catena-Poly[[[(acetato-κO,O')cadmium]-μ-acetato-κO,O':O'-μ-{1,2-bis-[4-(pyridin-3-yl)pyrimidin-2-ylsulfan-yl]ethane}-κN,N] trihydrate].

The title compound, {[Cd(CH(3)COO)(2)(C(20)H(16)N(6)S(2))]·3H(2)O}(n), exists as a one-dimensional zigzag polymer in which the Cd(II) ion shows a seven-coordinate [CdO(5)N(2)] distorted penta-gonal-bipyramidal geometry with the N atoms in axial positions and an N-Cd-N angle of 176.94 (13)°. The metal atoms are bridged by 1,2-bis-[4-(pyridin-3-yl)pyrimidin-2-ylsulfan-yl]ethane ligands, giving a polymeric chain extending along the b axis. Adjacent chains related by an inversion center are further bridged by Cd-O bonds formed between the O atom of one of the acetate ligands and the metal atom. The five Cd-O bond lengths are in the range 2.329 (3)-2.485 (3) Å. There are π-π stacking inter-actions between the aromatic rings of adjacent polymeric chains, the centroid-centroid distances being 3.556 (3) and 3.698 (3) Å, organizing the chains into a three-dimensional framework. This framework is additionally stabilized by extensive O-H⋯O and O-H⋯N hydrogen bonding between water mol-ecules and the ligands.

Related literature

For backgroud to coordination polymers with thio­ether ligands, see: Dong, Yang et al. (2008 ▶); Dong, Zhu et al. (2008 ▶); Dong et al. (2009 ▶).

Experimental

Crystal data

[Cd(C2H3O2)2(C20H16N6S2)]·3H2O

M = 689.07

Monoclinic,

a = 10.8000 (12) Å

b = 14.0816 (16) Å

c = 18.594 (2) Å

β = 95.997 (2)°

V = 2812.4 (5) Å3

Z = 4

Mo Kα radiation

μ = 0.98 mm−1

T = 291 K

0.20 × 0.10 × 0.03 mm

Data collection

Bruker SMART CCD area-detector diffractometer

Absorption correction: multi-scan (SADABS; Bruker, 2000 ▶) T min = 0.822, T max = 0.971

14681 measured reflections

5492 independent reflections

3846 reflections with I > 2σ(I)

R int = 0.048

Refinement

R[F 2 > 2σ(F 2)] = 0.054

wR(F 2) = 0.112

S = 1.01

5492 reflections

363 parameters

H-atom parameters constrained

Δρmax = 0.84 e Å−3

Δρmin = −0.77 e Å−3

Data collection: SMART (Bruker, 2000 ▶); cell refinement: SAINT (Bruker, 2000 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536811046794/gk2423sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811046794/gk2423Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

[Cd(C2H3O2)2(C20H16N6S2)]·3H2O	F(000) = 1400
Mr = 689	Dx = 1.628 Mg m−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 3846 reflections
a = 10.8000 (12) Å	θ = 1.8–25.2°
b = 14.0816 (16) Å	µ = 0.98 mm−1
c = 18.594 (2) Å	T = 291 K
β = 95.997 (2)°	Plate, colorless
V = 2812.4 (5) Å3	0.20 × 0.10 × 0.03 mm
Z = 4

Bruker SMART CCD area-detector diffractometer	5492 independent reflections
Radiation source: fine-focus sealed tube	3846 reflections with I > 2σ(I)
graphite	Rint = 0.048
φ and ω scan	θmax = 26.0°, θmin = 1.8°
Absorption correction: multi-scan (SADABS; Bruker, 2000)	h = −7→13
Tmin = 0.822, Tmax = 0.971	k = −16→17
14681 measured reflections	l = −22→22

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)] = 0.054	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.112	H-atom parameters constrained
S = 1.01	w = 1/[σ2(Fo2) + (0.0473P)2] where P = (Fo2 + 2Fc2)/3
5492 reflections	(Δ/σ)max = 0.005
363 parameters	Δρmax = 0.84 e Å−3
0 restraints	Δρmin = −0.77 e Å−3

