4,5-Diaza-9H-fluoren-9-imine

Abstract

In the title compound, C₁₁H₇N₃, the diaza­fluorene rings are almost coplanar with an r.m.s. deviation of 0.0160 Å. In the crystal structure, C—H⋯N hydrogen bonds link mol­ecules into sheets parallel to the ab plane. Mol­ecules are also stacked regularly along the c axis by a variety of π–π inter­actions with centroid–centroid distances in the range 3.527 (2)–3.908 (2) Å.

Related literature

For the use of the title compound in synthesizing complexes with inter­esting photochemical properties and for the synthesis, see: Wang & Rillema (1997 ▶). For reference bond-length data, see: Allen et al. (1987 ▶).

Experimental

Crystal data

• C₁₁H₇N₃

• M _r = 181.20

• Monoclinic,

• a = 10.008 (2) Å

• b = 12.407 (3) Å

• c = 6.8140 (14) Å

• β = 99.74 (3)°

• V = 833.9 (3) ų

• Z = 4

• Mo Kα radiation

• μ = 0.09 mm⁻¹

• T = 293 K

• 0.30 × 0.10 × 0.10 mm

Data collection

• Enraf–Nonius CAD-4 diffractometer

• Absorption correction: ψ scan (North et al., 1968 ▶) T _min = 0.973, T _max = 0.991

• 1638 measured reflections

• 1503 independent reflections

• 1010 reflections with I > 2σ(I)

• R _int = 0.022

• 3 standard reflections every 200 reflections intensity decay: none

Refinement

• R[F ² > 2σ(F ²)] = 0.066

• wR(F ²) = 0.194

• S = 1.06

• 1503 reflections

• 127 parameters

• 40 restraints

• H-atom parameters constrained

• Δρ_max = 0.28 e Å⁻³

• Δρ_min = −0.21 e Å⁻³

Data collection: CAD-4 Software (Enraf–Nonius, 1985 ▶); cell refinement: CAD-4 Software; data reduction: XCAD4 (Harms & Wocadlo, 1995 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C11—H11A⋯N3i	0.93	2.45	3.382 (4)	178
C4—H4A⋯N1ii	0.93	2.69	3.536 (4)	152

Symmetry codes: (i) ; (ii) .

supplementary crystallographic information

Comment

4,5-diazafluorene-9-imine is one of the important ligands, being utilized to synthesize complexes with interesting photochemical properties (Wang & Rillema, 1997). Here we report the crystal structure of the title compound, (I).

The molecular structure of (I) is shown in Fig. 1, and the selected geometric parameters are given in Table 1. The bond lengths and angles (Table 1) are within normal ranges (Allen et al., 1987). The diazafluorene rings are almost coplanar with an rms deviation 0.0160 Å.

In the crystal structure C—H···N hydrogen bonds link molecules into sheets parallel to the ab plane, Table 1. An extensive system of π–π contacts stacks molecules in an obverse fashion down the c axis, Fig. 2, with Cg1···Cg1 = 3.876 (2) /%A, Cg2···Cg2 = 3.572 (2) /%A, Cg(3)···Cg3 = 3.908 (2) and Cg1···Cg2 3.776 (2) Å and 3.863 (2) Å. Symmetry operations x, 1/2-y, 1/2+z, and x, 1/2-y, -1/2+z; Cg1, Cg2 and Cg3 are the centroids of the C2,C3,C5,C7,C8; N2,C1,C2,C3,C4,C5 and N3,C6,C7,C10,C11 rings, respectively.

Experimental

The title compound was synthesized by a method reported in literature (Wang & Rillema, 1997). Crystals were obtained by dissolving the compound (2.0 g, 11.0 mmol) in ethyl acetate(50 ml), and evaporating the solvent slowly at room temperature for about 5 d.

Refinement

H atoms were positioned geometrically, with N—H = 0.75 and C—H = 0.93Å for aromatic C–H, and constrained to ride on their parent atoms, with U_iso(H) = xU_eq(C/N), where x = 1.2 for aromatic H and x = 1.5 for the N–H.

Figures

Fig. 1.

A drawing of the title molecular structure, with the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level.

Fig. 2.

A packing diagram for (I). Hydrogen bonds are drawn as dashed lines.

