K₂LaCl₅

Abstract

The ternary title compound, dipotassium lanthanum penta­chloride, K₂LaCl₅, is isotypic with Y₂HfS₅ and various ternary rare-earth metal(III) halides with the general formula A ₂ MX ₅ (A = NH₄, In^I, Na–Cs; M = La–Dy; X = Cl–I). The La³⁺ cations and three of the four symmetry-independent chloride anions are located on a crystallographic mirror plane. The La³⁺ cations are surrounded by seven chloride anions, each in the shape of a monocapped trigonal prism, whereas the coordination spheres of the K⁺ cations exhibit one more cap. Three of the four independent chloride anions reside in a fivefold cationic coordination, leading to distorted square pyramids. The fourth chloride anion has only four cationic neighbours, forming no specific polyhedron.

Related literature

For the U₃ Ch ₅-type structure (Ch = S and Se) and its relationship to Y₂HfS₅, see: Moseley et al. (1972 ▶); Potel et al. (1972 ▶); Jeitschko & Donohue (1975 ▶). For the low-temperature phase of Yb₅Sb₃, see: Brunton & Steinfink (1971 ▶). For the series of the ternary rare-earth metal(III) halides with A = NH₄, In^I, Na – Cs; M = La – Dy; X = Cl – I, see: Meyer & Hüttl (1983 ▶); Meyer et al. (1985 ▶); Wickleder & Meyer (1995 ▶).

Experimental

Crystal data

• K₂LaCl₅

• M _r = 394.36

• Orthorhombic,

• a = 12.7402 (8) Å

• b = 8.8635 (6) Å

• c = 8.0174 (5) Å

• V = 905.35 (10) ų

• Z = 4

• Mo Kα radiation

• μ = 7.02 mm⁻¹

• T = 293 K

• 0.33 × 0.28 × 0.24 mm

Data collection

• Stoe IPDS-I diffractometer

• Absorption correction: numerical (X-SHAPE; Stoe & Cie, 1999 ▶) T _min = 0.106, T _max = 0.185

• 12421 measured reflections

• 1650 independent reflections

• 872 reflections with I > 2σ(I)

• R _int = 0.139

Refinement

• R[F ² > 2σ(F ²)] = 0.059

• wR(F ²) = 0.142

• S = 0.90

• 1650 reflections

• 44 parameters

• Δρ_max = 1.58 e Å⁻³

• Δρ_min = −2.64 e Å⁻³

Data collection: DIF4 (Stoe & Cie, 1992 ▶); cell refinement: DIF4; data reduction: REDU4 (Stoe & Cie, 1992 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: DIAMOND (Brandenburg, 2006 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

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

Table 1. Selected bond lengths (Å).

K—Cl1i	3.160 (3)
K—Cl2	3.177 (3)
K—Cl1ii	3.206 (3)
K—Cl2iii	3.234 (3)
K—Cl3iv	3.272 (4)
K—Cl4	3.304 (3)
K—Cl4iii	3.327 (3)
K—Cl3	3.351 (4)
La—Cl3v	2.812 (3)
La—Cl1i	2.833 (3)
La—Cl2vi	2.845 (3)
La—Cl4	2.858 (2)
La—Cl4vii	2.858 (2)
La—Cl4viii	2.895 (2)
La—Cl4ix	2.895 (2)

Symmetry codes: (i) ; (ii) ; (iii) ; (iv) ; (v) ; (vi) ; (vii) ; (viii) ; (ix) .

supplementary crystallographic information

Comment

The ternary rare-earth metal(III) halide K₂LaCl₅ (Fig. 1) belongs to the A₂MX₅ series (A = NH₄, In, Na – Cs; M = La – Dy; X = Cl – I) (Meyer & Hüttl, 1983; Meyer et al., 1985; Wickleder & Meyer 1995). It can be described as ordered structural variety of U₃Ch₅ (Ch = S and Se) or the low-temperature phase of Yb₅Sb₃, respectively, as anti-isotypical arrangement. While the K⁺ cations have eight contacts to Cl^- anions (Fig. 2), the La³⁺ cations are surrounded by only seven of them. In both cases distorted mono- or bicapped trigonal prisms [LaCl₇]^4– or [KCl₈]^7– originate. For the lanthanum bearing ones they are linked via common edges and form chains, which run along [010] (Fig. 3). Together with the chloride anions (Cl1)^-, (Cl2)^– and (Cl3)^-, La³⁺ occupies the 4c position and shows the site symmetry m, while the (Cl4)^- anion and the K⁺ cation are located at the 8d position with the site symmetry 1.