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 > 2sigma(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.

	x	y	z	Uiso*/Ueq
C1	0.6658 (4)	0.8014 (4)	−0.1567 (3)	0.0429 (13)
C2	0.7246 (5)	0.7596 (4)	−0.2185 (3)	0.0683 (18)
H2A	0.8133	0.7580	−0.2071	0.103*
H2B	0.7041	0.7976	−0.2609	0.103*
H2C	0.6941	0.6961	−0.2273	0.103*
C3	0.5891 (4)	1.1395 (4)	−0.0653 (2)	0.0363 (12)
C4	0.6550 (6)	1.1502 (5)	−0.1300 (3)	0.075 (2)
H4A	0.6646	1.2165	−0.1402	0.112*
H4B	0.6078	1.1202	−0.1704	0.112*
H4C	0.7355	1.1210	−0.1218	0.112*
C5	0.6748 (5)	0.8859 (3)	0.3150 (2)	0.0389 (12)
C6	0.8781 (6)	0.8792 (4)	0.3511 (3)	0.0592 (16)
H6	0.9437	0.8767	0.3876	0.071*
C7	0.9059 (5)	0.8780 (4)	0.2821 (3)	0.0532 (15)
H7	0.9879	0.8752	0.2713	0.064*
C8	0.8070 (5)	0.8813 (3)	0.2277 (2)	0.0363 (11)
C9	0.8240 (4)	0.8842 (3)	0.1498 (2)	0.0343 (11)
C10	0.9383 (5)	0.8957 (3)	0.1249 (3)	0.0426 (12)
H10	1.0103	0.8985	0.1570	0.051*
C11	0.9446 (5)	0.9032 (4)	0.0512 (3)	0.0472 (14)
H11	1.0212	0.9099	0.0331	0.057*
C12	0.8387 (5)	0.9007 (3)	0.0058 (3)	0.0417 (13)
H12	0.8441	0.9079	−0.0435	0.050*
C13	0.7214 (4)	0.8809 (3)	0.0997 (2)	0.0342 (11)
H13	0.6438	0.8731	0.1163	0.041*
C14	0.5271 (5)	0.9099 (4)	0.4283 (2)	0.0456 (14)
H14A	0.5958	0.9520	0.4439	0.055*
H14B	0.4511	0.9399	0.4404	0.055*
H24A	0.4748	0.7758	0.4556	0.055*
H24B	0.6195	0.7861	0.4566	0.055*
C15	0.4022 (5)	0.8463 (3)	0.5830 (2)	0.0393 (12)
C16	0.1985 (5)	0.8570 (4)	0.5474 (3)	0.0536 (15)
H16	0.1324	0.8566	0.5111	0.064*
C17	0.1719 (5)	0.8667 (3)	0.6172 (3)	0.0470 (14)
