3-(2,4-Di-chloro-phen-oxy)-1-(4-meth-oxy-benz-yl)-4-(4-nitro-phen-yl)azetidin-2-one.

The β-lactam ring of the title compound, C23H18Cl2N2O5, is nearly planar [maximum deviation = 0.019 (2) Å for the N atom] and its mean plane makes dihedral angles of 56.86 (15), 68.83 (15) and 83.75 (15)° with the di-chloro-, nitro- and meth-oxy-substituted benzene rings, respectively. In the crystal, mol-ecules are linked by pairs of C-H⋯O hydrogen bonds, forming inversion dimers with R 2 (2)(10) loops. The dimers are linked by further C-H⋯O hydrogen bonds, forming sheets lying parallel to (001). The mol-ecular packing is further stabilized by C-H⋯π inter-actions.

Related literature

For general background to β-lactams, see: Schunk & Enders (2000 ▶); France et al. (2004 ▶); Pitts & Lectka (2014 ▶); Arya et al. (2014 ▶); Banik et al. (2003 ▶); Delpiccolo et al. (2003 ▶); Hodous & Fu (2002 ▶). For the crystal structures of some β-lactams, see: Akkurt et al. (2011 ▶); Butcher et al. (2011 ▶).

Experimental

Crystal data

C23H18Cl2N2O5

M = 473.29

Monoclinic,

a = 5.0716 (5) Å

b = 20.9390 (12) Å

c = 20.1516 (18) Å

β = 96.457 (7)°

V = 2126.4 (3) Å3

Z = 4

Mo Kα radiation

μ = 0.35 mm−1

T = 296 K

0.59 × 0.28 × 0.06 mm

Data collection

Stoe IPDS 2 diffractometer

Absorption correction: integration (X-RED32; Stoe & Cie, 2002 ▶) T min = 0.901, T max = 0.972

15060 measured reflections

4179 independent reflections

2123 reflections with I > 2σ(I)

R int = 0.062

Refinement

R[F 2 > 2σ(F 2)] = 0.042

wR(F 2) = 0.061

S = 0.85

4179 reflections

289 parameters

H-atom parameters constrained

Δρmax = 0.16 e Å−3

Δρmin = −0.19 e Å−3

Data collection: X-AREA (Stoe & Cie, 2002 ▶); cell refinement: X-AREA; data reduction: X-RED32 (Stoe & Cie, 2002 ▶); program(s) used to solve structure: SHELXS2013 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL2013 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012 ▶); software used to prepare material for publication: WinGX (Farrugia, 2012 ▶).

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536814015013/su2747sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536814015013/su2747Isup2.hkl

Click here for additional data file.

Supporting information file. DOI: 10.1107/S1600536814015013/su2747Isup3.cml

CCDC reference: 1010327

Additional supporting information: crystallographic information; 3D view; checkCIF report

C23H18Cl2N2O5	F(000) = 976
Mr = 473.29	Dx = 1.478 Mg m−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 10788 reflections
a = 5.0716 (5) Å	θ = 1.4–28.4°
b = 20.9390 (12) Å	µ = 0.35 mm−1
c = 20.1516 (18) Å	T = 296 K
β = 96.457 (7)°	Prism, pale yellow
V = 2126.4 (3) Å3	0.59 × 0.28 × 0.06 mm
Z = 4

Stoe IPDS 2 diffractometer	4179 independent reflections
Radiation source: sealed X-ray tube, 12 x 0.4 mm long-fine focus	2123 reflections with I > 2σ(I)
Plane graphite monochromator	Rint = 0.062
Detector resolution: 6.67 pixels mm-1	θmax = 26.0°, θmin = 1.4°
ω scans	h = −6→6
Absorption correction: integration (X-RED32; Stoe & Cie, 2002)	k = −25→25
Tmin = 0.901, Tmax = 0.972	l = −24→24
15060 measured reflections

Refinement on F2	0 restraints
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.042	H-atom parameters constrained
wR(F2) = 0.061	w = 1/[σ2(Fo2) + (0.0162P)2] where P = (Fo2 + 2Fc2)/3
S = 0.85	(Δ/σ)max < 0.001
4179 reflections	Δρmax = 0.16 e Å−3
289 parameters	Δρmin = −0.19 e Å−3

