5-Amino-1,3,4-thia­diazol-2(3H)-one

Kang, S.K.; Cho, N.S.; Jang, S.

doi:10.1107/S1600536812012433

organic compounds

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ISSN: 2056-9890

Volume 68| Part 4| April 2012| Page o1198

doi:10.1107/S1600536812012433

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5-Amino-1,3,4-thiadiazol-2(3H)-one

Sung Kwon Kang,^a ^* Nam Sook Cho ^a and Siyoung Jang ^a

^aDepartment of Chemistry, Chungnam National University, Daejeon 305-764, Republic of Korea
^*Correspondence e-mail: skkang@cnu.ac.kr

(Received 21 March 2012; accepted 22 March 2012; online 28 March 2012)

The asymmetric unit of the title compound, C₂H₃N₃OS, contains three independent molecules which are essentially planar, with r.m.s. deviations of 0.011 (2)–0.027 (2) Å from the mean plane defined by the seven non-H atoms. In the crystal, N—H⋯N and N—H⋯O hydrogen bonds link the molecules into a sheet parallel to the (111) plane.

Related literature

For the structures and reactivity of thiadiazole derivatives, see: Parkanyi et al. (1989 ); Cho, Cho et al. (1996 ); Cho, Ra et al. (1996 ). For the biological activity of thiadiazole derivatives, see: Castro et al. (2008 ); Ra, Cho & Cho (1998 ); Ra, Cho, Moon & Kang (1998 ).

Experimental

Crystal data

C₂H₃N₃OS
M_r = 117.13
Triclinic, $[P \overline 1]$
a = 7.2860 (2) Å
b = 10.2982 (3) Å
c = 10.7727 (3) Å
α = 63.721 (3)°
β = 73.122 (2)°
γ = 76.737 (2)°
V = 688.74 (3) Å³
Z = 6
Mo Kα radiation
μ = 0.57 mm⁻¹
T = 296 K
0.15 × 0.1 × 0.05 mm

Data collection

Bruker SMART CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2002 ) T_min = 0.93, T_max = 0.97
23857 measured reflections
3433 independent reflections
2526 reflections with I > 2σ(I)
R_int = 0.055

Refinement

R[F² > 2σ(F²)] = 0.031
wR(F²) = 0.080
S = 0.94
3433 reflections
226 parameters
All H-atom parameters refined
Δρ_max = 0.30 e Å⁻³
Δρ_min = −0.26 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N3—H3⋯N18	0.854 (19)	2.004 (19)	2.8516 (19)	171.9 (18)
N7—H7A⋯O20ⁱ	0.87 (2)	2.07 (2)	2.907 (2)	160 (2)
N10—H10⋯N4	0.98 (2)	1.88 (2)	2.8558 (19)	175.7 (18)
N14—H14A⋯O6ⁱⁱ	0.83 (2)	2.10 (2)	2.897 (2)	162 (2)
N17—H17⋯N11	0.88 (2)	1.97 (2)	2.8424 (18)	179 (4)
N21—H21A⋯O13ⁱⁱⁱ	0.80 (3)	2.10 (3)	2.878 (2)	163 (2)
Symmetry codes: (i) x+1, y-1, z; (ii) x-1, y, z+1; (iii) x, y+1, z-1.

Data collection: SMART (Bruker, 2002); cell refinement: SAINT (Bruker, 2002); 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 ); software used to prepare material for publication: WinGX (Farrugia, 1999 ).

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536812012433/is5096sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536812012433/is5096Isup2.hkl

Supporting information file. DOI: 10.1107/S1600536812012433/is5096Isup3.cml

checkCIF report

Comment top

5-Amino-2H-1,2,4-thiadiazolin-3-one heterocycle is an analog of cytosine (Parkanyi et al., 1989). Derivatives of 5-amino-2H-1,2,4-thiadiazolin-3-one have recently attracted attention on the antibacterial activity, potential carcinogenicity, and kinase inhibitor activity (Castro et al., 2008; Cho, Ra et al., 1996; Ra, Cho, Moon & Kang, 1998). 5-Amino-3H-1,3,4-thiadiazolin-2-one is an isomer of 5-amino-2H-1,2,4-thiadiazolin-3-one, which has become an attractive moiety due to potential biological activities (Cho, Cho, Ra, Moon et al., 1996; Ra, Cho & Cho 1998).

