X-Ray diffraction study of crystal and molecular structure of acetylacetone azocompound - [C11H11N2O2F 1]

Article abstract of DOI:10.1134/S0022476611010276

The 3-[4-fluorophenylazopentandion]-2,4 reagent is synthesized based on acetylacetone, and its crystal and molecular structure is studied by X-ray diffraction. It is found that [C₁₁H₁₁N₂O ₂F] crystals 1 belong to the monoclinic symmetry, C2/c space group. The unit cell parameters of 1 are a = 18.827(3) A, b = 12.839(2) A, c = 26.475(5) A, β = 104.834(2)°. The analysis shows that the reagent is present in the solution as well as in the crystal. A comparative analysis of these three structures with the reported data is carried out.

Full text of DOI:10.1134/S0022476611010276

Journal of Structural Chemistry. Vol. 52, No. 1, pp. 198-202, 2011
Original Russian Text Copyright © 2011 by M. A. Magerramov, R. A. Alieva, R. Z. Nazarova, F. M. Chyragov, and K. A. Potekhin
X-RAY DIFFRACTION STUDY OF CRYSTAL AND
MOLECULAR STRUCTURE OF ACETYLACETONE
AZOCOMPOUND — [C H N O F ]
11 11
2
2 1
1 1
M. A. Magerramov, R. A. Alieva, R. Z. Nazarova,
2
UDC 548.54-4
©
1
F. M. Chyragov, and K. A. Potekhin
2
The 3-[4-fluorophenylazopentandion]-2,4 reagent is synthesized based on acetylacetone, and its crystal and
molecular structure is studied by X-ray diffraction. It is found that [C H N O F] crystals 1 belong to the
11 11 2 2
monoclinic symmetry, C2/c space group. The unit cell parameters of 1 are a = 18.827(3) Å,
b = 12.839(2) Å, c = 26.475(5) Å, β = 104.834(2)°. The analysis shows that the reagent is present in the
solution as well as in the crystal. A comparative analysis of these three structures with the reported data is
carried out.
Keywords: single crystal X-ray diffraction analysis, acetylacetone azoderivatives, intermolecular hydrogen
bonds, packing of the 3-[4-fluorophenylazopentadione]-2,4.
It is known from the literature that acetylacetone and its derivatives have been widely used to identify different
metals. [1-3]. It is also known that acetylacetone azocompounds can exist in solutions in at least three tautomeric forms: enol-
azo, keto-azo, and hydrazo.
By means of IR, NMR, and X-ray electron spectroscopy it is established that the most preferable form is hydrozone
due to three conjugated double bonds and the intramolecular (O---H) hygrogen bond.
Single crystal X-ray diffraction used to get more exact information about the crystal structure of these compounds is
the preferred estimation method.
This paper is dedicated to the synthesis of azocompounds based on acetylacetone and its single crystal X-ray
diffraction.
Experimental. Synthesis of C H N O F. The reagent is obtained by the azo coupling reaction of diazotized para-
11 11 2 2
fluoroanilin with acetylacetone in a weak base medium [1]; the composition and structure of the obtained compound were
determined by the elemental analysis.
1
2
Faculty of Chemical Sciences, Baku State University. Vladimir State University for the Humanities; nazarova-
roya@rambler.ru. Translated from Zhurnal Strukturnoi Khimii, Vol. 52, No. 1, pp. 201-205, January-February, 2011. Original
article submitted January 12, 2010; revision April 15, 2010.
198
0022-4766/11/5201-0198

