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inorganic compounds
| CRYSTALLOGRAPHIC COMMUNICATIONS |
accessA new mixed group 5 metal selenide, Nb1.41V0.59Se9
aDivision of Energy Systems Research and Department of Chemistry, Ajou University, Suwon 443-749, Republic of Korea
*Correspondence e-mail: hsyun@ajou.ac.kr
The new mixed-metallic phase, niobium vanadium nonaselenide, (Nb2-xVx)Se9 (0.18≤ x ≤ 0.59) is isostructural with monoclinic V2Se9. The structure is composed of chains of bicapped trigonal–prismatic [MSe8] units. The metal (M) site is occupied by statistically disordered Nb [0.706 (5)] and V [0.294 (5)] atoms. Two trigonal prisms are linked by sharing a rectangular face composed of two Se22− pairs. Through three edging and capping Se atoms, the chains are extended along [101]. The chain shows alternating short [2.8847 (7) Å] and long [3.7159 (7) Å] M—M distances. The structure shows a wide range of Se—Se interactions. In addition to the Se22− pairs of the rectangular face, an intermediate Se⋯Se separation [2.6584 (5) Å] is found. The amount of each metal can vary, [(Nb2-xVx)Se9, 0.18 ≤ x ≤m 0.59] and they seem to form a random substitutional The M—M distances increase gradually by increasing the amount of Nb atoms. The classical charge-balance of the compound can be described as [M4+]2[Se22−]2[Se54−].
Related literature
For related group 5 metal chalcogenide triclinic Nb2Se9 structures, see: Meerschaut et al. (1979![[Meerschaut, A., Guémas, L., Berger, R. & Rouxel, J. (1979). Acta Cryst. B35, 1747-1750.]](../../../../../../logos/arrows/e_arr.gif "Meerschaut, A., Guémas, L., Berger, R. & Rouxel, J. (1979). Acta Cryst. B35, 1747-1750.")
); Sunshine & Ibers (1987). For the synthesis and structures of related group 5 metal monoclinic V2Se9 chalcogenides, see: Furuseth & Klewe (1984).
Experimental
Crystal data
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Data collection: RAPID-AUTO (Rigaku, 2006); cell RAPID-AUTO; data reduction: RAPID-AUTO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: locally modified version of ORTEP (Johnson, 1965); software used to prepare material for publication: WinGX (Farrugia, 1999).
Supporting information
contains datablocks global, I. DOI: 10.1107/S1600536811033319/jj2093sup1.cif
Structure factors: contains datablock I. DOI: 10.1107/S1600536811033319/jj2093Isup2.hkl
The title compound, (Nb1.41V0.59)Se9 was prepared by the reaction of elements Nb, V, and Se at 873 K. A combination of the pure elements, Nb powder (CERAC 99.999%), V powder (Aldrich 99.5%), and Se powder (Aldrich 99.999%) were mixed in a fused silica tube in molar ratio of Nb: V: Se = 2: 1: 16. The tube was evacuated to 0.133 Pa, sealed, and heated gradually (20 K/h) to 873 K, where it was kept for 72 h. The tube was cooled to room temperature at the rate 3 K/h. The products were obtained as shiny black needle-shaped crystals. The crystals are stable in air and water. XRF analysis indicated the presence of Nb, V, and Se. Both X-ray diffraction studies and quantitative XRF analysis indicated that stoichiometries of each metal vary considerably for crystals even from the same reaction tube. The average Nb: V ratio for many crystals is 78: 22.
The disordered nature of the metals in the title compound was checked by refining the anisotropic displacement parameters (ADPs). When the structure was refined assuming Nb2Se9 and V2Se9, the displacement parameters of the metal sites were very large and small, respectively. In both cases the reliability indices were high (wR2 > 0.098). With the mixed-metal model, the ADPs of the metal atoms are comparable with those of the other atoms and the residuals were reduced significantly (wR2 = 0.051). The Se atoms were refined anisotropically.
