3,5-Bis(4-fluoro­phen­yl)-4,5-dihydro-1H-pyrazole-1-carbaldehyde

Baktır, Z.; Akkurt, M.; Samshuddin, S.; Narayana, B.; Yathirajan, H.S.

doi:10.1107/S160053681101587X

organic compounds

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ISSN: 2056-9890

Volume 67| Part 6| June 2011| Pages o1292-o1293

doi:10.1107/S160053681101587X

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3,5-Bis(4-fluorophenyl)-4,5-dihydro-1H-pyrazole-1-carbaldehyde

Zeliha Baktır,^a Mehmet Akkurt,^a ^* S. Samshuddin,^b B. Narayana ^b and H. S. Yathirajan ^c

^aDepartment of Physics, Faculty of Sciences, Erciyes University, 38039 Kayseri, Turkey, ^bDepartment of Studies in Chemistry, Mangalore University, Mangalagangotri 574 199, India, and ^cDepartment of Studies in Chemistry, University of Mysore, Manasagangotri, Mysore 570 006, India
^*Correspondence e-mail: akkurt@erciyes.edu.tr

(Received 17 April 2011; accepted 26 April 2011; online 7 May 2011)

In the title molecule, C₁₆H₁₂F₂N₂O, the pyrazole ring adopts a slight envelope conformation with the methylene C atom deviating by 0.114 (3) Å from the mean plane of the other four atoms [maximum deviation = 0.021 (3) Å]. The dihedral angles between the four essentially planar atoms of the pyrazole ring and the fluoro-substituted benzene rings are 2.6 (2) and 82.2 (2)°. The dihedral angle between the two benzene rings is 83.7 (2)°. The crystal packing is stabilized by weak intermolecular C—H⋯O hydrogen bonds.

Related literature

For the biological activity of pyrazolines, see: Hes et al. (1978 ); Manna et al. (2005 ); Amir et al. (2008 ); Regaila et al. (1979 ); Sarojini et al. (2010 ). For their importance in organic synthesis, see: Bhaskarreddy et al. (1997 ); Klimova et al. (1999 ). For related structures, see: Butcher et al. (2007 ); Cui & Li (2010 ); Fun et al. (2010a ,b ); Jasinski et al. (2010a ,b ); Baktır et al. (2011 ).

Experimental

Crystal data

C₁₆H₁₂F₂N₂O
M_r = 286.28
Triclinic, $[P \overline 1]$
a = 6.2141 (9) Å
b = 6.7802 (8) Å
c = 17.9857 (9) Å
α = 96.727 (4)°
β = 90.254 (4)°
γ = 116.791 (5)°
V = 670.39 (13) Å³
Z = 2
Mo Kα radiation
μ = 0.11 mm⁻¹
T = 294 K
0.30 × 0.20 × 0.10 mm

Data collection

Rigaku R-AXIS RAPID-S diffractometer
Absorption correction: multi-scan (Blessing, 1995 ) T_min = 0.968, T_max = 0.989
14070 measured reflections
2736 independent reflections
1011 reflections with I > 2σ(I)
R_int = 0.095

Refinement

R[F² > 2σ(F²)] = 0.062
wR(F²) = 0.206
S = 0.94
2736 reflections
191 parameters
H-atom parameters constrained
Δρ_max = 0.19 e Å⁻³
Δρ_min = −0.33 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C4—H4⋯O1ⁱ	0.93	2.50	3.421 (5)	171
C11—H11⋯O1ⁱⁱ	0.93	2.39	3.296 (5)	165
Symmetry codes: (i) x-2, y-1, z; (ii) x-1, y, z.

Data collection: CrystalClear (Rigaku/MSC, 2005 ); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SIR97 (Altomare et al., 1999 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ); molecular graphics: PLATON (Spek, 2009 ); software used to prepare material for publication: WinGX (Farrugia, 1999 ).

