5-Chloro-2-hy­droxy­benzoic acid

Raza, A.R.; Nisar, B.; Tahir, M.N.; Raza, A.

doi:10.1107/S1600536810042042

organic compounds

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ISSN: 2056-9890

Volume 66| Part 11| November 2010| Page o2921

https://doi.org/10.1107/S1600536810042042

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5-Chloro-2-hydroxybenzoic acid

Abdul Rauf Raza,^a Bushra Nisar,^a M. Nawaz Tahir ^b ^* and Ahmad Raza ^a

^aDepartment of Chemistry, University of Sargodha, Sargodha, Pakistan, and ^bDepartment of Physics, University of Sargodha, Sargodha, Pakistan
^*Correspondence e-mail: dmntahir_uos@yahoo.com

(Received 16 October 2010; accepted 17 October 2010; online 23 October 2010)

The asymmetric unit of the title compound, C₇H₅ClO₃, contains two molecules; both feature an intramolecular O—H⋯O hydrogen bond, which generates an S(6) ring. In the crystal, both molecules form inversion dimers linked by pairs of O—H⋯O hydrogen bonds with R₂²(8) ring motifs. The dimers are interlinked by C—H⋯O interactions.

Related literature

For biological background, see: Bright et al. (2010 ): Fattorusso et al. (2005 ); Miki et al. (2002 ). For a related structure, see: Raza et al. (2010 ). For graph-set notation, see: Bernstein et al. (1995 ).

Experimental

Crystal data

C₇H₅ClO₃
M_r = 172.56
Monoclinic, P 2₁ /c
a = 23.526 (2) Å
b = 3.7972 (4) Å
c = 16.7321 (16) Å
β = 104.852 (5)°
V = 1444.8 (2) Å³
Z = 8
Mo Kα radiation
μ = 0.48 mm⁻¹
T = 296 K
0.34 × 0.12 × 0.10 mm

Data collection

Bruker Kappa APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2005 ) T_min = 0.879, T_max = 0.888
14048 measured reflections
3697 independent reflections
2444 reflections with I > 2σ(I)
R_int = 0.047

Refinement

R[F² > 2σ(F²)] = 0.042
wR(F²) = 0.138
S = 1.03
3697 reflections
211 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.38 e Å⁻³
Δρ_min = −0.50 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H1⋯O2ⁱ	0.83 (3)	1.88 (3)	2.710 (2)	171 (3)
O3—H3⋯O2	0.80 (3)	1.92 (3)	2.620 (2)	146 (3)
O4—H4A⋯O5ⁱⁱ	0.93 (3)	1.76 (3)	2.694 (2)	175 (2)
O6—H6⋯O5	0.87 (3)	1.80 (3)	2.606 (2)	154 (3)
C5—H5⋯O6ⁱⁱⁱ	0.93	2.55	3.311 (3)	139
Symmetry codes: (i) -x+1, -y+1, -z+1; (ii) -x, -y, -z+1; (iii) $[x, -y+{\script{1\over 2}}, z-{\script{1\over 2}}]$ .

Data collection: APEX2 (Bruker, 2007 ); cell refinement: SAINT (Bruker, 2007); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997 ) and PLATON (Spek, 2009 ); software used to prepare material for publication: WinGX (Farrugia, 1999 ) and PLATON.

Supporting information

Crystal structure: contains datablocks global, I. DOI: https://doi.org/10.1107/S1600536810042042/hb5691sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536810042042/hb5691Isup2.hkl

checkCIF report

Comment top

The benzoxazepines have a plethora of biological activities ranging from anti-inflammatory effect (Miki et al., 2002) to degenerative diseases like AIDS (Fattorusso et al., 2005) and cancer (Bright et al., 2010). Salicylic acid is an attractive substrate for the synthesis of 4,1-benzoxazepine. The objective of this work is to synthesize a variety of substituted salicylic acid derivatives as precursors for the asymmetric synthesis of 4,1-benzoxazepines by chiral-pool strategy.

We have reported the crystal structure of 2-methylamino-5-nitrobenzoic acid (Raza et al., 2010) and in continuation to synthesize substituted benzoic acid, the title compound (I, Fig. 1) is being reported.

