Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270103003731/bc1007sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270103003731/bc1007Isup2.hkl |
The title compound, KYNb_{6}Cl_{18}, was initially obtained as shiny black cuboctahedral crystals from a reaction proposed to yield an oxychloride compound of the composition K_{2}Y_{2}Nb_{6}Cl_{14}O_{5}. The compound was prepared quantitatively from a stoichiometric mixture containing NbCl_{5} (Alfa, 99.8%), Nb powder (Alfa 99.8%), YCl_{3} (Alfa 99.9%), and KCl (Alfa, 99.99%). The mixture was handled under an argon atmosphere and the reaction was performed in a sealed quartz tube at 1023 K over a period of 4 d. The heating and cooling ramps were 20 and 10 K h^{−1}, respectively.
Data collection: XSCANS (Siemens, 1996); cell refinement: XSCANS; data reduction: SHELXTL (Bruker, 1999); program(s) used to solve structure: SHELXTL; program(s) used to refine structure: SHELXTL.
KYNb_{6}Cl_{18} | D_{x} = 3.500 Mg m^{−}^{3} |
M_{r} = 1323.57 | Mo Kα radiation, λ = 0.71073 Å |
Trigonal, R3 | Cell parameters from 38 reflections |
Hall symbol: -R 3 | θ = 2.7–12.5° |
a = 9.2527 (6) Å | µ = 7.00 mm^{−}^{1} |
c = 25.410 (2) Å | T = 293 K |
V = 1884.0 (2) Å^{3} | Truncated cuboctahedron, black |
Z = 3 | 0.20 × 0.17 × 0.15 mm |
F(000) = 1830 |
Bruker P4 diffractometer | 1045 reflections with I > 2σ(I) |
Radiation source: normal-focus sealed tube | R_{int} = 0.028 |
Graphite monochromator | θ_{max} = 31.0°, θ_{min} = 2.4° |
ω scans | h = −1→13 |
Absorption correction: empirical (using intensity measurements) via ψ scan (North et al., 1968) | k = −13→1 |
T_{min} = 0.709, T_{max} = 0.965 | l = −1→36 |
1803 measured reflections | 3 standard reflections every 297 reflections |
1342 independent reflections | intensity decay: none |
Refinement on F^{2} | 0 restraints |
Least-squares matrix: full | Primary atom site location: structure-invariant direct methods |
R[F^{2} > 2σ(F^{2})] = 0.032 | Secondary atom site location: difference Fourier map |
wR(F^{2}) = 0.050 | w = 1/[σ^{2}(F_{o}^{2}) + (0.0137P)^{2} + 0.4236P] where P = (F_{o}^{2} + 2F_{c}^{2})/3 |
S = 1.03 | (Δ/σ)_{max} = 0.001 |
1342 reflections | Δρ_{max} = 0.77 e Å^{−}^{3} |
42 parameters | Δρ_{min} = −0.90 e Å^{−}^{3} |
KYNb_{6}Cl_{18} | Z = 3 |
M_{r} = 1323.57 | Mo Kα radiation |
Trigonal, R3 | µ = 7.00 mm^{−}^{1} |
a = 9.2527 (6) Å | T = 293 K |
c = 25.410 (2) Å | 0.20 × 0.17 × 0.15 mm |
V = 1884.0 (2) Å^{3} |
Bruker P4 diffractometer | 1045 reflections with I > 2σ(I) |
Absorption correction: empirical (using intensity measurements) via ψ scan (North et al., 1968) | R_{int} = 0.028 |
