N-(4-Methyl­phenyl­sulfon­yl)maleamic acid

Purandara, H.; Foro, S.; Gowda, B.T.

doi:10.1107/S1600536812032084

organic compounds

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ISSN: 2056-9890

Volume 68| Part 8| August 2012| Page o2499

https://doi.org/10.1107/S1600536812032084

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N-(4-Methylphenylsulfonyl)maleamic acid

H. Purandara,^a Sabine Foro ^b and B. Thimme Gowda ^a ^*

^aDepartment of Chemistry, Mangalore University, Mangalagangotri 574 199, Mangalore, India, and ^bInstitute of Materials Science, Darmstadt University of Technology, Petersenstrasse 23, D-64287 Darmstadt, Germany
^*Correspondence e-mail: gowdabt@yahoo.com

(Received 7 July 2012; accepted 14 July 2012; online 18 July 2012)

In the title compound, C₁₁H₁₁NO₅S, the dihedral angle between the benzene ring and the amide group is 76.88 (6)°. In the crystal, N—H⋯O(S) and O—H⋯O hydrogen bonds connect the molecules into hydrogen-bonded layers perpendicular to the a axis.

Related literature

For studies on the effects of substituents on the structures and other aspects of N-(aryl)-amides, see: Gowda et al. (2001 ); Shahwar et al. (2012 ), of N-(arylsulfonyl)-succinamic acids, see: Purandara et al. (2012 ), of N-(aryl)-methanesulfonamides, see: Gowda et al. (2007 ) and of N-chloroarylsulfonamides, see: Gowda & Ramachandra (1989 ); Shetty & Gowda (2004 ).

Experimental

Crystal data

C₁₁H₁₁NO₅S
M_r = 269.27
Monoclinic, P 2₁ /c
a = 10.2652 (6) Å
b = 11.9064 (7) Å
c = 10.2416 (6) Å
β = 108.403 (7)°
V = 1187.73 (12) Å³
Z = 4
Mo Kα radiation
μ = 0.29 mm⁻¹
T = 293 K
0.44 × 0.42 × 0.40 mm

Data collection

Oxford Diffraction Xcalibur diffractometer with a Sapphire CCD detector
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2009 $[Oxford Diffraction (2009). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Yarnton, England.]$ ) T_min = 0.885, T_max = 0.894
4608 measured reflections
2424 independent reflections
2144 reflections with I > 2σ(I)
R_int = 0.010

Refinement

R[F² > 2σ(F²)] = 0.031
wR(F²) = 0.086
S = 1.07
2424 reflections
171 parameters
1 restraint
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.36 e Å⁻³
Δρ_min = −0.29 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1N⋯O2ⁱ	0.81 (1)	2.17 (1)	2.9786 (16)	176 (2)
O5—H5O⋯O4ⁱⁱ	0.91 (2)	1.75 (2)	2.6589 (16)	176 (2)
Symmetry codes: (i) $[x, -y+{\script{3\over 2}}, z+{\script{1\over 2}}]$ ; (ii) -x+1, -y+2, -z+1.

Data collection: CrysAlis CCD (Oxford Diffraction, 2009 $[Oxford Diffraction (2009). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Yarnton, England.]$ ); cell refinement: CrysAlis CCD; data reduction: CrysAlis RED (Oxford Diffraction, 2009 $[Oxford Diffraction (2009). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Yarnton, England.]$ ); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: PLATON (Spek, 2009 ); software used to prepare material for publication: SHELXL97.

Supporting information

Crystal structure: contains datablocks I, global. DOI: https://doi.org/10.1107/S1600536812032084/zl2493sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536812032084/zl2493Isup2.hkl

Supporting information file. DOI: https://doi.org/10.1107/S1600536812032084/zl2493Isup3.cml

checkCIF report

Comment top

As part of studies on the substituent effects on the structures and other aspects of N-(aryl)-amides (Gowda et al., 2001; Shahwar et al., 2012); N-(arylsulfonyl)-succinamic acids (Purandara et al., 2012); N-(aryl)-methanesulfonamides (Gowda et al., 2007) and N-chloroarylsulfonamides (Gowda & Ramachandra, 1989; Shetty & Gowda, 2004), in the present work, the crystal structure of N-(4-methylphenylsulfonyl)maleamic acid has been determined (Fig. 1).

