(E)-N-{3-[(m-Tolyl­imino)­meth­yl]pyridin-2-yl}pivalamide

Atalay, Ş.; Gerçeker, S.; Meral, S.

doi:10.1107/S2414314617017023

organic compounds

IUCrDATA

ISSN: 2414-3146

Volume 2| Part 11| November 2017| x171702

https://doi.org/10.1107/S2414314617017023

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(E)-N-{3-[(m-Tolylimino)methyl]pyridin-2-yl}pivalamide

Şehriman Atalay,^a ^* Semra Gerçeker ^a and Seher Meral ^b

^aDepartment of Physics, Faculty of Arts and Sciences, Ondokuz Mayıs University, Kurupelit, 55139 Samsun, Turkey, and ^bDepartment of Chemistry, Faculty of Arts and Sciences, Ondokuz Mayıs University, Kurupelit, 55139 Samsun, Turkey
^*Correspondence e-mail: atalays@omu.edu.tr

Edited by W. T. A. Harrison, University of Aberdeen, Scotland (Received 18 November 2017; accepted 27 November 2017; online 30 November 2017)

In the title compound, C₁₈H₂₁N₃O, the dihedral angle between the pyridine and benzene rings is 30.53 (7)° and the C—C=N—C torsion angle is −170.6 (2)°. An intramolecular N—H⋯N hydrogen bond generates an S(6) ring. In the crystal, very weak C—H⋯O hydrogen bonds link the molecules into C(8) [101] chains. The tert-butyl methyl groups are disordered over two sets of sites in a 0.783 (4):0.217 (4) ratio.

Keywords: crystal structure; Schiff base; hydrogen bonding.

CCDC reference: 1587716

Structure description

Schiff bases were first reported by Hugo Schiff in 1864 . As part of our studies in this area, we herein report the synthesis and structure of the title compound (Fig. 1).

Figure 1
The molecular structure, showing 50% probability displacement ellipsoids. Both orientations of the disordered tert-butyl group are shown.

The dihedral angle between the pyridine (N2/C9–C13) and benzene (C2–C7) ring systems is 30.53 (7)°. The molecular structure features an intramolecular N—H⋯N hydrogen bond, which generates an S(6) ring. The C—N bond distances of the imino-group atoms [C6—N1 = 1.420 (3) Å and C8=N1 = 1.273 (3) Å] are consistent with those in related structures such as 2,4-dichloro-N-[(E)-(5-nitrothiophen-2-yl) methylidene]aniline (Köysal et al., 2016 ).

In the crystal, weak C11—H11⋯O1 hydrogen bonds (Table 1, Fig. 2) link the molecules into [101] chains.

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N3—H3⋯N1	0.86 (3)	2.00 (3)	2.744 (3)	145 (3)
C11—H11⋯O1ⁱ	0.93	2.61	3.404 (4)	144
Symmetry code: (i) $[x-1, -y+{\script{1\over 2}}, z-{\script{1\over 2}}]$ .

Figure 2
The packing, viewed down [100], showing the hydrogen-bonding interactions (dashed lines).

Synthesis and crystallization

Solutions of N-(5-formylpyridin-2-yl)pivalamide (0.020 g, 0.96 mmol) in 20 ml ethanol and o-toluidine (0.0107 g, 0.90 mmol) in 20 ml ethanol were mixed and stirred for 1 h under reflux. Colourless needles were recovered upon slow evaporation of the solvent (yield 60%; m.p 457–459 K).

Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2.

