 304.33	Dx = 1.397 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71069 Å
a = 11.053 (2) Å	Cell parameters from 25 reflections
b = 7.409 (2) Å	θ = 17.5–21.8°
c = 17.956 (4) Å	µ = 0.09 mm^−1
β = 100.16 (2)°	T = 293 K
V = 1447.4 (6) Å^3	Prism, colourless
Z = 4	0.50 × 0.45 × 0.40 mm

Data collection

Nicolet R3m four-circle diffractometer	Rint = 0.015
Radiation source: fine-focus sealed tube	θmax = 30.1°, θmin = 2.3°
Graphite monochromator	h = 0→15
ω/2θ scans	k = 0→10
4606 measured reflections	l = −25→24
4258 independent reflections	3 standard reflections every 100 reflections
3025 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)] = 0.041	Hydrogen site location: difference Fourier map
wR(F^2) = 0.126	All H-atom parameters refined
S = 1.04	w = 1/[σ^2(Fo^2) + (0.0693P)^2 + 0.0755P] where P = (Fo^2 + 2Fc^2)/3
4258 reflections	(Δ/σ)max < 0.001
256 parameters	Δρmax = 0.19 e Å^−3
0 restraints	Δρmin = −0.21 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
C1	0.12733 (11)	0.45902 (17)	−0.09593 (8)	0.0477 (3)
H1A	0.1173 (12)	0.518 (2)	−0.1466 (8)	0.053 (4)*
H1B	0.1127 (13)	0.542 (2)	−0.0542 (9)	0.057 (4)*
N1A	0.31064 (9)	0.35311 (14)	−0.01017 (5)	0.0437 (2)
N2A	0.25352 (9)	0.39768 (14)	−0.07944 (5)	0.0435 (2)
N3A	0.32068 (10)	0.37400 (16)	−0.13275 (6)	0.0519 (3)
N4A	0.42708 (10)	0.31252 (16)	−0.09787 (6)	0.0516 (3)
C5A	0.41962 (10)	0.30024 (15)	−0.02336 (6)	0.0402 (2)
C6A	0.52024 (10)	0.23768 (15)	0.03519 (7)	0.0415 (2)
C7A	0.50769 (12)	0.2363 (2)	0.11072 (7)	0.0512 (3)
H7A	0.4346 (15)	0.278 (2)	0.1254 (9)	0.062 (4)*
C8A	0.60299 (14)	0.1781 (2)	0.16584 (8)	0.0595 (3)
H8A	0.5926 (15)	0.185 (2)	0.2179 (10)	0.065 (4)*
C9A	0.71158 (13)	0.1187 (2)	0.14608 (9)	0.0584 (3)
H9A	0.7806 (16)	0.070 (2)	0.1858 (10)	0.076 (5)*
C10A	0.72538 (12)	0.1201 (2)	0.07121 (9)	0.0565 (3)
H10A	0.8000 (15)	0.081 (2)	0.0555 (9)	0.071 (5)*
C11A	0.63074 (12)	0.17982 (17)	0.01598 (8)	0.0491 (3)
H11A	0.6419 (15)	0.184 (2)	−0.0358 (10)	0.067 (5)*
N1B	0.03684 (9)	0.17582 (13)	−0.14913 (5)	0.0428 (2)
N2B	0.04398 (9)	0.30665 (13)	−0.09793 (5)	0.0427 (2)