The conformations of the N—H and C═O bonds in the amide segment are anti to each other and the amide C═O is syn to the adjacent C–H bond. Further, the amide C═O and the carboxyl C═O of the acid segment orient themselves almost perpendicular to each other, in contrast to the almost anti conformation observed between the amide C═O and the carboxyl C═O in N-(4-methylphenylsulfonyl)-succinamic acid (Purandara et al., 2012). In the title compound, the C–H bonds on the –CH═ CH-group, adjacent to both the C═bonds, are syn to each other.

In the title compound, the C═O and O–H bonds of the acid group are in syn position to each other, similar to that observed in N-(4-methylphenylsulfonyl)-succinamic acid.

The molecule is bent at the S-atom with an C1–S1–N1–C7 torsion angle of 64.99 (13)°. Further, the dihedral angle between the phenyl ring and the amide group is 76.88 (6)°.

In the crystal, the intermolecular O—H···O and N—H···O(S) hydrogen bonds link the molecules into dimers and chains, respectively. The chains and dimers, in combination, form H-bonded layers perpendicular to the a-axis (Fig.2).

Related literature top

For studies on the effects of substituents on the structures and other aspects of N-(aryl)-amides, see: Gowda et al. (2001); Shahwar et al. (2012), of N-(arylsulfonyl)-succinamic acids, see: Purandara et al. (2012), of N-(aryl)-methanesulfonamides, see: Gowda et al. (2007) and of N-chloroarylsulfonamides, see: Gowda & Ramachandra (1989); Shetty & Gowda (2004).

Experimental top

Maleic anhydride (0.015 mole) and triethylamine (0.01 mole) were added to a solution of p-toluenesulfonamide (0.01 mole) in dichloromethane. The reaction mixture was strirred for 18 h at room temperature and set aside for completion of the reaction. The reaction mixture was concentrated to dryness. The resultant title compound was washed with dilute HCl and then with water thoroughly, to remove the unreacted base and the maleic anhydride. It was recrystallized to constant melting point from ethyl acetate (144°C). The purity of the compound was checked and characterized by its IR spectrum. The characteristic absorptions observed are 3222.8 cm^-1, 1700.7 cm^-1, 1338.7 cm^-1, 1257.4 cm^-1, 1135.5 cm^-1 and 851.3 cm^-1 for the stretching bands of N–H, C═O, S═O asymmetric, C–N, S═O symmetric and C–S, respectively.

Prism like colorless single crystals used in the X-ray diffraction study were grown from ethyl acetate solution by slow evaporation of the solvent.

Structure description top

In the title compound, the C═O and O–H bonds of the acid group are in syn position to each other, similar to that observed in N-(4-methylphenylsulfonyl)-succinamic acid.

The molecule is bent at the S-atom with an C1–S1–N1–C7 torsion angle of 64.99 (13)°. Further, the dihedral angle between the phenyl ring and the amide group is 76.88 (6)°.

For studies on the effects of substituents on the structures and other aspects of N-(aryl)-amides, see: Gowda et al. (2001); Shahwar et al. (2012), of N-(arylsulfonyl)-succinamic acids, see: Purandara et al. (2012), of N-(aryl)-methanesulfonamides, see: Gowda et al. (2007) and of N-chloroarylsulfonamides, see: Gowda & Ramachandra (1989); Shetty & Gowda (2004).

Computing details top

Data collection: CrysAlis CCD (Oxford Diffraction, 2009); cell refinement: CrysAlis CCD (Oxford Diffraction, 2009); data reduction: CrysAlis RED (Oxford Diffraction, 2009); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: PLATON (Spek, 2009); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top

	Fig. 1. Molecular structure of the title compound, showing the atom labelling scheme with the displacement ellipsoids drawn at the 50% probability level.
	Fig. 2. Molecular packing of the title compound with hydrogen bonding shown as dashed lines.