Data collection: RAPID-AUTO (Rigaku, 2006); cell RAPID-AUTO (Rigaku, 2006); data reduction: RAPID-AUTO (Rigaku, 2006); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: locally modified version of ORTEP (Johnson, 1965); software used to prepare material for publication: WinGX (Farrugia, 1999).
![[Figure 1]](./jj2093fig1thm.gif) | Fig. 1. A view of the chain fragment of (Nb1.41V0.59)Se9. Displacement ellipsoids are drawn at the 80% probability level. [Symmetry code: (i) -x + 1/2, -y + 1/2, -z + 1; (ii) -x, y, -z + 1/2] |
![[Figure 2]](./jj2093fig2thm.gif) | Fig. 2. The structure of the one-dimensional (Nb1.41V0.59)Se9. Atoms are as marked in Fig. 1. |
![[Figure 3]](./jj2093fig3thm.gif) | Fig. 3. Plots of M—M distances (Å) versus x in (Nb2 - xVx)Se9. [(a) x = 0 (Sunshine & Ibers, 1987); (b) x = 0.18; (c) x = 0.36; (d) x = 0.59; (e) x = 2 (Furuseth & Klewe, 1984)] |
| Nb1.41V0.59Se9 | F(000) = 1508.8 |
| Mr = 871.69 | Dx = 5.215 Mg m−3 |
| Monoclinic, C2/c | Mo Kα radiation, λ = 0.71073 Å |
| Hall symbol: -C 2yc | Cell parameters from 4525 reflections |
| a = 10.8039 (5) Å | θ = 3.2–27.5° |
| b = 12.6209 (7) Å | µ = 31.39 mm−1 |
| c = 8.1704 (3) Å | T = 290 K |
| β = 94.6473 (15)° | Needle, black |
| V = 1110.41 (9) Å3 | 0.36 × 0.02 × 0.02 mm |
| Z = 4 |
| Rigaku R-AXIS RAPID diffractometer | 1281 independent reflections |
| Radiation source: fine-focus sealed tube | 1141 reflections with I > 2σ(I) |
| Graphite monochromator | Rint = 0.038 |
| ω scans | θmax = 27.5°, θmin = 3.2° |
| Absorption correction: multi-scan (NUMABS; Higashi, 2000) | h = −11→14 |
| Tmin = 0.415, Tmax = 1.000 | k = −16→16 |
| 5325 measured reflections | l = −10→10 |
| Refinement on F2 | 52 parameters |
| Least-squares matrix: full | 0 restraints |
| R[F2 > 2σ(F2)] = 0.022 | w = 1/[σ2(Fo2) + (0.0198P)2 + 0.9634P] where P = (Fo2 + 2Fc2)/3 |
| wR(F2) = 0.051 | (Δ/σ)max = 0.001 |
| S = 1.12 | Δρmax = 1.07 e Å−3 |
| 1281 reflections | Δρmin = −0.72 e Å−3 |
| Nb1.41V0.59Se9 | V = 1110.41 (9) Å3 |
| Mr = 871.69 | Z = 4 |
| Monoclinic, C2/c | Mo Kα radiation |