Crystal data

C11H7N3	F(000) = 376
Mr = 181.20	Dx = 1.443 Mg m−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 25 reflections
a = 10.008 (2) Å	θ = 10–13°
b = 12.407 (3) Å	µ = 0.09 mm−1
c = 6.8140 (14) Å	T = 293 K
β = 99.74 (3)°	Block, colourless
V = 833.9 (3) Å3	0.30 × 0.10 × 0.10 mm
Z = 4

Data collection

Enraf–Nonius CAD-4 diffractometer	1010 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.022
graphite	θmax = 25.3°, θmin = 2.1°
ω/2θ scans	h = −11→11
Absorption correction: ψ scan (North et al., 1968)	k = 0→14
Tmin = 0.973, Tmax = 0.991	l = 0→8
1638 measured reflections	3 standard reflections every 200 reflections
1503 independent reflections	intensity decay: none

Refinement

Refinement on F2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.066	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.194	H-atom parameters constrained
S = 1.06	w = 1/[σ2(Fo2) + (0.0948P)2 + 0.5792P] where P = (Fo2 + 2Fc2)/3
1503 reflections	(Δ/σ)max < 0.001
127 parameters	Δρmax = 0.28 e Å−3
40 restraints	Δρmin = −0.21 e Å−3

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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	0.8062 (3)	0.5097 (2)	0.3404 (5)	0.0530 (8)
H1	0.7491	0.5497	0.3246	0.079*
N2	0.7922 (3)	0.1271 (2)	0.3022 (4)	0.0488 (8)
N3	0.5012 (3)	0.2137 (2)	0.2363 (4)	0.0455 (7)
C1	0.9253 (4)	0.1124 (3)	0.3376 (5)	0.0540 (10)
H1A	0.9567	0.0418	0.3391	0.065*
C2	0.7547 (3)	0.2304 (2)	0.3049 (5)	0.0410 (8)
C3	0.8433 (3)	0.3171 (2)	0.3340 (4)	0.0389 (8)
C4	0.9804 (4)	0.2998 (3)	0.3749 (5)	0.0508 (9)
H4A	1.0425	0.3559	0.4027	0.061*
C5	1.0202 (4)	0.1925 (3)	0.3720 (6)	0.0545 (10)
H5A	1.1119	0.1751	0.3935	0.065*
C6	0.6122 (3)	0.2709 (2)	0.2711 (4)	0.0360 (7)
C7	0.6173 (3)	0.3850 (2)	0.2811 (5)	0.0422 (8)
C8	0.7604 (3)	0.4188 (2)	0.3239 (5)	0.0441 (8)
C9	0.3856 (3)	0.2703 (3)	0.2096 (5)	0.0496 (9)
H9A	0.3044	0.2324	0.1837	0.060*
C10	0.3791 (3)	0.3820 (3)	0.2181 (6)	0.0546 (10)
H10A	0.2955	0.4167	0.2002	0.066*
C11	0.4973 (3)	0.4412 (3)	0.2531 (5)	0.0505 (9)
H11A	0.4959	0.5161	0.2576	0.061*

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
N1	0.0453 (17)	0.0273 (15)	0.083 (2)	−0.0112 (13)	0.0014 (15)	0.0041 (14)
N2	0.0498 (18)	0.0401 (16)	0.0546 (17)	0.0120 (14)	0.0033 (13)	0.0013 (13)
N3	0.0466 (17)	0.0278 (14)	0.0614 (17)	−0.0041 (12)	0.0071 (13)	−0.0015 (12)
C1	0.058 (2)	0.041 (2)	0.063 (2)	0.0158 (18)	0.0088 (17)	0.0032 (17)
C2	0.0445 (18)	0.0317 (17)	0.0454 (18)	0.0036 (14)	0.0032 (14)	−0.0001 (14)
C3	0.0430 (18)	0.0370 (17)	0.0380 (15)	−0.0060 (14)	0.0105 (13)	0.0004 (13)
C4	0.045 (2)	0.046 (2)	0.059 (2)	−0.0079 (16)	0.0011 (16)	0.0065 (16)
C5	0.0399 (19)	0.065 (3)	0.058 (2)	0.0084 (18)	0.0070 (15)	0.0018 (18)
C6	0.0387 (16)	0.0285 (16)	0.0390 (16)	−0.0005 (13)	0.0011 (12)	−0.0013 (12)
C7	0.0478 (19)	0.0246 (16)	0.0516 (18)	−0.0031 (14)	0.0013 (14)	0.0001 (13)
C8	0.0497 (19)	0.0282 (16)	0.0536 (19)	−0.0097 (15)	0.0062 (15)	−0.0024 (14)
C9	0.0339 (18)	0.045 (2)	0.068 (2)	−0.0037 (15)	0.0030 (15)	−0.0008 (17)
C10	0.045 (2)	0.040 (2)	0.079 (3)	0.0097 (17)	0.0094 (17)	−0.0004 (18)
C11	0.056 (2)	0.0250 (17)	0.069 (2)	0.0054 (16)	0.0049 (17)	0.0010 (16)