Table 2
Experimental details

Crystal data
Chemical formula	C₁₈H₂₁N₃O
M_r	295.38
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	293
a, b, c (Å)	5.572 (3), 24.9671 (11), 12.2380 (5)
β (°)	106.529 (3)
V (Å³)	1632.1 (7)
Z	4
Radiation type	Mo Kα
μ (mm⁻¹)	0.08
Crystal size (mm)	0.51 × 0.21 × 0.01

Data collection
Diffractometer	STOE IPDS 2
Absorption correction	Integration X-RED32 (Stoe & Cie, 2002 )
T_min, T_max	0.969, 0.993
No. of measured, independent and observed [I > 2σ(I)] reflections	19913, 2957, 1820
R_int	0.088
(sin θ/λ)_max (Å⁻¹)	0.600

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.060, 0.151, 1.02
No. of reflections	2957
No. of parameters	237
No. of restraints	127
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.21, −0.24
Computer programs: X-AREA and X-RED32 (Stoe & Cie, 2002), SHELXT2016/6 (Sheldrick, 2015a ), SHELXL2016/6 (Sheldrick, 2015b ), ORTEP-3 for Windows and WinGX (Farrugia, 2012 ) and PLATON (Spek, 2009 ).

Structural data

CCDC reference: 1587716

Crystal structure: contains datablocks seh24, I. DOI: https://doi.org/10.1107/S2414314617017023/hb4184sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2414314617017023/hb4184Isup2.hkl

Supporting information file. DOI: https://doi.org/10.1107/S2414314617017023/hb4184Isup3.cml

checkCIF report

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: SHELXT2016/6 (Sheldrick, 2015a); program(s) used to refine structure: SHELXL2016/6 (Sheldrick, 2015b); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012); software used to prepare material for publication: WinGX (Farrugia, 2012) and PLATON (Spek, 2009).

(E)-N-{3-[(m-Tolylimino)methyl]pyridin-2-yl}pivalamide top

Crystal data top

C₁₈H₂₁N₃O	F(000) = 632
M_r = 295.38	D_x = 1.202 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
a = 5.572 (3) Å	Cell parameters from 16183 reflections
b = 24.9671 (11) Å	θ = 1.6–26.5°
c = 12.2380 (5) Å	µ = 0.08 mm⁻¹
β = 106.529 (3)°	T = 293 K
V = 1632.1 (7) Å³	Needle, colorless
Z = 4	0.51 × 0.21 × 0.01 mm

Data collection top

STOE IPDS 2 diffractometer	2957 independent reflections
Radiation source: sealed X-ray tube, 12 x 0.4 mm long-fine focus	1820 reflections with I > 2σ(I)
Detector resolution: 6.67 pixels mm^-1	R_int = 0.088
w scans	θ_max = 25.3°, θ_min = 1.6°
Absorption correction: integration X-RED32 (Stoe & Cie, 2002)	h = −6→6
T_min = 0.969, T_max = 0.993	k = −29→29
19913 measured reflections	l = −14→14

Refinement top

Refinement on F²	127 restraints
Least-squares matrix: full	Hydrogen site location: mixed
R[F² > 2σ(F²)] = 0.060	H atoms treated by a mixture of independent and constrained refinement
wR(F²) = 0.151	w = 1/[σ²(F_o²) + (0.0694P)² + 0.1577P] where P = (F_o² + 2F_c²)/3
S = 1.02	(Δ/σ)_max < 0.001
2957 reflections	Δρ_max = 0.21 e Å⁻³
237 parameters	Δρ_min = −0.24 e Å⁻³