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S160053681101587X/lh5239sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S160053681101587X/lh5239Isup2.hkl

Supporting information file. DOI: 10.1107/S160053681101587X/lh5239Isup3.cml

checkCIF report

Comment top

Pyrazolines have been reported to exhibit a broad spectrum of biological activies such as antitumor, antibacterial, antifungal, antiviral, antiparasitic, anti-tubercular and insecticidal activities (Hes et al., 1978; Manna et al., 2005; Amir et al., 2008). Some of these compounds have also antioxidant, anti-diabetic, anaesthetic and analgesic properties (Sarojini et al., 2010; Regaila et al., 1979). In addition, pyrazolines have played a crucial part in the development of theory in heterocyclic chemistry and also used extensively in organic synthesis (Klimova et al., 1999 and Bhaskarreddy et al., 1997).

The crystal structure of some pyrazoline derivatives viz., 3-(4-methylphenyl)-5-[4-(methylthio)phenyl]-4,5-dihydro-1H-pyrazole-1-carbaldehyde (Butcher et al., 2007) and 5-(2-hydroxyphenyl)-3-methyl-4,5-dihydro-1H-pyrazole-1-carbaldehyde (Cui & Li, 2010) have been reported. In view of the importance of pyrazoline derivatives and in continuation of our work on synthesis of various derivatives of 4,4'-diflouro chalcone (Fun et al., 2010a,b; Jasinski et al., 2010a,b; Baktır et al., 2011), the title compound (I) is synthesized and its crystal structure is reported herein.

The molecular structure of the title compound is shown in Fig. 1. The pyrazole ring adopts a slight envelope comformation with the methylene C atom (C8) deviating by 0.114 (3)Å from the mean-plane of the other four atoms (C7/C9/N1/N2 with maximum deviation 0.021 (3)Å for N1). The dihedral angles between the four essentially planar atoms of the pyrazole ring and fluoro-substituted benzene rings are 2.6 (2) and 82.2 (2)°, respectively. The dihedral angle between the two benzene rings is 83.7 (2)°. The crystal packing is stabilized by weak intermolecular C—H···O hydrogen bonds (Fig .2).

Related literature top

For the biological activity of pyrazolines, see: Hes et al. (1978); Manna et al. (2005); Amir et al. (2008); Regaila et al. (1979); Sarojini et al. (2010). For their importance in organic synthesis, see: Bhaskarreddy et al. (1997); Klimova et al. (1999). For related structures, see: Butcher et al. (2007); Cui & Li (2010); Fun et al. (2010a,b); Jasinski et al. (2010a,b); Baktır et al. (2011).

Experimental top

A mixture of (2E)-1,3-bis(4-fluorophenyl)prop-2-en-1-one (2.44 g, 0.01 mol) and hydrazine hydrate (0.5 ml, 0.01 mol) in 20 ml formic acid was refluxed for 8 h. The reaction mixture was cooled and poured into 50 ml ice-cold water. The precipitate was collected by filtration and purified by recrystallization from ethanol. The single-crystal was grown from DMF by slow evaporation method and yield of the compound was 86%. (m. p.: 408 K).

Computing details top

Data collection: CrystalClear (Rigaku/MSC, 2005); cell refinement: CrystalClear (Rigaku/MSC, 2005); data reduction: CrystalClear (Rigaku/MSC, 2005); program(s) used to solve structure: SIR97 (Altomare et al., 1999); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: PLATON (Spek, 2009); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures top

	Fig. 1. The title molecule with displacement ellipsoids for non-H atoms are drawn at the 30% probability level.
	Fig. 2. Hydrogen bonding of the title compound viewed along the a axis. Hydrogen bonds are shown as dotted lines (symmetry code: (a) x-2, y-1, z).