In (I), three independent but similar molecules, which are linked by the intermolecular N—H···N hydrogen bonds (Fig. 1), comprise the asymmetric unit. The 1,3,4-thiadiazolin-2-one units are almost planar with r.m.s. deviations of 0.011 (2)–0.027 (2) Å from the corresponding least-squares plane defined by the seven constituent atoms. The bond distance of N4—C5 [1.291 (2) Å; N11—C12, 1.287 (2) Å; N18—C19, 1.282 (2) Å] is shorter than that of C2—N3 [1.333 (2) Å; C9—N10, 1.336 (2) Å; C16—N17, 1.327 Å], which is consistent with double bond character. The crystal structure is stabilized by the intermolecular N—H···N and N—H···O hydrogen bonds, which link the molecules into a two-dimensional sheet parallel to the (111) plane (Table 1 and Fig. 2).

Related literature top

For the structures and reactivity of thiadiazole derivatives, see: Parkanyi et al. (1989); Cho, Cho, Ra, Moon et al. (1996); Cho, Ra et al. (1996). For the biological activity of thiadiazole derivatives, see: Castro et al. (2008); Ra, Cho & Cho (1998); Ra, Cho, Moon & Kang (1998).

Experimental top

Synthesis of 5-amino-2-ethoxy-1,3,4-thiadiazole: Ethyl thiocarbazate (4.8 g, 0.04 mol) was dissolved in 24 ml of 2 N NaOH at 10 °C. Cyanogen bromide (4.2 g, 0.04 mol) dissolved in 20 ml of ethanol was added to the above solution keeping the temperature below 10 °C during 45 minutes. The solid product (4.1 g, 71%) was collected by filtration. To obtain the analytical sample the product was recrystallized from ethanol. m.p. 200–202 °C; IR (KBr, cm^-1) 3300 (NH), 3150 (NH), 3000 (CH), 2950 (CH), 1620 (C=O), 1580 (C=N); ¹H NMR (DMSO-d₆, p.p.m.) 6.65 (2H, b, NH₂), 4.25 (2H, q, CH₂), 1.29 (3H, t, CH₃); ¹³C NMR (DMSO-d₆, p.p.m.) 164.85 (C=N), 162.18 (C—O), 67.48 (CH₂), 14.35 (CH₃); Anal. Calcd. For C₄H₇N₃OS: C 33.09, H 4.86, N 28.94. Found: C 33.71, H 4.94, N 28.50.

Synthesis of title compound: 5-Amino-2-ethoxy-1,3,4-thiadiazole (5 g, 34.5 mmol) was dissolved in 50 ml of dioxane and 3.5 ml of c-HCl was added. The reaction mixture was refluxed for 4.5 h. The solvent was distilled off under reduced pressure. The residue product was washed with ether (3.7 g, 92.5%). To obtain the analytical sample the product was recrystallized from water. Recrystallization from DMSO afforded the colorless crystals suitable for X-ray diffraction. m.p. 176–178 °C; IR (KBr, cm^-1) 3450 (NH), 3150 (NH), 3100, 3000, 2900 (CH), 1700 (C=O), 1610, 1500 (C=N); ¹H NMR (DMSO-d₆, p.p.m.) 11.3 (1H, b, NH), 6.4 (2H, b, NH₂; ¹³C NMR (DMSO-d₆, p.p.m.) 169.4 (C=N), 153.0 (C=O); Anal. Calcd. For C₂H₃N₃OS: C 20.51, H 2.58, N 35.88, S 27.37. Found: C 20.19, H 2.65, N 34.28, S 27.22.

Structure description top

Computing details top

Data collection: SMART (Bruker, 2002); cell refinement: SAINT (Bruker, 2002); data reduction: SAINT (Bruker, 2002); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures top

	Fig. 1. Molecular structure of the title compound, showing the atom-numbering scheme and 30% probability ellipsoids. Intermolecular N—H···N hydrogen bonds are indicated by dashed lines.
	Fig. 2. Part of the crystal structure of the title compound, showing molecules linked by intermolecular N—H···N and N—H···O hydrogen bonds (dashed lines).