TABLE 1. Main Crystallographic Parameters and Running Characteristics of the X-ray Diffraction Experiment
for a 3-[4-fluorophenylazopentandion]-2,4 Molecule
Gross formula
Molecular weight
Symmetry class
a, b, c, Å
[C H N O F ]
11 11 2 2 1
222.22
Monoclinic
18.827(3), 12.839(2), 26.475(5)
104.834(2)
β, deg
3
V, Å
6186.1(18)
Z
24
01.01.32
3
d , g/cm
x
Crystal size, mm
0.30×0.20×0.20
1.99-29.42
θ range, deg
h, k, l limits
–23 ≤ h ≤ 24, –16 ≤ k ≤ 16, –33 ≤ l ≤ 24
18698/7245
Number of exp./indep. reflections
GOOF
97.2%
R1 = 0.0401, wR2 = 0.1228
R1 = 0.0488, wR2 = 0.1327
760750
R [I > 2σ(I)] factor
R over the whole array
CCDC deposit number
Calculated, % С 59.73, H 5.44, N 12.67, O 14.48, F 8.14. Found, % 58.35, H 5.76, N 12.15, O 15.71, F 8.01.
Diazotization. 2.775 ml (0.025 mol) of para-fluoroanilin was dissolved in 20ml of water with crystal potassium
hydroxide and slightly heated. The solution was cooled down to 0°C in an ice bath for 30 minutes with 1.725 g (0.025 mol)
of NaNO added in portions. The temperature should not exceed +5°C.
2
Azo coupling. A mixture of 1.952 ml (0.025 mol) of acetylacetone and 15 ml of ethanol was cooled down by adding
11.952 g (0.146 mol) of СН СООNa. The solution was cooled in an ice bath with para-fluoroanilin diazonium suspension.
3
The pH should be within 8-10 during the coupling. On the next day, the reagent residue was filtered off, dried in air, and
recrystallized with ethanol several times.
Single crystal XRD. The unit cell parameters and the intensity of 18698 (7245 independent ones) diffraction
reflection were measured on an automatic Bruker SMART APEX II CCD diffractometer (φ/ϕ-scanning, MoΚ radiation,
α
graphite monochromator, T = 100 K).The unit cell parameters and the space group were determined and refined on an
automatic Bruker SMART APEX II CCD diffractometer (θ/2θ-scanning method with МоΚ radiation λ = 0.71073 Å,
α
graphite monochromator, T = 100 K). Table 1 shows the main X-ray diffraction and calculation results. All crystallographic
data (CIF file) has been deposited with the CCDC and can be obtained upon request to the following website:
www.ccdc.cam.ac.uk/data_request/cif; the deposit number is given in Table 1.
The crystal structure was solved by the direct method using the SHELXTL-2001 program [4] in automatic mode and
was refined by the least squares method (LSM) in the anisotropic approximation using the SHELXTL-2001 program [4] for
non-hydrogen atoms. Hydrogen atoms in the intramolecular N–H…O hydrogen bond are localized by the difference electron
density synthesis for all three crystallographically independent molecules. The other hydrogen atoms were localized
geometrically and refined by the riding model.
199

Fig. 1. Structure (a) and packing (b) of the [C H N O F ] molecule in the crystal.
11 11 2 2 1
Discussion. Fig. 1a shows the spatial structure of the molecule according to single crystal XRD. The independent
part of the unit cell contains three molecules in the crystal. Geometrical parameters of the studied molecule (bond lengths,
bond and torsion angles) are listed in Table 2. Fig. 1 shows the structure and packing in the molecule.
All three crystallographically independent molecules are coplanar (Table 3) and are arranged centrosymmetrically.
Table 2 shows in length all valence bonds correspond to ordinary or double bonds [5]. The С(1)–N(2) and N(1)–N(2) bond
lengths are 1.412 Å and 1.307 Å respectively, which is typical of azocompounds. The N(1)–C(9) and C(10)–O(2) lengths are
elongated as compared to the average statistical values and they are partially conjugated. These bonds as well as N(2)---
O(2) = 2.581 Å distances prove that an intramolecular hydrogen bond appears in this part of the molecule (Fig. 1b) [5, 6]. At
first sight it is possible to suppose that both N–H---O=C, OH---N=N hydrogen bonds are strong. However, another acyl
group additionally strengthens this hydrogen bond, and this happens only in the hydrazo form.
Fig. 1b shows that each molecule is bonded to the others by intramolecular hydrogen bonds and due to these bonds
the molecules are packed.
The study of the structure of this molecule proves that the 3-[4-fluorophenylazopentandion]-2,4 azocompound, as
opposed to compounds with the OH group in the ortho position, can be used only as a monodentate ligand in complexation.
200