3,5-Bis(4-fluorophenyl)-4,5-dihydro-1H-pyrazole-1-carbaldehyde top

Crystal data top

C₁₆H₁₂F₂N₂O	Z = 2
M_r = 286.28	F(000) = 296
Triclinic, P1	D_x = 1.418 Mg m⁻³
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 6.2141 (9) Å	Cell parameters from 1748 reflections
b = 6.7802 (8) Å	θ = 2.3–26.3°
c = 17.9857 (9) Å	µ = 0.11 mm⁻¹
α = 96.727 (4)°	T = 294 K
β = 90.254 (4)°	Prism, pale yellow
γ = 116.791 (5)°	0.30 × 0.20 × 0.10 mm
V = 670.39 (13) Å³

Data collection top

Rigaku R-AXIS RAPID-S diffractometer	2736 independent reflections
Radiation source: Sealed Tube	1011 reflections with I > 2σ(I)
Graphite Monochromator monochromator	R_int = 0.095
Detector resolution: 10.0000 pixels mm^-1	θ_max = 26.5°, θ_min = 3.4°
dtprofit.ref scans	h = −7→7
Absorption correction: multi-scan (Blessing, 1995)	k = −8→8
T_min = 0.968, T_max = 0.989	l = −22→22
14070 measured reflections

Refinement top

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)] = 0.062	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.206	H-atom parameters constrained
S = 0.94	w = 1/[σ²(F_o²) + (0.0812P)²] where P = (F_o² + 2F_c²)/3
2736 reflections	(Δ/σ)_max < 0.001
191 parameters	Δρ_max = 0.19 e Å⁻³
0 restraints	Δρ_min = −0.33 e Å⁻³

Crystal data top

C₁₆H₁₂F₂N₂O	γ = 116.791 (5)°
M_r = 286.28	V = 670.39 (13) Å³
Triclinic, P1	Z = 2
a = 6.2141 (9) Å	Mo Kα radiation
b = 6.7802 (8) Å	µ = 0.11 mm⁻¹
c = 17.9857 (9) Å	T = 294 K
α = 96.727 (4)°	0.30 × 0.20 × 0.10 mm
β = 90.254 (4)°

Data collection top

Rigaku R-AXIS RAPID-S diffractometer	2736 independent reflections
Absorption correction: multi-scan (Blessing, 1995)	1011 reflections with I > 2σ(I)
T_min = 0.968, T_max = 0.989	R_int = 0.095
14070 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.062	0 restraints
wR(F²) = 0.206	H-atom parameters constrained
S = 0.94	Δρ_max = 0.19 e Å⁻³
2736 reflections	Δρ_min = −0.33 e Å⁻³
191 parameters

Special details top

Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles

Refinement. Refinement on F² for ALL reflections except those flagged by the user for potential systematic errors. Weighted R-factors wR and all goodnesses of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The observed criterion of F² > σ(F²) is used only for calculating -R-factor-obs 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 (Å²) top