The title compound consists of two molecules in the crystallographic asymmetric unit which differ from each other geometrically. Both molecules, A (C1—C7/O1/O2/O3/CL1) and B (C8—C14/O4/O5/O6/CL2) are close to planar with r. m. s deviations of 0.023 and 0.007 Å, respectively. The dihedral angle between A/B is 1.77 (4)°. In each molecule, there exists an S(6) ring motif (Bernstein et al., 1995) due to intramolecular H-bonding of O—H···O type (Table 1, Fig. 1). The molecules form dimers with themselves due to intermolecular H-bondings of O—H···O type (Table 1, Fig. 2) with R₂²(8) ring motifs. These dimers are interlinked with each other due to H-bonding of C—H···O type (Fig. 2).

Related literature top

For biological background, see: Bright et al. (2010): Fattorusso et al. (2005); Miki et al. (2002). For a related structure, see: Raza et al. (2010). For graph-set notation, see: Bernstein et al. (1995).

Experimental top

A solution of Cu₂Cl₂ (3.46 g, 0.0375 mol) in HCl (10 ml) was added as drops to the diazonium salt of 5-amino-2-hydroxybenzioc acid (3.825 g, 0.025 mol), which was prepared by adding ice chilled aqueous solution of NaNO₂ (2.58 g, 0.0375 mol) to the solution of 5-amino-2-hydroxybenzoic acid in EtOAc and H₂SO₄ (2.8 ml, 4.9 g, 0.05 mol). The temperature of the reaction mixture was controlled below 268 K. After the complete addition of Cu₂Cl₂, the reaction mixture was refluxed for one hour, cooled to room temperature, neutralized with aqueous NaHCO₃ (10%) and extracted with EtOAc (3 × 25 ml). The organic layer was combined, dried over anhydrous Na₂SO₄, filtered, concentrated under reduced pressure and left for 48 h to afford light yellow needles of (I).

Structure description top

For biological background, see: Bright et al. (2010): Fattorusso et al. (2005); Miki et al. (2002). For a related structure, see: Raza et al. (2010). For graph-set notation, see: Bernstein et al. (1995).

Computing details top

Data collection: APEX2 (Bruker, 2007); cell refinement: SAINT (Bruker, 2007); data reduction: SAINT (Bruker, 2007); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997) and PLATON (Spek, 2009); software used to prepare material for publication: WinGX (Farrugia, 1999) and PLATON (Spek, 2009).

Figures top

	Fig. 1. View of the title compound with displacement ellipsoids drawn at the 50% probability level. H-atoms are shown by small circles of arbitrary radius. The dotted lines indicate the intramolecular H-bonds.
	Fig. 2. The partial packing (PLATON; Spek, 2009) which shows that molecules form dimers and are interlinked.

5-Chloro-2-hydroxybenzoic acid top

Crystal data top

C₇H₅ClO₃	F(000) = 704
M_r = 172.56	D_x = 1.587 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 931 reflections
a = 23.526 (2) Å	θ = 2.8–26.0°
b = 3.7972 (4) Å	µ = 0.48 mm⁻¹
c = 16.7321 (16) Å	T = 296 K
β = 104.852 (5)°	Needle, light yellow
V = 1444.8 (2) Å³	0.34 × 0.12 × 0.10 mm
Z = 8

Data collection top

Bruker Kappa APEXII CCD diffractometer	3697 independent reflections
Radiation source: fine-focus sealed tube	2444 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.047
Detector resolution: 7.40 pixels mm^-1	θ_max = 28.7°, θ_min = 3.6°
ω scans	h = −31→31
Absorption correction: multi-scan (SADABS; Bruker, 2005)	k = −4→5
T_min = 0.879, T_max = 0.888	l = −22→22
14048 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)] = 0.042	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.138	H atoms treated by a mixture of independent and constrained refinement
S = 1.03	w = 1/[σ²(F_o²) + (0.073P)²] where P = (F_o² + 2F_c²)/3
3697 reflections	(Δ/σ)_max < 0.001
211 parameters	Δρ_max = 0.38 e Å⁻³
0 restraints	Δρ_min = −0.50 e Å⁻³

Crystal data top

C₇H₅ClO₃	V = 1444.8 (2) Å³
M_r = 172.56	Z = 8
Monoclinic, P2₁/c	Mo Kα radiation
a = 23.526 (2) Å	µ = 0.48 mm⁻¹
b = 3.7972 (4) Å	T = 296 K
c = 16.7321 (16) Å	0.34 × 0.12 × 0.10 mm
β = 104.852 (5)°