H17	0.0907	0.8746	0.6286	0.056*
C18	0.2728 (5)	0.8643 (3)	0.6708 (2)	0.0349 (12)
C19	0.2573 (5)	0.8719 (3)	0.7486 (2)	0.0357 (12)
C20	0.1445 (5)	0.8667 (3)	0.7764 (3)	0.0393 (13)
H20	0.0713	0.8598	0.7457	0.047*
C21	0.1409 (5)	0.8719 (3)	0.8492 (3)	0.0447 (13)
H21	0.0650	0.8688	0.8685	0.054*
C22	0.2486 (5)	0.8814 (3)	0.8939 (3)	0.0397 (12)
H22	0.2441	0.8834	0.9436	0.048*
C23	0.3635 (5)	0.8826 (3)	0.7981 (2)	0.0367 (11)
H23	0.4407	0.8862	0.7802	0.044*
C24	0.5447 (5)	0.8173 (4)	0.4694 (3)	0.0509 (15)
Cd1	0.54604 (3)	0.88993 (3)	−0.053496 (16)	0.03387 (13)
N1	0.6904 (4)	0.8839 (3)	0.24501 (19)	0.0355 (9)
N2	0.7636 (4)	0.8836 (3)	0.3705 (2)	0.0456 (11)
N3	0.7268 (4)	0.8883 (3)	0.0283 (2)	0.0384 (9)
N4	0.3887 (4)	0.8531 (3)	0.6531 (2)	0.0395 (10)
N5	0.3119 (4)	0.8480 (3)	0.5283 (2)	0.0511 (12)
N6	0.3595 (4)	0.8880 (3)	0.86954 (19)	0.0362 (9)
O1	0.6169 (3)	0.7495 (2)	−0.11385 (17)	0.0490 (9)
O2	0.6649 (3)	0.8906 (3)	−0.15103 (17)	0.0493 (9)
O3	0.5654 (3)	1.0578 (2)	−0.04314 (15)	0.0430 (8)
O4	0.5594 (3)	1.2110 (3)	−0.03123 (17)	0.0508 (9)
O5	0.3481 (4)	0.5134 (3)	0.2749 (2)	0.0912 (15)
H5A	0.3204	0.5168	0.2305	0.137*
H5B	0.2928	0.5397	0.2974	0.137*
O6	0.3059 (5)	0.4610 (4)	0.1302 (2)	0.1181 (18)
H6OA	0.3320	0.5000	0.1002	0.177*
H6OB	0.3213	0.4025	0.1184	0.177*
O7	0.3543 (4)	0.6001 (3)	0.0280 (2)	0.0916 (15)
H7OB	0.3312	0.5997	−0.0173	0.137*
H7OA	0.3742	0.6575	0.0380	0.137*
S1	0.51853 (13)	0.89534 (11)	0.33124 (7)	0.0523 (4)
S2	0.55806 (13)	0.83446 (11)	0.56618 (7)	0.0501 (4)