	x	y	z	U_iso*/U_eq
F1	−0.7910 (4)	0.0976 (4)	0.04914 (14)	0.1334 (11)
F2	0.7113 (5)	1.4342 (4)	0.49400 (14)	0.1284 (11)
O1	0.9124 (4)	0.8903 (4)	0.23729 (12)	0.0822 (9)
N1	0.3094 (4)	0.6264 (4)	0.16479 (13)	0.0621 (9)
N2	0.5069 (4)	0.7082 (4)	0.21640 (12)	0.0621 (9)
C1	−0.1494 (6)	0.4185 (7)	0.08534 (18)	0.1019 (16)
C2	−0.3750 (7)	0.3162 (8)	0.0481 (2)	0.120 (2)
C3	−0.5702 (6)	0.1944 (7)	0.0858 (2)	0.0937 (16)
C4	−0.5512 (6)	0.1715 (5)	0.1584 (2)	0.0798 (14)
C5	−0.3241 (6)	0.2737 (5)	0.19570 (18)	0.0718 (12)
C6	−0.1199 (5)	0.3980 (5)	0.15912 (16)	0.0643 (11)
C7	0.1190 (5)	0.5070 (5)	0.19872 (15)	0.0583 (11)
C8	0.1722 (5)	0.4922 (5)	0.27855 (16)	0.0728 (12)
C9	0.4427 (5)	0.6519 (5)	0.29283 (15)	0.0650 (11)
C10	0.5095 (5)	0.8590 (5)	0.34783 (15)	0.0637 (11)
C11	0.3760 (6)	0.9769 (6)	0.34948 (17)	0.0713 (11)
C12	0.4417 (7)	1.1706 (6)	0.39825 (19)	0.0820 (16)
C13	0.6424 (7)	1.2450 (6)	0.4449 (2)	0.0873 (16)
C14	0.7786 (7)	1.1343 (6)	0.44657 (19)	0.0870 (14)
C15	0.7124 (6)	0.9408 (6)	0.39679 (17)	0.0774 (14)
C16	0.7313 (6)	0.8185 (5)	0.19475 (18)	0.0696 (12)
H1	−0.01520	0.50270	0.06000	0.1230*
H2	−0.39330	0.33040	−0.00210	0.1440*
H4	−0.68760	0.08870	0.18310	0.0960*
H5	−0.30840	0.25880	0.24590	0.0860*
H8A	0.13880	0.34140	0.28510	0.0870*
H8B	0.07740	0.53940	0.31210	0.0870*
H9	0.52740	0.57050	0.30870	0.0780*
H11	0.23920	0.92430	0.31700	0.0850*
H12	0.35050	1.24820	0.39910	0.0990*
H14	0.91270	1.18720	0.48020	0.1040*
H15	0.80540	0.86500	0.39630	0.0930*
H16	0.75090	0.84190	0.14480	0.0830*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
F1	0.0603 (14)	0.164 (2)	0.142 (2)	0.0304 (15)	−0.0376 (13)	−0.0172 (17)
F2	0.1089 (18)	0.1004 (17)	0.133 (2)	0.0232 (15)	0.0018 (15)	−0.0407 (15)
O1	0.0474 (13)	0.0936 (18)	0.0902 (17)	0.0222 (13)	−0.0112 (12)	−0.0025 (13)
N1	0.0507 (15)	0.0728 (18)	0.0553 (14)	0.0242 (14)	−0.0057 (12)	−0.0030 (12)
N2	0.0451 (15)	0.0734 (18)	0.0576 (14)	0.0203 (14)	−0.0060 (11)	−0.0010 (12)
C1	0.059 (2)	0.159 (4)	0.061 (2)	0.027 (2)	−0.0034 (17)	0.011 (2)
C2	0.070 (3)	0.187 (5)	0.074 (2)	0.037 (3)	−0.015 (2)	0.001 (3)
C3	0.052 (2)	0.105 (3)	0.107 (3)	0.028 (2)	−0.022 (2)	−0.016 (2)
C4	0.051 (2)	0.072 (2)	0.104 (3)	0.0191 (18)	−0.0005 (18)	0.004 (2)
C5	0.059 (2)	0.069 (2)	0.080 (2)	0.0242 (18)	−0.0004 (17)	0.0038 (17)
C6	0.053 (2)	0.075 (2)	0.0613 (18)	0.0286 (18)	−0.0030 (14)	−0.0025 (15)
C7	0.0502 (19)	0.066 (2)	0.0554 (17)	0.0254 (16)	0.0004 (14)	0.0000 (14)
C8	0.063 (2)	0.074 (2)	0.068 (2)	0.0199 (18)	−0.0071 (15)	0.0074 (16)
C9	0.061 (2)	0.070 (2)	0.0583 (17)	0.0253 (17)	−0.0090 (14)	0.0073 (15)
C10	0.0568 (19)	0.072 (2)	0.0541 (17)	0.0232 (17)	−0.0080 (14)	0.0042 (15)
C11	0.065 (2)	0.084 (2)	0.0618 (18)	0.032 (2)	−0.0040 (15)	0.0066 (17)
C12	0.085 (3)	0.086 (3)	0.075 (2)	0.040 (2)	0.0065 (19)	0.0061 (19)
C13	0.082 (3)	0.077 (3)	0.080 (2)	0.022 (2)	0.002 (2)	−0.0147 (19)
C14	0.069 (2)	0.095 (3)	0.078 (2)	0.026 (2)	−0.0154 (18)	−0.011 (2)
C15	0.064 (2)	0.091 (3)	0.066 (2)	0.029 (2)	−0.0137 (16)	−0.0044 (18)
C16	0.050 (2)	0.081 (2)	0.072 (2)	0.0268 (18)	−0.0002 (16)	0.0009 (17)