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. The H3 and H11 atoms bonded to N3 and C11 were freely refined. All other H atoms were positioned geometrically and rifined using a riding model, with C—H distances of 0.93 Å and methyl C—H distances 0.96 Å.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq	Occ. (<1)
O1	0.0148 (4)	0.34395 (8)	0.93073 (15)	0.0765 (7)
N1	0.0847 (4)	0.33938 (9)	0.53592 (17)	0.0543 (6)
N2	−0.3301 (4)	0.28489 (9)	0.76396 (18)	0.0582 (6)
N3	−0.0212 (5)	0.34425 (9)	0.74136 (19)	0.0563 (6)
C1	0.7176 (6)	0.45364 (12)	0.4428 (3)	0.0762 (9)
H1A	0.661209	0.489716	0.447020	0.114*
H1B	0.814125	0.451961	0.389229	0.114*
H1C	0.819411	0.442612	0.516564	0.114*
C2	0.4947 (5)	0.41701 (11)	0.4044 (2)	0.0596 (7)
C3	0.3744 (7)	0.40961 (13)	0.2903 (3)	0.0732 (9)
H3A	0.436555	0.426282	0.235999	0.088*
C4	0.1643 (7)	0.37802 (13)	0.2552 (2)	0.0734 (9)
H4A	0.086189	0.373619	0.177745	0.088*
C5	0.0679 (6)	0.35273 (11)	0.3341 (2)	0.0625 (7)
H5	−0.074962	0.331639	0.309921	0.075*
C6	0.1859 (5)	0.35905 (10)	0.4495 (2)	0.0533 (7)
C7	0.3986 (5)	0.39123 (11)	0.4825 (2)	0.0572 (7)
H7	0.478515	0.395498	0.559810	0.069*
C8	−0.0425 (5)	0.29625 (11)	0.5208 (2)	0.0560 (7)
H8	−0.045267	0.275629	0.457161	0.067*
C9	−0.1845 (5)	0.27694 (10)	0.5967 (2)	0.0516 (6)
C10	−0.3483 (6)	0.23469 (11)	0.5595 (2)	0.0612 (8)
H10	−0.354012	0.217390	0.491512	0.073*
C11	−0.5023 (6)	0.21830 (12)	0.6229 (2)	0.0659 (8)
H11	−0.614229	0.190184	0.598442	0.079*
C12	−0.4870 (5)	0.24440 (11)	0.7229 (2)	0.0631 (8)
H12	−0.592703	0.233252	0.765170	0.076*
C13	−0.1813 (5)	0.30095 (9)	0.7022 (2)	0.0491 (6)
C14	0.0607 (5)	0.36424 (10)	0.8489 (2)	0.0525 (6)
C15	0.2151 (5)	0.41602 (10)	0.8613 (2)	0.0571 (7)
C16A	0.0395 (9)	0.46332 (15)	0.8459 (7)	0.1140 (19)	0.783 (4)
H16A	0.129858	0.495653	0.841931	0.171*	0.783 (4)
H16B	−0.029205	0.465312	0.909403	0.171*	0.783 (4)
H16C	−0.093634	0.459038	0.776741	0.171*	0.783 (4)
C17A	0.4209 (10)	0.4148 (2)	0.9742 (4)	0.115 (2)	0.783 (4)
H17A	0.522650	0.383497	0.977020	0.172*	0.783 (4)
H17B	0.346685	0.413798	1.036013	0.172*	0.783 (4)
H17C	0.522916	0.446261	0.980700	0.172*	0.783 (4)
C18A	0.3581 (8)	0.42136 (18)	0.7721 (4)	0.0810 (13)	0.783 (4)
H18A	0.464112	0.452371	0.788654	0.122*	0.783 (4)
H18B	0.241203	0.425071	0.697804	0.122*	0.783 (4)
H18C	0.458626	0.389982	0.773700	0.122*	0.783 (4)
C16B	0.090 (3)	0.4532 (5)	0.7612 (13)	0.094 (4)	0.217 (4)
H16D	−0.077479	0.461039	0.762392	0.141*	0.217 (4)