	U11	U22	U33	U12	U13	U23
C1	0.032 (3)	0.067 (4)	0.030 (3)	0.008 (3)	0.001 (2)	−0.010 (3)
C2	0.075 (5)	0.072 (5)	0.064 (4)	−0.003 (3)	0.034 (3)	−0.019 (3)
C3	0.035 (3)	0.049 (4)	0.024 (2)	−0.008 (2)	0.003 (2)	0.004 (2)
C4	0.095 (5)	0.095 (5)	0.039 (3)	−0.021 (4)	0.029 (3)	−0.002 (3)
C5	0.048 (3)	0.033 (3)	0.035 (3)	−0.004 (2)	0.001 (2)	0.004 (2)
C6	0.054 (4)	0.083 (5)	0.037 (3)	0.013 (3)	−0.011 (3)	−0.001 (3)
C7	0.041 (3)	0.079 (4)	0.039 (3)	0.009 (3)	0.000 (2)	0.004 (3)
C8	0.044 (3)	0.029 (3)	0.036 (3)	0.001 (2)	0.005 (2)	0.003 (2)
C9	0.036 (3)	0.029 (3)	0.038 (3)	0.001 (2)	0.003 (2)	0.003 (2)
C10	0.036 (3)	0.046 (3)	0.044 (3)	0.001 (3)	−0.003 (2)	0.000 (3)
C11	0.033 (3)	0.062 (4)	0.048 (3)	−0.005 (3)	0.012 (2)	0.002 (3)
C12	0.049 (3)	0.046 (3)	0.032 (3)	−0.003 (3)	0.010 (2)	0.000 (2)
C13	0.031 (3)	0.039 (3)	0.033 (3)	−0.001 (2)	0.005 (2)	0.007 (2)
C14	0.056 (4)	0.051 (4)	0.031 (3)	0.000 (3)	0.012 (2)	−0.004 (2)
C15	0.054 (4)	0.035 (3)	0.030 (3)	−0.010 (2)	0.005 (2)	0.000 (2)
C16	0.049 (4)	0.070 (4)	0.038 (3)	−0.016 (3)	−0.011 (3)	0.001 (3)
C17	0.044 (3)	0.061 (4)	0.034 (3)	−0.007 (3)	−0.006 (2)	0.006 (2)
C18	0.045 (3)	0.027 (3)	0.032 (3)	−0.004 (2)	0.001 (2)	−0.0037 (19)
C19	0.045 (3)	0.029 (3)	0.032 (2)	−0.001 (2)	−0.002 (2)	−0.003 (2)
C20	0.035 (3)	0.037 (3)	0.044 (3)	−0.005 (2)	−0.002 (2)	0.000 (2)
C21	0.040 (3)	0.049 (4)	0.047 (3)	−0.007 (2)	0.011 (3)	−0.004 (2)
C22	0.048 (3)	0.041 (3)	0.031 (3)	−0.002 (3)	0.006 (2)	−0.001 (2)
C23	0.042 (3)	0.037 (3)	0.032 (3)	0.004 (2)	0.012 (2)	0.007 (2)
C24	0.076 (4)	0.046 (4)	0.034 (3)	−0.010 (3)	0.022 (3)	−0.005 (2)
Cd1	0.0364 (2)	0.0440 (2)	0.02189 (17)	−0.00100 (18)	0.00639 (13)	−0.00316 (16)
N1	0.035 (3)	0.042 (2)	0.029 (2)	−0.002 (2)	−0.0005 (17)	0.0064 (18)
N2	0.049 (3)	0.057 (3)	0.030 (2)	0.005 (2)	−0.002 (2)	0.003 (2)
N3	0.038 (3)	0.043 (2)	0.035 (2)	0.000 (2)	0.0084 (18)	0.0018 (19)
N4	0.050 (3)	0.039 (3)	0.030 (2)	−0.005 (2)	0.003 (2)	−0.0017 (18)
N5	0.054 (3)	0.065 (3)	0.032 (2)	−0.015 (2)	−0.005 (2)	0.002 (2)
N6	0.039 (3)	0.040 (2)	0.030 (2)	0.001 (2)	0.0054 (18)	−0.0010 (19)
O1	0.056 (3)	0.058 (3)	0.0340 (19)	−0.0056 (18)	0.0105 (17)	−0.0006 (17)
O2	0.061 (3)	0.050 (2)	0.041 (2)	0.000 (2)	0.0203 (17)	−0.0083 (18)
O3	0.057 (2)	0.039 (2)	0.0349 (19)	−0.0042 (17)	0.0126 (16)	0.0034 (15)
O4	0.065 (3)	0.042 (2)	0.046 (2)	−0.0009 (18)	0.0081 (18)	−0.0023 (17)
O5	0.076 (3)	0.116 (4)	0.081 (3)	0.039 (3)	0.008 (2)	0.000 (3)
O6	0.151 (5)	0.115 (5)	0.090 (4)	0.020 (4)	0.022 (3)	0.005 (3)
O7	0.112 (4)	0.099 (4)	0.062 (3)	−0.025 (3)	0.006 (3)	0.004 (2)
S1	0.0456 (9)	0.0780 (11)	0.0339 (7)	−0.0040 (8)	0.0078 (6)	0.0002 (7)
S2	0.0574 (10)	0.0584 (9)	0.0354 (7)	−0.0007 (7)	0.0094 (6)	0.0021 (6)

