1-{(E)-[4-Bromo-2-(trifluoro­meth­oxy)phen­yl]imino­meth­yl}naphthalen-2-ol

Kargılı, H.; Macit, M.; Alpaslan, G.; Büyükgüngör, O.; Erdönmez, A.

doi:10.1107/S160053681300679X

organic compounds

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ISSN: 2056-9890

Volume 69| Part 4| April 2013| Page o535

doi:10.1107/S160053681300679X

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1-{(E)-[4-Bromo-2-(trifluoromethoxy)phenyl]iminomethyl}naphthalen-2-ol

Hakan Kargılı,^a Mustafa Macit,^b Gökhan Alpaslan,^c ^* Orhan Büyükgüngör ^a and Ahmet Erdönmez ^a

^aDepartment of Physics, Faculty of Arts & Science, Ondokuz Mayıs University, TR-55139 Kurupelit-Samsun, Turkey, ^bDepartment of Chemistry, Faculty of Arts & Science, Ondokuz Mayıs University, TR-55139 Kurupelit-Samsun, Turkey, and ^cDepartment of Medical Services and Techniques, Vocational School of Health Services, Giresun University, TR-28200 Giresun, Turkey
^*Correspondence e-mail: gokhan.alpaslan@giresun.edu.tr

(Received 25 February 2013; accepted 11 March 2013; online 16 March 2013)

The title compound, C₁₈H₁₁BrF₃NO₂, crystallizes in the phenol–imine tautomeric form, with a strong intramolecular O—H⋯N hydrogen bond. The dihedral angle between the naphthalene ring system and the benzene ring is 28.54 (10)°.

Related literature

For biological properties of Schiff bases, see: Layer (1963 ); Ingold (1969 ); Barton & Ollis (1979 ). For Schiff base tautomerism, see: Hökelek et al. (2000 ); Tüfekçi et al. (2009 ). For related strucures, see: Bingöl Alpaslan et al. (2010 ); Soydemir et al. (2011 ).

Experimental

Crystal data

C₁₈H₁₁BrF₃NO₂
M_r = 410.19
Monoclinic, P 2₁ /c
a = 4.5315 (3) Å
b = 16.3228 (7) Å
c = 21.7622 (12) Å
β = 93.025 (4)°
V = 1607.44 (15) Å³
Z = 4
Mo Kα radiation
μ = 2.60 mm⁻¹
T = 296 K
0.73 × 0.32 × 0.08 mm

Data collection

Stoe IPDS-II diffractometer
Absorption correction: integration (X-RED32; Stoe & Cie, 2002 ) T_min = 0.176, T_max = 0.772
17993 measured reflections
3160 independent reflections
1932 reflections with I > 2σ(I)
R_int = 0.080

Refinement

R[F² > 2σ(F²)] = 0.050
wR(F²) = 0.092
S = 1.02
3160 reflections
230 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.35 e Å⁻³
Δρ_min = −0.20 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H1⋯N1	0.85 (5)	1.77 (6)	2.551 (5)	151 (5)

Data collection: X-AREA (Stoe & Cie, 2002); cell refinement: X-AREA; data reduction: X-RED32 (Stoe & Cie, 2002); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012 ); software used to prepare material for publication: WinGX (Farrugia, 2012).

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S160053681300679X/bg2500sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S160053681300679X/bg2500Isup2.hkl

Supporting information file. DOI: 10.1107/S160053681300679X/bg2500Isup3.cml

checkCIF report

Comment top

Schiff bases are used as starting materials in the synthesis of important drugs, such as antibiotics and antiallergic, antiphlogistic, and antitumor substance (Layer 1963; Ingold 1969; Barton & Ollis, 1979). There are two types of intramolecular hydrogen bonds in Schiff bases, namely N—H···O in keto (NH) (Hökelek et al., 2000) and N···H—O in enol (OH) (Tüfekçi et al., 2009) tautomeric forms. The present X-ray investigation shows that the title compound is a Schiff base and exists in the phenol-imine form in the solid-state. An ORTEP-3 (Farrugia, 2012) plot of the molecule of (I) is shown in Fig.1. The C2-O1 bond length of 1.335 (5) Å indicates single-bond character while the N1-C11 bond length of 1.284 (4) Å indicates double-bond character.These bond distances are comparable with those of compounds previously reported as phenol-imine (Bingöl Alpaslan et al., 2010; Soydemir et al., 2011). The dihedral angle between the naphthalene ring system and the benzene ring is 28.54 (10)°.