H16E	0.184157	0.485869	0.767965	0.141*	0.217 (4)
H16F	0.086620	0.435823	0.690736	0.141*	0.217 (4)
C17B	0.171 (4)	0.4469 (5)	0.9637 (13)	0.088 (4)	0.217 (4)
H17D	0.227235	0.483230	0.962648	0.132*	0.217 (4)
H17E	0.263494	0.430012	1.033458	0.132*	0.217 (4)
H17F	−0.003913	0.446646	0.958390	0.132*	0.217 (4)
C18B	0.4808 (15)	0.4025 (5)	0.8628 (18)	0.101 (4)	0.217 (4)
H18D	0.488336	0.365988	0.839495	0.151*	0.217 (4)
H18E	0.589883	0.407175	0.938581	0.151*	0.217 (4)
H18F	0.532814	0.425795	0.811415	0.151*	0.217 (4)
H3	0.044 (5)	0.3550 (11)	0.690 (2)	0.062 (8)*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.0948 (16)	0.0850 (14)	0.0462 (11)	−0.0347 (12)	0.0143 (10)	0.0012 (10)
N1	0.0632 (15)	0.0538 (14)	0.0484 (12)	−0.0040 (12)	0.0196 (11)	−0.0008 (10)
N2	0.0647 (15)	0.0543 (13)	0.0571 (13)	−0.0130 (12)	0.0200 (11)	−0.0020 (10)
N3	0.0737 (16)	0.0524 (13)	0.0455 (12)	−0.0199 (12)	0.0214 (11)	−0.0067 (10)
C1	0.079 (2)	0.068 (2)	0.091 (2)	0.0003 (17)	0.0400 (18)	0.0070 (16)
C2	0.0664 (19)	0.0541 (16)	0.0658 (18)	0.0112 (14)	0.0309 (15)	0.0055 (13)
C3	0.095 (3)	0.073 (2)	0.0622 (19)	0.0041 (19)	0.0403 (18)	0.0064 (15)
C4	0.097 (2)	0.080 (2)	0.0483 (16)	0.007 (2)	0.0279 (16)	0.0018 (15)
C5	0.0720 (19)	0.0660 (17)	0.0506 (16)	0.0018 (15)	0.0191 (14)	−0.0040 (13)
C6	0.0647 (17)	0.0504 (15)	0.0492 (15)	0.0058 (14)	0.0233 (13)	0.0014 (12)
C7	0.0660 (18)	0.0557 (16)	0.0523 (15)	0.0079 (14)	0.0208 (14)	0.0042 (12)
C8	0.0698 (19)	0.0518 (16)	0.0450 (14)	0.0023 (14)	0.0142 (13)	−0.0038 (12)
C9	0.0598 (17)	0.0430 (14)	0.0482 (14)	0.0008 (12)	0.0095 (12)	−0.0009 (11)
C10	0.078 (2)	0.0486 (16)	0.0513 (15)	−0.0087 (14)	0.0096 (14)	−0.0065 (12)
C11	0.070 (2)	0.0563 (17)	0.0643 (18)	−0.0137 (15)	0.0085 (15)	−0.0027 (14)
C12	0.0618 (18)	0.0599 (17)	0.0679 (18)	−0.0120 (15)	0.0189 (15)	0.0008 (14)
C13	0.0560 (16)	0.0448 (14)	0.0447 (13)	−0.0033 (12)	0.0113 (12)	0.0027 (11)
C14	0.0636 (17)	0.0497 (14)	0.0432 (14)	−0.0042 (12)	0.0136 (12)	0.0010 (11)
C15	0.0727 (18)	0.0482 (14)	0.0516 (14)	−0.0143 (13)	0.0195 (13)	−0.0057 (11)
C16A	0.096 (3)	0.066 (3)	0.192 (6)	−0.004 (2)	0.059 (4)	−0.023 (3)
C17A	0.134 (4)	0.115 (4)	0.069 (3)	−0.072 (3)	−0.015 (3)	0.010 (3)
C18A	0.080 (3)	0.082 (3)	0.086 (3)	−0.035 (2)	0.032 (2)	−0.012 (2)
C16B	0.121 (8)	0.050 (6)	0.102 (7)	−0.023 (6)	0.015 (7)	0.004 (6)
C17B	0.121 (8)	0.066 (7)	0.090 (6)	−0.053 (7)	0.049 (6)	−0.034 (5)
C18B	0.088 (6)	0.106 (8)	0.107 (9)	−0.022 (6)	0.025 (6)	−0.012 (7)