N3B	−0.02780 (11)	0.28286 (16)	−0.04728 (6)	0.0531 (3)
N4B	−0.08581 (11)	0.13010 (16)	−0.06540 (6)	0.0531 (3)
C5B	−0.04471 (9)	0.06613 (16)	−0.12719 (6)	0.0397 (2)
C6B	−0.08221 (9)	−0.10783 (16)	−0.16309 (6)	0.0397 (2)
C7B	−0.04800 (11)	−0.15581 (18)	−0.23142 (7)	0.0458 (3)
H7B	−0.0021 (13)	−0.075 (2)	−0.2564 (9)	0.059 (4)*
C8B	−0.08235 (12)	−0.32230 (19)	−0.26353 (7)	0.0528 (3)
H8B	−0.0555 (15)	−0.356 (2)	−0.3121 (9)	0.066 (4)*
C9B	−0.15069 (12)	−0.4402 (2)	−0.22802 (8)	0.0538 (3)
H9B	−0.1710 (15)	−0.556 (2)	−0.2488 (10)	0.075 (5)*
C10B	−0.18588 (12)	−0.39208 (19)	−0.16055 (8)	0.0522 (3)
H10B	−0.2349 (15)	−0.471 (2)	−0.1343 (9)	0.070 (5)*
C11B	−0.15178 (11)	−0.22668 (18)	−0.12797 (7)	0.0458 (3)
H11B	−0.1763 (12)	−0.1904 (19)	−0.0810 (8)	0.050 (4)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0459 (6)	0.0418 (6)	0.0534 (7)	0.0008 (5)	0.0027 (5)	−0.0002 (5)
N1A	0.0429 (5)	0.0460 (5)	0.0419 (5)	−0.0017 (4)	0.0068 (4)	0.0000 (4)
N2A	0.0446 (5)	0.0434 (5)	0.0418 (5)	−0.0029 (4)	0.0058 (4)	−0.0002 (4)
N3A	0.0537 (6)	0.0587 (6)	0.0439 (5)	−0.0031 (5)	0.0105 (4)	0.0011 (5)
N4A	0.0494 (6)	0.0613 (7)	0.0459 (5)	−0.0016 (5)	0.0129 (4)	−0.0004 (5)
C5A	0.0422 (6)	0.0364 (5)	0.0434 (5)	−0.0054 (4)	0.0112 (4)	−0.0016 (4)
C6A	0.0400 (5)	0.0362 (5)	0.0485 (6)	−0.0039 (4)	0.0086 (4)	−0.0005 (4)
C7A	0.0456 (6)	0.0580 (7)	0.0516 (7)	0.0026 (6)	0.0127 (5)	0.0030 (6)
C8A	0.0613 (8)	0.0669 (9)	0.0499 (7)	0.0007 (7)	0.0091 (6)	0.0081 (6)
C9A	0.0500 (7)	0.0572 (8)	0.0648 (8)	0.0010 (6)	0.0008 (6)	0.0099 (6)
C10A	0.0432 (6)	0.0555 (8)	0.0712 (9)	0.0033 (6)	0.0112 (6)	0.0026 (6)
C11A	0.0464 (6)	0.0486 (7)	0.0540 (7)	−0.0013 (5)	0.0132 (5)	−0.0019 (5)
N1B	0.0413 (5)	0.0447 (5)	0.0428 (5)	−0.0008 (4)	0.0087 (4)	−0.0023 (4)
N2B	0.0407 (5)	0.0432 (5)	0.0434 (5)	0.0027 (4)	0.0054 (4)	−0.0023 (4)
N3B	0.0567 (6)	0.0559 (6)	0.0488 (6)	0.0000 (5)	0.0147 (5)	−0.0071 (5)
N4B	0.0570 (6)	0.0570 (6)	0.0489 (6)	−0.0049 (5)	0.0197 (5)	−0.0072 (5)
C5B	0.0346 (5)	0.0463 (6)	0.0379 (5)	0.0032 (4)	0.0054 (4)	0.0027 (4)
C6B	0.0326 (5)	0.0460 (6)	0.0395 (5)	0.0008 (4)	0.0030 (4)	0.0018 (4)