Experimental

Colourless, transparent, brick-shaped single crystals of K₂LaCl₅ were obtained as by-product from the reaction of potassium azide (KN₃), lanthanum (La), the corresponding sesquioxide (La₂O₃) and trichloride (LaCl₃) in the presence of KCl as flux with the purpose to synthesize K₂La₄ONCl₉. The mixture was transferred into a torch-sealed, evacuated, fused silica vessel, heated at 1123 K for seven days, followed by cooling to room temperature within 24 h.

Figures

Fig. 1.

Crystal structure of K2LaCl5 as viewed along [010].

Fig. 2.

Coordination sphere of the K+ cations with the shape of a bicapped trigonal prism. [Symmetry codes: (i) –x+1/2, –y + 1, z–1/2; (ii) x+1/2, y, –z+3/2; (iii) –x+3/2, –y + 1, z+1/2; (iv) –x+3/2, –y + 1, z–1/2.]

Fig. 3.

View at the chain formed by edge-sharing monocapped trigonal prisms [LaCl7]4– with its contacts to the K+ cations. Displacement ellipsoids are drawn at 90% probability level.

Crystal data

K2LaCl5	F(000) = 720
Mr = 394.36	Dx = 2.893 Mg m−3
Orthorhombic, Pnma	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2n	θ = 3.4–33.0°
a = 12.7402 (8) Å	µ = 7.02 mm−1
b = 8.8635 (6) Å	T = 293 K
c = 8.0174 (5) Å	Bricks, colourless
V = 905.35 (10) Å3	0.33 × 0.28 × 0.24 mm
Z = 4

Data collection

Stoe IPDS-I diffractometer	1650 independent reflections
Radiation source: fine-focus sealed tube	872 reflections with I > 2σ(I)
graphite	Rint = 0.139
imaging plate detector system scans	θmax = 33.0°, θmin = 3.4°
Absorption correction: numerical (X-SHAPE; Stoe & Cie, 1999)	h = −19→19
Tmin = 0.106, Tmax = 0.185	k = −11→11
12421 measured reflections	l = −12→12

Refinement

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)] = 0.059	w = 1/[σ2(Fo2) + (0.0799P)2] where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.142	(Δ/σ)max = 0.004
S = 0.90	Δρmax = 1.58 e Å−3
1650 reflections	Δρmin = −2.64 e Å−3
44 parameters	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
0 restraints	Extinction coefficient: 0.0094 (12)

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq
K	0.67125 (15)	0.4946 (3)	0.5481 (3)	0.0379 (5)
La	0.50680 (5)	0.2500	0.07776 (8)	0.0248 (2)
Cl1	−0.0065 (2)	0.7500	0.9311 (4)	0.0310 (6)
Cl2	0.7911 (2)	0.2500	0.3299 (4)	0.0333 (7)
Cl3	0.6828 (2)	0.2500	0.8662 (4)	0.0374 (8)
Cl4	0.57990 (17)	0.5441 (3)	0.1663 (3)	0.0342 (5)

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
K	0.0381 (10)	0.0363 (14)	0.0393 (11)	0.0014 (8)	−0.0014 (7)	−0.0070 (9)
La	0.0286 (3)	0.0234 (4)	0.0222 (3)	0.000	0.0022 (3)	0.000
Cl1	0.0347 (13)	0.0354 (17)	0.0228 (11)	0.000	0.0016 (12)	0.000
Cl2	0.0282 (13)	0.039 (2)	0.0322 (15)	0.000	0.0006 (11)	0.000
Cl3	0.0368 (15)	0.045 (2)	0.0308 (15)	0.000	0.0088 (12)	0.000
Cl4	0.0460 (12)	0.0267 (13)	0.0301 (10)	−0.0030 (9)	−0.0102 (8)	0.0025 (8)

Geometric parameters (Å, °)

