Thio­cyanates of nickel and caesium: Cs₂NiAg₂(SCN)₆·2H₂O and CsNi(SCN)₃

The crystal structures of dicaesium nickel disilver hexa­thio­cyanate dihydrate, Cs₂NiAg₂(SCN)₆·2H₂O, (I), and caesium nickel tri­thio­cyanate, CsNi(SCN)₃, (II), have been determined by single-crystal X-ray diffraction at 273 K. Compounds (I) and (II) are monoclinic, with P2₁/c and P2₁/n symmetry, respectively. In (I), the Ni atom lies on an inversion centre; in (II), there are two independent Ni atoms, each of which lies on an inversion centre. The coordination polyhedra and the bonding schemes in the structures are discussed.

S1. Comment

A detailed search through the literature revealed that more than 80 inorganic thiocyanates are known. They include two compounds containing nickel (Kuo Chan & Porai-Koshits, 1960) and 13 containing caesium (Bohatý & Fröhlich, 1992), but none that contain both. The NCS⁻ anion can interact with metal atoms in various ways, whereby both the N and S atoms can act as ligands forming covalent or ionic bonds, or by simple van der Waals interactions. In the present structures, the Ni—N and Ag—S bonds are covalent, whereas the Ni—S bonds and all bonds to Cs are ionic. \sch

The structure of compound (I) (Fig. 1) is characterized by corner-linked irregular [AgS₄] tetrahedra forming chains along [001] (Fig. 3). The length of the Ag—S1 bond [2.7716 (14) Å] indicates an ionic rather than covalent interaction, as estimated from the sums of the covalent and ionic radii of 2.55 and 2.84 Å, respectively (Sanderson, 1962; Sutton, 1965; Shannon, 1976). These polyhedral chains are interconnected by octahedral [Ni(H₂O)₂(SCN)₄] groups, in which the central Ni atom forms four equatorial covalent Ni—N bonds and two apical Ni—O bonds. The Ag-(SCN)-Ni framework forms slightly puckered sheets parallel to (100). Cs atoms are located between these sheets and link them into a three-dimensional structure by forming ionic bonds with the thiocyanate groups (Fig. 2). In addition, hydrogen bonds are formed between the H atoms of the water molecules and the N atoms of adjacent sheets.

The structure of compound (II) (Fig. 3) is altogether different. The prominent features are the coordination polyhedra of the Ni atoms, which are of two different types. Atom Ni1 is [4 + 2]-coordinated, with four covalent Ni—N bonds [mean distance 2.052 (2) Å; calculated sum of covalent radii 1.96 Å] and two ionic Ni—S bonds [distances 2.5411 (8) Å; calculated sum of ionic radii 2.53 Å]. The coordination polyhedron of atom Ni2 can be described as a [2 + 4] coordination, with two covalent Ni—N bonds [distances 2.015 (2) Å] and four ionic Ni—S bonds [mean distance 2.5204 (8) Å]. It is remarkable that the Ni atoms in the unit cell form a pseudo-tetragonal F-centred lattice. However, the irregularity of the polyhedra and the positions of the other atoms clearly show that the symmetry is monoclinic·The thiocyanate groups are all approximately parallel to the (010) plane, connecting the Ni polyhedra into sheets parallel to (010) (Fig. 4). The Cs atoms are located between these sheets and are connected to the thiocyanate groups by ionic bonds.

X-ray powder diffraction data have been collected for both compounds and the resulting data have been submitted to the powder diffraction file of the International Centre for Diffraction Data (JCPDS-ICDD).

S2. Experimental

For compound (I), stoichiometric quantities of Cs₂CO₃ (1680 mg), NiCl₂·6H₂O (1089 mg), AgSCN (821 mg) and NH₄SCN (392 mg) were dissolved in approximately 150 ml of distilled water. For compound (II), stoichiometric quantities of Cs₂CO₃ (1702 mg), NiCl₂·6H₂O (1065 mg) and NH₄SCN (402 mg) and approximately 120 ml distilled water were used. The solutions were heated to a temperature of 353 K until the material was completely dissolved, and subsequently cooled to 293 K over a period of 14 d. The syntheses yielded small (up to 0.5 mm) blue [for (I)] or green [for (II)] crystals. In both cases, the products were accompanied by large, colourless crystals of NH₄Cl. The products were picked manually from the supernatant liquors and carefully washed with distilled water.

S3. Refinement

The H atoms in (I) were refined freely. After the refinement, the residual electron-density maxima and minima were 2.18 (0.79 Å from Ag) and −1.59 e Å⁻³ (0.76 Å from Ag), respectively, for (I), and 1.40 (0.76 Å from Cs) and −1.28 e Å⁻³ (0.65 Å from Cs), respectively, for (II).