Geometric parameters (Å, º) top

O1—C14	1.213 (3)	C11—C12	1.368 (4)
N1—C8	1.273 (3)	C11—H11	0.9300
N1—C6	1.420 (3)	C12—H12	0.9300
N2—C13	1.333 (3)	C14—C15	1.536 (4)
N2—C12	1.338 (3)	C15—C16A	1.511 (4)
N3—C14	1.359 (3)	C15—C18B	1.513 (7)
N3—C13	1.397 (3)	C15—C17A	1.524 (4)
N3—H3	0.86 (3)	C15—C18A	1.530 (4)
C1—C2	1.506 (4)	C15—C16B	1.536 (7)
C1—H1A	0.9600	C15—C17B	1.549 (6)
C1—H1B	0.9600	C16A—H16A	0.9600
C1—H1C	0.9600	C16A—H16B	0.9600
C2—C3	1.380 (4)	C16A—H16C	0.9600
C2—C7	1.380 (4)	C17A—H17A	0.9600
C3—C4	1.375 (4)	C17A—H17B	0.9600
C3—H3A	0.9300	C17A—H17C	0.9600
C4—C5	1.384 (4)	C18A—H18A	0.9600
C4—H4A	0.9300	C18A—H18B	0.9600
C5—C6	1.387 (4)	C18A—H18C	0.9600
C5—H5	0.9300	C16B—H16D	0.9600
C6—C7	1.393 (4)	C16B—H16E	0.9600
C7—H7	0.9300	C16B—H16F	0.9600
C8—C9	1.462 (4)	C17B—H17D	0.9600
C8—H8	0.9300	C17B—H17E	0.9600
C9—C10	1.384 (4)	C17B—H17F	0.9600
C9—C13	1.419 (3)	C18B—H18D	0.9600
C10—C11	1.373 (4)	C18B—H18E	0.9600
C10—H10	0.9300	C18B—H18F	0.9600

C8—N1—C6	120.4 (2)	N3—C14—C15	115.4 (2)
C13—N2—C12	117.4 (2)	C16A—C15—C17A	115.0 (4)
C14—N3—C13	128.5 (2)	C16A—C15—C18A	107.1 (4)
C14—N3—H3	120.2 (19)	C17A—C15—C18A	103.8 (3)
C13—N3—H3	110.7 (18)	C18B—C15—C16B	111.3 (11)
C2—C1—H1A	109.5	C16A—C15—C14	108.7 (3)
C2—C1—H1B	109.5	C18B—C15—C14	109.4 (5)
H1A—C1—H1B	109.5	C17A—C15—C14	109.1 (2)
C2—C1—H1C	109.5	C18A—C15—C14	113.2 (2)
H1A—C1—H1C	109.5	C16B—C15—C14	108.4 (5)
H1B—C1—H1C	109.5	C18B—C15—C17B	118.7 (10)
C3—C2—C7	117.8 (3)	C16B—C15—C17B	101.8 (11)
C3—C2—C1	121.1 (3)	C14—C15—C17B	106.6 (4)
C7—C2—C1	121.0 (3)	C15—C16A—H16A	109.5
C4—C3—C2	121.2 (3)	C15—C16A—H16B	109.5
C4—C3—H3A	119.4	H16A—C16A—H16B	109.5
C2—C3—H3A	119.4	C15—C16A—H16C	109.5
C3—C4—C5	120.6 (3)	H16A—C16A—H16C	109.5
C3—C4—H4A	119.7	H16B—C16A—H16C	109.5
C5—C4—H4A	119.7	C15—C17A—H17A	109.5
C4—C5—C6	119.6 (3)	C15—C17A—H17B	109.5
C4—C5—H5	120.2	H17A—C17A—H17B	109.5
C6—C5—H5	120.2	C15—C17A—H17C	109.5
C5—C6—C7	118.6 (2)	H17A—C17A—H17C	109.5
C5—C6—N1	123.0 (3)	H17B—C17A—H17C	109.5
C7—C6—N1	118.0 (2)	C15—C18A—H18A	109.5
C2—C7—C6	122.3 (3)	C15—C18A—H18B	109.5
C2—C7—H7	118.9	H18A—C18A—H18B	109.5
C6—C7—H7	118.9	C15—C18A—H18C	109.5
N1—C8—C9	124.5 (2)	H18A—C18A—H18C	109.5
N1—C8—H8	117.8	H18B—C18A—H18C	109.5
C9—C8—H8	117.8	C15—C16B—H16D	109.5
C10—C9—C13	117.2 (2)	C15—C16B—H16E	109.5
C10—C9—C8	117.9 (2)	H16D—C16B—H16E	109.5
C13—C9—C8	124.7 (2)	C15—C16B—H16F	109.5
C11—C10—C9	120.1 (3)	H16D—C16B—H16F	109.5
C11—C10—H10	120.0	H16E—C16B—H16F	109.5
C9—C10—H10	120.0	C15—C17B—H17D	109.5
C12—C11—C10	118.3 (3)	C15—C17B—H17E	109.5
C12—C11—H11	120.9	H17D—C17B—H17E	109.5
C10—C11—H11	120.9	C15—C17B—H17F	109.5
N2—C12—C11	124.3 (3)	H17D—C17B—H17F	109.5
N2—C12—H12	117.8	H17E—C17B—H17F	109.5
C11—C12—H12	117.8	C15—C18B—H18D	109.5
N2—C13—N3	118.5 (2)	C15—C18B—H18E	109.5
N2—C13—C9	122.7 (2)	H18D—C18B—H18E	109.5
N3—C13—C9	118.7 (2)	C15—C18B—H18F	109.5
O1—C14—N3	123.7 (2)	H18D—C18B—H18F	109.5
O1—C14—C15	120.9 (2)	H18E—C18B—H18F	109.5