Related literature top

For biological properties of Schiff bases, see: Layer (1963); Ingold (1969); Barton & Ollis (1979). For Schiff base tautomerism, see: Hökelek et al. (2000); Tüfekçi et al. (2009). For related strucures, see: Bingöl Alpaslan et al. (2010); Soydemir et al. (2011).

Experimental top

(E)-1-[(4-bromo-2-(trifluoromethoxy)phenylimino)methyl]naphthalen-2-ol was prepared by refluxing a mixture of a solution containing 2-hydroxy-1-naphthaldehyde (17,22 mg, 0,1 mmol) in ethanol (20 ml) and a solution containing 4-bromo-2-(trifluoromethoxy)aniline (25,60 mg, 0,1 mmol) in ethanol (20 ml). The reaction mixture was stirred for 5 hour under reflux. Single crystals of the title compound for x-ray analysis were obtained by slow evaporation of an ethanol solution (Yield 68%; m.p. 376 - 378 K).

Computing details top

Data collection: X-AREA (Stoe & Cie, 2002); cell refinement: X-AREA (Stoe & Cie, 2002); data reduction: X-RED32 (Stoe & Cie, 2002); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012); software used to prepare material for publication: WinGX (Farrugia, 2012).

Figures top

Fig. 1. The molecular structure of (I), showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 30% probability.

1-{(E)-[4-Bromo-2-(trifluoromethoxy)phenyl]iminomethyl}naphthalen-2-ol top

Crystal data top

C₁₈H₁₁BrF₃NO₂	F(000) = 816
M_r = 410.19	D_x = 1.695 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 16693 reflections
a = 4.5315 (3) Å	θ = 1.6–27.3°
b = 16.3228 (7) Å	µ = 2.60 mm⁻¹
c = 21.7622 (12) Å	T = 296 K
β = 93.025 (4)°	Needle, yellow
V = 1607.44 (15) Å³	0.73 × 0.32 × 0.08 mm
Z = 4

Data collection top

Stoe IPDS-II diffractometer	3160 independent reflections
Radiation source: fine-focus sealed tube	1932 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.080
Detector resolution: 6.67 pixels mm^-1	θ_max = 26.0°, θ_min = 1.6°
ω scans	h = −5→5
Absorption correction: integration (X-RED32; Stoe & Cie, 2002)	k = −20→20
T_min = 0.176, T_max = 0.772	l = −26→26
17993 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)] = 0.050	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.092	H atoms treated by a mixture of independent and constrained refinement
S = 1.02	w = 1/[σ²(F_o²) + (0.0355P)²] where P = (F_o² + 2F_c²)/3
3160 reflections	(Δ/σ)_max < 0.001
230 parameters	Δρ_max = 0.35 e Å⁻³
0 restraints	Δρ_min = −0.20 e Å⁻³

Crystal data top

C₁₈H₁₁BrF₃NO₂	V = 1607.44 (15) Å³
M_r = 410.19	Z = 4
Monoclinic, P2₁/c	Mo Kα radiation
a = 4.5315 (3) Å	µ = 2.60 mm⁻¹
b = 16.3228 (7) Å	T = 296 K
c = 21.7622 (12) Å	0.73 × 0.32 × 0.08 mm
β = 93.025 (4)°