Data collection top

Bruker Kappa APEXII CCD diffractometer	3697 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 2005)	2444 reflections with I > 2σ(I)
T_min = 0.879, T_max = 0.888	R_int = 0.047
14048 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.042	0 restraints
wR(F²) = 0.138	H atoms treated by a mixture of independent and constrained refinement
S = 1.03	Δρ_max = 0.38 e Å⁻³
3697 reflections	Δρ_min = −0.50 e Å⁻³
211 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 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 (Å²) top

	x	y	z	U_iso*/U_eq
Cl1	0.37512 (3)	0.69966 (16)	0.07736 (3)	0.0501 (2)
O1	0.49060 (7)	0.6286 (5)	0.38781 (10)	0.0531 (6)
O2	0.43512 (7)	0.3536 (5)	0.45885 (9)	0.0497 (5)
O3	0.32656 (7)	0.1864 (5)	0.38353 (10)	0.0504 (6)
C1	0.44188 (9)	0.4711 (6)	0.39317 (12)	0.0372 (6)
C2	0.39581 (8)	0.4495 (5)	0.31555 (11)	0.0325 (6)
C3	0.34043 (9)	0.3106 (5)	0.31526 (13)	0.0363 (6)
C4	0.29691 (10)	0.3000 (6)	0.24180 (14)	0.0427 (7)
C5	0.30768 (9)	0.4181 (6)	0.16973 (13)	0.0425 (7)
C6	0.36245 (9)	0.5504 (5)	0.16965 (12)	0.0359 (6)
C7	0.40631 (9)	0.5677 (5)	0.24125 (12)	0.0355 (6)
Cl2	0.13798 (3)	0.73267 (17)	0.21674 (4)	0.0624 (3)
O4	0.01191 (7)	0.1719 (5)	0.39980 (11)	0.0604 (6)
O5	0.06701 (7)	0.1273 (5)	0.52956 (10)	0.0553 (6)
O6	0.17545 (7)	0.3485 (5)	0.56545 (10)	0.0538 (6)
C8	0.06128 (9)	0.2160 (6)	0.45705 (14)	0.0402 (7)
C9	0.10935 (9)	0.3749 (5)	0.42825 (12)	0.0349 (6)
C10	0.16403 (9)	0.4322 (6)	0.48436 (13)	0.0383 (7)
C11	0.20911 (9)	0.5788 (6)	0.45616 (14)	0.0447 (7)
C12	0.20146 (10)	0.6683 (6)	0.37478 (15)	0.0453 (8)
C13	0.14736 (10)	0.6137 (6)	0.31970 (13)	0.0413 (7)
C14	0.10148 (9)	0.4679 (6)	0.34525 (13)	0.0397 (7)
H1	0.5163 (12)	0.635 (7)	0.4326 (18)	0.0636*
H3	0.3557 (12)	0.189 (7)	0.4210 (18)	0.0604*
H4	0.25996	0.21164	0.24137	0.0512*
H5	0.27810	0.40924	0.12074	0.0510*
H7	0.44297	0.65761	0.24065	0.0425*
H4A	−0.0156 (12)	0.058 (8)	0.4222 (16)	0.0725*
H6	0.1424 (13)	0.258 (7)	0.5696 (19)	0.0646*
H11	0.24542	0.61752	0.49328	0.0536*
H12	0.23233	0.76478	0.35677	0.0543*
H14	0.06536	0.43138	0.30750	0.0476*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Cl1	0.0588 (4)	0.0597 (4)	0.0332 (3)	−0.0012 (3)	0.0142 (3)	0.0039 (2)
O1	0.0349 (9)	0.0858 (13)	0.0354 (9)	−0.0154 (8)	0.0034 (7)	0.0057 (8)
O2	0.0443 (9)	0.0749 (11)	0.0300 (8)	−0.0096 (8)	0.0096 (7)	0.0028 (7)
O3	0.0427 (10)	0.0719 (11)	0.0399 (9)	−0.0131 (8)	0.0167 (7)	0.0048 (8)
C1	0.0340 (11)	0.0433 (12)	0.0359 (10)	−0.0004 (9)	0.0119 (9)	−0.0002 (9)
C2	0.0314 (10)	0.0349 (10)	0.0318 (10)	0.0006 (8)	0.0092 (8)	−0.0018 (8)
C3	0.0356 (11)	0.0370 (11)	0.0395 (11)	−0.0004 (9)	0.0153 (9)	−0.0010 (8)
C4	0.0324 (11)	0.0477 (13)	0.0473 (13)	−0.0058 (9)	0.0091 (10)	−0.0004 (9)
C5	0.0358 (12)	0.0474 (13)	0.0405 (12)	−0.0017 (10)	0.0028 (9)	−0.0011 (9)
C6	0.0408 (11)	0.0353 (10)	0.0319 (10)	0.0017 (9)	0.0098 (9)	−0.0008 (8)
C7	0.0331 (11)	0.0386 (11)	0.0358 (10)	−0.0009 (9)	0.0109 (8)	−0.0028 (8)
Cl2	0.0825 (5)	0.0671 (5)	0.0442 (3)	−0.0108 (3)	0.0284 (3)	0.0069 (3)
O4	0.0345 (9)	0.0962 (14)	0.0511 (10)	−0.0143 (9)	0.0121 (8)	0.0148 (9)
O5	0.0414 (9)	0.0852 (13)	0.0429 (9)	−0.0100 (8)	0.0173 (7)	0.0136 (8)
O6	0.0402 (9)	0.0821 (12)	0.0387 (9)	−0.0076 (9)	0.0093 (7)	0.0030 (8)
C8	0.0313 (11)	0.0481 (13)	0.0447 (12)	0.0001 (9)	0.0159 (10)	0.0023 (9)
C9	0.0326 (11)	0.0374 (11)	0.0386 (11)	0.0008 (9)	0.0163 (9)	0.0002 (8)
C10	0.0357 (11)	0.0429 (12)	0.0378 (11)	0.0017 (9)	0.0123 (9)	−0.0023 (9)
C11	0.0317 (11)	0.0528 (14)	0.0499 (13)	−0.0065 (10)	0.0113 (10)	−0.0034 (10)
C12	0.0413 (13)	0.0420 (12)	0.0597 (15)	−0.0090 (10)	0.0261 (11)	−0.0056 (10)
C13	0.0517 (14)	0.0385 (11)	0.0400 (11)	−0.0019 (10)	0.0230 (10)	−0.0004 (9)
C14	0.0374 (11)	0.0450 (12)	0.0386 (11)	−0.0018 (9)	0.0130 (9)	0.0005 (9)