K—Cl1i	3.160 (3)	La—Cl4x	2.895 (2)
K—Cl2	3.177 (3)	La—Kvi	4.389 (2)
K—Cl1ii	3.206 (3)	La—Kxi	4.389 (2)
K—Cl2iii	3.234 (3)	Cl1—Laxii	2.833 (3)
K—Cl3iv	3.272 (4)	Cl1—Kxii	3.160 (3)
K—Cl4	3.304 (3)	Cl1—Kxiii	3.160 (3)
K—Cl4iii	3.327 (3)	Cl1—Kxiv	3.206 (3)
K—Cl3	3.351 (4)	Cl1—Kxv	3.206 (3)
K—Kv	4.336 (5)	Cl2—Laxvi	2.845 (3)
K—Lavi	4.389 (2)	Cl2—Kv	3.177 (3)
K—Kvi	4.432 (4)	Cl2—Kxvii	3.234 (3)
K—Kiii	4.4838 (18)	Cl2—Kiv	3.234 (3)
La—Cl3vii	2.812 (3)	Cl3—Laxviii	2.812 (3)
La—Cl1i	2.833 (3)	Cl3—Kiii	3.272 (4)
La—Cl2viii	2.845 (3)	Cl3—Kxix	3.272 (3)
La—Cl4	2.858 (2)	Cl3—Kv	3.351 (4)
La—Cl4v	2.858 (2)	Cl4—Lax	2.895 (2)
La—Cl4ix	2.895 (2)	Cl4—Kiv	3.327 (3)
Cl1i—K—Cl2	71.80 (8)	Cl3vii—La—Cl4	83.68 (6)
Cl1i—K—Cl1ii	91.76 (5)	Cl1i—La—Cl4	75.64 (5)
Cl2—K—Cl1ii	148.21 (10)	Cl2viii—La—Cl4	104.48 (5)
Cl1i—K—Cl2iii	141.81 (10)	Cl3vii—La—Cl4v	83.68 (6)
Cl2—K—Cl2iii	142.29 (7)	Cl1i—La—Cl4v	75.64 (5)
Cl1ii—K—Cl2iii	64.80 (8)	Cl2viii—La—Cl4v	104.48 (5)
Cl1i—K—Cl3iv	136.03 (10)	Cl4—La—Cl4v	131.62 (9)
Cl2—K—Cl3iv	87.34 (7)	Cl3vii—La—Cl4ix	84.06 (7)
Cl1ii—K—Cl3iv	86.34 (8)	Cl1i—La—Cl4ix	132.50 (6)
Cl2iii—K—Cl3iv	75.11 (8)	Cl2viii—La—Cl4ix	78.89 (7)
Cl1i—K—Cl4	65.30 (7)	Cl4—La—Cl4ix	150.15 (6)
Cl2—K—Cl4	75.52 (8)	Cl4v—La—Cl4ix	73.58 (7)
Cl1ii—K—Cl4	72.88 (8)	Cl3vii—La—Cl4x	84.06 (7)
Cl2iii—K—Cl4	127.34 (10)	Cl1i—La—Cl4x	132.50 (6)
Cl3iv—K—Cl4	72.27 (8)	Cl2viii—La—Cl4x	78.89 (7)
Cl1i—K—Cl4iii	130.30 (10)	Cl4—La—Cl4x	73.58 (7)
Cl2—K—Cl4iii	68.18 (8)	Cl4v—La—Cl4x	150.15 (6)
Cl1ii—K—Cl4iii	136.98 (9)	Cl4ix—La—Cl4x	78.15 (9)
Cl2iii—K—Cl4iii	74.46 (8)	Cl3vii—La—Kvi	145.53 (4)
Cl3iv—K—Cl4iii	69.93 (8)	Cl1i—La—Kvi	46.84 (5)
Cl4—K—Cl4iii	127.83 (9)	Cl2viii—La—Kvi	47.41 (5)
Cl1i—K—Cl3	79.12 (8)	Cl4—La—Kvi	61.85 (6)
Cl2—K—Cl3	87.50 (8)	Cl4v—La—Kvi	117.97 (6)
Cl1ii—K—Cl3	116.64 (9)	Cl4ix—La—Kvi	126.15 (5)
Cl2iii—K—Cl3	85.10 (7)	Cl4x—La—Kvi	86.55 (6)
Cl3iv—K—Cl3	139.63 (8)	Cl3vii—La—Kxi	145.53 (4)
Cl4—K—Cl3	143.76 (10)	Cl1i—La—Kxi	46.84 (5)
Cl4iii—K—Cl3	71.00 (8)	Cl2viii—La—Kxi	47.41 (5)
