N-(4-Chloro­phenyl­sulfon­yl)-4-iodo­benzamide

Naveen, S.; Sudha, A.G.; Suresha, E.; Lokanath, N.K.; Suchetan, P.A.; Warad, I.

doi:10.1107/S2414314617000256

organic compounds

IUCrDATA

ISSN: 2414-3146

Volume 2| Part 1| January 2017| x170025

https://doi.org/10.1107/S2414314617000256

Open

access

N-(4-Chlorophenylsulfonyl)-4-iodobenzamide

S. Naveen,^a A. G. Sudha,^b E. Suresha,^b N. K. Lokanath,^c P. A. Suchetan ^b ^* and Ismail Warad ^d ^*

^aInstitution of Excellence, University of Mysore, Manasagangotri, Mysuru-6, India, ^bDepartment of Chemistry, University College of Science, Tumkur University, Tumkur 572 103, India, ^cDepartment of Studies in Physics, University of Mysore, Manasagangotri, Mysuru-6, India, and ^dDepartment of Chemistry, Science College, An-Najah National University, PO Box 7, Nablus, Palestinian Territories
^*Correspondence e-mail: pasuchetan@yahoo.co.in, khalil.i@najah.edu

Edited by H. Stoeckli-Evans, University of Neuchâtel, Switzerland (Received 1 January 2017; accepted 6 January 2017; online 13 January 2017)

In the title compound, C₁₃H₉ClINO₃S, the benzene rings are inclined to one another by 81.6 (2)°. In the crystal, molecules are linked by pairs of N—H⋯O hydrogen bonds, forming inversion dimers with an R₂²(8) ring motif. The dimers are linked by C—H⋯O hydrogen bonds, forming sheets parallel to the bc plane. Neighbouring sheets are linked via offset π–π interactions involving inversion-related iodobenzene rings [intercentroid distance = 3.807 (3) Å], forming a three-dimensional supramolecular structure.

Keywords: crystal structure; sulfonamides; benzamides; N-(arylsulfonyl)arylamides; hydrogen bonding; offset π–π interactions.

CCDC reference: 1525994

Structure description

Sulfonamide and amide moieties play a significant role as key constituents in a number of biologically active molecules (Mohan et al., 2013 ; Manojkumar et al., 2013 ; Hamad & Abed, 2014 ). In recent years, N-(arylsulfonyl)-arylamides have received much attention as they constitute an important class of drugs for Alzheimer's disease (Hasegawa & Yamamoto, 2000 ), anti-bacterial inhibitors of tRNA synthetases (Banwell et al., 2000 ), antagonists for angiotensin II (Chang et al., 1994 ) and as leukotriene D4-receptors (Musser et al., 1990 ). Further, N-(arylsulfonyl)-arylamides are known to be potent anti-tumour agents against a broad spectrum of human tumour xenografts (colon, lung, breast, ovary and prostate) in nude mice (Mader et al., 2005 ). In view of the importance of N-(arylsulfonyl)-arylamides and in continuation of our work on the synthesis and crystal structures of N-(4-chlorophenylsulfonyl)-arylamides (Suchetan et al., 2010a ,b ,c , 2011 ), the title compound was synthesized and we report herein on its crystal structure.

The molecular structure of the title compound is illustrated in Fig. 1. The molecule is V-shaped with the dihedral angle between the chlorobenzene and iodobenzene rings (C1–C6 and C8–C13, respectively) being 81.6 (2)°.

Figure 1
A view of the molecular structure of the title compound, showing the atom labelling. Displacement ellipsoids are drawn at the 50% probability level.