| a = 10.8039 (5) Å | µ = 31.39 mm−1 |
| b = 12.6209 (7) Å | T = 290 K |
| c = 8.1704 (3) Å | 0.36 × 0.02 × 0.02 mm |
| β = 94.6473 (15)° |
| Rigaku R-AXIS RAPID diffractometer | 1281 independent reflections |
| Absorption correction: multi-scan (NUMABS; Higashi, 2000) | 1141 reflections with I > 2σ(I) |
| Tmin = 0.415, Tmax = 1.000 | Rint = 0.038 |
| 5325 measured reflections |
| R[F2 > 2σ(F2)] = 0.022 | 52 parameters |
| wR(F2) = 0.051 | 0 restraints |
| S = 1.12 | Δρmax = 1.07 e Å−3 |
| 1281 reflections | Δρmin = −0.72 e Å−3 |
Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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 > 2σ(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 | Occ. (<1) | |
| Nb1 | 0.13016 (4) | 0.26771 (3) | 0.41322 (4) | 0.01363 (17) | 0.706 (5) |
| V1 | 0.13016 (4) | 0.26771 (3) | 0.41322 (4) | 0.01363 (17) | 0.294 (5) |
| Se1 | 0 | 0.41770 (5) | 0.25 | 0.02302 (15) | |
| Se2 | −0.06049 (4) | 0.35079 (4) | 0.54157 (5) | 0.02270 (13) | |
| Se3 | −0.10370 (4) | 0.19147 (4) | 0.39677 (5) | 0.01982 (12) | |
| Se4 | 0.23604 (4) | 0.08172 (4) | 0.44427 (5) | 0.02230 (12) | |
| Se5 | 0.16278 (4) | 0.15311 (4) | 0.67875 (5) | 0.02290 (12) |
| U11 | U22 | U33 | U12 | U13 | U23 | |
| Nb1 | 0.0106 (2) | 0.0172 (3) | 0.0130 (2) | 0.00056 (16) | 0.00004 (14) | 0.00019 (15) |
| V1 | 0.0106 (2) | 0.0172 (3) | 0.0130 (2) | 0.00056 (16) | 0.00004 (14) | 0.00019 (15) |
| Se1 | 0.0181 (3) | 0.0191 (3) | 0.0305 (3) | 0 | −0.0063 (2) | 0 |
| Se2 | 0.0191 (2) | 0.0305 (3) | 0.0185 (2) | 0.00413 (18) | 0.00163 (15) | −0.00470 (17) |
| Se3 | 0.0163 (2) | 0.0254 (3) | 0.0177 (2) | −0.00295 (18) | 0.00143 (14) | 0.00224 (16) |
| Se4 | 0.0207 (2) | 0.0198 (2) | 0.0256 (2) | 0.00210 (18) | −0.00346 (16) | −0.00309 (17) |
| Se5 | 0.0180 (2) | 0.0314 (3) | 0.0191 (2) | −0.00145 (19) | 0.00056 (14) | 0.00614 (17) |
| Nb1—Se4i | 2.6046 (6) | Se1—Nb1ii | 2.6524 (6) |
| Nb1—Se2 | 2.6061 (6) | Se1—Se2ii | 2.6584 (5) |
| Nb1—Se5 | 2.6075 (6) | Se1—Se2 | 2.6584 (5) |
| Nb1—Se4 | 2.6146 (6) | Se2—Se3 | 2.3603 (6) |
| Nb1—Se5i | 2.6153 (6) | Se3—V1ii | 2.7028 (5) |