T_{min} = 0.709, T_{max} = 0.965 | 3 standard reflections every 297 reflections |
1803 measured reflections | intensity decay: none |
1342 independent reflections |
R[F^{2} > 2σ(F^{2})] = 0.032 | 42 parameters |
wR(F^{2}) = 0.050 | 0 restraints |
S = 1.03 | Δρ_{max} = 0.77 e Å^{−}^{3} |
1342 reflections | Δρ_{min} = −0.90 e Å^{−}^{3} |
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 F^{2} against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F^{2}, conventional R-factors R are based on F, with F set to zero for negative F^{2}. The threshold expression of F^{2} > σ(F^{2}) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F^{2} 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 | U_{iso}*/U_{eq} | Occ. (<1) | |
Nb | 0.04066 (4) | −0.15832 (4) | 0.046790 (12) | 0.00829 (7) | |
Cl1 | 0.08430 (13) | −0.36696 (13) | 0.10715 (4) | 0.01615 (19) | |
Cl2 | −0.18582 (12) | −0.23352 (12) | 0.11040 (3) | 0.01529 (18) | |
Cl3 | 0.27860 (13) | −0.14169 (13) | −0.00074 (4) | 0.01407 (18) | |
Y | 0.33333 | −0.33333 | 0.16667 | 0.01086 (17) | |
K | −0.33333 | −0.66667 | 0.11103 (19) | 0.0419 (11) | 0.50 |
U^{11} | U^{22} | U^{33} | U^{12} | U^{13} | U^{23} | |
Nb | 0.00856 (15) | 0.00834 (16) | 0.00833 (11) | 0.00451 (13) | −0.00005 (13) | 0.00062 (13) |
Cl1 | 0.0166 (5) | 0.0164 (4) | 0.0169 (4) | 0.0094 (4) | −0.0032 (4) | 0.0027 (4) |
Cl2 | 0.0162 (5) | 0.0181 (5) | 0.0139 (4) | 0.0104 (4) | 0.0046 (4) | 0.0058 (4) |
Cl3 | 0.0139 (4) | 0.0169 (5) | 0.0159 (3) | 0.0111 (4) | 0.0023 (4) | 0.0034 (3) |
Y | 0.0111 (3) | 0.0111 (3) | 0.0103 (4) | 0.00556 (13) | 0.000 | 0.000 |
K | 0.0420 (16) | 0.0420 (16) | 0.042 (2) | 0.0210 (8) | 0.000 | 0.000 |
Nb—Cl3 | 2.4476 (10) | Y—Cl1^{vii} | 2.6414 (10) |
Nb—Cl3^{i} | 2.4498 (10) | Y—Cl1^{viii} | 2.6414 (10) |
Nb—Cl2^{ii} | 2.4554 (10) | Y—Cl1^{ix} | 2.6414 (10) |
Nb—Cl2 | 2.4556 (10) | Y—Cl1^{x} | 2.6414 (10) |
Nb—Cl1 | 2.6497 (10) | Y—Cl1^{xi} | 2.6414 (10) |
Nb—Nb^{i} | 2.9143 (6) | K—Cl1^{xii} | 3.4520 (11) |
Nb—Nb^{iii} | 2.9142 (6) | K—Cl1^{xiii} | 3.4520 (11) |
Nb—Nb^{ii} | 2.9182 (6) | K—Cl2^{x} | 3.463 (4) |
Nb—Nb^{iv} | 2.9182 (6) | K—Cl2^{v} | 3.464 (4) |
Cl1—Y | 2.6414 (10) | K—Cl2^{xiv} | 3.464 (4) |
Cl1—K | 3.4520 (11) | K—Cl3^{vi} | 3.486 (4) |
Cl2—Nb^{iv} | 2.4554 (10) | K—Cl3^{xv} | 3.486 (4) |
Cl2—K^{v} | 3.464 (4) | K—Cl3^{i} | 3.486 (4) |
Cl2—K | 3.5292 (10) | K—Cl2^{xii} | 3.5292 (10) |
Cl3—Nb^{iii} | 2.4498 (10) | K—Cl2^{xiii} | 3.5292 (10) |
Cl3—K^{vi} | 3.486 (4) | ||
Cl3—Nb—Cl3^{i} | 88.818 (12) | Cl1—K—Cl1^{xiii} | 119.919 (8) |
Cl3—Nb—Cl2^{ii} | 89.67 (4) | Cl1^{xii}—K—Cl2^{x} | 61.00 (4) |
