[Journal logo]

Volume 66 
Part 6 
Pages i61-i63  
June 2010  

Received 20 April 2010
Accepted 6 May 2010
Online 14 May 2010

[VO(SeO3)(H2O)2]·0.5H2O

aDepartment of Chemistry, University of Aberdeen, Meston Walk, Aberdeen AB24 3UE, Scotland
Correspondence e-mail: w.harrison@abdn.ac.uk

In poly[[diaquaoxido[[mu]3-trioxidoselenato(2-)]vanadium(IV)] hemihydrate], {[VO(SeO3)(H2O)2]·0.5H2O}n, the octahedral V(H2O)2O4 and pyramidal SeO3 building units are linked by V-O-Se bonds to generate ladder-like chains propagating along the [010] direction. A network of O-H...O hydrogen bonds helps to consolidate the structure. The O atom of the uncoordinated water molecule lies on a crystallographic twofold axis. The title compound has a similar structure to those of the reported phases [VO(OH)(H2O)(SeO3)]4·2H2O and VO(H2O)2(HPO4)·2H2O.

Comment

Vanadium phosphates (VPOs) have been intensively studied for many years due to their catalytic (Hutchings, 2009[Hutchings, G. J. (2009). J. Mater. Chem. 19, 1222-1235.]) and electrochemical applications (Yang et al., 2010[Yang, G., Liu, H., Ji, H., Chen, Z. & Jiang, X. (2010). Electrochim. Acta, 55, 2951-2958.]), and their magnetic properties (Geupel et al., 2002[Geupel, S., Pilz, K., van Smaalen, S., Büllesfeld, F., Prokofiev, A. & Assmus, W. (2002). Acta Cryst. C58, i9-i13.]). Crystallochemically, VPOs display remarkable structural diversity due to the accessibility of different vanadium oxidation states (VIII, VIV and VV) with different coordination preferences to O atoms and the variety of bonding modes of the linking (hydrogen) phosphate anions (Amorós et al., 1999[Amorós, P., Marcos, M. D., Beltrán-Porter, A. & Beltrán-Porter, D. (1999). Curr. Opin. Solid State Mater. Sci. 4, 123-131.]; Whittingham et al., 2005[Whittingham, M. S., Song, Y.-N., Lutta, S., Zavalij, P. Y. & Chernova, N. A. (2005). J. Mater. Chem. 15, 3362-3379.]); when organic templates are employed in the synthesis, still further structural variety is possible (Finn et al., 2003[Finn, R. C., Zubieta, J. & Haushalter, R. C. (2003). Prog. Inorg. Chem. 51, 421-601.]). Compared to phosphates, other oxo-anions such as selenite in combination with vanadium cations have been less well studied. We now describe the structure of the vanadium(IV)-containing compound poly[[diaquaoxido[[mu]3-trioxidoselenato(2-)]vanadium(IV)] hemihydrate], (I). The only other well characterized vanadium selenite hydrates are VIVO(H2O)(SeO3), (II) (Huan et al., 1991[Huan, G., Johnson, J. W., Jacobson, A. J., Goshorn, D. P. & Merola, J. S. (1991). Chem. Mater. 3, 539-541.]), and [VVO(OH)(H2O)(SeO3)]4·2H2O, (III) (Dai et al., 2003[Dai, Z., Shi, Z., Li, G., Lu, X., Xu, Y. & Feng, S. (2003). J. Solid State Chem. 172, 205-211.]).

The polyhedral building units of (I) are a vanadium(IV) atom bonded to six O atoms (two of which are from water molecules) in a distorted octahedral arrangement and a pyramidal selenite group (Fig. 1[link] and Table 1[link]). An uncoordinated water molecule (O-atom site symmetry 2) completes the structure of this hemihydrate.