| Nb1—Se1 | 2.6524 (6) | Se3—Nb1ii | 2.7028 (5) |
| Nb1—Se3 | 2.6968 (6) | Se4—Se5 | 2.3140 (6) |
| Nb1—Se3ii | 2.7028 (5) | Se4—V1i | 2.6046 (6) |
| Nb1—V1i | 2.8847 (7) | Se4—Nb1i | 2.6046 (6) |
| Nb1—Nb1i | 2.8847 (7) | Se5—V1i | 2.6153 (6) |
| Se1—V1ii | 2.6524 (6) | Se5—Nb1i | 2.6153 (6) |
| Se4i—Nb1—Se2 | 87.402 (19) | Se4i—Nb1—Nb1i | 56.614 (16) |
| Se4i—Nb1—Se5 | 90.002 (18) | Se2—Nb1—Nb1i | 124.88 (2) |
| Se2—Nb1—Se5 | 86.924 (18) | Se5—Nb1—Nb1i | 56.603 (16) |
| Se4i—Nb1—Se4 | 112.894 (17) | Se4—Nb1—Nb1i | 56.281 (17) |
| Se2—Nb1—Se4 | 132.53 (2) | Se5i—Nb1—Nb1i | 56.345 (16) |
| Se5—Nb1—Se4 | 52.604 (16) | Se1—Nb1—Nb1i | 140.90 (3) |
| Se4i—Nb1—Se5i | 52.629 (16) | Se3—Nb1—Nb1i | 140.29 (3) |
| Se2—Nb1—Se5i | 133.17 (2) | Se3ii—Nb1—Nb1i | 115.34 (2) |
| Se5—Nb1—Se5i | 112.948 (17) | V1i—Nb1—Nb1i | 0.00 (2) |
| Se4—Nb1—Se5i | 89.611 (19) | V1ii—Se1—Nb1 | 88.93 (3) |
| Se4i—Nb1—Se1 | 87.508 (19) | Nb1ii—Se1—Nb1 | 88.93 (3) |
| Se2—Nb1—Se1 | 60.729 (13) | V1ii—Se1—Se2ii | 58.774 (15) |
| Se5—Nb1—Se1 | 147.63 (2) | Nb1ii—Se1—Se2ii | 58.774 (15) |
| Se4—Nb1—Se1 | 154.09 (2) | Nb1—Se1—Se2ii | 93.73 (2) |
| Se5i—Nb1—Se1 | 90.793 (17) | V1ii—Se1—Se2 | 93.73 (2) |
| Se4i—Nb1—Se3 | 140.03 (2) | Nb1ii—Se1—Se2 | 93.73 (2) |
| Se2—Nb1—Se3 | 52.827 (16) | Nb1—Se1—Se2 | 58.774 (15) |
| Se5—Nb1—Se3 | 84.635 (18) | Se2ii—Se1—Se2 | 142.96 (3) |
| Se4—Nb1—Se3 | 94.89 (2) | Se3—Se2—Nb1 | 65.560 (17) |
| Se5i—Nb1—Se3 | 160.346 (19) | Se3—Se2—Se1 | 82.79 (2) |
| Se1—Nb1—Se3 | 76.889 (16) | Nb1—Se2—Se1 | 60.497 (15) |
| Se4i—Nb1—Se3ii | 133.74 (2) | Se2—Se3—Nb1 | 61.613 (16) |
| Se2—Nb1—Se3ii | 119.558 (18) | Se2—Se3—V1ii | 99.67 (2) |
| Se5—Nb1—Se3ii | 125.39 (2) | Nb1—Se3—V1ii | 86.973 (17) |
| Se4—Nb1—Se3ii | 77.498 (17) | Se2—Se3—Nb1ii | 99.67 (2) |
| Se5i—Nb1—Se3ii | 83.958 (17) | Nb1—Se3—Nb1ii | 86.973 (17) |
| Se1—Nb1—Se3ii | 76.786 (16) | Se5—Se4—V1i | 63.925 (18) |
| Se3—Nb1—Se3ii | 78.391 (18) | Se5—Se4—Nb1i | 63.925 (18) |
| Se4i—Nb1—V1i | 56.614 (16) | Se5—Se4—Nb1 | 63.540 (17) |
| Se2—Nb1—V1i | 124.88 (2) | V1i—Se4—Nb1 | 67.105 (17) |
