9-Oxo-4,5-diazo­niafluorene sulfate

The diimine ligand 4,5-diaza­fluoren-9-one crystallized from an acid solution as the diprotonated sulfate salt, C₁₁H₈N₂O²⁺·SO₄^2-. Both H atoms reside on the N atoms of the diaza­fluorenone ring and the sulfate anion hydrogen bonds to them. Both ions lie on a mirror plane.

Key indicators

• Single-crystal X-ray study
• T = 150 K
• Mean [sigma](C-C) = 0.005 Å
• R factor = 0.057
• wR factor = 0.138
• Data-to-parameter ratio = 12.1

checkCIF/PLATON results

No syntax errors found



Alert level B
PLAT432_ALERT_2_B Short Inter X...Y Contact  O4     ..  C6      ..       2.77 Ang.

Alert level C
RINTA01_ALERT_3_C  The value of Rint is greater than 0.10
            Rint given   0.134
PLAT020_ALERT_3_C The value of Rint is greater than 0.10 .........       0.13
PLAT042_ALERT_1_C Calc. and Rep. MoietyFormula Strings Differ ....          ?
PLAT340_ALERT_3_C Low Bond Precision on C-C Bonds (x 1000) Ang ...          5

   0 ALERT level A = In general: serious problem
   1 ALERT level B = Potentially serious problem
   4 ALERT level C = Check and explain
   0 ALERT level G = General alerts; check

   1 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   1 ALERT type 2 Indicator that the structure model may be wrong or deficient
   3 ALERT type 3 Indicator that the structure quality may be low
   0 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

The structure of the title compound, (I), is shown below. The molecule is of interest because the non-protonated form is used to make metal complexes in our laboratory. Some synthetic reactions need to be executed in acidic solutions, so a better understanding of the protonation behavior is useful for designing synthetic routes. Some monoprotonated forms have been reported (Balagopalakrishna et al., 1996), (Menon et al., 1994), (Ravikumar et al., 1995), (Zhang et al., 2003). The compound sits on a mirror plane in the orthorhombic space group Pnma. Each diazafluorenone ring has a 2+ charge which is balanced by the 2- charge of the sulfate group that is hydrogen bonded. Table 1 gives the bond distances for selected atoms and Figure 2 shows the placement of the bonds. The ketone group on the ring structure forms hydrogen bonds with the protons, but this could also be electrostatic attraction between the oxygen and nitrogen. The sulfate group forms two hydrogen bonds with the ring structure at a distance of 1.82 Å from the hydrogen atoms and 2.665 Å from the nitrogen atoms. The sulfate anion also forms hydrogen bonds with the hydrogen atoms on the ring. These distances are long and not included in the table but can be viewed in the cif file. The angles listed in Table 1 are obtained from the angle formed by the first three atoms listed in table. The angles formed by the S—O– –H(N) and C=O– –H(N) are slightly larger than the H—O—H angle of 109.5 found for water.

Related literature

For related literature, see: Balagopalakrishna et al. (1996); Menon et al. (1994); Ravikumar et al. (1995); Siemeling & Scheppelmann (2004); Zhang et al. (2003).

S2. Experimental

1,8-diazafluoren-9-one was synthesized as previously reported (Siemeling & Scheppelmann, 2004). The title compound was crystallized by allowing slow evaporation of a dilute sulfuric acid solution (1 M) containing the compound. The crystals formed on the bottom of the beaker and were collected for analysis.

S3. Refinement

All H atoms were initially located in a difference Fourier map but were eventually placed in their geometrically idealized positions and constrained to ride on their parent atoms, with N—H = 0.88Å and C—H = 0.95 Å, and with U_iso(H) = 1.2_eq(C,N).

Computing details

Data collection: APEX2 (Bruker, 2006); cell refinement: APEX2; data reduction: SAINT (Bruker, 2006); program(s) used to solve structure: SHELXTL (Bruker, 2006); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: SHELXTL.

Figures

	Fig. 1. ORTEP drawing with 50% elipsoids.
	Fig. 2. Drawing showing hydrogen bonds

9-Oxo-4,5-diazoniafluorene sulfate

Crystal data

C11H8N2O^2+·SO4^2^−	F(000) = 576
Mr = 280.25	Dx = 1.673 Mg m^−3
Orthorhombic, Pnma	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P2ac2n	Cell parameters from 2024 reflections
a = 11.9016 (12) Å	θ = 3.1–25.5°
b = 11.9344 (12) Å	µ = 0.31 mm^−1
c = 7.8351 (7) Å	T = 150 K
V = 1112.89 (19) Å^3	Block, colorless
Z = 4	0.15 × 0.13 × 0.12 mm

Data collection

Bruker Kappa APEX II CCD area-detector diffractometer	1140 independent reflections
Radiation source: fine-focus sealed tube	794 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.134
φ and ω scans	θmax = 26.0°, θmin = 3.1°
Absorption correction: numerical (SADABS; Sheldrick, 1997)	h = −14→10
Tmin = 0.956, Tmax = 0.965	k = −14→14
9704 measured reflections	l = −9→9