Computing details

For both compounds, data collection: COLLECT (Nonius, 2003); cell refinement: HKL SCALEPACK (Otwinowski & Minor 1997); data reduction: HKL DENZO (Otwinowski & Minor 1997) and SCALEPACK; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: DIAMOND (Bergerhoff et al., 1996) and ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: SHELXL97.

Figures

	Fig. 1. The connectivity in Cs2NiAg2(SCN)6·2H2O, shown with displacement ellipsoids at the 50% probability level. [Symmetry codes: (i) x, −1/2 − y, z − 1/2; (ii) 1 − x, −y, 1 − z; (iii) 1 − x, −y, 2 − z.]
	Fig. 2. The structure of Cs2NiAg2(SCN)6·2H2O, viewed along [100]. The S—C—N groups are represented as sticks, and the Ag and Cs atoms are displayed as small and large grey spheres, respectively.
	Fig. 3. The connectivity in CsNi(SCN)3, shown with displacement ellipsoids at the 50% probability level. [Symmetry codes: (i) 2 − x, 2 − y, 2 − z; (ii) 1 − x, 2 − y, 1 − z; (v) 2 − x, 2 − y, 1 − z; (vi) 1 + x, y, z; (vii) x − 1, y, z.]
	Fig. 4. The structure of CsNi(SCN)3, viewed along [100]. The coding is as in Fig. 2.

(I) dicaesium disilver nickel hexathiocyanate dihydrate

Crystal data

Cs2NiAg2(SCN)6·2H2O	F(000) = 852
Mr = 924.82	Dx = 2.824 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 3260 reflections
a = 7.503 (2) Å	θ = 4.1–30.0°
b = 18.766 (4) Å	µ = 6.53 mm^−1
c = 7.733 (2) Å	T = 293 K
β = 92.59 (3)°	Prism, blue
V = 1087.7 (5) Å^3	0.17 × 0.10 × 0.08 mm
Z = 2

Data collection

Nonius KappaCCD area-detector diffractometer	3167 independent reflections
Radiation source: fine-focus sealed tube	2538 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.017
Detector resolution: 9 pixels mm^-1	θmax = 30.0°, θmin = 4.2°
ϕ and ω scans	h = −10→10
Absorption correction: multi-scan (Otwinowski & Minor, 1997)	k = −26→26
Tmin = 0.403, Tmax = 0.623	l = −10→10
6227 measured reflections

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.032	All H-atom parameters refined
wR(F^2) = 0.077	w = 1/[σ^2(Fo^2) + (0.0279P)^2 + 2.7068P] where P = (Fo^2 + 2Fc^2)/3
S = 1.05	(Δ/σ)max = 0.001
3167 reflections	Δρmax = 2.18 e Å^−3
124 parameters	Δρmin = −1.59 e Å^−3
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 1997), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0024 (2)

Special details

Experimental. The single-crystal data were collected on a Nonius Kappa CCD four-circle diffractometer using 595 frames with phi and omega-increments of 1 degree and a counting time of 60 s per frame. The crystal to detector distance was 30 mm. The whole Ewald sphere was measured.

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. Single-crystal X-ray intensity data were collected at 293 K on a Nonius Kappa diffractometer with CCD area detector, using Mo—Kα radiation. The reflection data were processed with the Nonius program suite DENZO-SMN and corrected for Lorentz, polarization, background and absorption effects (Otwinowski and Minor, 1997). The crystal structure was determined by either automatic Patterson or direct methods (SHELXS97 - Sheldrick, 1997) and subsequent Fourier and difference Fourier syntheses, followed by full-matrix least-squares refinements on F² (SHELXL97 - Sheldrick, 1997).

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 (Ų)