| Se5—Nb1—V1i | 56.603 (16) | Nb1i—Se4—Nb1 | 67.105 (17) |
| Se4—Nb1—V1i | 56.281 (17) | Se4—Se5—Nb1 | 63.856 (18) |
| Se5i—Nb1—V1i | 56.345 (16) | Se4—Se5—V1i | 63.447 (18) |
| Se1—Nb1—V1i | 140.90 (3) | Nb1—Se5—V1i | 67.052 (17) |
| Se3—Nb1—V1i | 140.29 (3) | Se4—Se5—Nb1i | 63.447 (18) |
| Se3ii—Nb1—V1i | 115.34 (2) | Nb1—Se5—Nb1i | 67.052 (17) |
| Se4i—Nb1—Se1—V1ii | 176.568 (19) | Se2—Nb1—Se3—V1ii | 102.699 (18) |
| Se2—Nb1—Se1—V1ii | −95.014 (17) | Se5—Nb1—Se3—V1ii | −167.096 (18) |
| Se5—Nb1—Se1—V1ii | −97.37 (4) | Se4—Nb1—Se3—V1ii | −115.431 (19) |
| Se4—Nb1—Se1—V1ii | 33.29 (4) | Se5i—Nb1—Se3—V1ii | −12.76 (8) |
| Se5i—Nb1—Se1—V1ii | 124.029 (18) | Se1—Nb1—Se3—V1ii | 39.663 (15) |
| Se3—Nb1—Se1—V1ii | −40.511 (11) | Se3ii—Nb1—Se3—V1ii | −39.28 (2) |
| Se3ii—Nb1—Se1—V1ii | 40.424 (11) | V1i—Nb1—Se3—V1ii | −155.17 (3) |
| V1i—Nb1—Se1—V1ii | 154.52 (4) | Nb1i—Nb1—Se3—V1ii | −155.17 (3) |
| Nb1i—Nb1—Se1—V1ii | 154.52 (4) | Se4i—Nb1—Se3—Nb1ii | 109.33 (2) |
| Se4i—Nb1—Se1—Nb1ii | 176.568 (19) | Se2—Nb1—Se3—Nb1ii | 102.699 (18) |
| Se2—Nb1—Se1—Nb1ii | −95.014 (17) | Se5—Nb1—Se3—Nb1ii | −167.096 (18) |
| Se5—Nb1—Se1—Nb1ii | −97.37 (4) | Se4—Nb1—Se3—Nb1ii | −115.431 (19) |
| Se4—Nb1—Se1—Nb1ii | 33.29 (4) | Se5i—Nb1—Se3—Nb1ii | −12.76 (8) |
| Se5i—Nb1—Se1—Nb1ii | 124.029 (18) | Se1—Nb1—Se3—Nb1ii | 39.663 (15) |
| Se3—Nb1—Se1—Nb1ii | −40.511 (11) | Se3ii—Nb1—Se3—Nb1ii | −39.28 (2) |
| Se3ii—Nb1—Se1—Nb1ii | 40.424 (11) | V1i—Nb1—Se3—Nb1ii | −155.17 (3) |
| V1i—Nb1—Se1—Nb1ii | 154.52 (4) | Nb1i—Nb1—Se3—Nb1ii | −155.17 (3) |
| Nb1i—Nb1—Se1—Nb1ii | 154.52 (4) | Se4i—Nb1—Se4—Se5 | 71.168 (19) |
| Se4i—Nb1—Se1—Se2ii | 117.956 (18) | Se2—Nb1—Se4—Se5 | −37.53 (3) |
| Se2—Nb1—Se1—Se2ii | −153.63 (2) | Se5i—Nb1—Se4—Se5 | 119.734 (16) |
| Se5—Nb1—Se1—Se2ii | −155.98 (4) | Se1—Nb1—Se4—Se5 | −149.25 (5) |
| Se4—Nb1—Se1—Se2ii | −25.33 (5) | Se3—Nb1—Se4—Se5 | −79.423 (19) |
| Se5i—Nb1—Se1—Se2ii | 65.416 (18) | Se3ii—Nb1—Se4—Se5 | −156.37 (2) |
| Se3—Nb1—Se1—Se2ii | −99.124 (18) | V1i—Nb1—Se4—Se5 | 71.168 (19) |
| Se3ii—Nb1—Se1—Se2ii | −18.189 (16) | Nb1i—Nb1—Se4—Se5 | 71.168 (19) |