Data collection top

Stoe IPDS-II diffractometer	3160 independent reflections
Absorption correction: integration (X-RED32; Stoe & Cie, 2002)	1932 reflections with I > 2σ(I)
T_min = 0.176, T_max = 0.772	R_int = 0.080
17993 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.050	0 restraints
wR(F²) = 0.092	H atoms treated by a mixture of independent and constrained refinement
S = 1.02	Δρ_max = 0.35 e Å⁻³
3160 reflections	Δρ_min = −0.20 e Å⁻³
230 parameters

Special details top

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 > 2sigma(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 (Å²) top

	x	y	z	U_iso*/U_eq
C1	1.2279 (8)	0.2342 (2)	0.35440 (16)	0.0573 (9)
C2	1.2003 (8)	0.3194 (3)	0.35626 (18)	0.0655 (10)
C3	1.3639 (10)	0.3657 (3)	0.4008 (2)	0.0776 (11)
H3	1.3428	0.4223	0.4018	0.093*
C4	1.5515 (9)	0.3281 (3)	0.44213 (19)	0.0765 (11)
H4	1.6587	0.3596	0.4710	0.092*
C5	1.5892 (8)	0.2423 (3)	0.44265 (17)	0.0657 (10)
C6	1.7837 (9)	0.2042 (3)	0.48585 (19)	0.0812 (12)
H6	1.8893	0.2362	0.5147	0.097*
C7	1.8217 (10)	0.1228 (4)	0.4867 (2)	0.0936 (14)
H7	1.9523	0.0986	0.5157	0.112*
C8	1.6626 (11)	0.0748 (3)	0.4434 (2)	0.0923 (14)
H8	1.6867	0.0182	0.4441	0.111*
C9	1.4735 (9)	0.1092 (3)	0.40055 (19)	0.0777 (11)
H9	1.3718	0.0759	0.3720	0.093*
C10	1.4281 (8)	0.1944 (2)	0.39847 (17)	0.0602 (9)
C11	1.0578 (8)	0.1889 (2)	0.30832 (17)	0.0622 (9)
H11	1.0735	0.1321	0.3078	0.075*
C12	0.7139 (8)	0.1804 (2)	0.22366 (16)	0.0597 (9)
C13	0.6122 (9)	0.1007 (3)	0.23012 (17)	0.0684 (10)
H13	0.6661	0.0716	0.2657	0.082*
C14	0.4340 (8)	0.0637 (3)	0.18521 (17)	0.0693 (10)
H14	0.3668	0.0104	0.1906	0.083*
C15	0.3558 (8)	0.1062 (2)	0.13217 (17)	0.0632 (10)
C16	0.4535 (8)	0.1847 (2)	0.12336 (17)	0.0648 (10)
H16	0.4010	0.2129	0.0873	0.078*
C17	0.6300 (8)	0.2206 (2)	0.16873 (18)	0.0609 (9)
C18	0.5876 (11)	0.3632 (3)	0.1640 (2)	0.0827 (12)
Br1	0.11465 (10)	0.05593 (3)	0.06926 (2)	0.08462 (18)
F1	0.4514 (8)	0.36567 (18)	0.21522 (15)	0.1282 (11)
F2	0.7514 (7)	0.42801 (17)	0.16068 (19)	0.1371 (12)
F3	0.3769 (6)	0.36943 (18)	0.11946 (14)	0.1162 (9)
N1	0.8849 (7)	0.22428 (19)	0.26788 (14)	0.0653 (8)
O1	1.0213 (7)	0.36180 (19)	0.31728 (16)	0.0838 (9)
O2	0.7558 (6)	0.29790 (17)	0.15836 (12)	0.0725 (7)
H1	0.963 (11)	0.327 (3)	0.290 (2)	0.12 (2)*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
C1	0.062 (2)	0.055 (2)	0.055 (2)	−0.0034 (18)	0.0068 (18)	−0.0039 (17)
C2	0.069 (2)	0.063 (3)	0.065 (3)	0.002 (2)	0.009 (2)	−0.004 (2)
C3	0.089 (3)	0.058 (3)	0.086 (3)	−0.003 (2)	0.007 (2)	−0.015 (2)
C4	0.080 (3)	0.077 (3)	0.072 (3)	−0.012 (2)	−0.002 (2)	−0.018 (2)
C5	0.064 (2)	0.073 (3)	0.060 (2)	−0.003 (2)	0.0049 (19)	−0.008 (2)
C6	0.076 (3)	0.095 (4)	0.071 (3)	0.004 (3)	−0.007 (2)	−0.011 (2)
C7	0.093 (3)	0.109 (4)	0.077 (3)	0.021 (3)	−0.020 (2)	0.000 (3)
C8	0.117 (4)	0.070 (3)	0.088 (3)	0.015 (3)	−0.008 (3)	0.007 (3)
C9	0.099 (3)	0.063 (3)	0.069 (3)	0.006 (2)	−0.010 (2)	−0.006 (2)
C10	0.063 (2)	0.064 (3)	0.054 (2)	−0.0020 (19)	0.0071 (17)	−0.0050 (18)
C11	0.070 (2)	0.059 (3)	0.058 (2)	0.0022 (19)	0.0080 (19)	−0.0040 (19)
C12	0.063 (2)	0.062 (3)	0.054 (2)	0.0051 (19)	0.0022 (18)	−0.0035 (19)
C13	0.090 (3)	0.064 (3)	0.051 (2)	−0.005 (2)	−0.004 (2)	0.0055 (19)
C14	0.082 (2)	0.059 (2)	0.066 (2)	−0.008 (2)	0.0015 (19)	0.000 (2)
C15	0.069 (2)	0.064 (3)	0.056 (2)	0.0049 (19)	−0.0028 (18)	−0.0029 (19)
C16	0.069 (2)	0.065 (3)	0.059 (2)	0.004 (2)	−0.0098 (18)	0.007 (2)
C17	0.062 (2)	0.052 (2)	0.069 (2)	0.0020 (18)	0.0004 (19)	0.0051 (19)
C18	0.086 (3)	0.064 (3)	0.097 (4)	0.004 (3)	0.001 (3)	0.017 (3)
Br1	0.0931 (3)	0.0795 (3)	0.0783 (3)	−0.0037 (3)	−0.02406 (19)	−0.0046 (3)
F1	0.157 (3)	0.111 (2)	0.120 (2)	0.0348 (19)	0.034 (2)	−0.0057 (19)
F2	0.119 (2)	0.0595 (18)	0.230 (4)	−0.0058 (17)	−0.011 (2)	0.026 (2)
F3	0.1036 (19)	0.107 (2)	0.134 (2)	0.0219 (16)	−0.0291 (17)	0.0330 (18)
N1	0.0728 (19)	0.063 (2)	0.0594 (19)	0.0005 (16)	−0.0006 (16)	−0.0015 (16)
O1	0.103 (2)	0.063 (2)	0.084 (2)	0.0087 (17)	−0.0090 (18)	−0.0022 (17)
O2	0.0727 (16)	0.0599 (18)	0.0845 (19)	0.0017 (15)	0.0006 (14)	0.0078 (14)