N-(4-Methylphenylsulfonyl)maleamic acid top

Crystal data top

C₁₁H₁₁NO₅S	F(000) = 560
M_r = 269.27	D_x = 1.506 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 2735 reflections
a = 10.2652 (6) Å	θ = 3.0–27.8°
b = 11.9064 (7) Å	µ = 0.28 mm⁻¹
c = 10.2416 (6) Å	T = 293 K
β = 108.403 (7)°	Prism, colourless
V = 1187.73 (12) Å³	0.44 × 0.42 × 0.40 mm
Z = 4

Data collection top

Oxford Diffraction Xcalibur diffractometer with a Sapphire CCD detector	2424 independent reflections
Radiation source: fine-focus sealed tube	2144 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.010
Rotation method data acquisition using ω and phi scans	θ_max = 26.4°, θ_min = 3.0°
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2009)	h = −12→12
T_min = 0.885, T_max = 0.894	k = −6→14
4608 measured reflections	l = −12→12

Refinement top

Refinement on F²	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F² > 2σ(F²)] = 0.031	H atoms treated by a mixture of independent and constrained refinement
wR(F²) = 0.086	w = 1/[σ²(F_o²) + (0.0449P)² + 0.3604P] where P = (F_o² + 2F_c²)/3
S = 1.07	(Δ/σ)_max = 0.001
2424 reflections	Δρ_max = 0.36 e Å⁻³
171 parameters	Δρ_min = −0.29 e Å⁻³
1 restraint	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.029 (2)

Crystal data top

C₁₁H₁₁NO₅S	V = 1187.73 (12) Å³
M_r = 269.27	Z = 4
Monoclinic, P2₁/c	Mo Kα radiation
a = 10.2652 (6) Å	µ = 0.28 mm⁻¹
b = 11.9064 (7) Å	T = 293 K
c = 10.2416 (6) Å	0.44 × 0.42 × 0.40 mm
β = 108.403 (7)°

Data collection top

Oxford Diffraction Xcalibur diffractometer with a Sapphire CCD detector	2424 independent reflections
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2009)	2144 reflections with I > 2σ(I)
T_min = 0.885, T_max = 0.894	R_int = 0.010
4608 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.031	1 restraint
wR(F²) = 0.086	H atoms treated by a mixture of independent and constrained refinement
S = 1.07	Δρ_max = 0.36 e Å⁻³
2424 reflections	Δρ_min = −0.29 e Å⁻³
171 parameters