| V1i—Nb1—Se1—Se2ii | 95.90 (4) | Se4i—Nb1—Se4—V1i | 0.0 |
| Nb1i—Nb1—Se1—Se2ii | 95.90 (4) | Se2—Nb1—Se4—V1i | −108.70 (3) |
| Se4i—Nb1—Se1—Se2 | −88.417 (19) | Se5—Nb1—Se4—V1i | −71.168 (19) |
| Se5—Nb1—Se1—Se2 | −2.35 (4) | Se5i—Nb1—Se4—V1i | 48.565 (15) |
| Se4—Nb1—Se1—Se2 | 128.30 (5) | Se1—Nb1—Se4—V1i | 139.58 (5) |
| Se5i—Nb1—Se1—Se2 | −140.96 (2) | Se3—Nb1—Se4—V1i | −150.59 (2) |
| Se3—Nb1—Se1—Se2 | 54.503 (16) | Se3ii—Nb1—Se4—V1i | 132.46 (2) |
| Se3ii—Nb1—Se1—Se2 | 135.44 (2) | Nb1i—Nb1—Se4—V1i | 0.0 |
| V1i—Nb1—Se1—Se2 | −110.47 (4) | Se4i—Nb1—Se4—Nb1i | 0.0 |
| Nb1i—Nb1—Se1—Se2 | −110.47 (4) | Se2—Nb1—Se4—Nb1i | −108.70 (3) |
| Se4i—Nb1—Se2—Se3 | −175.74 (2) | Se5—Nb1—Se4—Nb1i | −71.168 (19) |
| Se5—Nb1—Se2—Se3 | −85.597 (19) | Se5i—Nb1—Se4—Nb1i | 48.565 (15) |
| Se4—Nb1—Se2—Se3 | −56.60 (3) | Se1—Nb1—Se4—Nb1i | 139.58 (5) |
| Se5i—Nb1—Se2—Se3 | 155.39 (3) | Se3—Nb1—Se4—Nb1i | −150.59 (2) |
| Se1—Nb1—Se2—Se3 | 95.663 (19) | Se3ii—Nb1—Se4—Nb1i | 132.46 (2) |
| Se3ii—Nb1—Se2—Se3 | 43.91 (2) | V1i—Nb1—Se4—Nb1i | 0.0 |
| V1i—Nb1—Se2—Se3 | −130.41 (3) | V1i—Se4—Se5—Nb1 | 76.099 (17) |
| Nb1i—Nb1—Se2—Se3 | −130.41 (3) | Nb1i—Se4—Se5—Nb1 | 76.099 (17) |
| Se4i—Nb1—Se2—Se1 | 88.598 (19) | Nb1i—Se4—Se5—V1i | 0.0 |
| Se5—Nb1—Se2—Se1 | 178.74 (2) | Nb1—Se4—Se5—V1i | −76.099 (17) |
| Se4—Nb1—Se2—Se1 | −152.27 (3) | V1i—Se4—Se5—Nb1i | 0.0 |
| Se5i—Nb1—Se2—Se1 | 59.73 (3) | Nb1—Se4—Se5—Nb1i | −76.099 (17) |
| Se3—Nb1—Se2—Se1 | −95.663 (19) | Se4i—Nb1—Se5—Se4 | −119.319 (18) |
| Se3ii—Nb1—Se2—Se1 | −51.75 (2) | Se2—Nb1—Se5—Se4 | 153.28 (2) |
| V1i—Nb1—Se2—Se1 | 133.92 (3) | Se5i—Nb1—Se5—Se4 | −70.55 (2) |
| Nb1i—Nb1—Se2—Se1 | 133.92 (3) | Se1—Nb1—Se5—Se4 | 155.34 (4) |
| V1ii—Se1—Se2—Se3 | 20.533 (18) | Se3—Nb1—Se5—Se4 | 100.35 (2) |
| Nb1ii—Se1—Se2—Se3 | 20.533 (18) | Se3ii—Nb1—Se5—Se4 | 28.69 (2) |
| Nb1—Se1—Se2—Se3 | −65.948 (18) | V1i—Nb1—Se5—Se4 | −70.55 (2) |
| Se2ii—Se1—Se2—Se3 | −18.564 (12) | Nb1i—Nb1—Se5—Se4 | −70.55 (2) |
| V1ii—Se1—Se2—Nb1 | 86.48 (2) | Se4i—Nb1—Se5—V1i | −48.766 (16) |