	x	y	z	Uiso*/Ueq
Ag	0.76600 (5)	−0.286655 (18)	0.50326 (5)	0.05315 (12)
Ni	0.5000	0.0000	0.5000	0.03128 (15)
Cs	0.73749 (4)	0.117368 (15)	0.97081 (4)	0.04816 (11)
S1	0.53818 (15)	−0.24142 (5)	0.71930 (13)	0.0386 (2)
C1	0.5165 (5)	−0.16058 (19)	0.6369 (5)	0.0320 (7)
N1	0.5001 (5)	−0.10316 (18)	0.5855 (5)	0.0423 (8)
S2	0.79442 (15)	−0.07904 (5)	0.99078 (13)	0.0382 (2)
C2	0.6886 (5)	−0.05434 (18)	1.1626 (5)	0.0301 (7)
N2	0.6098 (5)	−0.0340 (2)	1.2769 (5)	0.0464 (9)
S3	1.02943 (16)	−0.21508 (6)	0.40624 (15)	0.0465 (3)
C3	1.0220 (5)	−0.1503 (2)	0.5490 (6)	0.0395 (9)
N3	1.0205 (6)	−0.1031 (2)	0.6453 (6)	0.0588 (11)
OW	0.7605 (4)	0.01837 (18)	0.6107 (4)	0.0421 (7)
H1W	0.810 (10)	−0.013 (4)	0.624 (10)	0.09 (3)*
H2W	0.787 (6)	0.042 (3)	0.519 (7)	0.043 (13)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Ag	0.0518 (2)	0.03179 (17)	0.0766 (3)	−0.00260 (13)	0.01119 (18)	−0.00135 (15)
Ni	0.0360 (3)	0.0249 (3)	0.0336 (3)	0.0035 (2)	0.0083 (3)	−0.0006 (2)
Cs	0.04069 (15)	0.03630 (15)	0.0670 (2)	−0.00005 (10)	−0.00311 (12)	0.00055 (12)
S1	0.0539 (6)	0.0267 (4)	0.0352 (5)	−0.0041 (4)	0.0017 (4)	0.0020 (4)
C1	0.0315 (17)	0.0322 (18)	0.0325 (18)	0.0006 (14)	0.0031 (14)	−0.0004 (14)
N1	0.0447 (19)	0.0347 (17)	0.048 (2)	0.0058 (14)	0.0035 (15)	0.0045 (15)
S2	0.0510 (6)	0.0275 (4)	0.0372 (5)	0.0028 (4)	0.0149 (4)	0.0000 (4)
C2	0.0314 (17)	0.0248 (16)	0.0339 (18)	0.0007 (13)	0.0007 (14)	−0.0016 (13)
N2	0.050 (2)	0.0428 (19)	0.048 (2)	0.0041 (16)	0.0158 (17)	−0.0076 (16)
S3	0.0525 (6)	0.0391 (5)	0.0487 (6)	−0.0060 (4)	0.0113 (5)	−0.0005 (4)
C3	0.039 (2)	0.034 (2)	0.046 (2)	−0.0060 (16)	0.0089 (17)	0.0053 (17)
N3	0.065 (3)	0.049 (2)	0.064 (3)	−0.005 (2)	0.019 (2)	−0.005 (2)
OW	0.0433 (17)	0.0369 (16)	0.0462 (17)	−0.0002 (13)	0.0042 (13)	0.0069 (14)

Geometric parameters (Å, º)