Cl3^{i}—Nb—Cl2^{ii} | 162.98 (4) | Cl1—K—Cl2^{x} | 93.03 (7) |
Cl3—Nb—Cl2 | 162.94 (3) | Cl1^{xiii}—K—Cl2^{x} | 120.15 (11) |
Cl3^{i}—Nb—Cl2 | 88.05 (4) | Cl1^{xii}—K—Cl2^{v} | 120.15 (11) |
Cl2^{ii}—Nb—Cl2 | 88.43 (5) | Cl1—K—Cl2^{v} | 61.00 (4) |
Cl3—Nb—Cl1 | 82.62 (3) | Cl1^{xiii}—K—Cl2^{v} | 93.03 (7) |
Cl3^{i}—Nb—Cl1 | 80.56 (3) | Cl2^{x}—K—Cl2^{v} | 59.26 (8) |
Cl2^{ii}—Nb—Cl1 | 82.43 (3) | Cl1^{xii}—K—Cl2^{xiv} | 93.03 (7) |
Cl2—Nb—Cl1 | 80.32 (3) | Cl1—K—Cl2^{xiv} | 120.15 (11) |
Cl3—Nb—Nb^{i} | 95.50 (3) | Cl1^{xiii}—K—Cl2^{xiv} | 61.00 (4) |
Cl3^{i}—Nb—Nb^{i} | 53.45 (3) | Cl2^{x}—K—Cl2^{xiv} | 59.26 (8) |
Cl2^{ii}—Nb—Nb^{i} | 143.55 (3) | Cl2^{v}—K—Cl2^{xiv} | 59.26 (8) |
Cl2—Nb—Nb^{i} | 96.08 (3) | Cl1^{xii}—K—Cl3^{vi} | 56.81 (4) |
Cl1—Nb—Nb^{i} | 134.01 (3) | Cl1—K—Cl3^{vi} | 89.81 (7) |
Cl3—Nb—Nb^{iii} | 53.52 (2) | Cl1^{xiii}—K—Cl3^{vi} | 118.80 (11) |
Cl3^{i}—Nb—Nb^{iii} | 96.62 (3) | Cl2^{x}—K—Cl3^{vi} | 108.69 (2) |
Cl2^{ii}—Nb—Nb^{iii} | 96.09 (3) | Cl2^{v}—K—Cl3^{vi} | 145.52 (2) |
Cl2—Nb—Nb^{iii} | 143.54 (3) | Cl2^{xiv}—K—Cl3^{vi} | 146.64 (3) |
Cl1—Nb—Nb^{iii} | 136.13 (3) | Cl1^{xii}—K—Cl3^{xv} | 89.81 (7) |
Nb^{i}—Nb—Nb^{iii} | 60.090 (15) | Cl1—K—Cl3^{xv} | 118.80 (11) |
Cl3—Nb—Nb^{ii} | 96.57 (3) | Cl1^{xiii}—K—Cl3^{xv} | 56.81 (4) |
Cl3^{i}—Nb—Nb^{ii} | 143.44 (3) | Cl2^{x}—K—Cl3^{xv} | 145.52 (2) |
Cl2^{ii}—Nb—Nb^{ii} | 53.55 (3) | Cl2^{v}—K—Cl3^{xv} | 146.64 (3) |
Cl2—Nb—Nb^{ii} | 95.92 (2) | Cl2^{xiv}—K—Cl3^{xv} | 108.69 (2) |
Cl1—Nb—Nb^{ii} | 135.97 (3) | Cl3^{vi}—K—Cl3^{xv} | 62.01 (8) |
Nb^{i}—Nb—Nb^{ii} | 90.0 | Cl1^{xii}—K—Cl3^{i} | 118.80 (11) |
Nb^{iii}—Nb—Nb^{ii} | 59.955 (8) | Cl1—K—Cl3^{i} | 56.81 (4) |
Cl3—Nb—Nb^{iv} | 143.51 (2) | Cl1^{xiii}—K—Cl3^{i} | 89.81 (7) |
Cl3^{i}—Nb—Nb^{iv} | 95.35 (3) | Cl2^{x}—K—Cl3^{i} | 146.64 (3) |
Cl2^{ii}—Nb—Nb^{iv} | 95.92 (2) | Cl2^{v}—K—Cl3^{i} | 108.69 (2) |
Cl2—Nb—Nb^{iv} | 53.54 (3) | Cl2^{xiv}—K—Cl3^{i} | 145.52 (2) |
Cl1—Nb—Nb^{iv} | 133.85 (3) | Cl3^{vi}—K—Cl3^{i} | 62.01 (8) |
Nb^{i}—Nb—Nb^{iv} | 59.955 (8) | Cl3^{xv}—K—Cl3^{i} | 62.01 (8) |
Nb^{iii}—Nb—Nb^{iv} | 90.0 | Cl1^{xii}—K—Cl2^{xii} | 56.33 (2) |
Nb^{ii}—Nb—Nb^{iv} | 60.0 | Cl1—K—Cl2^{xii} | 63.68 (2) |
Y—Cl1—Nb | 133.42 (4) | Cl1^{xiii}—K—Cl2^{xii} | 175.87 (8) |
Y—Cl1—K | 129.68 (7) | Cl2^{x}—K—Cl2^{xii} | 60.38 (5) |
Nb—Cl1—K | 94.86 (6) | Cl2^{v}—K—Cl2^{xii} | 90.62 (7) |
Nb^{iv}—Cl2—Nb | 72.91 (3) | Cl2^{xiv}—K—Cl2^{xii} | 119.64 (11) |
Nb^{iv}—Cl2—K^{v} | 106.06 (5) | Cl3^{vi}—K—Cl2^{xii} | 58.15 (4) |
Nb—Cl2—K^{v} | 106.05 (5) | Cl3^{xv}—K—Cl2^{xii} | 120.13 (11) |
Nb^{iv}—Cl2—K | 134.16 (8) | Cl3^{i}—K—Cl2^{xii} | 90.85 (7) |