| Nb1ii—Se1—Se2—Nb1 | 86.48 (2) | Se2—Nb1—Se5—V1i | −136.16 (2) |
| Se2ii—Se1—Se2—Nb1 | 47.384 (12) | Se4—Nb1—Se5—V1i | 70.55 (2) |
| Se1—Se2—Se3—Nb1 | 60.808 (13) | Se5i—Nb1—Se5—V1i | 0.0 |
| Nb1—Se2—Se3—V1ii | −81.199 (17) | Se1—Nb1—Se5—V1i | −134.11 (5) |
| Se1—Se2—Se3—V1ii | −20.391 (16) | Se3—Nb1—Se5—V1i | 170.90 (3) |
| Nb1—Se2—Se3—Nb1ii | −81.199 (17) | Se3ii—Nb1—Se5—V1i | 99.24 (3) |
| Se1—Se2—Se3—Nb1ii | −20.391 (16) | Nb1i—Nb1—Se5—V1i | 0.0 |
| Se4i—Nb1—Se3—Se2 | 6.64 (3) | Se4i—Nb1—Se5—Nb1i | −48.766 (16) |
| Se5—Nb1—Se3—Se2 | 90.205 (19) | Se2—Nb1—Se5—Nb1i | −136.16 (2) |
| Se4—Nb1—Se3—Se2 | 141.87 (2) | Se4—Nb1—Se5—Nb1i | 70.55 (2) |
| Se5i—Nb1—Se3—Se2 | −115.45 (7) | Se5i—Nb1—Se5—Nb1i | 0.0 |
| Se1—Nb1—Se3—Se2 | −63.036 (16) | Se1—Nb1—Se5—Nb1i | −134.11 (5) |
| Se3ii—Nb1—Se3—Se2 | −141.981 (19) | Se3—Nb1—Se5—Nb1i | 170.90 (3) |
| V1i—Nb1—Se3—Se2 | 102.13 (4) | Se3ii—Nb1—Se5—Nb1i | 99.24 (3) |
| Nb1i—Nb1—Se3—Se2 | 102.13 (4) | V1i—Nb1—Se5—Nb1i | 0.0 |
| Se4i—Nb1—Se3—V1ii | 109.33 (2) |
| Symmetry codes: (i) −x+1/2, −y+1/2, −z+1; (ii) −x, y, −z+1/2. |
Experimental details
| Crystal data | |
| Chemical formula | Nb1.41V0.59Se9 |
| Mr | 871.69 |
| Crystal system, space group | Monoclinic, C2/c |
| Temperature (K) | 290 |
| a, b, c (Å) | 10.8039 (5), 12.6209 (7), 8.1704 (3) |
| β (°) | 94.6473 (15) |
| V (Å3) | 1110.41 (9) |
| Z | 4 |
| Radiation type | Mo Kα |
| µ (mm−1) | 31.39 |
| Crystal size (mm) | 0.36 × 0.02 × 0.02 |
| Data collection | |
| Diffractometer | Rigaku R-AXIS RAPID diffractometer |
| Absorption correction | Multi-scan (NUMABS; Higashi, 2000) |
| Tmin, Tmax | 0.415, 1.000 |
| No. of measured, independent and observed [I > 2σ(I)] reflections | 5325, 1281, 1141 |
| Rint | 0.038 |
| (sin θ/λ)max (Å−1) | 0.649 |
| Refinement | |
| R[F2 > 2σ(F2)], wR(F2), S | 0.022, 0.051, 1.12 |
| No. of reflections | 1281 |
| No. of parameters | 52 |
| Δρmax, Δρmin (e Å−3) | 1.07, −0.72 |
Computer programs: RAPID-AUTO (Rigaku, 2006), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), locally modified version of ORTEP (Johnson, 1965), WinGX (Farrugia, 1999).