Ag—S3	2.5314 (13)	Cs—C2^iii	3.520 (4)
Ag—S2^i	2.5316 (11)	Cs—N2^iii	3.530 (4)
Ag—S1	2.5868 (13)	Cs—C2	3.573 (4)
Ag—S1^i	2.7716 (14)	Cs—S2^v	3.5841 (15)
Ni—N1	2.046 (3)	Cs—S1^vi	3.6315 (12)
Ni—N1^ii	2.046 (3)	S1—C1	1.651 (4)
Ni—N2^iii	2.047 (3)	C1—N1	1.153 (5)
Ni—N2^iv	2.047 (3)	S2—C2	1.645 (4)
Ni—OW	2.126 (3)	C2—N2	1.151 (5)
Ni—OW^ii	2.126 (3)	S3—C3	1.645 (4)
Cs—OW	3.359 (3)	C3—N3	1.157 (6)
Cs—N3^v	3.420 (5)
S3—Ag—S2^i	116.66 (4)	S3^ix—Cs—C1^iii	81.94 (6)
S3—Ag—S1	124.39 (4)	S2—Cs—C1^iii	104.07 (6)
S2^i—Ag—S1	114.24 (3)	OW—Cs—N2	97.21 (8)
S3—Ag—S1^i	97.25 (4)	N3^v—Cs—N2	62.93 (9)
S2^i—Ag—S1^i	102.06 (3)	C2^iii—Cs—N2	71.59 (9)
S1—Ag—S1^i	92.72 (4)	N2^iii—Cs—N2	78.95 (10)
S3—Ag—Cs^vii	62.07 (3)	C2—Cs—N2	17.35 (8)
S2^i—Ag—Cs^vii	59.40 (3)	S2^v—Cs—N2	94.08 (6)
S1—Ag—Cs^vii	137.04 (3)	S1^vi—Cs—N2	129.41 (6)
S1^i—Ag—Cs^vii	130.04 (3)	S3^ix—Cs—N2	126.66 (6)
S3—Ag—Cs^viii	163.37 (3)	S2—Cs—N2	43.35 (5)
S2^i—Ag—Cs^viii	69.65 (3)	C1^iii—Cs—N2	60.73 (8)
S1—Ag—Cs^viii	59.18 (3)	OW—Cs—S3^x	66.47 (6)
S1^i—Ag—Cs^viii	66.13 (3)	N3^v—Cs—S3^x	116.42 (7)
Cs^vii—Ag—Cs^viii	128.430 (19)	C2^iii—Cs—S3^x	111.64 (7)
N1—Ni—N1^ii	180.00 (6)	N2^iii—Cs—S3^x	98.44 (7)
N1—Ni—N2^iii	90.94 (15)	C2—Cs—S3^x	141.98 (6)
N1^ii—Ni—N2^iii	89.06 (15)	S2^v—Cs—S3^x	71.78 (3)
N1—Ni—N2^iv	89.06 (15)	S1^vi—Cs—S3^x	67.84 (3)
N1^ii—Ni—N2^iv	90.94 (15)	S3^ix—Cs—S3^x	64.69 (2)
N2^iii—Ni—N2^iv	180.00 (11)	S2—Cs—S3^x	116.15 (3)
N1—Ni—OW	92.09 (14)	C1^iii—Cs—S3^x	139.60 (6)
N1^ii—Ni—OW	87.91 (14)	N2—Cs—S3^x	159.17 (5)
N2^iii—Ni—OW	90.46 (15)	C1—S1—Ag	96.23 (13)
N2^iv—Ni—OW	89.54 (15)	C1—S1—Ag^xi	100.23 (14)
N1—Ni—OW^ii	87.91 (14)	Ag—S1—Ag^xi	99.92 (4)
N1^ii—Ni—OW^ii	92.09 (14)	C1—S1—Cs^viii	118.04 (14)
N2^iii—Ni—OW^ii	89.54 (15)	Ag—S1—Cs^viii	83.10 (3)
N2^iv—Ni—OW^ii	90.46 (15)	Ag^xi—S1—Cs^viii	141.17 (3)
OW—Ni—OW^ii	180.00 (8)	C1—S1—Cs^iii	69.56 (13)
OW—Cs—N3^v	129.14 (10)	Ag—S1—Cs^iii	162.93 (4)
OW—Cs—C2^iii	69.58 (8)	Ag^xi—S1—Cs^iii	74.39 (3)
N3^v—Cs—C2^iii	131.90 (9)	Cs^viii—S1—Cs^iii	111.59 (3)
OW—Cs—N2^iii	50.88 (8)	N1—C1—S1	177.4 (4)
N3^v—Cs—N2^iii	141.85 (10)	N1—C1—Cs^iii	91.5 (3)
C2^iii—Cs—N2^iii	18.79 (8)	S1—C1—Cs^iii	86.04 (14)
OW—Cs—C2	81.69 (9)	C1—N1—Ni	173.8 (3)
N3^v—Cs—C2	68.23 (9)	C2—S2—Ag^xi	101.84 (13)
C2^iii—Cs—C2	73.13 (9)	C2—S2—Cs^v	119.75 (14)
N2^iii—Cs—C2	74.84 (9)	Ag^xi—S2—Cs^v	83.16 (3)
OW—Cs—S2^v	82.57 (6)	C2—S2—Cs	72.25 (12)
N3^v—Cs—S2^v	55.42 (8)	Ag^xi—S2—Cs	168.57 (4)
C2^iii—Cs—S2^v	146.16 (6)	Cs^v—S2—Cs	108.25 (3)
N2^iii—Cs—S2^v	130.74 (6)	C2—S2—Cs^iii	58.77 (13)
C2—Cs—S2^v	84.44 (6)	Ag^xi—S2—Cs^iii	74.77 (3)
OW—Cs—S1^vi	96.76 (7)	Cs^v—S2—Cs^iii	156.47 (3)
N3^v—Cs—S1^vi	132.77 (7)	Cs—S2—Cs^iii	93.84 (2)
C2^iii—Cs—S1^vi	68.49 (6)	N2—C2—S2	175.9 (4)
N2^iii—Cs—S1^vi	73.19 (7)	N2—C2—Cs^iii	81.1 (3)
C2—Cs—S1^vi	139.37 (6)	S2—C2—Cs^iii	97.67 (15)
S2^v—Cs—S1^vi	135.89 (3)	N2—C2—Cs	94.9 (3)
OW—Cs—S3^ix	129.90 (6)	S2—C2—Cs	81.74 (13)
N3^v—Cs—S3^ix	67.51 (7)	Cs^iii—C2—Cs	106.87 (9)
C2^iii—Cs—S3^ix	140.64 (6)	C2—N2—Ni^xii	172.4 (4)
N2^iii—Cs—S3^ix	147.65 (7)	C2—N2—Cs^iii	80.1 (3)
C2—Cs—S3^ix	135.69 (6)	Ni^xii—N2—Cs^iii	106.27 (14)
S2^v—Cs—S3^ix	72.50 (3)	C2—N2—Cs	67.8 (2)
S1^vi—Cs—S3^ix	74.81 (3)	Ni^xii—N2—Cs	114.19 (14)
OW—Cs—S2	58.35 (6)	Cs^iii—N2—Cs	101.05 (10)
N3^v—Cs—S2	80.24 (7)	C3—S3—Ag	98.20 (14)
C2^iii—Cs—S2	77.28 (6)	C3—S3—Cs^vii	119.05 (16)
N2^iii—Cs—S2	70.31 (7)	Ag—S3—Cs^vii	80.75 (3)
C2—Cs—S2	26.01 (6)	C3—S3—Cs^x	100.55 (14)
S2^v—Cs—S2	71.75 (3)	Ag—S3—Cs^x	148.08 (5)
S1^vi—Cs—S2	143.48 (3)	Cs^vii—S3—Cs^x	111.52 (3)
S3^ix—Cs—S2	141.31 (3)	N3—C3—S3	177.4 (4)
OW—Cs—C1^iii	147.02 (8)	C3—N3—Cs^v	118.5 (4)
N3^v—Cs—C1^iii	65.38 (9)	Ni—OW—Cs	110.04 (12)
C2^iii—Cs—C1^iii	79.71 (8)	Ni—OW—H1W	113 (6)
N2^iii—Cs—C1^iii	98.37 (8)	Cs—OW—H1W	113 (6)
C2—Cs—C1^iii	78.08 (8)	Ni—OW—H2W	90 (3)
S2^v—Cs—C1^iii	120.61 (6)	Cs—OW—H2W	114 (3)
S1^vi—Cs—C1^iii	82.44 (6)	H1W—OW—H2W	114 (7)