Geometric parameters (Å, º) top

F1—C3	1.352 (5)	C10—C15	1.385 (5)
F2—C13	1.358 (4)	C11—C12	1.380 (5)
O1—C16	1.225 (4)	C12—C13	1.356 (6)
N1—N2	1.390 (4)	C13—C14	1.363 (6)
N1—C7	1.299 (4)	C14—C15	1.388 (5)
N2—C9	1.478 (4)	C1—H1	0.9300
N2—C16	1.337 (5)	C2—H2	0.9300
C1—C2	1.379 (6)	C4—H4	0.9300
C1—C6	1.370 (4)	C5—H5	0.9300
C2—C3	1.360 (6)	C8—H8A	0.9700
C3—C4	1.344 (5)	C8—H8B	0.9700
C4—C5	1.387 (5)	C9—H9	0.9800
C5—C6	1.388 (5)	C11—H11	0.9300
C6—C7	1.461 (5)	C12—H12	0.9300
C7—C8	1.497 (4)	C14—H14	0.9300
C8—C9	1.534 (5)	C15—H15	0.9300
C9—C10	1.506 (4)	C16—H16	0.9300
C10—C11	1.386 (5)

N2—N1—C7	107.5 (2)	C13—C14—C15	118.4 (4)
N1—N2—C9	113.9 (2)	C10—C15—C14	120.9 (4)
N1—N2—C16	120.5 (2)	O1—C16—N2	123.4 (3)
C9—N2—C16	125.6 (3)	C2—C1—H1	119.00
C2—C1—C6	121.0 (4)	C6—C1—H1	119.00
C1—C2—C3	119.0 (3)	C1—C2—H2	120.00
F1—C3—C2	118.6 (3)	C3—C2—H2	121.00
F1—C3—C4	119.2 (4)	C3—C4—H4	121.00
C2—C3—C4	122.2 (4)	C5—C4—H4	121.00
C3—C4—C5	118.7 (3)	C4—C5—H5	120.00
C4—C5—C6	120.9 (3)	C6—C5—H5	120.00
C1—C6—C5	118.1 (3)	C7—C8—H8A	111.00
C1—C6—C7	121.1 (3)	C7—C8—H8B	111.00
C5—C6—C7	120.8 (3)	C9—C8—H8A	111.00
N1—C7—C6	120.7 (3)	C9—C8—H8B	111.00
N1—C7—C8	113.8 (3)	H8A—C8—H8B	109.00
C6—C7—C8	125.5 (3)	N2—C9—H9	109.00
C7—C8—C9	103.6 (2)	C8—C9—H9	109.00
N2—C9—C8	100.7 (2)	C10—C9—H9	109.00
N2—C9—C10	111.1 (2)	C10—C11—H11	119.00
C8—C9—C10	116.5 (3)	C12—C11—H11	119.00
C9—C10—C11	121.5 (3)	C11—C12—H12	121.00
C9—C10—C15	120.4 (3)	C13—C12—H12	121.00
C11—C10—C15	118.1 (3)	C13—C14—H14	121.00
C10—C11—C12	121.4 (4)	C15—C14—H14	121.00
C11—C12—C13	118.4 (4)	C10—C15—H15	120.00
F2—C13—C12	119.9 (4)	C14—C15—H15	120.00
F2—C13—C14	117.3 (4)	O1—C16—H16	118.00
C12—C13—C14	122.8 (4)	N2—C16—H16	118.00