In the crystal, molecules are linked by pairs of N1—HN1⋯O1ⁱ (Table 1) hydrogen bonds, forming an inversion dimer with an $[R_{2}^{2}]$ (8) ring motif. The dimers are linked via C12—H12⋯O3ⁱⁱ (Table 1) hydrogen bonds, forming sheets parallel to the bc plane (Fig. 2). Neighbouring sheets are linked via offset π–π interactions involving inversion-related iodobenzene rings (Cg = centroid of ring C8–C13), forming a three-dimensional supramolecular structure, as illustrated in Fig. 3 [Cg⋯Cgⁱⁱⁱ = 3.807 (3) Å; interplanar distance = 3.653 (2) Å; slippage 1.072 Å; symmetry code (iii) −x + 2, −y, −z + 2].

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—HN1⋯O1ⁱ	0.81 (4)	2.14 (4)	2.943 (5)	168 (6)
C12—H12⋯O3ⁱⁱ	0.93	2.43	3.124 (6)	131
Symmetry codes: (i) $[-x+{\script{3\over 2}}, -y+{\script{1\over 2}}, -z+2]$ ; (ii) $[x, -y, z+{\script{1\over 2}}]$ .

Figure 2
A view along the a axis of the crystal packing of the title compound, showing the N—H⋯O and C—H⋯O hydrogen bonds (see Table 1

) as dashed lines. For clarity, only H atoms HN1 and H12 have been included.

Figure 3
A view along the b axis of the crystal packing of the title compound, showing the N—H⋯O and C—H⋯O hydrogen bonds (dashed lines; see Table 1

) and the π–π interactions (dashed arrows). For clarity, only H atoms HN1 and H12 have been included.

Synthesis and crystallization

The title compound was prepared by refluxing a mixture of 4-iodobenzoic acid (0.372 g, 1.5 mmol), 4-chlorobenzenesulfonamide (0.287 g, 1.5 mmol) and phosphorousoxychloride (7 ml) for 3 h on a water bath. The resultant mixture was cooled and poured into ice-cold water. The solid obtained was filtered, washed thoroughly with water and then dissolved in sodium bicarbonate solution. The compound was later re-precipitated by acidifying the filtered solution with dilute HCl. It was then filtered, dried and recrystallized from methanol (m.p. 425 K). Colourless prismatic crystals were obtained by slow evaporation of a solution of the title compound in methanol (with a few drops of water).

Refinement

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

Table 2
Experimental details

Crystal data
Chemical formula	C₁₃H₉ClINO₃S
M_r	421.62
Crystal system, space group	Monoclinic, C2/c
Temperature (K)	296
a, b, c (Å)	18.1163 (18), 13.3947 (13), 12.3002 (13)
β (°)	104.223 (4)
V (Å³)	2893.3 (5)
Z	8
Radiation type	Cu Kα
μ (mm⁻¹)	20.51
Crystal size (mm)	0.28 × 0.27 × 0.25

Data collection
Diffractometer	Bruker APEXII CCD
Absorption correction	Multi-scan (SADABS; Bruker, 2009 )
T_min, T_max	0.069, 0.080
No. of measured, independent and observed [I > 2σ(I)] reflections	13818, 2369, 2178
R_int	0.072
(sin θ/λ)_max (Å⁻¹)	0.584

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.064, 0.172, 1.08
No. of reflections	2369
No. of parameters	185
No. of restraints	1
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	1.58, −1.82
Computer programs: APEX2, SAINT-Plus and XPREP (Bruker, 2009), SHELXS97 and SHELXL97 (Sheldrick, 2008 ) and Mercury (Macrae et al., 2008 ).