Symmetry codes: (i) x, −y−1/2, z−1/2; (ii) −x+1, −y, −z+1; (iii) −x+1, −y, −z+2; (iv) x, y, z−1; (v) −x+2, −y, −z+2; (vi) −x+1, y+1/2, −z+3/2; (vii) −x+2, y−1/2, −z+3/2; (viii) −x+1, y−1/2, −z+3/2; (ix) −x+2, y+1/2, −z+3/2; (x) −x+2, −y, −z+1; (xi) x, −y−1/2, z+1/2; (xii) x, y, z+1.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
OW—H1W···N3	0.71 (8)	2.31 (8)	3.004 (6)	168 (8)
OW—H2W···N3^x	0.87 (5)	2.27 (5)	3.072 (5)	153 (4)

Symmetry code: (x) −x+2, −y, −z+1.

(II) caesium nickel trithiocyanate

Crystal data

CsNi(SCN)3	F(000) = 680
Mr = 365.86	Dx = 2.633 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 2800 reflections
a = 5.554 (1) Å	θ = 4.1–30.0°
b = 13.294 (3) Å	µ = 6.61 mm^−1
c = 12.589 (3) Å	T = 293 K
β = 96.87 (3)°	Fragment, green
V = 922.8 (3) Å^3	0.15 × 0.08 × 0.05 mm
Z = 4

Data collection

Nonius KappaCCD area-detector diffractometer	2695 independent reflections
Radiation source: fine-focus sealed tube	2441 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.014
Detector resolution: 9 pixels mm^-1	θmax = 30.0°, θmin = 4.2°
ϕ and ω scans	h = −7→7
Absorption correction: multi-scan (Otwinowski & Minor, 1997)	k = −18→17
Tmin = 0.437, Tmax = 0.734	l = −17→17
5137 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.022	w = 1/[σ^2(Fo^2) + (0.0231P)^2 + 1.4456P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.057	(Δ/σ)max = 0.001
S = 1.05	Δρmax = 1.40 e Å^−3
2695 reflections	Δρmin = −1.28 e Å^−3
104 parameters	Extinction correction: SHELXL97 (Sheldrick, 1997), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
0 restraints	Extinction coefficient: 0.0042 (4)

Special details

Experimental. The single-crystal data were collected on a Nonius Kappa CCD four-circle diffractometer using 534 frames with phi and omega-increments of 1 degrees and a counting time of 300 s per frame. The crystal to detector distance was 30 mm. The whole ewald sphere was measured.