5-Amino-1,3,4-thiadiazol-2(3H)-one top

Crystal data top

C₂H₃N₃OS	Z = 6
M_r = 117.13	F(000) = 360
Triclinic, P1	D_x = 1.694 Mg m⁻³
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 7.2860 (2) Å	Cell parameters from 5437 reflections
b = 10.2982 (3) Å	θ = 2.2–26.1°
c = 10.7727 (3) Å	µ = 0.57 mm⁻¹
α = 63.721 (3)°	T = 296 K
β = 73.122 (2)°	Block, colourless
γ = 76.737 (2)°	0.15 × 0.1 × 0.05 mm
V = 688.74 (3) Å³

Data collection top

Bruker SMART CCD area-detector diffractometer	2526 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.055
φ and ω scans	θ_max = 28.3°, θ_min = 2.2°
Absorption correction: multi-scan (SADABS; Bruker, 2002)	h = −9→9
T_min = 0.93, T_max = 0.97	k = −13→13
23857 measured reflections	l = −14→14
3433 independent 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)] = 0.031	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.080	All H-atom parameters refined
S = 0.94	w = 1/[σ²(F_o²) + (0.0423P)²] where P = (F_o² + 2F_c²)/3
3433 reflections	(Δ/σ)_max < 0.001
226 parameters	Δρ_max = 0.30 e Å⁻³
0 restraints	Δρ_min = −0.26 e Å⁻³

Crystal data top

C₂H₃N₃OS	γ = 76.737 (2)°
M_r = 117.13	V = 688.74 (3) Å³
Triclinic, P1	Z = 6
a = 7.2860 (2) Å	Mo Kα radiation
b = 10.2982 (3) Å	µ = 0.57 mm⁻¹
c = 10.7727 (3) Å	T = 296 K
α = 63.721 (3)°	0.15 × 0.1 × 0.05 mm
β = 73.122 (2)°

Data collection top

Bruker SMART CCD area-detector diffractometer	3433 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 2002)	2526 reflections with I > 2σ(I)
T_min = 0.93, T_max = 0.97	R_int = 0.055
23857 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.031	0 restraints
wR(F²) = 0.080	All H-atom parameters refined
S = 0.94	Δρ_max = 0.30 e Å⁻³
3433 reflections	Δρ_min = −0.26 e Å⁻³
226 parameters