Structural data

CCDC reference: 1525994

Crystal structure: contains datablocks I, Global. DOI: https://doi.org/10.1107/S2414314617000256/su4120sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2414314617000256/su4120Isup2.hkl

Supporting information file. DOI: https://doi.org/10.1107/S2414314617000256/su4120Isup3.cml

checkCIF report

Computing details top

Data collection: APEX2 (Bruker, 2009); cell refinement: APEX2 and SAINT-Plus (Bruker, 2009); data reduction: SAINT-Plus and XPREP (Bruker, 2009); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: Mercury (Macrae et al., 2008); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

N-(4-Chlorophenylsulfonyl)-4-iodobenzamide top

Crystal data top

C₁₃H₉ClINO₃S	F(000) = 1632
M_r = 421.62	D_x = 1.936 Mg m⁻³
Monoclinic, C2/c	Melting point: 425 K
Hall symbol: -C 2yc	Cu Kα radiation, λ = 1.54178 Å
a = 18.1163 (18) Å	Cell parameters from 144 reflections
b = 13.3947 (13) Å	θ = 4.2–64.2°
c = 12.3002 (13) Å	µ = 20.51 mm⁻¹
β = 104.223 (4)°	T = 296 K
V = 2893.3 (5) Å³	Prism, colourless
Z = 8	0.28 × 0.27 × 0.25 mm

Data collection top

Bruker APEXII CCD diffractometer	2369 independent reflections
Radiation source: fine-focus sealed tube	2178 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.072
phi and φ scans	θ_max = 64.2°, θ_min = 4.2°
Absorption correction: multi-scan (SADABS; Bruker, 2009)	h = −21→20
T_min = 0.069, T_max = 0.080	k = −15→15
13818 measured reflections	l = −12→14

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)] = 0.064	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.172	H atoms treated by a mixture of independent and constrained refinement
S = 1.08	w = 1/[σ²(F_o²) + (0.1376P)² + 0.079P] where P = (F_o² + 2F_c²)/3
2369 reflections	(Δ/σ)_max = 0.001
185 parameters	Δρ_max = 1.58 e Å⁻³
1 restraint	Δρ_min = −1.82 e Å⁻³