TABLE 2. Bond Lengths (d, Å) Bond (ω, deg) and Torsion Angles (ϕ, deg) in the [C H N O F ] Molecule
11 11 2 2 1
Bond
d
Bond
d
Bond
d
F(1)–C(4)
O(1)–C(8)
O(2)–C(10)
N(1)–N(2)
N(1)–C(9)
N(2)–C(1)
N(2)–O(2)
C(8)–C(9)
C(9)–C(10)
1.361(1)
1.219(1)
1.237(1)
1.306(1)
1.322(1)
1.411(1)
2.581(2)
1.491(2)
1.473(2)
F(1A)–C(4A)
O(1A)–C(8A)
O(2A)–C(10A)
N(1A)–N(2A)
N(1A)–C(9A)
N(2A)–C(1A)
N(2A)–O(2A)
C(8A)–C(9A)
C(9A)–C(10A)
1.359(1)
1.220(1)
1.238(1)
1.305(1)
1.325(1)
1.413(1)
2.573(2)
1.492(2)
1.474(2)
F(1B)–C(4B)
O(1B)–C(8B)
O(2B)–C(10B)
N(1B)–N(2B)
N(1B)–C(9B)
N(2B)–C(1B)
N(2B)–O(2B)
C(8B)–C(9B)
C(9B)–C(10B)
1.362(1)
1.217(1)
1.236(1)
1.307(1)
1.321(1)
1.411(1)
2.589(2)
1.486(2)
1.474(2)
Angle
Angle
Angle
ω
ω
ω
N2N1C9
N1N2C1
C6C1N2
C2C1N2
O1C8C9
O1C8C7
C9C8C7
N1C9C10
N1C9C8
O2C10C9
O2C10C11
121.69(9)
118.72(9)
121.3(1)
117.9(1)
121.4(1)
120.44(1)
118.12(9)
123.65(9)
112.76(9)
119.8(1)
119.7(1)
N2AN1AC9A
N1AN2AC1A
C6AC1AN2A
C2AC1AN2A
O1AC8AC9A
O1AC8AC7A
C9AC8AC7A
N1AC9AC10A
N1AC9AC8A
O2AC10AC9A
O2AC10AC11A
121.55(9)
119.01(9)
121.56(9)
117.72(9)
121.3(1)
120.3(1)
118.3(1)
123.51(9)
112.67(9)
119.7(1)
119.5(1)
N2BN1BC9B
N1BN2BC1B
C6BC1BN2B
C2BC1BN2B
O1BC8BC9B
O1BC8BC7B
C9BC8BC7B
N1BC9BC10B
N1BC9BC8B
O2BC10BC9B
O2BC10BC11B
121.72(9)
118.66(9)
121.50(9)
117.56(9)
121.3(1)
120.5(1)
118.08(9)
123.66(9)
112.72(9)
119.9(1)
119.7(1)
Angle
Angle
Angle
ϕ
ϕ
ϕ
C1N2N1C9
N2N1C9C8
N2N1C9C10
N1C9C8O1
N1C9C10O2
C6C1N2N1
179.19(9)
–179.29(9)
–1.36(16)
–171.0(1)
3.2(1)
C1AN2AN1AC9A
N2AN1AC9AC8A
N2AN1AC9AC10A
N1AC9AC8AO1A
N1AC9AC10AO2A
C6AC1AN2AN1A
–179.07(9)
–179.44(9)
–1.85(15)
–172.8(1)
–0.8(1)
C1BN2BN1BC9B
N2BN1BC9BC8B
N2BN1BC9BC10B
N1BC9BC8BO1B
N1BC9BC10BO2B
C6BC1BN2BN1B
179.76(9)
176.81(9)
–3.33(15)
–168.6(1)
6.9(1)
8.2(1)
–4.70(15)
–6.26(15)
TABLE 3. Mean Average Deviation from the Plane of Some Atoms
Atom
Deviation
Atom
Deviation
Atom
Deviation
N1
N2
C1
0.0333 (0.0008)
0.0214 (0.0008)
0.0092 (0.0007)
–0.1738 (0.0008)
0.0277 (0.0009)
0.0292 (0.0009)
–0.0180 (0.0009)
–0.1191 (0.0009)
0.1854 (0.0008)
0.0048 (0.0007)
N1А
N2А
C1А
C7А
C8А
C9А
C10А
C11А
O1А
O2А
0.0254 (0.0008)
0.0226 (0.0008)
0.0439 (0.0007)
0.1560 (0.0008)
0.0147 (0.0009)
0.0244 (0.0010)
0.0196 (0.0009)
0.0222 (0.0008)
0.1422 (0.0008)
0.0748 (0.0007)
N1B
N2B
C1B
C7B
C8B
C9B
C10B
C11B
O1B
O2B
0.0091 (0.0008)
–0.0267 (0.0008)
–0.0072 (0.0007)
0.1754 (0.0008)
–0.0317 (0.0009)
–0.0018 (0.0009)
0.0170 (0.0009)
0.2011 (0.0008)
–0.2494 (0.0008)
–0.0858 (0.0007)
C7
C8
C9
C10
C11
O1
O2
201

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202