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. Single-crystal X-ray intensity data were collected at 293 K on a Nonius Kappa diffractometer with CCD area detector, using Mo—Kα radiation. The reflection data were processed with the Nonius program suite DENZO-SMN and corrected for Lorentz, polarization, background and absorption effects (Otwinowski and Minor, 1997). The crystal structure was determined by either automatic Patterson or direct methods (SHELXS97 - Sheldrick, 1997) and subsequent Fourier and difference Fourier syntheses, followed by full-matrix least-squares refinements on F² (SHELXL97 - Sheldrick, 1997).

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 (Ų)

	x	y	z	Uiso*/Ueq
Cs	0.84679 (3)	0.770463 (15)	0.782236 (14)	0.03794 (8)
Ni1	1.0000	1.0000	1.0000	0.01849 (9)
Ni2	1.0000	1.0000	0.5000	0.01929 (10)
S1	0.73286 (11)	1.14465 (5)	0.42234 (6)	0.03133 (15)
C1	0.4635 (4)	1.09370 (18)	0.42543 (18)	0.0212 (4)
N1	0.2735 (3)	1.05985 (16)	0.42909 (16)	0.0239 (4)
S2	0.75413 (10)	1.16164 (5)	0.98419 (5)	0.02523 (13)
C2	1.4903 (4)	1.11767 (18)	1.01032 (18)	0.0216 (4)
N2	1.3046 (4)	1.08680 (16)	1.02800 (18)	0.0264 (4)
S3	1.14552 (14)	1.10980 (5)	0.65465 (5)	0.03376 (15)
C3	1.0811 (4)	1.04944 (19)	0.76231 (19)	0.0252 (5)
N3	1.0350 (4)	1.01092 (18)	0.83928 (17)	0.0311 (5)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cs	0.04006 (12)	0.04138 (12)	0.03114 (10)	0.00496 (7)	−0.00081 (7)	−0.00430 (7)
Ni1	0.01560 (18)	0.0232 (2)	0.01736 (18)	−0.00227 (14)	0.00478 (13)	0.00133 (14)
Ni2	0.01391 (17)	0.0246 (2)	0.01988 (19)	−0.00270 (14)	0.00413 (14)	0.00280 (14)
S1	0.0172 (3)	0.0292 (3)	0.0479 (4)	−0.0036 (2)	0.0053 (2)	0.0109 (3)
C1	0.0184 (9)	0.0234 (10)	0.0218 (10)	0.0023 (8)	0.0034 (8)	0.0048 (8)
N1	0.0172 (8)	0.0283 (10)	0.0267 (9)	−0.0004 (7)	0.0050 (7)	0.0051 (8)
S2	0.0180 (2)	0.0243 (3)	0.0339 (3)	−0.0026 (2)	0.0051 (2)	0.0048 (2)
C2	0.0203 (10)	0.0201 (10)	0.0243 (10)	0.0027 (8)	0.0028 (8)	−0.0007 (8)
N2	0.0180 (9)	0.0241 (10)	0.0377 (11)	−0.0003 (8)	0.0060 (8)	−0.0018 (8)
S3	0.0473 (4)	0.0331 (3)	0.0214 (3)	−0.0161 (3)	0.0064 (2)	0.0007 (2)
C3	0.0260 (11)	0.0276 (12)	0.0224 (10)	−0.0022 (9)	0.0043 (9)	−0.0023 (9)
N3	0.0365 (12)	0.0372 (12)	0.0205 (9)	−0.0015 (10)	0.0075 (8)	0.0013 (8)

Geometric parameters (Å, º)