C7—N1—N2—C9	−4.2 (3)	C5—C6—C7—N1	−178.8 (3)
C7—N1—N2—C16	173.1 (3)	C5—C6—C7—C8	2.3 (5)
N2—N1—C7—C8	−1.3 (4)	C1—C6—C7—N1	0.1 (5)
N2—N1—C7—C6	179.7 (3)	C6—C7—C8—C9	−175.2 (3)
C16—N2—C9—C10	66.3 (4)	N1—C7—C8—C9	5.9 (4)
C16—N2—C9—C8	−169.7 (3)	C7—C8—C9—N2	−7.3 (3)
C9—N2—C16—O1	−1.5 (5)	C7—C8—C9—C10	112.8 (3)
N1—N2—C9—C8	7.4 (3)	C8—C9—C10—C11	−40.0 (4)
N1—N2—C9—C10	−116.5 (3)	C8—C9—C10—C15	142.1 (3)
N1—N2—C16—O1	−178.4 (3)	N2—C9—C10—C15	−103.5 (3)
C2—C1—C6—C7	−179.8 (4)	N2—C9—C10—C11	74.4 (4)
C6—C1—C2—C3	0.3 (7)	C9—C10—C15—C14	178.6 (3)
C2—C1—C6—C5	−0.9 (6)	C9—C10—C11—C12	−177.9 (3)
C1—C2—C3—C4	0.5 (7)	C15—C10—C11—C12	0.0 (5)
C1—C2—C3—F1	179.0 (4)	C11—C10—C15—C14	0.6 (5)
F1—C3—C4—C5	−179.3 (3)	C10—C11—C12—C13	0.3 (5)
C2—C3—C4—C5	−0.8 (6)	C11—C12—C13—C14	−1.3 (6)
C3—C4—C5—C6	0.2 (5)	C11—C12—C13—F2	−179.5 (3)
C4—C5—C6—C1	0.6 (5)	F2—C13—C14—C15	−179.8 (3)
C4—C5—C6—C7	179.5 (3)	C12—C13—C14—C15	1.9 (6)
C1—C6—C7—C8	−178.8 (3)	C13—C14—C15—C10	−1.6 (5)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C4—H4···O1ⁱ	0.93	2.50	3.421 (5)	171
C11—H11···O1ⁱⁱ	0.93	2.39	3.296 (5)	165

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

Experimental details

Crystal data
Chemical formula	C₁₆H₁₂F₂N₂O
M_r	286.28
Crystal system, space group	Triclinic, P1
Temperature (K)	294
a, b, c (Å)	6.2141 (9), 6.7802 (8), 17.9857 (9)
α, β, γ (°)	96.727 (4), 90.254 (4), 116.791 (5)
V (Å³)	670.39 (13)
Z	2
Radiation type	Mo Kα
µ (mm⁻¹)	0.11
Crystal size (mm)	0.30 × 0.20 × 0.10

Data collection
Diffractometer	Rigaku R-AXIS RAPID-S diffractometer
Absorption correction	Multi-scan (Blessing, 1995)
T_min, T_max	0.968, 0.989
No. of measured, independent and observed [I > 2σ(I)] reflections	14070, 2736, 1011
R_int	0.095
(sin θ/λ)_max (Å⁻¹)	0.627

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.062, 0.206, 0.94
No. of reflections	2736
No. of parameters	191
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.19, −0.33

Computer programs: CrystalClear (Rigaku/MSC, 2005), SIR97 (Altomare et al., 1999), SHELXL97 (Sheldrick, 2008), PLATON (Spek, 2009), WinGX (Farrugia, 1999).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C4—H4···O1ⁱ	0.93	2.50	3.421 (5)	171
C11—H11···O1ⁱⁱ	0.93	2.39	3.296 (5)	165

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

Acknowledgements

ZB and MA thank the Unit of the Scientific Research Projects of Erciyes University, Turkey, for the research grant FBD-10–2949, and for support of the data collection at Atatürk University, Turkey. SS and BN thank Mangalore University and the UGC SAP for financial assistance for the purchase of chemicals. HSY thanks the UOM for sabbatical leave.

References

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