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
S1	0.86165 (6)	−0.07773 (5)	−0.06572 (4)	0.03647 (13)
C2	0.7587 (2)	0.10880 (18)	−0.13554 (16)	0.0339 (4)
N3	0.6466 (2)	0.13649 (15)	−0.02585 (14)	0.0329 (3)
H3	0.580 (3)	0.219 (2)	−0.0362 (19)	0.044 (5)*
N4	0.62764 (19)	0.02538 (14)	0.10886 (13)	0.0303 (3)
C5	0.7333 (2)	−0.09181 (17)	0.10313 (16)	0.0289 (3)
O6	0.7853 (2)	0.19397 (15)	−0.26078 (12)	0.0517 (4)
N7	0.7416 (3)	−0.21857 (17)	0.21825 (17)	0.0472 (4)
H7A	0.825 (3)	−0.291 (3)	0.210 (2)	0.072 (7)*
H7B	0.672 (3)	−0.224 (2)	0.297 (2)	0.052 (6)*
S8	0.15828 (7)	0.02436 (5)	0.59226 (4)	0.03889 (13)
C9	0.3260 (2)	−0.05097 (18)	0.47618 (16)	0.0338 (4)
N10	0.3484 (2)	0.05559 (15)	0.34594 (14)	0.0353 (3)
H10	0.439 (3)	0.047 (2)	0.262 (2)	0.065 (6)*
N11	0.2481 (2)	0.19183 (14)	0.32756 (13)	0.0354 (3)
C12	0.1437 (2)	0.19073 (18)	0.44702 (16)	0.0348 (4)
O13	0.40594 (19)	−0.17651 (13)	0.51031 (13)	0.0485 (3)
N14	0.0375 (3)	0.3114 (2)	0.4619 (2)	0.0592 (5)
H14A	−0.048 (3)	0.297 (2)	0.536 (3)	0.070 (7)*
H14B	0.019 (3)	0.387 (2)	0.386 (2)	0.050 (6)*
S15	0.23799 (7)	0.66689 (5)	−0.15169 (5)	0.04302 (14)
C16	0.1723 (2)	0.55543 (18)	0.03347 (17)	0.0363 (4)
N17	0.2688 (2)	0.42407 (15)	0.05437 (15)	0.0353 (3)
H17	0.262 (3)	0.352 (2)	0.138 (2)	0.053 (6)*
N18	0.3933 (2)	0.40035 (14)	−0.06009 (13)	0.0354 (3)
C19	0.3895 (2)	0.51734 (17)	−0.17336 (17)	0.0356 (4)
O20	0.0594 (2)	0.59341 (14)	0.12439 (14)	0.0537 (4)
N21	0.4930 (3)	0.5249 (2)	−0.30232 (18)	0.0651 (6)
H21A	0.492 (4)	0.606 (3)	−0.363 (3)	0.081 (8)*
H21B	0.566 (3)	0.455 (3)	−0.304 (2)	0.071 (8)*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
S1	0.0365 (2)	0.0374 (2)	0.0315 (2)	0.00386 (18)	0.00096 (17)	−0.01947 (18)
C2	0.0319 (9)	0.0371 (9)	0.0289 (8)	−0.0040 (7)	−0.0003 (7)	−0.0139 (7)
N3	0.0386 (8)	0.0250 (7)	0.0254 (6)	0.0032 (6)	−0.0008 (6)	−0.0089 (6)
N4	0.0345 (7)	0.0262 (7)	0.0233 (6)	0.0000 (6)	−0.0004 (5)	−0.0091 (5)
C5	0.0290 (8)	0.0292 (8)	0.0274 (7)	−0.0007 (7)	−0.0024 (6)	−0.0139 (7)
O6	0.0631 (9)	0.0485 (8)	0.0246 (6)	−0.0049 (7)	0.0027 (6)	−0.0064 (6)
N7	0.0625 (12)	0.0306 (9)	0.0324 (8)	0.0104 (8)	−0.0046 (8)	−0.0096 (7)
S8	0.0458 (3)	0.0368 (2)	0.02102 (19)	−0.00454 (19)	0.00086 (17)	−0.00531 (17)
C9	0.0375 (9)	0.0317 (9)	0.0270 (8)	−0.0028 (7)	−0.0059 (7)	−0.0084 (7)
N10	0.0412 (8)	0.0293 (7)	0.0241 (6)	0.0039 (6)	−0.0013 (6)	−0.0080 (6)
N11	0.0412 (8)	0.0276 (7)	0.0224 (6)	0.0029 (6)	0.0011 (6)	−0.0052 (6)
C12	0.0366 (9)	0.0310 (9)	0.0261 (8)	−0.0022 (7)	0.0009 (7)	−0.0078 (7)
O13	0.0601 (9)	0.0290 (7)	0.0423 (7)	0.0049 (6)	−0.0128 (6)	−0.0056 (6)
N14	0.0692 (13)	0.0386 (10)	0.0393 (10)	0.0088 (9)	0.0126 (9)	−0.0111 (8)
S15	0.0533 (3)	0.0232 (2)	0.0365 (2)	0.00734 (19)	−0.0052 (2)	−0.00628 (18)
C16	0.0386 (10)	0.0298 (9)	0.0342 (9)	0.0008 (7)	−0.0040 (7)	−0.0121 (7)
N17	0.0417 (9)	0.0258 (7)	0.0255 (7)	0.0029 (6)	−0.0009 (6)	−0.0061 (6)
N18	0.0423 (8)	0.0241 (7)	0.0267 (7)	0.0036 (6)	0.0006 (6)	−0.0074 (6)
C19	0.0428 (10)	0.0240 (8)	0.0305 (8)	0.0000 (7)	−0.0020 (7)	−0.0083 (7)
O20	0.0561 (9)	0.0453 (8)	0.0474 (7)	0.0072 (6)	0.0046 (6)	−0.0238 (6)
N21	0.0938 (16)	0.0328 (10)	0.0314 (9)	0.0067 (10)	0.0134 (9)	−0.0036 (8)

Geometric parameters (Å, º) top

S1—C5	1.7449 (15)	N10—H10	0.98 (2)
S1—C2	1.7905 (17)	N11—C12	1.2874 (19)
C2—O6	1.2270 (19)	C12—N14	1.354 (2)
C2—N3	1.333 (2)	N14—H14A	0.83 (2)
N3—N4	1.3857 (18)	N14—H14B	0.86 (2)
N3—H3	0.854 (19)	S15—C19	1.7419 (17)
N4—C5	1.2905 (19)	S15—C16	1.7876 (17)
C5—N7	1.349 (2)	C16—O20	1.2298 (19)
N7—H7A	0.87 (2)	C16—N17	1.327 (2)
N7—H7B	0.84 (2)	N17—N18	1.3853 (18)
S8—C12	1.7419 (16)	N17—H17	0.88 (2)
S8—C9	1.7874 (17)	N18—C19	1.2821 (19)
C9—O13	1.2264 (19)	C19—N21	1.352 (2)
C9—N10	1.336 (2)	N21—H21A	0.80 (3)
N10—N11	1.3817 (18)	N21—H21B	0.79 (2)