C7B	0.0414 (6)	0.0535 (7)	0.0428 (6)	−0.0014 (5)	0.0085 (5)	0.0007 (5)
C8B	0.0504 (7)	0.0606 (8)	0.0466 (6)	0.0002 (6)	0.0065 (5)	−0.0091 (6)
C9B	0.0460 (6)	0.0518 (7)	0.0592 (8)	−0.0037 (5)	−0.0028 (5)	−0.0075 (6)
C10B	0.0425 (6)	0.0528 (7)	0.0592 (7)	−0.0071 (5)	0.0033 (5)	0.0065 (6)
C11B	0.0408 (5)	0.0543 (7)	0.0423 (6)	−0.0017 (5)	0.0077 (4)	0.0040 (5)

Geometric parameters (Å, º)

C1—N2A	1.4470 (16)	C10A—H10A	0.961 (16)
C1—N2B	1.4535 (16)	C11A—H11A	0.959 (17)
C1—H1A	0.997 (15)	N1B—C5B	1.3242 (15)
C1—H1B	1.003 (15)	N1B—N2B	1.3287 (13)
N1A—C5A	1.3271 (15)	N2B—N3B	1.3200 (15)
N1A—N2A	1.3333 (14)	N3B—N4B	1.3131 (16)
N2A—N3A	1.3223 (14)	N4B—C5B	1.3564 (15)
N3A—N4A	1.3127 (16)	C5B—C6B	1.4677 (16)
N4A—C5A	1.3579 (15)	C6B—C11B	1.3913 (16)
C5A—C6A	1.4645 (17)	C6B—C7B	1.3922 (16)
C6A—C7A	1.3873 (17)	C7B—C8B	1.3860 (19)
C6A—C11A	1.3939 (17)	C7B—H7B	0.949 (15)
C7A—C8A	1.3812 (19)	C8B—C9B	1.382 (2)
C7A—H7A	0.945 (16)	C8B—H8B	1.001 (16)
C8A—C9A	1.382 (2)	C9B—C10B	1.383 (2)
C8A—H8A	0.964 (16)	C9B—H9B	0.946 (18)
C9A—C10A	1.379 (2)	C10B—C11B	1.3813 (19)
C9A—H9A	1.014 (19)	C10B—H10B	0.973 (17)
C10A—C11A	1.3812 (19)	C11B—H11B	0.968 (14)
N2A—C1—N2B	110.18 (10)	C10A—C11A—C6A	120.43 (13)
N2A—C1—H1A	105.8 (8)	C10A—C11A—H11A	119.6 (10)
N2B—C1—H1A	110.4 (8)	C6A—C11A—H11A	119.9 (10)
N2A—C1—H1B	108.4 (9)	C5B—N1B—N2B	101.67 (9)
N2B—C1—H1B	108.0 (8)	N3B—N2B—N1B	114.19 (10)
H1A—C1—H1B	114.0 (12)	N3B—N2B—C1	122.82 (10)
C5A—N1A—N2A	101.65 (10)	N1B—N2B—C1	122.94 (10)
N3A—N2A—N1A	114.11 (10)	N4B—N3B—N2B	105.72 (10)
N3A—N2A—C1	122.51 (10)	N3B—N4B—C5B	106.53 (10)
N1A—N2A—C1	123.32 (10)	N1B—C5B—N4B	111.88 (11)
N4A—N3A—N2A	105.71 (10)	N1B—C5B—C6B	124.23 (10)
N3A—N4A—C5A	106.75 (10)	N4B—C5B—C6B	123.83 (10)
N1A—C5A—N4A	111.77 (10)	C11B—C6B—C7B	119.71 (11)
N1A—C5A—C6A	124.30 (10)	C11B—C6B—C5B	119.51 (10)
N4A—C5A—C6A	123.92 (10)	C7B—C6B—C5B	120.78 (10)
C7A—C6A—C11A	118.86 (12)	C8B—C7B—C6B	119.79 (12)
C7A—C6A—C5A	120.66 (11)	C8B—C7B—H7B	119.8 (9)
C11A—C6A—C5A	120.48 (11)	C6B—C7B—H7B	120.4 (9)
C8A—C7A—C6A	120.51 (12)	C9B—C8B—C7B	120.16 (12)