Geometric parameters (Å, º) top

C1—C2	1.397 (5)	C11—N1	1.284 (4)
C1—C11	1.437 (5)	C11—H11	0.9300
C1—C10	1.440 (5)	C12—C13	1.390 (5)
C2—O1	1.335 (5)	C12—C17	1.399 (5)
C2—C3	1.409 (6)	C12—N1	1.401 (5)
C3—C4	1.352 (6)	C13—C14	1.375 (5)
C3—H3	0.9300	C13—H13	0.9300
C4—C5	1.411 (6)	C14—C15	1.377 (5)
C4—H4	0.9300	C14—H14	0.9300
C5—C6	1.400 (6)	C15—C16	1.372 (5)
C5—C10	1.412 (5)	C15—Br1	1.893 (4)
C6—C7	1.339 (6)	C16—C17	1.369 (5)
C6—H6	0.9300	C16—H16	0.9300
C7—C8	1.396 (6)	C17—O2	1.408 (4)
C7—H7	0.9300	C18—F2	1.297 (5)
C8—C9	1.356 (6)	C18—F1	1.302 (5)
C8—H8	0.9300	C18—O2	1.320 (5)
C9—C10	1.406 (5)	C18—F3	1.329 (5)
C9—H9	0.9300	O1—H1	0.85 (5)