Special details top

Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'s 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 > 2σ(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	0.7762 (2)	0.3242 (4)	0.7483 (4)	0.0274 (10)
C2	0.7821 (3)	0.3116 (4)	0.6400 (4)	0.0361 (11)
H2	0.7548	0.2611	0.5958	0.043*
C3	0.8284 (3)	0.3737 (5)	0.5966 (4)	0.0425 (12)
H3	0.8333	0.3650	0.5237	0.051*
C4	0.8676 (3)	0.4492 (4)	0.6636 (5)	0.0370 (12)
C5	0.8628 (3)	0.4624 (4)	0.7727 (5)	0.0391 (12)
H5	0.8902	0.5128	0.8168	0.047*
C6	0.8161 (3)	0.3987 (4)	0.8160 (5)	0.0336 (11)
H6	0.8119	0.4063	0.8894	0.040*
C7	0.8082 (3)	0.0884 (4)	0.8118 (4)	0.0244 (10)
C8	0.8589 (2)	0.0109 (3)	0.8799 (4)	0.0220 (9)
C9	0.9104 (3)	−0.0367 (4)	0.8302 (4)	0.0319 (11)
H9	0.9131	−0.0180	0.7584	0.038*
C10	0.9575 (3)	−0.1108 (4)	0.8851 (4)	0.0334 (11)
H10	0.9926	−0.1413	0.8519	0.040*
C11	0.9518 (2)	−0.1392 (4)	0.9901 (4)	0.0268 (10)
C12	0.9013 (3)	−0.0940 (4)	1.0412 (4)	0.0295 (10)
H12	0.8981	−0.1142	1.1122	0.035*
C13	0.8553 (3)	−0.0179 (3)	0.9861 (4)	0.0264 (10)
H13	0.8217	0.0139	1.0210	0.032*
O1	0.69380 (19)	0.2958 (3)	0.8916 (3)	0.0374 (8)
O2	0.66080 (18)	0.2040 (3)	0.7129 (3)	0.0377 (8)
O3	0.79821 (18)	0.0931 (3)	0.7109 (3)	0.0340 (8)
S1	0.71643 (8)	0.24483 (8)	0.80304 (11)	0.0264 (4)
Cl1	0.92287 (8)	0.52981 (13)	0.60795 (14)	0.0601 (5)
I1	1.02099 (2)	−0.25581 (3)	1.07348 (3)	0.0422 (3)
N1	0.7722 (2)	0.1537 (3)	0.8684 (3)	0.0251 (8)
HN1	0.788 (3)	0.169 (4)	0.934 (3)	0.023 (12)*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
C1	0.029 (2)	0.018 (2)	0.030 (2)	0.0099 (18)	−0.0016 (17)	0.0023 (18)
C2	0.044 (3)	0.025 (3)	0.034 (2)	−0.003 (2)	0.0003 (19)	0.000 (2)
C3	0.052 (3)	0.034 (3)	0.039 (3)	0.000 (2)	0.007 (2)	0.003 (2)
C4	0.031 (2)	0.020 (3)	0.055 (3)	0.005 (2)	0.002 (2)	0.017 (2)
C5	0.037 (2)	0.018 (3)	0.054 (3)	0.004 (2)	−0.003 (2)	0.002 (2)
C6	0.039 (3)	0.016 (3)	0.042 (3)	0.010 (2)	0.003 (2)	0.001 (2)
C7	0.023 (2)	0.017 (3)	0.032 (2)	−0.0035 (18)	0.0049 (17)	−0.0002 (19)
C8	0.024 (2)	0.008 (2)	0.033 (2)	−0.0047 (16)	0.0054 (16)	−0.0032 (17)
C9	0.043 (3)	0.021 (3)	0.035 (2)	0.007 (2)	0.0149 (19)	0.0056 (19)
C10	0.037 (2)	0.023 (3)	0.044 (3)	0.010 (2)	0.017 (2)	0.005 (2)
C11	0.0203 (19)	0.015 (2)	0.041 (2)	0.0018 (17)	0.0004 (17)	−0.0008 (18)
C12	0.039 (2)	0.018 (2)	0.030 (2)	0.0058 (19)	0.0069 (18)	0.0031 (18)
C13	0.029 (2)	0.013 (2)	0.038 (2)	0.0068 (18)	0.0107 (17)	−0.0039 (18)
O1	0.0419 (19)	0.029 (2)	0.0407 (18)	0.0185 (16)	0.0087 (14)	0.0006 (16)
O2	0.0268 (16)	0.030 (2)	0.0481 (19)	0.0005 (15)	−0.0071 (14)	−0.0011 (17)
O3	0.0409 (17)	0.028 (2)	0.0330 (17)	0.0073 (14)	0.0079 (13)	0.0012 (14)
S1	0.0267 (8)	0.0184 (7)	0.0315 (7)	0.0071 (4)	0.0020 (5)	0.0020 (4)
Cl1	0.0554 (9)	0.0455 (9)	0.0771 (10)	−0.0123 (7)	0.0119 (7)	0.0213 (7)
I1	0.0384 (4)	0.0233 (4)	0.0621 (4)	0.01269 (11)	0.0068 (3)	0.01117 (13)
N1	0.0307 (19)	0.016 (2)	0.0258 (19)	0.0058 (16)	0.0024 (14)	−0.0003 (16)

Geometric parameters (Å, º) top

C1—C2	1.374 (7)	C8—C13	1.379 (7)
C1—C6	1.385 (8)	C8—C9	1.390 (6)
C1—S1	1.764 (5)	C9—C10	1.374 (7)
C2—C3	1.379 (8)	C9—H9	0.9300
C2—H2	0.9300	C10—C11	1.375 (7)
C3—C4	1.385 (8)	C10—H10	0.9300
C3—H3	0.9300	C11—C12	1.370 (7)
C4—C5	1.377 (8)	C11—I1	2.105 (4)
C4—Cl1	1.725 (5)	C12—C13	1.384 (7)
C5—C6	1.395 (8)	C12—H12	0.9300
C5—H5	0.9300	C13—H13	0.9300
C6—H6	0.9300	O1—S1	1.429 (4)
C7—O3	1.211 (6)	O2—S1	1.413 (4)
C7—N1	1.379 (6)	S1—N1	1.661 (4)
C7—C8	1.499 (7)	N1—HN1	0.81 (3)