Experimental. Spectroscopic data for the title compound:IR (KBr, cm-1): 1758 (CO β-lactam), 1352, 1520 (NO2). 1H-NMR (CDCl3) δ (p.p.m.): 3.78 (OMe, s, 3H), 3.94 (CH2, d, J =14.6 Hz, 1H), 4.78 (CH2, d, J = 14.6 Hz, 1H), 4.85 (H-4, d, J = 4.8 Hz, 1H), 5.38 (H-3, d, J = 4.8 Hz, 1H), 6.80 (ArH, d, J = 8.7 Hz, 2H), 7.00 (ArH, d, J = 8.8 Hz, 1H), 7.03 (ArH, d, J = 8.7 Hz, 2H), 7.08 (ArH, d, J = 8.8 Hz, 1H), 7.19 (ArH, s, 1H), 7.45 (ArH, d, J = 8.8 Hz, 2H), 8.17 (ArH, d, J = 8.8 Hz, 2H). 13C-NMR (CDCl3) δ (p.p.m.): 44.4 (CH2), 55.3 (OMe) 59.8 (C-4), 82.5 (C-3), 114.3, 116.2, 123.4, 123.8, 125.8, 127.5, 127.7, 129.4, 130.0, 130.1, 140.3, 148.1, 151.1, 159.5 (aromatic carbon), 164.36 (CO β-lactam). MS m/z = 472 [M+].

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 on F2 for ALL reflections except those flagged by the user for potential systematic errors. Weighted R-factors wR and all goodnesses of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The observed criterion of F2 > σ(F2) is used only for calculating -R-factor-obs 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.

	x	y	z	Uiso*/Ueq
Cl1	0.91503 (14)	0.22124 (4)	0.29769 (3)	0.0722 (3)
Cl2	0.23669 (16)	0.35928 (3)	0.13099 (3)	0.0705 (3)
O1	0.2489 (4)	0.10566 (8)	0.01887 (8)	0.0716 (7)
O2	0.0396 (3)	0.23885 (7)	0.08223 (8)	0.0598 (6)
O3	−0.2578 (5)	0.50783 (10)	−0.05297 (12)	0.1058 (10)
O4	0.0490 (5)	0.48354 (10)	−0.11293 (12)	0.1037 (10)
O5	−0.9069 (4)	−0.04073 (8)	−0.20251 (9)	0.0712 (7)
N1	−0.0881 (4)	0.15859 (8)	−0.04739 (9)	0.0501 (7)
N2	−0.1189 (6)	0.46924 (12)	−0.07734 (13)	0.0730 (11)
C1	0.0631 (5)	0.14198 (12)	0.00884 (11)	0.0488 (9)
C2	−0.0932 (5)	0.18554 (11)	0.05155 (11)	0.0499 (9)
C3	−0.2519 (5)	0.20533 (11)	−0.01636 (11)	0.0493 (8)