Cs—N2^i	3.240 (2)	Ni1—N3	2.061 (2)
Cs—N3	3.413 (3)	Ni1—S2	2.5411 (8)
Cs—C1^ii	3.462 (2)	Ni1—S2^i	2.5411 (8)
Cs—N1^ii	3.491 (2)	Ni2—N1^ii	2.015 (2)
Cs—S3^iii	3.5508 (9)	Ni2—N1^vi	2.015 (2)
Cs—S2^i	3.5798 (13)	Ni2—S3^v	2.4896 (8)
Cs—S3^iv	3.6317 (10)	Ni2—S3	2.4896 (8)
Cs—S2^iv	3.6341 (10)	Ni2—S1^v	2.5511 (8)
Cs—C2^i	3.702 (2)	Ni2—S1	2.5511 (8)
Cs—C3^iv	3.778 (3)	S1—C1	1.647 (2)
Cs—S1^v	3.8464 (12)	C1—N1	1.154 (3)
Cs—S1^ii	4.0357 (14)	S2—C2^vii	1.647 (2)
Ni1—N2^i	2.043 (2)	C2—N2	1.156 (3)
Ni1—N2	2.043 (2)	S3—C3	1.651 (3)
Ni1—N3^i	2.061 (2)	C3—N3	1.152 (3)
N2^i—Cs—N3	52.85 (5)	N3—Ni1—S2	88.65 (7)
N2^i—Cs—C1^ii	95.83 (6)	N2^i—Ni1—S2^i	87.82 (6)
N3—Cs—C1^ii	77.44 (6)	N2—Ni1—S2^i	92.18 (6)
N2^i—Cs—N1^ii	98.08 (6)	N3^i—Ni1—S2^i	88.65 (7)
N3—Cs—N1^ii	65.23 (5)	N3—Ni1—S2^i	91.35 (7)
C1^ii—Cs—N1^ii	19.09 (5)	S2—Ni1—S2^i	180.0
N2^i—Cs—S3^iii	117.16 (4)	N2^i—Ni1—Cs^i	129.31 (6)
N3—Cs—S3^iii	107.54 (5)	N2—Ni1—Cs^i	50.69 (6)
C1^ii—Cs—S3^iii	142.46 (4)	N3^i—Ni1—Cs^i	55.62 (7)
N1^ii—Cs—S3^iii	129.32 (4)	N3—Ni1—Cs^i	124.38 (7)
N2^i—Cs—S2^i	55.69 (4)	S2—Ni1—Cs^i	59.49 (2)
N3—Cs—S2^i	56.43 (4)	S2^i—Ni1—Cs^i	120.51 (2)
C1^ii—Cs—S2^i	133.80 (4)	N2^i—Ni1—Cs	50.69 (6)
N1^ii—Cs—S2^i	120.41 (4)	N2—Ni1—Cs	129.31 (6)
S3^iii—Cs—S2^i	64.58 (2)	N3^i—Ni1—Cs	124.38 (7)
N2^i—Cs—S3^iv	85.10 (4)	N3—Ni1—Cs	55.62 (7)
N3—Cs—S3^iv	136.42 (4)	S2—Ni1—Cs	120.51 (2)
C1^ii—Cs—S3^iv	98.75 (4)	S2^i—Ni1—Cs	59.49 (2)
N1^ii—Cs—S3^iv	117.80 (4)	Cs^i—Ni1—Cs	180.0
S3^iii—Cs—S3^iv	101.29 (2)	N1^ii—Ni2—N1^vi	180.00 (11)
S2^i—Cs—S3^iv	112.15 (2)	N1^ii—Ni2—S3^v	85.62 (7)
N2^i—Cs—S2^iv	152.72 (4)	N1^vi—Ni2—S3^v	94.38 (7)
N3—Cs—S2^iv	125.21 (4)	N1^ii—Ni2—S3	94.38 (7)
C1^ii—Cs—S2^iv	60.19 (4)	N1^vi—Ni2—S3	85.62 (7)
N1^ii—Cs—S2^iv	63.87 (4)	S3^v—Ni2—S3	180.0
S3^iii—Cs—S2^iv	89.87 (3)	N1^ii—Ni2—S1^v	88.12 (6)
S2^i—Cs—S2^iv	150.51 (2)	N1^vi—Ni2—S1^v	91.88 (6)
S3^iv—Cs—S2^iv	86.03 (3)	S3^v—Ni2—S1^v	88.70 (3)
N2^i—Cs—C2^i	17.60 (5)	S3—Ni2—S1^v	91.30 (3)
N3—Cs—C2^i	69.10 (5)	N1^ii—Ni2—S1	91.88 (6)
C1^ii—Cs—C2^i	94.31 (5)	N1^vi—Ni2—S1	88.12 (6)
N1^ii—Cs—C2^i	102.19 (5)	S3^v—Ni2—S1	91.30 (3)
S3^iii—Cs—C2^i	122.60 (4)	S3—Ni2—S1	88.70 (3)
S2^i—Cs—C2^i	68.59 (4)	S1^v—Ni2—S1	180.0