Geometric parameters (Å, º) top

Cl1—C6	1.741 (2)	C4—C5	1.370 (3)
Cl2—C13	1.740 (2)	C5—C6	1.383 (3)
O1—C1	1.316 (3)	C6—C7	1.368 (3)
O2—C1	1.234 (3)	C4—H4	0.9300
O3—C3	1.351 (3)	C5—H5	0.9300
O1—H1	0.83 (3)	C7—H7	0.9300
O3—H3	0.80 (3)	C8—C9	1.468 (3)
O4—C8	1.313 (3)	C9—C14	1.399 (3)
O5—C8	1.233 (3)	C9—C10	1.402 (3)
O6—C10	1.352 (3)	C10—C11	1.383 (3)
O4—H4A	0.93 (3)	C11—C12	1.370 (3)
O6—H6	0.87 (3)	C12—C13	1.382 (3)
C1—C2	1.465 (3)	C13—C14	1.375 (3)
C2—C7	1.402 (3)	C11—H11	0.9300
C2—C3	1.404 (3)	C12—H12	0.9300
C3—C4	1.384 (3)	C14—H14	0.9300

C1—O1—H1	113.3 (19)	C6—C7—H7	120.00
C3—O3—H3	108 (2)	C2—C7—H7	120.00
C8—O4—H4A	109.9 (16)	O5—C8—C9	122.4 (2)
C10—O6—H6	103 (2)	O4—C8—C9	115.14 (19)
O1—C1—C2	115.11 (17)	O4—C8—O5	122.4 (2)
O2—C1—C2	122.3 (2)	C8—C9—C14	120.85 (19)
O1—C1—O2	122.58 (19)	C8—C9—C10	119.74 (18)
C1—C2—C7	120.64 (18)	C10—C9—C14	119.4 (2)
C3—C2—C7	119.43 (18)	O6—C10—C11	117.7 (2)
C1—C2—C3	119.93 (17)	O6—C10—C9	123.2 (2)
C2—C3—C4	119.24 (19)	C9—C10—C11	119.09 (19)
O3—C3—C4	117.2 (2)	C10—C11—C12	121.5 (2)
O3—C3—C2	123.58 (19)	C11—C12—C13	119.3 (2)
C3—C4—C5	120.7 (2)	Cl2—C13—C12	118.86 (18)
C4—C5—C6	120.2 (2)	Cl2—C13—C14	120.14 (17)
Cl1—C6—C7	119.94 (17)	C12—C13—C14	121.0 (2)
C5—C6—C7	120.69 (19)	C9—C14—C13	119.7 (2)
Cl1—C6—C5	119.37 (16)	C10—C11—H11	119.00
C2—C7—C6	119.77 (19)	C12—C11—H11	119.00
C5—C4—H4	120.00	C11—C12—H12	120.00
C3—C4—H4	120.00	C13—C12—H12	120.00
C4—C5—H5	120.00	C9—C14—H14	120.00
C6—C5—H5	120.00	C13—C14—H14	120.00