C4	0.2330 (5)	0.23048 (11)	0.13478 (11)	0.0484 (9)
C5	0.3203 (5)	0.17250 (12)	0.16032 (11)	0.0560 (9)
C6	0.5282 (5)	0.16962 (12)	0.21112 (11)	0.0559 (10)
C7	0.6458 (5)	0.22470 (13)	0.23584 (11)	0.0518 (9)
C8	0.5564 (5)	0.28303 (12)	0.21190 (11)	0.0561 (9)
C9	0.3495 (5)	0.28593 (11)	0.16161 (10)	0.0493 (9)
C10	−0.2222 (4)	0.27389 (11)	−0.03557 (10)	0.0438 (8)
C11	−0.3762 (5)	0.31962 (12)	−0.00929 (12)	0.0576 (10)
C12	−0.3445 (6)	0.38355 (13)	−0.02211 (13)	0.0638 (11)
C13	−0.1588 (6)	0.40110 (12)	−0.06275 (12)	0.0536 (10)
C14	−0.0052 (5)	0.35691 (13)	−0.09064 (12)	0.0588 (10)
C15	−0.0372 (5)	0.29338 (12)	−0.07617 (11)	0.0547 (9)
C16	−0.0924 (5)	0.13434 (12)	−0.11484 (10)	0.0558 (9)
C17	−0.3177 (5)	0.08960 (11)	−0.13711 (11)	0.0465 (9)
C18	−0.4539 (5)	0.09594 (11)	−0.19956 (11)	0.0526 (9)
C19	−0.6509 (5)	0.05349 (12)	−0.22383 (11)	0.0540 (9)
C20	−0.7172 (5)	0.00404 (12)	−0.18411 (13)	0.0529 (9)
C21	−0.5827 (6)	−0.00258 (12)	−0.12111 (13)	0.0647 (10)
C22	−0.3856 (5)	0.03948 (12)	−0.09822 (12)	0.0614 (10)
C23	−1.0492 (6)	−0.03553 (13)	−0.26693 (14)	0.0812 (12)
H2	−0.20000	0.16210	0.08110	0.0600*
H3	−0.43840	0.19230	−0.01930	0.0590*
H5	0.23980	0.13510	0.14350	0.0670*
H6	0.58760	0.13030	0.22830	0.0670*
H8	0.63500	0.32040	0.22950	0.0670*
H11	−0.50410	0.30700	0.01770	0.0690*
H12	−0.44720	0.41410	−0.00350	0.0770*
H14	0.11830	0.36960	−0.11880	0.0710*
H15	0.06820	0.26310	−0.09420	0.0660*
H16A	0.07350	0.11230	−0.11850	0.0670*
H16B	−0.10090	0.17030	−0.14530	0.0670*
H18	−0.41260	0.12980	−0.22640	0.0630*
H19	−0.73760	0.05840	−0.26670	0.0650*
H21	−0.62600	−0.03590	−0.09380	0.0780*
H22	−0.29650	0.03400	−0.05570	0.0740*
H23A	−1.17560	−0.06970	−0.27350	0.1210*
H23B	−1.14060	0.00470	−0.27080	0.1210*
H23C	−0.92780	−0.03800	−0.30010	0.1210*