Nb—Cl2—K | 96.63 (6) | Cl1^{xii}—K—Cl2^{xiii} | 63.68 (2) |
K^{v}—Cl2—K | 119.62 (5) | Cl1—K—Cl2^{xiii} | 175.87 (8) |
Nb—Cl3—Nb^{iii} | 73.03 (3) | Cl1^{xiii}—K—Cl2^{xiii} | 56.33 (2) |
Nb—Cl3—K^{vi} | 136.02 (4) | Cl2^{x}—K—Cl2^{xiii} | 90.62 (7) |
Nb^{iii}—Cl3—K^{vi} | 97.85 (5) | Cl2^{v}—K—Cl2^{xiii} | 119.64 (11) |
Cl1—Y—Cl1^{vii} | 90.47 (3) | Cl2^{xiv}—K—Cl2^{xiii} | 60.38 (5) |
Cl1—Y—Cl1^{viii} | 90.47 (3) | Cl3^{vi}—K—Cl2^{xiii} | 90.85 (7) |
Cl1^{vii}—Y—Cl1^{viii} | 90.47 (3) | Cl3^{xv}—K—Cl2^{xiii} | 58.15 (4) |
Cl1—Y—Cl1^{ix} | 180.0 | Cl3^{i}—K—Cl2^{xiii} | 120.13 (11) |
Cl1^{vii}—Y—Cl1^{ix} | 89.53 (3) | Cl2^{xii}—K—Cl2^{xiii} | 119.998 (1) |
Cl1^{viii}—Y—Cl1^{ix} | 89.53 (3) | Cl1^{xii}—K—Cl2 | 175.87 (8) |
Cl1—Y—Cl1^{x} | 89.53 (3) | Cl1—K—Cl2 | 56.33 (2) |
Cl1^{vii}—Y—Cl1^{x} | 180.0 | Cl1^{xiii}—K—Cl2 | 63.68 (2) |
Cl1^{viii}—Y—Cl1^{x} | 89.53 (3) | Cl2^{x}—K—Cl2 | 119.64 (11) |
Cl1^{ix}—Y—Cl1^{x} | 90.47 (3) | Cl2^{v}—K—Cl2 | 60.38 (5) |
Cl1—Y—Cl1^{xi} | 89.53 (3) | Cl2^{xiv}—K—Cl2 | 90.62 (7) |
Cl1^{vii}—Y—Cl1^{xi} | 89.53 (3) | Cl3^{vi}—K—Cl2 | 120.13 (11) |
Cl1^{viii}—Y—Cl1^{xi} | 180.00 (4) | Cl3^{xv}—K—Cl2 | 90.85 (7) |
Cl1^{ix}—Y—Cl1^{xi} | 90.47 (3) | Cl3^{i}—K—Cl2 | 58.15 (4) |
Cl1^{x}—Y—Cl1^{xi} | 90.47 (3) | Cl2^{xii}—K—Cl2 | 119.998 (1) |
Cl1^{xii}—K—Cl1 | 119.919 (8) | Cl2^{xiii}—K—Cl2 | 119.998 (1) |
Cl1^{xii}—K—Cl1^{xiii} | 119.919 (8) |
Symmetry codes: (i) y, −x+y, −z; (ii) −y, x−y, z; (iii) x−y, x, −z; (iv) −x+y, −x, z; (v) −x−1/3, −y−2/3, −z+1/3; (vi) −x, −y−1, −z; (vii) −x+y+1, −x, z; (viii) −y, x−y−1, z; (ix) −x+2/3, −y−2/3, −z+1/3; (x) x−y−1/3, x−2/3, −z+1/3; (xi) y+2/3, −x+y+1/3, −z+1/3; (xii) −x+y, −x−1, z; (xiii) −y−1, x−y−1, z; (xiv) y−1/3, −x+y−2/3, −z+1/3; (xv) x−y−1, x−1, −z. |
Experimental details
Crystal data | |
Chemical formula | KYNb_{6}Cl_{18} |
M_{r} | 1323.57 |
Crystal system, space group | Trigonal, R3 |
Temperature (K) | 293 |
a, c (Å) | 9.2527 (6), 25.410 (2) |
V (Å^{3}) | 1884.0 (2) |
Z | 3 |
Radiation type | Mo Kα |
µ (mm^{−}^{1}) | 7.00 |
Crystal size (mm) | 0.20 × 0.17 × 0.15 |
Data collection | |
Diffractometer | Bruker P4 diffractometer |
Absorption correction | Empirical (using intensity measurements) via ψ scan (North et al., 1968) |
T_{min}, T_{max} | 0.709, 0.965 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 1803, 1342, 1045 |
R_{int} | 0.028 |
(sin θ/λ)_{max} (Å^{−}^{1}) | 0.725 |
Refinement | |
R[F^{2} > 2σ(F^{2})], wR(F^{2}), S | 0.032, 0.050, 1.03 |
No. of reflections | 1342 |
No. of parameters | 42 |
Δρ_{max}, Δρ_{min} (e Å^{−}^{3}) | 0.77, −0.90 |
Computer programs: XSCANS (Siemens, 1996), XSCANS, SHELXTL (Bruker, 1999), SHELXTL.