C2—C1—C6	121.1 (5)	C10—C9—C8	121.2 (4)
C2—C1—S1	119.9 (4)	C10—C9—H9	119.4
C6—C1—S1	119.0 (4)	C8—C9—H9	119.4
C1—C2—C3	120.1 (5)	C9—C10—C11	118.7 (4)
C1—C2—H2	119.9	C9—C10—H10	120.6
C3—C2—H2	119.9	C11—C10—H10	120.6
C2—C3—C4	118.8 (5)	C12—C11—C10	121.5 (4)
C2—C3—H3	120.6	C12—C11—I1	119.3 (3)
C4—C3—H3	120.6	C10—C11—I1	119.3 (3)
C5—C4—C3	121.9 (5)	C11—C12—C13	119.4 (4)
C5—C4—Cl1	119.2 (4)	C11—C12—H12	120.3
C3—C4—Cl1	118.9 (4)	C13—C12—H12	120.3
C4—C5—C6	118.8 (5)	C8—C13—C12	120.4 (4)
C4—C5—H5	120.6	C8—C13—H13	119.8
C6—C5—H5	120.6	C12—C13—H13	119.8
C1—C6—C5	119.2 (5)	O2—S1—O1	120.0 (2)
C1—C6—H6	120.4	O2—S1—N1	109.1 (2)
C5—C6—H6	120.4	O1—S1—N1	103.7 (2)
O3—C7—N1	121.0 (4)	O2—S1—C1	108.6 (2)
O3—C7—C8	121.7 (4)	O1—S1—C1	108.7 (2)
N1—C7—C8	117.2 (4)	N1—S1—C1	105.7 (2)
C13—C8—C9	118.8 (4)	C7—N1—S1	121.9 (3)
C13—C8—C7	124.0 (4)	C7—N1—HN1	125 (4)
C9—C8—C7	117.2 (4)	S1—N1—HN1	109 (4)

C6—C1—C2—C3	0.0 (7)	C9—C10—C11—I1	178.1 (4)
S1—C1—C2—C3	179.7 (4)	C10—C11—C12—C13	−0.2 (7)
C1—C2—C3—C4	−0.9 (8)	I1—C11—C12—C13	−179.4 (3)
C2—C3—C4—C5	1.5 (8)	C9—C8—C13—C12	−1.0 (7)
C2—C3—C4—Cl1	−177.7 (4)	C7—C8—C13—C12	176.5 (4)
C3—C4—C5—C6	−1.1 (7)	C11—C12—C13—C8	1.3 (7)
Cl1—C4—C5—C6	178.1 (4)	C2—C1—S1—O2	−22.7 (4)
C2—C1—C6—C5	0.4 (7)	C6—C1—S1—O2	156.9 (4)
S1—C1—C6—C5	−179.3 (4)	C2—C1—S1—O1	−155.0 (4)
C4—C5—C6—C1	0.2 (7)	C6—C1—S1—O1	24.7 (4)
O3—C7—C8—C13	−159.7 (5)	C2—C1—S1—N1	94.3 (4)
N1—C7—C8—C13	19.3 (6)	C6—C1—S1—N1	−86.1 (4)
O3—C7—C8—C9	17.9 (7)	O3—C7—N1—S1	−2.7 (6)
N1—C7—C8—C9	−163.1 (4)	C8—C7—N1—S1	178.3 (3)
C13—C8—C9—C10	−0.3 (7)	O2—S1—N1—C7	53.2 (4)
C7—C8—C9—C10	−178.0 (5)	O1—S1—N1—C7	−177.7 (4)
C8—C9—C10—C11	1.4 (8)	C1—S1—N1—C7	−63.5 (4)
C9—C10—C11—C12	−1.1 (8)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—HN1···O1ⁱ	0.81 (4)	2.14 (4)	2.943 (5)	168 (6)
C12—H12···O3ⁱⁱ	0.93	2.43	3.124 (6)	131

Symmetry codes: (i) −x+3/2, −y+1/2, −z+2; (ii) x, −y, z+1/2.