V1 makes a characteristic short `vanadyl' bond to O5, which must have significant double-bond character: such short V=O bonds are typical of both VIV (Mentre et al., 2009[Mentre, O., Koo, H.-J. & Whangbo, M.-H. (2009). Chem. Mater. 20, 6929-6938.]) and VV (Yakubovich et al., 2008[Yakubovich, O. V., Steele, I. M. & Dimitrova, O. V. (2008). Acta Cryst. C64, i62-i65.]). Sometimes the vanadyl O atom can make a weak bond to another metal ion (Duc et al., 2006[Duc, F., Gonthier, S., Brunelli, M. & Trombe, J. C. (2006). J. Solid State Chem. 179, 3591-3598.]; Meng et al., 2009[Meng, L., Ma, Y., Zhang, X. & Xu, Y. (2009). Acta Cryst. C65, i45-i47.]), but here it is bonded only to V1, although it also acts as an acceptor for two O-H...O hydrogen bonds (see below). Water atom O6 in (I) is coordinated trans to O5 at a relatively long V-O distance, whereas the V-O bond lengths of the other four O atoms are clustered in a narrow range around 2.0 Å. The second water molecule (O4) is bonded to V1 in a cis orientation with respect to O6, and its trans oxygen atom (O2) also links to the Se atom. Atoms O1 and O3 complete the vanadium coordination sphere; both of these also link to Se. The bond valence sum (BVS) for V1, calculated by the Brown & Altermatt (1985[Brown, I. D. & Altermatt, D. (1985). Acta Cryst. B41, 244-247.]) method, is 4.09 (expected value 4.00) assuming that VIV is present, which is supported by the pale-blue crystal colour of (I) (Bircsak et al., 1999[Bircsak, Z., Hall, A. K. & Harrison, W. T. A. (1999). J. Solid State Chem. 142, 168-173.]).

Se1 shows its expected trigonal pyramidal geometry (Verma, 1999[Verma, V. P. (1999). Thermochim. Acta, 327, 63-102.]) with respect to O1, O2 and O3, which can be understood in terms of its unseen formal [Ar]3d104s2 lone pair of electrons occupying the fourth tetrahedral vertex. The mean Se-O separation is 1.698 Å and the Se BVS of 4.08 compares well to the expected value of 4.00. Se1 is displaced from the plane of its attached O atoms by 0.7724 (11) Å, which is comparable to the situation in related compounds (Johnston & Harrison, 2007[Johnston, M. G. & Harrison, W. T. A. (2007). Acta Cryst. C63, i28-i30.]).

The polyhedral connectivity in (I) means that each V atom is linked to three Se atoms and each Se atom is linked to three V atoms, thus there are no V-O-V links. Ladder-like chains propagating along the [010] direction (Fig. 1[link]) occur in the crystal of (I) featuring vertex sharing of the constituent V(H2O)2O4 octahedra and SeO3 pyramids, generating edge-shared 4-rings.

The water molecules in (I) form O-H...O hydrogen bonds with all their available H atoms (Table 2[link]). O6 makes two hydrogen bonds to an adjacent chain displaced in the c direction. O4 makes one hydrogen bond to a chain displaced in the a direction; its other H atom bonds to the uncoordinated water molecule (O7). Finally, O7, makes two symmetry-equivalent hydrogen bonds to the vanadyl O atom to reinforce the inter-chain connectivity in the a direction (Fig. 2[link]).