C5—S1—C2	88.70 (7)	C12—N11—N10	110.16 (13)
O6—C2—N3	126.79 (16)	N11—C12—N14	123.00 (15)
O6—C2—S1	126.30 (13)	N11—C12—S8	115.37 (12)
N3—C2—S1	106.90 (12)	N14—C12—S8	121.53 (13)
C2—N3—N4	119.16 (14)	C12—N14—H14A	116.1 (16)
C2—N3—H3	122.2 (13)	C12—N14—H14B	117.8 (13)
N4—N3—H3	118.5 (13)	H14A—N14—H14B	118 (2)
C5—N4—N3	109.74 (12)	C19—S15—C16	88.49 (8)
N4—C5—N7	122.96 (15)	O20—C16—N17	126.47 (16)
N4—C5—S1	115.48 (12)	O20—C16—S15	126.48 (13)
N7—C5—S1	121.54 (12)	N17—C16—S15	107.05 (12)
C5—N7—H7A	118.8 (15)	C16—N17—N18	119.02 (14)
C5—N7—H7B	119.4 (14)	C16—N17—H17	122.9 (13)
H7A—N7—H7B	122 (2)	N18—N17—H17	118.0 (13)
C12—S8—C9	88.73 (7)	C19—N18—N17	109.75 (13)
O13—C9—N10	126.70 (16)	N18—C19—N21	122.74 (16)
O13—C9—S8	126.29 (13)	N18—C19—S15	115.68 (12)
N10—C9—S8	107.01 (12)	N21—C19—S15	121.57 (13)
C9—N10—N11	118.72 (13)	C19—N21—H21A	113.9 (17)
C9—N10—H10	125.0 (12)	C19—N21—H21B	116.2 (17)
N11—N10—H10	116.1 (12)	H21A—N21—H21B	128 (2)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N3—H3···N18	0.854 (19)	2.004 (19)	2.8516 (19)	171.9 (18)
N7—H7A···O20ⁱ	0.87 (2)	2.07 (2)	2.907 (2)	160 (2)
N10—H10···N4	0.98 (2)	1.88 (2)	2.8558 (19)	175.7 (18)
N14—H14A···O6ⁱⁱ	0.83 (2)	2.10 (2)	2.897 (2)	162 (2)
N17—H17···N11	0.88 (2)	1.97 (2)	2.8424 (18)	179 (4)
N21—H21A···O13ⁱⁱⁱ	0.80 (3)	2.10 (3)	2.878 (2)	163 (2)

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

Experimental details

Crystal data
Chemical formula	C₂H₃N₃OS
M_r	117.13
Crystal system, space group	Triclinic, P1
Temperature (K)	296
a, b, c (Å)	7.2860 (2), 10.2982 (3), 10.7727 (3)
α, β, γ (°)	63.721 (3), 73.122 (2), 76.737 (2)
V (Å³)	688.74 (3)
Z	6
Radiation type	Mo Kα
µ (mm⁻¹)	0.57
Crystal size (mm)	0.15 × 0.1 × 0.05

Data collection
Diffractometer	Bruker SMART CCD area-detector
Absorption correction	Multi-scan (SADABS; Bruker, 2002)
T_min, T_max	0.93, 0.97
No. of measured, independent and observed [I > 2σ(I)] reflections	23857, 3433, 2526
R_int	0.055
(sin θ/λ)_max (Å⁻¹)	0.668

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.031, 0.080, 0.94
No. of reflections	3433
No. of parameters	226
H-atom treatment	All H-atom parameters refined
Δρ_max, Δρ_min (e Å⁻³)	0.30, −0.26

Computer programs: SMART (Bruker, 2002), SAINT (Bruker, 2002), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 (Farrugia, 1997), WinGX (Farrugia, 1999).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N3—H3···N18	0.854 (19)	2.004 (19)	2.8516 (19)	171.9 (18)
N7—H7A···O20ⁱ	0.87 (2)	2.07 (2)	2.907 (2)	160 (2)
N10—H10···N4	0.98 (2)	1.88 (2)	2.8558 (19)	175.7 (18)
N14—H14A···O6ⁱⁱ	0.83 (2)	2.10 (2)	2.897 (2)	162 (2)
N17—H17···N11	0.88 (2)	1.97 (2)	2.8424 (18)	179 (4)
N21—H21A···O13ⁱⁱⁱ	0.80 (3)	2.10 (3)	2.878 (2)	163 (2)

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

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Volume 68| Part 4| April 2012| Page o1198

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