C1—O1	1.239 (6)	C15—S2	1.752 (5)
C1—O2	1.260 (6)	C16—N5	1.317 (6)
C1—C2	1.492 (6)	C16—C17	1.365 (7)
C2—H2A	0.9600	C16—H16	0.9300
C2—H2B	0.9600	C17—C18	1.398 (6)
C2—H2C	0.9600	C17—H17	0.9300
C3—O4	1.249 (6)	C18—N4	1.336 (6)
C3—O3	1.259 (6)	C18—C19	1.478 (6)
C3—C4	1.468 (7)	C19—C20	1.373 (7)
C4—H4A	0.9600	C19—C23	1.401 (6)
C4—H4B	0.9600	C20—C21	1.361 (6)
C4—H4C	0.9600	C20—H20	0.9300
C5—N1	1.330 (5)	C21—C22	1.363 (6)
C5—N2	1.333 (6)	C21—H21	0.9300
C5—S1	1.750 (5)	C22—N6	1.328 (6)
C6—N2	1.324 (7)	C22—H22	0.9300
C6—C7	1.347 (7)	C23—N6	1.336 (5)
C6—H6	0.9300	C23—H23	0.9300
C7—C8	1.393 (6)	C24—S2	1.806 (5)
C7—H7	0.9300	C24—H24A	0.9679
C8—N1	1.333 (6)	C24—H24B	0.9703
C8—C9	1.480 (6)	Cd1—O2	2.329 (3)
C9—C13	1.372 (6)	Cd1—N3	2.346 (4)
C9—C10	1.373 (6)	Cd1—N6i	2.346 (4)
C10—C11	1.382 (6)	Cd1—O3	2.378 (3)
C10—H10	0.9300	Cd1—O3ii	2.382 (3)
C11—C12	1.350 (6)	Cd1—O1	2.437 (3)
C11—H11	0.9300	Cd1—O4ii	2.485 (3)
C12—N3	1.331 (6)	N6—Cd1iii	2.346 (4)
C12—H12	0.9300	O3—Cd1ii	2.382 (3)
C13—N3	1.340 (5)	O4—Cd1ii	2.485 (3)
C13—H13	0.9300	O5—H5A	0.8500
C14—C24	1.514 (7)	O5—H5B	0.8500
C14—S1	1.810 (4)	O6—H6OA	0.8520
C14—H14A	0.9700	O6—H6OB	0.8735
C14—H14B	0.9700	O7—H7OB	0.8519
C15—N4	1.329 (5)	O7—H7OA	0.8528
C15—N5	1.334 (6)
O1—C1—O2	121.8 (5)	C20—C19—C23	117.2 (4)
O1—C1—C2	120.4 (5)	C20—C19—C18	124.0 (4)
O2—C1—C2	117.8 (5)	C23—C19—C18	118.7 (5)
C1—C2—H2A	109.5	C21—C20—C19	119.3 (5)
C1—C2—H2B	109.5	C21—C20—H20	120.4
H2A—C2—H2B	109.5	C19—C20—H20	120.4
C1—C2—H2C	109.5	C20—C21—C22	120.1 (5)
H2A—C2—H2C	109.5	C20—C21—H21	120.0
H2B—C2—H2C	109.5	C22—C21—H21	120.0
O4—C3—O3	119.9 (4)	N6—C22—C21	122.8 (4)
O4—C3—C4	120.4 (5)	N6—C22—H22	118.6
O3—C3—C4	119.7 (5)	C21—C22—H22	118.6
C3—C4—H4A	109.5	N6—C23—C19	123.3 (4)
C3—C4—H4B	109.5	N6—C23—H23	118.3
H4A—C4—H4B	109.5	C19—C23—H23	118.3
C3—C4—H4C	109.5	C14—C24—S2	112.3 (4)
H4A—C4—H4C	109.5	C14—C24—H24A	109.4
H4B—C4—H4C	109.5	S2—C24—H24A	108.9
N1—C5—N2	127.0 (5)	C14—C24—H24B	109.2
N1—C5—S1	113.2 (3)	S2—C24—H24B	108.9
N2—C5—S1	119.9 (4)	H24A—C24—H24B	108.0
N2—C6—C7	124.5 (5)	O2—Cd1—N3	90.92 (13)
N2—C6—H6	117.7	O2—Cd1—N6i	91.89 (12)
C7—C6—H6	117.7	N3—Cd1—N6i	176.94 (13)
C6—C7—C8	117.4 (5)	O2—Cd1—O3	90.46 (12)