C8A—C7A—H7A	119.0 (10)	C9B—C8B—H8B	121.1 (10)
C6A—C7A—H7A	120.5 (10)	C7B—C8B—H8B	118.7 (10)
C7A—C8A—C9A	120.16 (14)	C8B—C9B—C10B	120.16 (13)
C7A—C8A—H8A	118.2 (10)	C8B—C9B—H9B	120.1 (10)
C9A—C8A—H8A	121.6 (10)	C10B—C9B—H9B	119.7 (10)
C10A—C9A—C8A	119.88 (13)	C11B—C10B—C9B	120.12 (12)
C10A—C9A—H9A	119.3 (9)	C11B—C10B—H10B	117.4 (10)
C8A—C9A—H9A	120.8 (9)	C9B—C10B—H10B	122.5 (10)
C9A—C10A—C11A	120.14 (13)	C10B—C11B—C6B	120.06 (12)
C9A—C10A—H10A	122.1 (10)	C10B—C11B—H11B	121.2 (8)
C11A—C10A—H10A	117.7 (10)	C6B—C11B—H11B	118.7 (8)
C5A—N1A—N2A—N3A	0.36 (13)	C5B—N1B—N2B—N3B	−0.21 (13)
C5A—N1A—N2A—C1	177.73 (10)	C5B—N1B—N2B—C1	177.35 (10)
N2B—C1—N2A—N3A	99.30 (13)	N2A—C1—N2B—N3B	112.74 (13)
N2B—C1—N2A—N1A	−77.85 (14)	N2A—C1—N2B—N1B	−64.61 (14)
N1A—N2A—N3A—N4A	−0.46 (14)	N1B—N2B—N3B—N4B	−0.23 (14)
C1—N2A—N3A—N4A	−177.85 (11)	C1—N2B—N3B—N4B	−177.79 (11)
N2A—N3A—N4A—C5A	0.35 (14)	N2B—N3B—N4B—C5B	0.56 (14)
N2A—N1A—C5A—N4A	−0.12 (13)	N2B—N1B—C5B—N4B	0.58 (13)
N2A—N1A—C5A—C6A	179.37 (10)	N2B—N1B—C5B—C6B	−176.81 (10)
N3A—N4A—C5A—N1A	−0.15 (14)	N3B—N4B—C5B—N1B	−0.75 (14)
N3A—N4A—C5A—C6A	−179.64 (11)	N3B—N4B—C5B—C6B	176.65 (10)
N1A—C5A—C6A—C7A	−2.31 (18)	N1B—C5B—C6B—C11B	168.85 (11)
N4A—C5A—C6A—C7A	177.13 (12)	N4B—C5B—C6B—C11B	−8.23 (17)
N1A—C5A—C6A—C11A	178.22 (11)	N1B—C5B—C6B—C7B	−10.54 (17)
N4A—C5A—C6A—C11A	−2.35 (17)	N4B—C5B—C6B—C7B	172.38 (11)
C11A—C6A—C7A—C8A	−0.2 (2)	C11B—C6B—C7B—C8B	−0.69 (17)
C5A—C6A—C7A—C8A	−179.67 (12)	C5B—C6B—C7B—C8B	178.70 (11)
C6A—C7A—C8A—C9A	−0.7 (2)	C6B—C7B—C8B—C9B	0.21 (19)
C7A—C8A—C9A—C10A	0.9 (2)	C7B—C8B—C9B—C10B	0.5 (2)
C8A—C9A—C10A—C11A	−0.3 (2)	C8B—C9B—C10B—C11B	−0.7 (2)
C9A—C10A—C11A—C6A	−0.6 (2)	C9B—C10B—C11B—C6B	0.18 (19)
C7A—C6A—C11A—C10A	0.80 (19)	C7B—C6B—C11B—C10B	0.49 (17)
C5A—C6A—C11A—C10A	−179.71 (12)	C5B—C6B—C11B—C10B	−178.90 (11)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C1—H1B···N3B^i	1.003 (15)	2.548 (15)	3.5324 (18)	166.9 (12)
C10A—H10A···CgTz^ii	0.961 (16)	3.116 (16)	3.9153 (18)	141.6 (12)
C9B—H9B···CgBz^iii	0.946 (18)	2.877 (16)	3.6548 (18)	140.1 (13)

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