	U11	U22	U33	U12	U13	U23
Cl1	0.0632 (5)	0.0887 (5)	0.0622 (4)	−0.0012 (4)	−0.0041 (3)	0.0047 (4)
Cl2	0.1082 (6)	0.0417 (4)	0.0589 (4)	0.0053 (4)	−0.0028 (4)	−0.0010 (3)
O1	0.0839 (15)	0.0666 (12)	0.0620 (11)	0.0211 (12)	−0.0019 (10)	−0.0016 (10)
O2	0.0835 (13)	0.0417 (10)	0.0498 (10)	−0.0014 (9)	−0.0113 (9)	−0.0032 (8)
O3	0.136 (2)	0.0596 (14)	0.1232 (19)	0.0290 (15)	0.0202 (16)	0.0043 (13)
O4	0.138 (2)	0.0701 (15)	0.1078 (18)	−0.0071 (14)	0.0353 (16)	0.0130 (13)
O5	0.0738 (13)	0.0555 (11)	0.0812 (13)	−0.0087 (11)	−0.0044 (10)	−0.0089 (10)
N1	0.0607 (14)	0.0447 (12)	0.0437 (12)	0.0053 (11)	0.0008 (11)	−0.0081 (9)
N2	0.090 (2)	0.0609 (19)	0.0651 (17)	0.0106 (17)	−0.0044 (14)	0.0040 (14)
C1	0.0589 (19)	0.0406 (14)	0.0465 (15)	−0.0059 (14)	0.0046 (14)	0.0002 (13)
C2	0.0589 (17)	0.0437 (15)	0.0474 (14)	−0.0096 (13)	0.0075 (13)	−0.0017 (12)
C3	0.0402 (15)	0.0532 (15)	0.0548 (14)	−0.0045 (13)	0.0068 (12)	−0.0074 (13)
C4	0.0645 (17)	0.0472 (15)	0.0338 (12)	0.0010 (14)	0.0067 (12)	−0.0024 (12)
C5	0.0755 (19)	0.0424 (15)	0.0492 (15)	−0.0051 (15)	0.0025 (14)	−0.0012 (12)
C6	0.072 (2)	0.0489 (16)	0.0470 (15)	0.0060 (15)	0.0072 (14)	0.0036 (12)
C7	0.0547 (17)	0.0572 (17)	0.0439 (14)	−0.0010 (15)	0.0075 (12)	−0.0019 (13)
C8	0.0727 (18)	0.0465 (16)	0.0496 (15)	−0.0083 (15)	0.0087 (13)	−0.0078 (13)
C9	0.0691 (18)	0.0409 (15)	0.0381 (13)	−0.0018 (14)	0.0071 (13)	−0.0026 (11)
C10	0.0395 (14)	0.0495 (15)	0.0419 (13)	0.0010 (14)	0.0020 (11)	−0.0058 (12)
C11	0.0569 (18)	0.0614 (18)	0.0568 (15)	0.0101 (15)	0.0164 (13)	−0.0009 (14)
C12	0.068 (2)	0.0553 (18)	0.0683 (18)	0.0209 (15)	0.0080 (16)	−0.0036 (14)
C13	0.0605 (19)	0.0469 (17)	0.0505 (15)	0.0055 (15)	−0.0067 (14)	0.0030 (13)
C14	0.0599 (19)	0.0576 (17)	0.0602 (16)	0.0011 (16)	0.0123 (14)	0.0032 (14)
C15	0.0550 (17)	0.0492 (17)	0.0611 (15)	0.0059 (14)	0.0118 (14)	−0.0051 (13)
C16	0.0653 (18)	0.0551 (16)	0.0463 (14)	0.0029 (15)	0.0034 (12)	−0.0103 (13)
C17	0.0563 (17)	0.0410 (14)	0.0417 (14)	0.0041 (13)	0.0037 (12)	−0.0066 (12)
C18	0.0659 (18)	0.0450 (15)	0.0460 (15)	0.0013 (14)	0.0029 (13)	0.0012 (12)
C19	0.0637 (18)	0.0499 (16)	0.0455 (14)	0.0027 (14)	−0.0061 (13)	−0.0033 (13)
C20	0.0568 (17)	0.0396 (15)	0.0610 (17)	0.0043 (14)	0.0004 (14)	−0.0092 (13)
C21	0.087 (2)	0.0469 (15)	0.0570 (17)	−0.0076 (16)	−0.0059 (15)	0.0051 (13)
C22	0.082 (2)	0.0517 (16)	0.0470 (15)	0.0020 (16)	−0.0084 (14)	0.0000 (13)
C23	0.070 (2)	0.076 (2)	0.092 (2)	−0.0058 (17)	−0.0155 (17)	−0.0193 (17)