Special details top

Experimental. CrysAlis RED (Oxford Diffraction, 2009) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'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 > 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
C1	0.36379 (14)	0.75860 (12)	0.11249 (15)	0.0323 (3)
C2	0.45226 (16)	0.69418 (14)	0.21423 (16)	0.0408 (4)
H2	0.4187	0.6370	0.2566	0.049*
C3	0.59187 (17)	0.71591 (16)	0.25246 (17)	0.0463 (4)
H3	0.6519	0.6731	0.3216	0.056*
C4	0.64338 (16)	0.79985 (14)	0.18983 (18)	0.0431 (4)
C5	0.55266 (18)	0.86083 (15)	0.0852 (2)	0.0482 (4)
H5	0.5865	0.9161	0.0404	0.058*
C6	0.41309 (17)	0.84149 (14)	0.04582 (18)	0.0432 (4)
H6	0.3532	0.8835	−0.0243	0.052*
C7	0.13459 (13)	0.94544 (13)	0.14452 (14)	0.0315 (3)
C8	0.08229 (14)	1.00963 (12)	0.24353 (15)	0.0339 (3)
H8	−0.0104	1.0285	0.2148	0.041*
C9	0.15667 (15)	1.04155 (13)	0.36794 (15)	0.0364 (3)
H9	0.1136	1.0807	0.4214	0.044*
C10	0.30479 (15)	1.01820 (13)	0.42652 (14)	0.0343 (3)
C11	0.79430 (18)	0.8267 (2)	0.2343 (3)	0.0666 (6)
H11A	0.8436	0.7723	0.3007	0.100*
H11B	0.8093	0.9002	0.2746	0.100*
H11C	0.8263	0.8246	0.1558	0.100*
N1	0.13089 (12)	0.83006 (11)	0.15952 (12)	0.0317 (3)
H1N	0.1246 (18)	0.8042 (14)	0.2308 (15)	0.038*
O1	0.16042 (12)	0.63163 (9)	0.12040 (14)	0.0492 (3)
O2	0.12374 (12)	0.76432 (11)	−0.07348 (11)	0.0468 (3)
O3	0.16830 (11)	0.99099 (10)	0.05504 (11)	0.0421 (3)
O4	0.36494 (11)	0.95387 (10)	0.37140 (11)	0.0442 (3)
O5	0.36415 (12)	1.07342 (11)	0.53916 (12)	0.0492 (3)
H5O	0.456 (3)	1.060 (2)	0.571 (2)	0.074*
S1	0.18624 (3)	0.73748 (3)	0.06857 (4)	0.03364 (14)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
C1	0.0310 (7)	0.0372 (8)	0.0306 (7)	−0.0021 (6)	0.0125 (6)	−0.0062 (6)
C2	0.0415 (8)	0.0442 (9)	0.0368 (8)	−0.0014 (7)	0.0126 (7)	0.0031 (7)
C3	0.0383 (8)	0.0549 (10)	0.0409 (9)	0.0062 (7)	0.0059 (7)	−0.0004 (7)
C4	0.0326 (8)	0.0456 (9)	0.0534 (10)	−0.0019 (7)	0.0168 (7)	−0.0155 (7)
C5	0.0415 (9)	0.0447 (9)	0.0656 (12)	−0.0033 (7)	0.0268 (8)	0.0035 (8)
C6	0.0381 (8)	0.0457 (9)	0.0482 (9)	0.0026 (7)	0.0170 (7)	0.0088 (7)
C7	0.0237 (6)	0.0401 (8)	0.0265 (7)	−0.0002 (5)	0.0020 (5)	−0.0001 (6)
C8	0.0276 (7)	0.0355 (7)	0.0374 (8)	0.0039 (6)	0.0082 (6)	0.0001 (6)
C9	0.0358 (7)	0.0366 (8)	0.0370 (8)	0.0045 (6)	0.0119 (6)	−0.0049 (6)
C10	0.0355 (7)	0.0351 (7)	0.0297 (7)	−0.0005 (6)	0.0064 (6)	−0.0034 (6)
C11	0.0335 (9)	0.0736 (14)	0.0916 (16)	−0.0064 (9)	0.0183 (10)	−0.0190 (12)
N1	0.0323 (6)	0.0375 (7)	0.0272 (6)	−0.0026 (5)	0.0121 (5)	−0.0023 (5)
O1	0.0494 (7)	0.0371 (6)	0.0666 (8)	−0.0124 (5)	0.0261 (6)	−0.0097 (5)
O2	0.0399 (6)	0.0664 (8)	0.0305 (6)	−0.0013 (5)	0.0060 (5)	−0.0148 (5)
O3	0.0444 (6)	0.0467 (7)	0.0363 (6)	0.0003 (5)	0.0143 (5)	0.0070 (5)
O4	0.0350 (6)	0.0494 (7)	0.0419 (6)	0.0057 (5)	0.0032 (5)	−0.0146 (5)
O5	0.0400 (6)	0.0629 (8)	0.0386 (6)	−0.0005 (6)	0.0037 (5)	−0.0203 (5)
S1	0.0305 (2)	0.0382 (2)	0.0325 (2)	−0.00642 (14)	0.01037 (15)	−0.00955 (14)

Geometric parameters (Å, º) top

C1—C2	1.379 (2)	C8—C9	1.318 (2)
C1—C6	1.384 (2)	C8—H8	0.9300
C1—S1	1.7520 (14)	C9—C10	1.474 (2)
C2—C3	1.386 (2)	C9—H9	0.9300
C2—H2	0.9300	C10—O4	1.2274 (18)
C3—C4	1.380 (2)	C10—O5	1.3002 (17)
C3—H3	0.9300	C11—H11A	0.9600
C4—C5	1.383 (3)	C11—H11B	0.9600
C4—C11	1.505 (2)	C11—H11C	0.9600
C5—C6	1.380 (2)	N1—S1	1.6551 (12)
C5—H5	0.9300	N1—H1N	0.813 (13)
C6—H6	0.9300	O1—S1	1.4246 (12)
C7—O3	1.2059 (17)	O2—S1	1.4286 (12)
C7—N1	1.384 (2)	O5—H5O	0.91 (2)
C7—C8	1.498 (2)