Geometric parameters (Å, °)

N1—C8	1.216 (4)	C4—C5	1.391 (5)
N1—H1	0.7500	C4—H4A	0.9300
N2—C1	1.325 (4)	C5—H5A	0.9300
N2—C2	1.336 (4)	C6—C7	1.417 (4)
N3—C6	1.305 (4)	C7—C11	1.373 (4)
N3—C9	1.340 (4)	C7—C8	1.473 (4)
C1—C5	1.367 (5)	C9—C10	1.389 (5)
C1—H1A	0.9300	C9—H9A	0.9300
C2—C3	1.386 (4)	C10—C11	1.379 (5)
C2—C6	1.493 (4)	C10—H10A	0.9300
C3—C4	1.371 (5)	C11—H11A	0.9300
C3—C8	1.505 (4)
C8—N1—H1	109.5	N3—C6—C7	125.1 (3)
C1—N2—C2	113.9 (3)	N3—C6—C2	127.3 (3)
C6—N3—C9	115.4 (3)	C7—C6—C2	107.6 (3)
N2—C1—C5	125.4 (3)	C11—C7—C6	118.5 (3)
N2—C1—H1A	117.3	C11—C7—C8	132.9 (3)
C5—C1—H1A	117.3	C6—C7—C8	108.6 (3)
N2—C2—C3	124.9 (3)	N1—C8—C7	128.4 (3)
N2—C2—C6	125.7 (3)	N1—C8—C3	125.3 (3)
C3—C2—C6	109.4 (3)	C7—C8—C3	106.3 (2)
C4—C3—C2	120.1 (3)	N3—C9—C10	124.3 (3)
C4—C3—C8	131.7 (3)	N3—C9—H9A	117.9
C2—C3—C8	108.0 (3)	C10—C9—H9A	117.9
C3—C4—C5	115.2 (3)	C11—C10—C9	119.5 (3)
C3—C4—H4A	122.4	C11—C10—H10A	120.2
C5—C4—H4A	122.4	C9—C10—H10A	120.2
C1—C5—C4	120.4 (3)	C7—C11—C10	117.3 (3)
C1—C5—H5A	119.8	C7—C11—H11A	121.3
C4—C5—H5A	119.8	C10—C11—H11A	121.3
C2—N2—C1—C5	−0.8 (5)	N3—C6—C7—C11	0.2 (5)
C1—N2—C2—C3	2.3 (5)	C2—C6—C7—C11	179.6 (3)
C1—N2—C2—C6	−179.7 (3)	N3—C6—C7—C8	179.7 (3)
N2—C2—C3—C4	−4.0 (5)	C2—C6—C7—C8	−0.9 (4)
C6—C2—C3—C4	177.8 (3)	C11—C7—C8—N1	−1.9 (6)
N2—C2—C3—C8	179.3 (3)	C6—C7—C8—N1	178.7 (4)
C6—C2—C3—C8	1.1 (3)	C11—C7—C8—C3	−179.1 (3)
C2—C3—C4—C5	3.7 (5)	C6—C7—C8—C3	1.5 (4)
C8—C3—C4—C5	179.5 (3)	C4—C3—C8—N1	5.0 (6)
N2—C1—C5—C4	1.0 (6)	C2—C3—C8—N1	−178.9 (3)
C3—C4—C5—C1	−2.4 (5)	C4—C3—C8—C7	−177.8 (3)
C9—N3—C6—C7	−0.2 (5)	C2—C3—C8—C7	−1.6 (3)
C9—N3—C6—C2	−179.5 (3)	C6—N3—C9—C10	−0.4 (5)
N2—C2—C6—N3	1.0 (5)	N3—C9—C10—C11	1.0 (6)
C3—C2—C6—N3	179.3 (3)	C6—C7—C11—C10	0.4 (5)
N2—C2—C6—C7	−178.4 (3)	C8—C7—C11—C10	−179.0 (3)
C3—C2—C6—C7	−0.1 (3)	C9—C10—C11—C7	−0.9 (5)

Hydrogen-bond geometry (Å, °)

D—H···A	D—H	H···A	D···A	D—H···A
C11—H11A···N3i	0.93	2.45	3.382 (4)	178
C4—H4A···N1ii	0.93	2.69	3.536 (4)	152

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