Cl1—C7	1.744 (2)	C14—C15	1.375 (4)
Cl2—C9	1.729 (2)	C16—C17	1.506 (3)
O1—C1	1.210 (3)	C17—C18	1.372 (3)
O2—C2	1.410 (3)	C17—C22	1.377 (3)
O2—C4	1.371 (3)	C18—C19	1.385 (3)
O3—N2	1.212 (4)	C19—C20	1.374 (4)
O4—N2	1.211 (4)	C20—C21	1.379 (4)
O5—C20	1.364 (3)	C21—C22	1.373 (4)
O5—C23	1.417 (3)	C2—H2	0.9800
N1—C1	1.341 (3)	C3—H3	0.9800
N1—C3	1.468 (3)	C5—H5	0.9300
N1—C16	1.449 (3)	C6—H6	0.9300
N2—C13	1.475 (4)	C8—H8	0.9300
C1—C2	1.534 (3)	C11—H11	0.9300
C2—C3	1.564 (3)	C12—H12	0.9300
C3—C10	1.499 (3)	C14—H14	0.9300
C4—C5	1.372 (3)	C15—H15	0.9300
C4—C9	1.385 (3)	C16—H16A	0.9700
C5—C6	1.386 (3)	C16—H16B	0.9700
C6—C7	1.367 (4)	C18—H18	0.9300
C7—C8	1.371 (4)	C19—H19	0.9300
C8—C9	1.376 (3)	C21—H21	0.9300
C10—C11	1.379 (3)	C22—H22	0.9300
C10—C15	1.374 (3)	C23—H23A	0.9600
C11—C12	1.376 (4)	C23—H23B	0.9600
C12—C13	1.366 (4)	C23—H23C	0.9600
C13—C14	1.370 (4)
C2—O2—C4	120.15 (17)	O5—C20—C19	124.8 (2)
C20—O5—C23	117.9 (2)	O5—C20—C21	116.2 (2)
C1—N1—C3	96.33 (18)	C19—C20—C21	119.0 (2)
C1—N1—C16	130.5 (2)	C20—C21—C22	120.7 (2)
C3—N1—C16	133.13 (19)	C17—C22—C21	121.2 (2)
O3—N2—O4	123.7 (3)	O2—C2—H2	114.00
O3—N2—C13	117.7 (3)	C1—C2—H2	113.00
O4—N2—C13	118.6 (3)	C3—C2—H2	114.00
O1—C1—N1	131.7 (2)	N1—C3—H3	112.00
O1—C1—C2	136.2 (2)	C2—C3—H3	112.00
N1—C1—C2	92.14 (19)	C10—C3—H3	112.00
O2—C2—C1	117.7 (2)	C4—C5—H5	120.00
O2—C2—C3	110.33 (18)	C6—C5—H5	120.00
C1—C2—C3	85.08 (17)	C5—C6—H6	120.00
N1—C3—C2	86.32 (17)	C7—C6—H6	120.00
N1—C3—C10	116.77 (19)	C7—C8—H8	120.00
C2—C3—C10	115.03 (19)	C9—C8—H8	120.00
O2—C4—C5	125.1 (2)	C10—C11—H11	119.00
O2—C4—C9	115.5 (2)	C12—C11—H11	119.00
C5—C4—C9	119.3 (2)	C11—C12—H12	121.00
C4—C5—C6	120.1 (2)	C13—C12—H12	121.00
C5—C6—C7	119.8 (2)	C13—C14—H14	121.00
Cl1—C7—C6	120.0 (2)	C15—C14—H14	121.00
Cl1—C7—C8	119.3 (2)	C10—C15—H15	119.00
C6—C7—C8	120.7 (2)	C14—C15—H15	119.00
C7—C8—C9	119.5 (2)	N1—C16—H16A	108.00
Cl2—C9—C4	119.74 (18)	N1—C16—H16B	108.00
Cl2—C9—C8	119.78 (18)	C17—C16—H16A	108.00
C4—C9—C8	120.5 (2)	C17—C16—H16B	108.00
C3—C10—C11	119.2 (2)	H16A—C16—H16B	107.00
C3—C10—C15	122.2 (2)	C17—C18—H18	119.00
C11—C10—C15	118.5 (2)	C19—C18—H18	119.00
C10—C11—C12	121.4 (2)	C18—C19—H19	120.00
C11—C12—C13	118.5 (3)	C20—C19—H19	120.00
N2—C13—C12	119.9 (2)	C20—C21—H21	120.00
N2—C13—C14	118.3 (2)	C22—C21—H21	120.00
C12—C13—C14	121.8 (2)	C17—C22—H22	119.00
C13—C14—C15	118.7 (2)	C21—C22—H22	119.00