Nb—Cl3 | 2.4476 (10) | Nb—Nb^{ii} | 2.9182 (6) |
Nb—Cl2 | 2.4556 (10) | Cl1—Y | 2.6414 (10) |
Nb—Cl1 | 2.6497 (10) | Cl1—K | 3.4520 (11) |
Nb—Nb^{i} | 2.9143 (6) | Cl2—K | 3.5292 (10) |
Nb^{i}—Nb—Nb^{iii} | 60.090 (15) | Nb—Cl3—Nb^{iii} | 73.03 (3) |
Symmetry codes: (i) y, −x+y, −z; (ii) −y, x−y, z; (iii) x−y, x, −z. |
A large number of metal-rich niobium chlorides with [Nb_{6}Cl_{18}]^{n-}-type cluster units have been previously crystallized using a variety of metal cations, for instance, the two series ARENb_{6}Cl_{18} (where A is an alkali and RE is a rare earth element; Ihmaine et al., 1987, 1988, 1989) and ATiNb_{6}Cl_{18} (where A is an alkali or group 13 element; Nagele et al., 2000), and the recently prepared cluster compounds Cs_{2}PbNb_{6}Cl_{18} (Gulo et al., 2001) and K_{2}SrNb_{6}Cl_{18} (Duraisamy & Lachgar, 2002), which contain Pb^{2+} and Sr^{2+}, respectively. For the series ARENb_{6}Cl_{18}, the crystal structures of compounds with RE = Gd^{3+} (Ihmaine et al., 1987) and Lu^{3+} (Ihmaine et al., 1988, 1989) have been reported, while compounds with other rare-earth metal cations are still unknown.
In the present paper, we report the crystal structure of potassium yttrium hexaniobium octadecachloride, KYNb_{6}Cl_{18}. The title compound crystallizes in trigonal space group R3. The structure is based on discrete anionic cluster units, [Nb_{6}Cl^{i}_{12}Cl^{a}_{6}]^{4−} (where `i' and `a' denote `inner' and `outer' ligands, respectively). The anionic cluster unit consists of an Nb_{6} octahedron in which all edges are bridged by chloride ligands, and six other ligands are in apical positions (Fig. 1). The intra-cluster bond lengths, Nb—Nb = 2.9143 (6)–2.9182 (6), Nb—Cl^{i} = 2.4476 (10)–2.4556 (10) and Nb—Cl^{a} = 2.6497 (10) Å are typical for [Nb_{6}Cl_{18}]^{4−} clusters. The Nb—Nb bond length indicates that the VEC (valence electrons per cluster) is 16. The three-dimensional structure of the title compound is based on the cluster units interlinked to each other by K^{+} and Y^{3+} cations (Fig. 2). The cluster layers are arranged according to a face-centered cubic stacking along the c axis. The K^{+} ions occupy tetrahedral vacancies between the units and are coordinated -to 12 Cl ligands, with K—Cl distances in the range 3.4520 (11)–3.5292 (10) Å. The yttrium ions are located in octahedral sites between the units and are bonded to six Cl ligands from six different units in a regular octahedral geometry, with Y—Cl distances of 2.6414 (10) Å. Only half of the tetrahedral sites are occupied by K in the title compound, in contrast to to situation in both Cs_{2}PbNb_{6}Cl_{18} (Gulo et al., 2001) and K_{2}SrNb_{6}Cl_{18} (Duraisamy & Lachgar, 2002) where the alkali metal site is fully occupied.