Acknowledgements

The authors are thankful to the Institution of Excellence, Vijnana Bhavana, University of Mysore, Mysore, for providing the single-crystal X-ray diffraction data.

References

Banwell, M. G., Crasto, C. F., Easton, C. J., Forrest, A. K., Karoli, T., March, D. R., Mensah, L., Nairn, M. R., O'Hanlon, P. J., Oldham, M. D. & Yue, W. (2000). Bioorg. Med. Chem. Lett. 10, 2263–2266. Web of Science CrossRef PubMed CAS Google Scholar
Bruker (2009). APEX2, SAINT-Plus, XPREP and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Chang, L. L., Ashton, W. T., Flanagan, K. L., Chen, T. B., O'Malley, S. S., Zingaro, G. J., Siegl, P. K. S., Kivlighn, S. D., Lotti, V. J. & Chang, R. S. L. (1994). J. Med. Chem. 37, 4464–4478. CrossRef CAS Web of Science Google Scholar
Hamad, A. S. & Abed, F. S. (2014). J. Appl. Chem, 3, 56–63. Google Scholar
Hasegawa, T. & Yamamoto, H. (2000). Bull. Chem. Soc. Jpn, 73, 423–428. Web of Science CSD CrossRef CAS Google Scholar
Macrae, C. F., Bruno, I. J., Chisholm, J. A., Edgington, P. R., McCabe, P., Pidcock, E., Rodriguez-Monge, L., Taylor, R., van de Streek, J. & Wood, P. A. (2008). J. Appl. Cryst. 41, 466–470. Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
Mader, M., Shih, C., Considine, E., Dios, A. D., Grossman, C., Hipskind, P., Lin, H., Lobb, K., Lopez, B., Lopez, J., Cabrejas, L., Richett, M., White, W., Cheung, Y., Huang, Z., Reilly, J. & Dinn, S. (2005). Bioorg. Med. Chem. Lett. 15, 617–620. Web of Science CrossRef PubMed CAS Google Scholar
Manojkumar, K. E., Sreenivasa, S., Mohan, N. R., Madhu Chakrapani Rao, T. & Harikrishna, T. (2013). J. Appl. Chem, 2, 730–737. CAS Google Scholar
Mohan, N. R., Sreenivasa, S., Manojkumar, K. E. & Chakrapani Rao, T. M. (2013). J. Appl. Chem, 2, 722–729. Google Scholar
Musser, J. H., Kreft, A. F., Bender, R. H. W., Kubrak, D. M., Grimes, D., Carlson, R. P., Hand, J. M. & Chang, J. (1990). J. Med. Chem. 33, 240–245. CrossRef CAS PubMed Web of Science Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Suchetan, P. A., Foro, S. & Gowda, B. T. (2011). Acta Cryst. E67, o904. Web of Science CSD CrossRef IUCr Journals Google Scholar
Suchetan, P. A., Gowda, B. T., Foro, S. & Fuess, H. (2010a). Acta Cryst. E66, o766. Web of Science CSD CrossRef IUCr Journals Google Scholar
Suchetan, P. A., Gowda, B. T., Foro, S. & Fuess, H. (2010b). Acta Cryst. E66, o1253. Web of Science CSD CrossRef IUCr Journals Google Scholar
Suchetan, P. A., Gowda, B. T., Foro, S. & Fuess, H. (2010c). Acta Cryst. E66, o1501. Web of Science CSD CrossRef IUCr Journals Google Scholar

This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.