Cl1i—K—Kv	46.68 (5)	Cl4—La—Kxi	117.97 (6)
Cl2—K—Kv	46.96 (6)	Cl4v—La—Kxi	61.85 (6)
Cl1ii—K—Kv	134.91 (5)	Cl4ix—La—Kxi	86.55 (6)
Cl2iii—K—Kv	134.42 (6)	Cl4x—La—Kxi	126.15 (6)
Cl3iv—K—Kv	133.77 (6)	Kvi—La—Kxi	62.09 (7)
Cl4—K—Kv	97.63 (6)	Laxii—Cl1—Kxii	107.21 (8)
Cl4iii—K—Kv	84.07 (6)	Laxii—Cl1—Kxiii	107.21 (8)
Cl3—K—Kv	49.68 (5)	Kxii—Cl1—Kxiii	86.64 (11)
Cl1i—K—Lavi	102.32 (7)	Laxii—Cl1—Kxiv	93.04 (7)
Cl2—K—Lavi	167.59 (9)	Kxii—Cl1—Kxiv	159.73 (10)
Cl1ii—K—Lavi	40.13 (5)	Kxiii—Cl1—Kxiv	88.24 (5)
Cl2iii—K—Lavi	40.37 (6)	Laxii—Cl1—Kxv	93.04 (7)
Cl3iv—K—Lavi	103.97 (7)	Kxii—Cl1—Kxv	88.24 (5)
Cl4—K—Lavi	112.49 (7)	Kxiii—Cl1—Kxv	159.73 (10)
Cl4iii—K—Lavi	110.55 (6)	Kxiv—Cl1—Kxv	89.82 (11)
Cl3—K—Lavi	80.57 (6)	Laxvi—Cl2—Kv	108.72 (9)
Kv—K—Lavi	121.04 (3)	Laxvi—Cl2—K	108.72 (9)
Cl1i—K—Kvi	46.30 (6)	Kv—Cl2—K	86.07 (11)
Cl2—K—Kvi	113.09 (10)	Laxvi—Cl2—Kxvii	92.22 (8)
Cl1ii—K—Kvi	45.45 (6)	Kv—Cl2—Kxvii	88.75 (3)
Cl2iii—K—Kvi	104.62 (9)	K—Cl2—Kxvii	159.00 (11)
Cl3iv—K—Kvi	117.84 (10)	Laxvi—Cl2—Kiv	92.22 (8)
Cl4—K—Kvi	59.28 (6)	Kv—Cl2—Kiv	159.00 (11)
Cl4iii—K—Kvi	171.90 (11)	K—Cl2—Kiv	88.75 (3)
Cl3—K—Kvi	100.93 (9)	Kxvii—Cl2—Kiv	88.84 (11)
Kv—K—Kvi	91.23 (7)	Laxviii—Cl3—Kiii	100.62 (8)
Lavi—K—Kvi	66.36 (5)	Laxviii—Cl3—Kxix	100.62 (8)
Cl1i—K—Kiii	125.25 (10)	Kiii—Cl3—Kxix	87.54 (11)
Cl2—K—Kiii	106.95 (10)	Laxviii—Cl3—K	115.09 (9)
Cl1ii—K—Kiii	104.75 (8)	Kiii—Cl3—K	85.21 (4)
Cl2iii—K—Kiii	45.10 (6)	Kxix—Cl3—K	144.27 (10)
Cl3iv—K—Kiii	97.44 (9)	Laxviii—Cl3—Kv	115.10 (9)
Cl4—K—Kiii	169.44 (11)	Kiii—Cl3—Kv	144.27 (10)
Cl4iii—K—Kiii	47.24 (6)	Kxix—Cl3—Kv	85.21 (4)
Cl3—K—Kiii	46.65 (6)	K—Cl3—Kv	80.64 (10)
Kv—K—Kiii	91.22 (6)	La—Cl4—Lax	106.42 (7)
Lavi—K—Kiii	67.00 (4)	La—Cl4—K	102.93 (8)
Kvi—K—Kiii	126.56 (8)	Lax—Cl4—K	147.62 (10)
Cl3vii—La—Cl1i	127.18 (9)	La—Cl4—Kiv	98.37 (8)
Cl3vii—La—Cl2viii	157.97 (10)	Lax—Cl4—Kiv	103.65 (8)
Cl1i—La—Cl2viii	74.85 (9)	K—Cl4—Kiv	85.10 (6)

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