C10—C15—C14	121.2 (2)	O5—C23—H23A	109.00
N1—C16—C17	115.36 (19)	O5—C23—H23B	109.00
C16—C17—C18	120.0 (2)	O5—C23—H23C	109.00
C16—C17—C22	122.3 (2)	H23A—C23—H23B	110.00
C18—C17—C22	117.6 (2)	H23A—C23—H23C	110.00
C17—C18—C19	122.1 (2)	H23B—C23—H23C	109.00
C18—C19—C20	119.5 (2)
C2—O2—C4—C5	2.3 (3)	O2—C4—C5—C6	176.2 (2)
C4—O2—C2—C1	−71.2 (3)	C5—C4—C9—C8	2.1 (4)
C4—O2—C2—C3	−166.47 (19)	O2—C4—C9—Cl2	3.1 (3)
C2—O2—C4—C9	−179.5 (2)	C9—C4—C5—C6	−1.9 (4)
C23—O5—C20—C21	−180.0 (2)	C4—C5—C6—C7	0.1 (4)
C23—O5—C20—C19	−1.0 (4)	C5—C6—C7—Cl1	−177.73 (19)
C16—N1—C1—C2	−173.9 (2)	C5—C6—C7—C8	1.4 (4)
C3—N1—C1—O1	−177.6 (3)	C6—C7—C8—C9	−1.2 (4)
C1—N1—C16—C17	103.0 (3)	Cl1—C7—C8—C9	177.94 (18)
C3—N1—C16—C17	−72.5 (3)	C7—C8—C9—Cl2	−179.75 (19)
C16—N1—C3—C10	−70.0 (3)	C7—C8—C9—C4	−0.5 (4)
C1—N1—C3—C2	−2.85 (19)	C3—C10—C15—C14	−177.0 (2)
C16—N1—C3—C2	173.8 (2)	C3—C10—C11—C12	175.9 (2)
C3—N1—C1—C2	2.90 (19)	C11—C10—C15—C14	−0.1 (3)
C1—N1—C3—C10	113.4 (2)	C15—C10—C11—C12	−1.1 (4)
C16—N1—C1—O1	5.7 (5)	C10—C11—C12—C13	1.1 (4)
O4—N2—C13—C14	−0.5 (4)	C11—C12—C13—N2	−179.8 (2)
O3—N2—C13—C12	−1.0 (4)	C11—C12—C13—C14	0.0 (4)
O4—N2—C13—C12	179.2 (3)	N2—C13—C14—C15	178.7 (2)
O3—N2—C13—C14	179.2 (3)	C12—C13—C14—C15	−1.1 (4)
N1—C1—C2—C3	−2.72 (18)	C13—C14—C15—C10	1.2 (4)
O1—C1—C2—O2	67.4 (4)	N1—C16—C17—C22	−47.4 (3)
O1—C1—C2—C3	177.8 (3)	N1—C16—C17—C18	136.2 (2)
N1—C1—C2—O2	−113.1 (2)	C16—C17—C22—C21	−176.6 (2)
C1—C2—C3—N1	2.49 (16)	C18—C17—C22—C21	−0.1 (4)
O2—C2—C3—C10	2.4 (3)	C16—C17—C18—C19	175.8 (2)
C1—C2—C3—C10	−115.4 (2)	C22—C17—C18—C19	−0.8 (4)
O2—C2—C3—N1	120.25 (19)	C17—C18—C19—C20	1.3 (4)
C2—C3—C10—C15	94.1 (3)	C18—C19—C20—C21	−0.9 (4)
N1—C3—C10—C15	−4.9 (3)	C18—C19—C20—O5	−179.9 (2)
C2—C3—C10—C11	−82.7 (3)	O5—C20—C21—C22	179.1 (2)
N1—C3—C10—C11	178.3 (2)	C19—C20—C21—C22	0.0 (4)
C5—C4—C9—Cl2	−178.70 (19)	C20—C21—C22—C17	0.5 (4)
O2—C4—C9—C8	−176.2 (2)

D—H···A	D—H	H···A	D···A	D—H···A
C3—H3···O1i	0.98	2.58	3.417 (3)	143
C6—H6···O5ii	0.93	2.57	3.328 (3)	139
C12—H12···O3iii	0.93	2.57	3.495 (4)	176
C16—H16A···Cgiv	0.97	2.70	3.649 (3)	166

Table 1

Hydrogen-bond geometry (Å, °)

Cg is the centroid of the C17–C22 benzene ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C3—H3⋯O1i	0.98	2.58	3.417 (3)	143
C6—H6⋯O5ii	0.93	2.57	3.328 (3)	139
C12—H12⋯O3iii	0.93	2.57	3.495 (4)	176
C16—H16A⋯Cg iv	0.97	2.70	3.649 (3)	166

Symmetry codes: (i) ; (ii) ; (iii) ; (iv) .