C7—C2—C3—C4	0.6 (4)	C12—N2—C13—C9	0.0 (4)
C1—C2—C3—C4	−177.1 (3)	C14—N3—C13—N2	20.5 (4)
C2—C3—C4—C5	0.0 (5)	C14—N3—C13—C9	−161.5 (3)
C3—C4—C5—C6	−0.5 (4)	C10—C9—C13—N2	−1.0 (4)
C4—C5—C6—C7	0.4 (4)	C8—C9—C13—N2	174.0 (2)
C4—C5—C6—N1	172.9 (3)	C10—C9—C13—N3	−179.0 (2)
C8—N1—C6—C5	33.4 (4)	C8—C9—C13—N3	−4.0 (4)
C8—N1—C6—C7	−154.0 (3)	C13—N3—C14—O1	4.9 (5)
C3—C2—C7—C6	−0.7 (4)	C13—N3—C14—C15	−174.0 (2)
C1—C2—C7—C6	177.0 (2)	O1—C14—C15—C16A	−88.8 (4)
C5—C6—C7—C2	0.2 (4)	N3—C14—C15—C16A	90.1 (4)
N1—C6—C7—C2	−172.7 (2)	O1—C14—C15—C18B	101.5 (9)
C6—N1—C8—C9	−170.6 (2)	N3—C14—C15—C18B	−79.6 (9)
N1—C8—C9—C10	168.9 (3)	O1—C14—C15—C17A	37.3 (4)
N1—C8—C9—C13	−6.0 (4)	N3—C14—C15—C17A	−143.8 (4)
C13—C9—C10—C11	1.2 (4)	O1—C14—C15—C18A	152.4 (3)
C8—C9—C10—C11	−174.1 (3)	N3—C14—C15—C18A	−28.7 (4)
C9—C10—C11—C12	−0.6 (4)	O1—C14—C15—C16B	−136.9 (10)
C13—N2—C12—C11	0.7 (4)	N3—C14—C15—C16B	42.0 (10)
C10—C11—C12—N2	−0.4 (4)	O1—C14—C15—C17B	−28.0 (10)
C12—N2—C13—N3	178.0 (2)	N3—C14—C15—C17B	150.9 (9)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N3—H3···N1	0.86 (3)	2.00 (3)	2.744 (3)	145 (3)
C11—H11···O1ⁱ	0.93	2.61	3.404 (4)	144

Symmetry code: (i) x−1, −y+1/2, z−1/2.

Acknowledgements

The authors wish to acknowledge the Faculty of Arts and Sciences, Ondokuz Mayıs University, Turkey, for the use of the Stoe IPDS II diffractometer(purchased under grant F.279 of the University Research Fund).

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