C2—C1—C11	119.1 (3)	N1—C11—C1	122.2 (4)
C2—C1—C10	118.9 (3)	N1—C11—H11	118.9
C11—C1—C10	121.9 (3)	C1—C11—H11	118.9
O1—C2—C1	123.3 (4)	C13—C12—C17	116.7 (3)
O1—C2—C3	116.1 (4)	C13—C12—N1	125.7 (3)
C1—C2—C3	120.6 (4)	C17—C12—N1	117.5 (4)
C4—C3—C2	120.3 (4)	C14—C13—C12	121.7 (4)
C4—C3—H3	119.9	C14—C13—H13	119.2
C2—C3—H3	119.9	C12—C13—H13	119.2
C3—C4—C5	121.9 (4)	C13—C14—C15	119.3 (4)
C3—C4—H4	119.1	C13—C14—H14	120.3
C5—C4—H4	119.1	C15—C14—H14	120.3
C6—C5—C4	121.2 (4)	C16—C15—C14	121.2 (4)
C6—C5—C10	119.7 (4)	C16—C15—Br1	118.8 (3)
C4—C5—C10	119.0 (4)	C14—C15—Br1	120.0 (3)
C7—C6—C5	121.7 (4)	C17—C16—C15	118.7 (4)
C7—C6—H6	119.1	C17—C16—H16	120.7
C5—C6—H6	119.1	C15—C16—H16	120.7
C6—C7—C8	119.1 (4)	C16—C17—C12	122.5 (4)
C6—C7—H7	120.5	C16—C17—O2	119.6 (3)
C8—C7—H7	120.5	C12—C17—O2	117.6 (3)
C9—C8—C7	121.1 (5)	F2—C18—F1	108.7 (5)
C9—C8—H8	119.5	F2—C18—O2	108.6 (4)
C7—C8—H8	119.5	F1—C18—O2	114.1 (4)
C8—C9—C10	121.3 (4)	F2—C18—F3	106.7 (4)
C8—C9—H9	119.4	F1—C18—F3	105.5 (4)
C10—C9—H9	119.4	O2—C18—F3	113.0 (4)
C9—C10—C5	117.1 (4)	C11—N1—C12	122.4 (3)
C9—C10—C1	123.6 (4)	C2—O1—H1	104 (4)
C5—C10—C1	119.3 (4)	C18—O2—C17	117.9 (3)

C11—C1—C2—O1	0.3 (5)	C2—C1—C11—N1	1.4 (5)
C10—C1—C2—O1	179.8 (3)	C10—C1—C11—N1	−178.1 (3)
C11—C1—C2—C3	−180.0 (3)	C17—C12—C13—C14	−1.0 (5)
C10—C1—C2—C3	−0.5 (5)	N1—C12—C13—C14	177.0 (3)
O1—C2—C3—C4	−179.8 (4)	C12—C13—C14—C15	0.6 (6)
C1—C2—C3—C4	0.5 (6)	C13—C14—C15—C16	0.2 (5)
C2—C3—C4—C5	−0.5 (6)	C13—C14—C15—Br1	179.2 (3)
C3—C4—C5—C6	−179.8 (4)	C14—C15—C16—C17	−0.5 (5)
C3—C4—C5—C10	0.5 (6)	Br1—C15—C16—C17	−179.5 (3)
C4—C5—C6—C7	−179.9 (4)	C15—C16—C17—C12	−0.1 (5)
C10—C5—C6—C7	−0.1 (6)	C15—C16—C17—O2	174.0 (3)
C5—C6—C7—C8	−0.2 (7)	C13—C12—C17—C16	0.8 (5)
C6—C7—C8—C9	0.6 (7)	N1—C12—C17—C16	−177.4 (3)
C7—C8—C9—C10	−0.7 (7)	C13—C12—C17—O2	−173.3 (3)
C8—C9—C10—C5	0.4 (6)	N1—C12—C17—O2	8.4 (5)
C8—C9—C10—C1	−179.3 (4)	C1—C11—N1—C12	−178.6 (3)
C6—C5—C10—C9	0.0 (5)	C13—C12—N1—C11	27.1 (5)
C4—C5—C10—C9	179.8 (4)	C17—C12—N1—C11	−154.8 (3)
C6—C5—C10—C1	179.8 (3)	F2—C18—O2—C17	171.8 (4)
C4—C5—C10—C1	−0.5 (5)	F1—C18—O2—C17	50.4 (6)
C2—C1—C10—C9	−179.8 (3)	F3—C18—O2—C17	−70.0 (5)
C11—C1—C10—C9	−0.3 (5)	C16—C17—O2—C18	79.8 (5)
C2—C1—C10—C5	0.5 (5)	C12—C17—O2—C18	−105.9 (4)
C11—C1—C10—C5	180.0 (3)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···N1	0.85 (5)	1.77 (6)	2.551 (5)	151 (5)