Acknowledgements
This work was supported by an Ajou University Research Fellowship (2010). Use was made of the X-ray facilities supported by Ajou University.
References
Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837–838. CrossRef CAS IUCr Journals Google Scholar
Furuseth, S. & Klewe, B. (1984). Acta Chem. Scand. Ser. A, 38, 467–471. Google Scholar
Higashi, T. (2000). NUMABS. Rigaku Corporation, Tokyo, Japan. Google Scholar
Johnson, C. K. (1965). ORTEP. Report ORNL-3794. Oak Ridge National Laboratory, Tennessee, USA. Google Scholar
Meerschaut, A., Guémas, L., Berger, R. & Rouxel, J. (1979). Acta Cryst. B35, 1747–1750. Google Scholar
Rigaku (2006). RAPID-AUTO. Rigaku Corporation, Tokyo, Japan. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Sunshine, S. A. & Ibers, J. A. (1987). Acta Cryst. C43, 1019–1022. CAS Web of Science Google Scholar
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| CRYSTALLOGRAPHIC COMMUNICATIONS |
Group 5 metal chalcogenides usually have low-dimensional structures. In particular, both triclinic Nb2Se9 (Meerschaut et al., 1979; Sunshine & Ibers, 1987) and monoclinic V2Se9 (Furuseth & Klewe, 1984) have been reported to have one-dimensional chain structures. These compounds share the same one-dimensional chain structure. However they show different packing of the chains and the twofold rotational symmetry is not observed in Nb2Se9. During our search for new group 5 metal chalcogenides, we have found a new mixed-metallic phase, (Nb2 - xVx)Se9 (0.18≤x≤0.59) and here we report the synthesis and crystal structure of (Nb1.41V0.59)Se9.
The title compound is isostructural with monoclinic V2Se9 (Furuseth & Klewe, 1984). The structure is composed of one-dimensional chains made of the bicapped trigonal prismatic [M2Se10] unit. The metal (M) site is occupied by statistically disordered Nb (0.706 (5) %) and V (0.294 (5) %) atoms. The Se atoms are found as Se2 or Se5 units. Each Nb atom is surrounded by two Se2 and one Se5 units. Two trigonal prisms are linked by sharing a rectangular face composed of two Se22- pairs (Fig. 1). Through three edging and capping Se atoms of the Se5 unit, the chains are extended along [101] (Fig. 2). The shortest interchain Se—Se distance is 3.5479 (8) Å and thus there is no strong bonding interaction among the chains. The chain shows alternating short (2.8847 (7) Å) and long (3.7159 (7) Å) M—M distances. The short M—M distance is in-between those found in V2Se9 (2.842 (2) Å, Furuseth & Klewe, 1984) and Nb2Se9 (2.895 (2) Å, Sunshine & Ibers, 1987). The structure shows a wide range of Se—Se interactions. In the prism, two Se4—Se5 pairs (2.3140 (6) Å) forming a rectangular face exhibit the regular Se—Se bonds. In addition, the intermediate Se1···Se2 separation (2.6584 (5) Å) is found along with the short Se2—Se3 distance (2.3603 (6) Å) in the Se5 unit.
The structural investigations of the three different crystals from the same reaction tube showed that the stoichiometries of each metal can vary, [(Nb2- xVx)Se9, 0.18≤x≤0.59] and they seem to form a random substitutional solid solution. The intermetallic distances are affected by the contribution of each constituent metal. The M—M distances increase gradually by increasing the amount of Nb atoms (Fig.3). The classical charge balance of the compound can be described as [M4+]2[Se22-]2[Se54-].