C6—C7—H7	121.3	N3—Cd1—O3	84.09 (12)
C8—C7—H7	121.3	N6i—Cd1—O3	97.09 (12)
N1—C8—C7	119.8 (4)	O2—Cd1—O3ii	161.70 (12)
N1—C8—C9	116.9 (4)	N3—Cd1—O3ii	88.04 (12)
C7—C8—C9	123.2 (5)	N6i—Cd1—O3ii	89.68 (12)
C13—C9—C10	117.8 (4)	O3—Cd1—O3ii	71.26 (12)
C13—C9—C8	119.3 (4)	O2—Cd1—O1	54.50 (11)
C10—C9—C8	122.8 (4)	N3—Cd1—O1	90.60 (12)
C9—C10—C11	118.8 (4)	N6i—Cd1—O1	90.04 (12)
C9—C10—H10	120.6	O3—Cd1—O1	144.54 (11)
C11—C10—H10	120.6	O3ii—Cd1—O1	143.75 (11)
C12—C11—C10	119.5 (5)	O2—Cd1—O4ii	145.35 (12)
C12—C11—H11	120.3	N3—Cd1—O4ii	89.36 (12)
C10—C11—H11	120.3	N6i—Cd1—O4ii	87.65 (12)
N3—C12—C11	123.0 (5)	O3—Cd1—O4ii	124.00 (11)
N3—C12—H12	118.5	O3ii—Cd1—O4ii	52.93 (12)
C11—C12—H12	118.5	O1—Cd1—O4ii	90.85 (12)
N3—C13—C9	123.7 (4)	C5—N1—C8	117.2 (4)
N3—C13—H13	118.1	C6—N2—C5	114.1 (4)
C9—C13—H13	118.1	C12—N3—C13	117.1 (4)
C24—C14—S1	113.4 (4)	C12—N3—Cd1	121.1 (3)
C24—C14—H14A	108.9	C13—N3—Cd1	121.6 (3)
S1—C14—H14A	108.9	C15—N4—C18	116.9 (4)
C24—C14—H14B	108.9	C16—N5—C15	114.9 (4)
S1—C14—H14B	108.9	C22—N6—C23	117.3 (4)
H14A—C14—H14B	107.7	C22—N6—Cd1iii	122.7 (3)
N4—C15—N5	126.9 (5)	C23—N6—Cd1iii	119.5 (3)
N4—C15—S2	112.8 (4)	C1—O1—Cd1	89.5 (3)
N5—C15—S2	120.3 (4)	C1—O2—Cd1	94.0 (3)
N5—C16—C17	124.1 (5)	C3—O3—Cd1	154.4 (3)
N5—C16—H16	118.0	C3—O3—Cd1ii	95.8 (3)
C17—C16—H16	118.0	Cd1—O3—Cd1ii	108.74 (12)
C16—C17—C18	116.7 (5)	C3—O4—Cd1ii	91.2 (3)
C16—C17—H17	121.6	H5A—O5—H5B	105.1
C18—C17—H17	121.6	H6OA—O6—H6OB	111.0
N4—C18—C17	120.5 (5)	H7OB—O7—H7OA	105.3
N4—C18—C19	117.1 (4)	C5—S1—C14	103.4 (2)
C17—C18—C19	122.4 (5)	C15—S2—C24	102.3 (2)

D—H···A	D—H	H···A	D···A	D—H···A
O6—H6OB···O1iv	0.87	2.24	3.102 (6)	167
O7—H7OB···N2v	0.85	2.15	3.000 (5)	173
O7—H7OA···O4ii	0.85	2.00	2.819 (6)	162
O5—H5A···O6	0.85	2.01	2.782 (5)	150
O5—H5B···O2vi	0.85	2.02	2.864 (5)	177
C6—H6···O1vii	0.93	2.58	3.163 (7)	121
C10—H10···O5viii	0.93	2.48	3.263 (7)	142

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O6—H6OB⋯O1i	0.87	2.24	3.102 (6)	167
O7—H7OB⋯N2ii	0.85	2.15	3.000 (5)	173
O7—H7OA⋯O4iii	0.85	2.00	2.819 (6)	162
O5—H5A⋯O6	0.85	2.01	2.782 (5)	150
O5—H5B⋯O2iv	0.85	2.02	2.864 (5)	177

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