Experimental details

Crystal data
Chemical formula	C₁₈H₁₁BrF₃NO₂
M_r	410.19
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	296
a, b, c (Å)	4.5315 (3), 16.3228 (7), 21.7622 (12)
β (°)	93.025 (4)
V (Å³)	1607.44 (15)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	2.60
Crystal size (mm)	0.73 × 0.32 × 0.08

Data collection
Diffractometer	Stoe IPDS-II diffractometer
Absorption correction	Integration (X-RED32; Stoe & Cie, 2002)
T_min, T_max	0.176, 0.772
No. of measured, independent and observed [I > 2σ(I)] reflections	17993, 3160, 1932
R_int	0.080
(sin θ/λ)_max (Å⁻¹)	0.617

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.050, 0.092, 1.02
No. of reflections	3160
No. of parameters	230
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.35, −0.20

Computer programs: X-AREA (Stoe & Cie, 2002), X-RED32 (Stoe & Cie, 2002), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 for Windows (Farrugia, 2012), WinGX (Farrugia, 2012).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···N1	0.85 (5)	1.77 (6)	2.551 (5)	151 (5)

Acknowledgements

The authors acknowledge the Faculty of Arts and Sciences, Ondokuz Mayıs University, Turkey, for the use of the Stoe IPDS-II diffractometer (purchased under grant No. F279 of the University Research Fund).

References

Barton, D. & Ollis, W. D. (1979). In Comprehensive Organic Chemistry, Vol 2. Oxford: Pergamon. Google Scholar
Bingöl Alpaslan, Y., Alpaslan, G., Ağar, A. & Işık, Ş. (2010). Acta Cryst. E66, o510. Web of Science CSD CrossRef IUCr Journals Google Scholar
Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849–854. Web of Science CrossRef CAS IUCr Journals Google Scholar
Hökelek, T., Kılıç, Z., Işıklan, M. & Toy, M. (2000). J. Mol. Struct. 523, 61–69. Web of Science CSD CrossRef CAS Google Scholar
Ingold, C. K. (1969). In Structure and Mechanism in Organic Chemistry, 2nd ed. Ithaca: Cornell University Press. Google Scholar
Layer, R. W. (1963). Chem. Rev. 63, 489–510. CrossRef CAS Web of Science Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Soydemir, E., Büyükgüngör, O., Albayrak, Ç. & Odabaşoğlu, M. (2011). Acta Cryst. E67, o599–o600. Web of Science CSD CrossRef IUCr Journals Google Scholar
Stoe & Cie (2002). X-AREA and X-RED32. Stoe & Cie, Darmstadt, Germany. Google Scholar
Tüfekçi, M., Bingöl Alpaslan, Y., Macit, M. & Erdönmez, A. (2009). Acta Cryst. E65, o2704. Web of Science CrossRef IUCr Journals Google Scholar