O1—C1—C2—C3	−175.24 (19)	O4—C8—C9—C10	−179.8 (2)
O1—C1—C2—C7	4.5 (3)	O4—C8—C9—C14	−0.2 (3)
O2—C1—C2—C3	4.0 (3)	O5—C8—C9—C10	−0.4 (3)
O2—C1—C2—C7	−176.3 (2)	O5—C8—C9—C14	179.1 (2)
C1—C2—C3—O3	−1.1 (3)	C8—C9—C10—O6	−0.1 (3)
C1—C2—C3—C4	178.4 (2)	C8—C9—C10—C11	179.3 (2)
C7—C2—C3—O3	179.12 (19)	C14—C9—C10—O6	−179.7 (2)
C7—C2—C3—C4	−1.3 (3)	C14—C9—C10—C11	−0.2 (3)
C1—C2—C7—C6	−178.98 (19)	C8—C9—C14—C13	−179.5 (2)
C3—C2—C7—C6	0.8 (3)	C10—C9—C14—C13	0.1 (3)
O3—C3—C4—C5	−179.4 (2)	O6—C10—C11—C12	179.4 (2)
C2—C3—C4—C5	1.0 (3)	C9—C10—C11—C12	−0.1 (3)
C3—C4—C5—C6	−0.1 (3)	C10—C11—C12—C13	0.5 (3)
C4—C5—C6—Cl1	−179.91 (18)	C11—C12—C13—Cl2	179.34 (18)
C4—C5—C6—C7	−0.5 (3)	C11—C12—C13—C14	−0.7 (3)
Cl1—C6—C7—C2	179.56 (15)	Cl2—C13—C14—C9	−179.65 (17)
C5—C6—C7—C2	0.2 (3)	C12—C13—C14—C9	0.4 (3)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···O2ⁱ	0.83 (3)	1.88 (3)	2.710 (2)	171 (3)
O3—H3···O2	0.80 (3)	1.92 (3)	2.620 (2)	146 (3)
O4—H4A···O5ⁱⁱ	0.93 (3)	1.76 (3)	2.694 (2)	175 (2)
O6—H6···O5	0.87 (3)	1.80 (3)	2.606 (2)	154 (3)
C5—H5···O6ⁱⁱⁱ	0.93	2.55	3.311 (3)	139

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

Experimental details

Crystal data
Chemical formula	C₇H₅ClO₃
M_r	172.56
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	296
a, b, c (Å)	23.526 (2), 3.7972 (4), 16.7321 (16)
β (°)	104.852 (5)
V (Å³)	1444.8 (2)
Z	8
Radiation type	Mo Kα
µ (mm⁻¹)	0.48
Crystal size (mm)	0.34 × 0.12 × 0.10

Data collection
Diffractometer	Bruker Kappa APEXII CCD
Absorption correction	Multi-scan (SADABS; Bruker, 2005)
T_min, T_max	0.879, 0.888
No. of measured, independent and observed [I > 2σ(I)] reflections	14048, 3697, 2444
R_int	0.047
(sin θ/λ)_max (Å⁻¹)	0.676

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.042, 0.138, 1.03
No. of reflections	3697
No. of parameters	211
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.38, −0.50

Computer programs: APEX2 (Bruker, 2007), SAINT (Bruker, 2007), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 (Farrugia, 1997) and PLATON (Spek, 2009), WinGX (Farrugia, 1999) and PLATON (Spek, 2009).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···O2ⁱ	0.83 (3)	1.88 (3)	2.710 (2)	171 (3)
O3—H3···O2	0.80 (3)	1.92 (3)	2.620 (2)	146 (3)
O4—H4A···O5ⁱⁱ	0.93 (3)	1.76 (3)	2.694 (2)	175 (2)
O6—H6···O5	0.87 (3)	1.80 (3)	2.606 (2)	154 (3)
C5—H5···O6ⁱⁱⁱ	0.93	2.55	3.311 (3)	139

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

Acknowledgements

The authors acknowledge the provision of funds for the purchase of the diffractometer and encouragement by Dr Muhammad Akram Chaudhary, Vice Chancellor, University of Sargodha, Pakistan. ARR also acknowledges the Higher Education Commission, Government of Pakistan, for generous support of a research project (20–819).

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