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)] = 0.057	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.138	H-atom parameters constrained
S = 1.07	w = 1/[σ^2(Fo^2) + (0.0556P)^2 + 0.4328P] where P = (Fo^2 + 2Fc^2)/3
1140 reflections	(Δ/σ)max < 0.001
94 parameters	Δρmax = 0.35 e Å^−3
0 restraints	Δρmin = −0.41 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	0.7931 (3)	0.3118 (2)	0.0791 (4)	0.0184 (7)
C2	0.7283 (3)	0.4924 (3)	0.0531 (4)	0.0239 (8)
H2	0.6695	0.5427	0.0239	0.029*
C3	0.8294 (3)	0.5351 (3)	0.1087 (4)	0.0254 (8)
H3	0.8394	0.6138	0.1182	0.031*
C4	0.9162 (3)	0.4635 (3)	0.1509 (4)	0.0239 (8)
H4	0.9863	0.4914	0.1903	0.029*
C5	0.8977 (3)	0.3494 (3)	0.1336 (4)	0.0204 (7)
C6	0.9715 (4)	0.2500	0.1631 (5)	0.0218 (10)
N1	0.7103 (2)	0.3809 (2)	0.0387 (3)	0.0209 (6)
H1	0.6451	0.3549	0.0033	0.025*
O1	1.0703 (3)	0.2500	0.2015 (4)	0.0292 (8)
O2	0.6620 (3)	0.7500	0.1629 (4)	0.0324 (9)
O3	0.50345 (19)	0.64879 (17)	0.0518 (3)	0.0260 (6)
O4	0.4856 (3)	0.7500	0.3159 (4)	0.0326 (9)
S1	0.54194 (10)	0.7500	0.15386 (13)	0.0199 (4)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0169 (18)	0.0198 (15)	0.0186 (15)	0.0004 (14)	0.0038 (14)	0.0017 (12)
C2	0.025 (2)	0.0187 (16)	0.0277 (17)	−0.0010 (15)	0.0020 (15)	−0.0002 (13)
C3	0.029 (2)	0.0190 (16)	0.0287 (17)	−0.0034 (15)	0.0040 (15)	−0.0045 (13)
C4	0.022 (2)	0.0264 (17)	0.0236 (16)	−0.0079 (15)	0.0034 (14)	−0.0059 (13)
C5	0.0170 (19)	0.0253 (16)	0.0191 (15)	−0.0016 (15)	0.0033 (13)	−0.0008 (12)
C6	0.017 (3)	0.032 (3)	0.017 (2)	0.000	0.0011 (19)	0.000
N1	0.0183 (16)	0.0207 (14)	0.0238 (14)	−0.0024 (12)	−0.0011 (11)	−0.0010 (10)
O1	0.021 (2)	0.0406 (19)	0.0264 (16)	0.000	−0.0040 (15)	0.000
O2	0.016 (2)	0.0286 (18)	0.053 (2)	0.000	−0.0058 (15)	0.000
O3	0.0276 (14)	0.0200 (12)	0.0304 (12)	−0.0006 (11)	−0.0048 (11)	−0.0035 (9)
O4	0.034 (2)	0.042 (2)	0.0221 (16)	0.000	0.0025 (15)	0.000
S1	0.0160 (7)	0.0192 (6)	0.0246 (6)	0.000	−0.0022 (5)	0.000

Geometric parameters (Å, º)

C1—N1	1.323 (4)	C4—H4	0.9500
C1—C5	1.390 (4)	C5—C6	1.494 (4)
C1—C1^i	1.476 (6)	C6—O1	1.214 (5)
C2—N1	1.352 (4)	C6—C5^i	1.494 (4)
C2—C3	1.377 (5)	N1—H1	0.8800
C2—H2	0.9500	O2—S1	1.430 (3)
C3—C4	1.381 (5)	O3—S1	1.519 (2)
C3—H3	0.9500	O4—S1	1.436 (3)
C4—C5	1.386 (4)	S1—O3^ii	1.519 (2)
N1—C1—C5	122.7 (3)	C1—C5—C6	108.6 (3)
N1—C1—C1^i	128.54 (17)	O1—C6—C5^i	127.45 (18)
C5—C1—C1^i	108.80 (17)	O1—C6—C5	127.45 (18)
N1—C2—C3	121.9 (3)	C5^i—C6—C5	105.1 (4)
N1—C2—H2	119.0	C1—N1—C2	118.4 (3)
C3—C2—H2	119.0	C1—N1—H1	120.8
C2—C3—C4	120.0 (3)	C2—N1—H1	120.8
C2—C3—H3	120.0	O2—S1—O4	115.0 (2)
C4—C3—H3	120.0	O2—S1—O3	109.11 (12)
C3—C4—C5	117.7 (3)	O4—S1—O3	108.96 (12)
C3—C4—H4	121.1	O2—S1—O3^ii	109.11 (12)
C5—C4—H4	121.1	O4—S1—O3^ii	108.96 (12)
C4—C5—C1	119.3 (3)	O3—S1—O3^ii	105.29 (17)
C4—C5—C6	132.2 (3)

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