S3^iv—Cs—C2^i	67.94 (4)	C1—S1—Ni2	99.74 (8)
S2^iv—Cs—C2^i	140.87 (4)	C1—S1—Cs^v	139.67 (9)
N2^i—Cs—C3^iv	110.54 (5)	Ni2—S1—Cs^v	96.08 (2)
N3—Cs—C3^iv	158.59 (6)	C1—S1—Cs^ii	58.17 (8)
C1^ii—Cs—C3^iv	92.64 (6)	Ni2—S1—Cs^ii	146.96 (3)
N1^ii—Cs—C3^iv	109.26 (5)	Cs^v—S1—Cs^ii	89.57 (2)
S3^iii—Cs—C3^iv	91.95 (4)	C1—S1—Cs^viii	87.14 (9)
S2^i—Cs—C3^iv	129.39 (4)	Ni2—S1—Cs^viii	94.58 (3)
S3^iv—Cs—C3^iv	25.64 (4)	Cs^v—S1—Cs^viii	128.33 (2)
S2^iv—Cs—C3^iv	61.88 (4)	Cs^ii—S1—Cs^viii	107.27 (3)
C2^i—Cs—C3^iv	93.15 (5)	N1—C1—S1	178.4 (2)
N2^i—Cs—S1^v	123.62 (4)	N1—C1—Cs^ii	81.86 (15)
N3—Cs—S1^v	70.79 (4)	S1—C1—Cs^ii	98.00 (9)
C1^ii—Cs—S1^v	68.20 (4)	C1—N1—Ni2^vii	156.00 (19)
N1^ii—Cs—S1^v	51.41 (4)	C1—N1—Cs^ii	79.05 (15)
S3^iii—Cs—S1^v	78.28 (2)	Ni2^vii—N1—Cs^ii	120.47 (8)
S2^i—Cs—S1^v	96.33 (2)	C2^vii—S2—Ni1	99.61 (8)
S3^iv—Cs—S1^v	148.450 (18)	C2^vii—S2—Cs^i	113.81 (9)
S2^iv—Cs—S1^v	62.47 (2)	Ni1—S2—Cs^i	82.80 (2)
C2^i—Cs—S1^v	138.86 (4)	C2^vii—S2—Cs^viii	106.44 (9)
C3^iv—Cs—S1^v	123.38 (4)	Ni1—S2—Cs^viii	115.53 (3)
N2^i—Cs—S1^ii	92.82 (4)	Cs^i—S2—Cs^viii	132.05 (2)
N3—Cs—S1^ii	94.20 (4)	N2—C2—S2^vi	179.6 (2)
C1^ii—Cs—S1^ii	23.83 (4)	N2—C2—Cs^i	57.91 (15)
N1^ii—Cs—S1^ii	42.92 (4)	S2^vi—C2—Cs^i	122.37 (11)
S3^iii—Cs—S1^ii	149.599 (18)	C2—N2—Ni1	155.0 (2)
S2^i—Cs—S1^ii	145.28 (2)	C2—N2—Cs^i	104.49 (17)
S3^iv—Cs—S1^ii	74.93 (2)	Ni1—N2—Cs^i	100.11 (8)
S2^iv—Cs—S1^ii	59.94 (2)	C3—S3—Ni2	105.97 (9)
C2^i—Cs—S1^ii	84.59 (4)	C3—S3—Cs^ix	110.67 (9)
C3^iv—Cs—S1^ii	71.53 (4)	Ni2—S3—Cs^ix	134.63 (3)
S1^v—Cs—S1^ii	89.57 (2)	C3—S3—Cs^viii	82.15 (9)
N2^i—Ni1—N2	180.00 (10)	Ni2—S3—Cs^viii	109.48 (3)
N2^i—Ni1—N3^i	87.50 (10)	Cs^ix—S3—Cs^viii	101.29 (2)
N2—Ni1—N3^i	92.50 (10)	N3—C3—S3	177.3 (2)
N2^i—Ni1—N3	92.50 (10)	N3—C3—Cs^viii	105.75 (19)
N2—Ni1—N3	87.50 (10)	S3—C3—Cs^viii	72.21 (9)
N3^i—Ni1—N3	180.000 (1)	C3—N3—Ni1	156.1 (2)
N2^i—Ni1—S2	92.18 (6)	C3—N3—Cs	109.44 (18)
N2—Ni1—S2	87.82 (6)	Ni1—N3—Cs	94.48 (8)
N3^i—Ni1—S2	91.35 (7)

Symmetry codes: (i) −x+2, −y+2, −z+2; (ii) −x+1, −y+2, −z+1; (iii) −x+5/2, y−1/2, −z+3/2; (iv) −x+3/2, y−1/2, −z+3/2; (v) −x+2, −y+2, −z+1; (vi) x+1, y, z; (vii) x−1, y, z; (viii) −x+3/2, y+1/2, −z+3/2; (ix) −x+5/2, y+1/2, −z+3/2.