C2—C1—C6	120.89 (14)	C7—C8—H8	117.3
C2—C1—S1	119.85 (12)	C8—C9—C10	123.19 (13)
C6—C1—S1	119.24 (12)	C8—C9—H9	118.4
C1—C2—C3	119.04 (15)	C10—C9—H9	118.4
C1—C2—H2	120.5	O4—C10—O5	124.10 (13)
C3—C2—H2	120.5	O4—C10—C9	122.31 (13)
C4—C3—C2	121.19 (15)	O5—C10—C9	113.58 (13)
C4—C3—H3	119.4	C4—C11—H11A	109.5
C2—C3—H3	119.4	C4—C11—H11B	109.5
C3—C4—C5	118.52 (14)	H11A—C11—H11B	109.5
C3—C4—C11	121.47 (17)	C4—C11—H11C	109.5
C5—C4—C11	120.01 (17)	H11A—C11—H11C	109.5
C6—C5—C4	121.46 (16)	H11B—C11—H11C	109.5
C6—C5—H5	119.3	C7—N1—S1	124.90 (10)
C4—C5—H5	119.3	C7—N1—H1N	119.2 (13)
C5—C6—C1	118.86 (15)	S1—N1—H1N	113.1 (13)
C5—C6—H6	120.6	C10—O5—H5O	111.8 (15)
C1—C6—H6	120.6	O1—S1—O2	120.05 (7)
O3—C7—N1	123.73 (14)	O1—S1—N1	104.01 (7)
O3—C7—C8	122.35 (14)	O2—S1—N1	107.49 (7)
N1—C7—C8	113.76 (12)	O1—S1—C1	109.40 (7)
C9—C8—C7	125.42 (13)	O2—S1—C1	109.01 (7)
C9—C8—H8	117.3	N1—S1—C1	105.91 (6)

C6—C1—C2—C3	2.1 (2)	C8—C9—C10—O4	−10.6 (3)
S1—C1—C2—C3	−176.73 (12)	C8—C9—C10—O5	168.24 (15)
C1—C2—C3—C4	−0.5 (3)	O3—C7—N1—S1	6.5 (2)
C2—C3—C4—C5	−1.4 (3)	C8—C7—N1—S1	−177.98 (9)
C2—C3—C4—C11	177.78 (16)	C7—N1—S1—O1	−179.73 (12)
C3—C4—C5—C6	1.9 (3)	C7—N1—S1—O2	−51.43 (13)
C11—C4—C5—C6	−177.29 (17)	C7—N1—S1—C1	64.99 (13)
C4—C5—C6—C1	−0.4 (3)	C2—C1—S1—O1	−16.74 (14)
C2—C1—C6—C5	−1.6 (2)	C6—C1—S1—O1	164.41 (12)
S1—C1—C6—C5	177.22 (13)	C2—C1—S1—O2	−149.80 (12)
O3—C7—C8—C9	−96.45 (19)	C6—C1—S1—O2	31.35 (14)
N1—C7—C8—C9	87.94 (18)	C2—C1—S1—N1	94.81 (13)
C7—C8—C9—C10	0.5 (3)	C6—C1—S1—N1	−84.04 (13)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1N···O2ⁱ	0.81 (1)	2.17 (1)	2.9786 (16)	176 (2)
O5—H5O···O4ⁱⁱ	0.91 (2)	1.75 (2)	2.6589 (16)	176 (2)

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

Experimental details

Crystal data
Chemical formula	C₁₁H₁₁NO₅S
M_r	269.27
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	293
a, b, c (Å)	10.2652 (6), 11.9064 (7), 10.2416 (6)
β (°)	108.403 (7)
V (Å³)	1187.73 (12)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.28
Crystal size (mm)	0.44 × 0.42 × 0.40

Data collection
Diffractometer	Oxford Diffraction Xcalibur diffractometer with a Sapphire CCD detector
Absorption correction	Multi-scan (CrysAlis RED; Oxford Diffraction, 2009)
T_min, T_max	0.885, 0.894
No. of measured, independent and observed [I > 2σ(I)] reflections	4608, 2424, 2144
R_int	0.010
(sin θ/λ)_max (Å⁻¹)	0.625

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.031, 0.086, 1.07
No. of reflections	2424
No. of parameters	171
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)	0.36, −0.29

Computer programs: CrysAlis CCD (Oxford Diffraction, 2009), CrysAlis RED (Oxford Diffraction, 2009), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), PLATON (Spek, 2009).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1N···O2ⁱ	0.813 (13)	2.167 (14)	2.9786 (16)	175.9 (17)
O5—H5O···O4ⁱⁱ	0.91 (2)	1.75 (2)	2.6589 (16)	176 (2)

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

Acknowledgements

HP thanks the Department of Science and Technology, Government of India, New Delhi, for a research fellowship under its INSPIRE Program. BTG thanks the University Grants Commission, Government of India, New Delhi, for a special grant under the UGC–BSR one-time grant to faculty.

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