Although they share similar polyhedral building units, the structures of (I) and (II) are completely different, with the latter adopting a layered network of vertex- and edge-sharing V(H2O)O5 and SeO3 polyhedra akin to that in VO(HPO4)·0.5H2O (Leonowicz et al., 1985[Leonowicz, M. E., Johnson, J. W., Shannon, H. F. Jr, Brody, J. F. & Newsam, J. M. (1985). J. Solid State Chem. 56, 370-378.]). The relationship of (I) and (III) deserves some comment: if the formula for (III) of [VO(OH)(H2O)(SeO3)]4·2H2O stated by Dai et al. (2003[Dai, Z., Shi, Z., Li, G., Lu, X., Xu, Y. & Feng, S. (2003). J. Solid State Chem. 172, 205-211.]) is rewritten as VO(OH)(H2O)(SeO3)·0.5H2O, the similarity to (I) is apparent, with an OH group bonded to VV in (III) replacing a water molecule bonded to VIV in (I) to maintain charge balance. The reported unit cell of (III) is much larger than that of (I), but the structural motif of polyhedral chains is similar to that of (I). The H atoms in (III) were not located, so the hydrogen-bonding networks cannot be compared. Dai et al. (2003[Dai, Z., Shi, Z., Li, G., Lu, X., Xu, Y. & Feng, S. (2003). J. Solid State Chem. 172, 205-211.]) synthesized their compound from V2O5 and the crystal colour of (III) was described as green. The presumed terminal V-OH bond in (III) is uncommon and perhaps unexpected, given the low-pH synthesis used. However, it is known that VV can undergo facile reduction to VIV in hydrothermal reactions (Meng et al., 2009[Meng, L., Ma, Y., Zhang, X. & Xu, Y. (2009). Acta Cryst. C65, i45-i47.]) and that some VIV compounds are green in colour (Geupel et al., 2002[Geupel, S., Pilz, K., van Smaalen, S., Büllesfeld, F., Prokofiev, A. & Assmus, W. (2002). Acta Cryst. C58, i9-i13.]). Thus, an alternative formulation for (III) could be VIVO(H2O)2(SeO3)·0.5H2O, i.e. a polymorph with the same formula as (I); such polymorphism is a known feature of vanadium phosphate chemistry (Le Bail et al., 1989[Le Bail, A., Férey, G., Aromós, P., Beltrán-Porter, D. & Villeneuve, G. (1989). J. Solid State Chem. 79, 169-176.]).

In terms of vanadium phosphates, (I) bears a close resemblance to VO(H2O)2(HPO4)·2H2O, (IV) (Leonowicz et al., 1985[Leonowicz, M. E., Johnson, J. W., Shannon, H. F. Jr, Brody, J. F. & Newsam, J. M. (1985). J. Solid State Chem. 56, 370-378.]; Fratzky et al., 1999[Fratzky, D., Worzala, H., Goetze, T. & Meisel, M. (1999). Z. Kristallogr. New Cryst. Struct. 214, 9-10.]), which features ladder-like chains constructed from V(H2O)2O4 and HPO4 building units; the hydrogen phosphate ion is topologically equivalent to selenite, as the P-OH vertex does not link to vanadium. However, the presence of two uncoordinated water molecules per chain-formula-unit in (IV) compared to half a water molecule in (I) leads to a completely different hydrogen-bonding arrangement.

[Figure 1]
Figure 1
Fragment of an [010] chain in (I), showing the vertex-sharing connectivity of the V(H2O)2O4 and SeO3 building units and the hydrogen bond (double-dashed line) between the uncoordinated water molecule and atom O5. Displacement ellipsoids are drawn at the 50% probability level. [Symmetry codes: (i) [-x+{\script{1\over 2}}, y+{\script{1\over 2}}, -z+{\script{1\over 2}}]; (ii) [-x+{\script{1\over 2}}, y-{\script{1\over 2}}, -z+{\script{1\over 2}}].]
[Figure 2]
Figure 2
Unit-cell packing for (I), viewed approximately down [010]. In the electronic version of the paper, the V(H2O)2O4 groups are shown as green polyhedra, Se atoms as purple spheres, O atoms as red spheres, H atoms as grey spheres, and hydrogen bonds as thin yellow lines.

Experimental

For the preparation of (I), 20 ml of 0.5 M H2SeO3 and 0.086 g of vanadium metal were sealed in a 60-ml PTFE bottle and heated to 353 K. After a few days, the bottle was removed from the oven to reveal a pale-blue gel. The sealed bottle was left at room temperature for several months, after which time 0.11 g (27% yield) of pale-blue rods of (I) was recovered from the pale-blue liquors by vacuum filtration and rinsing with water and acetone.

Crystal data
  • [VO(SeO3)(H2O)2]·0.5H2O

  • Mr = 238.9

  • Monoclinic, C 2/c

  • a = 18.7819 (13) Å

  • b = 6.2881 (4) Å

  • c = 10.5581 (4) Å

  • [beta] = 116.443 (4)°

  • V = 1116.48 (11) Å3

  • Z = 8

  • Mo K[alpha] radiation

  • [mu] = 8.26 mm-1

  • T = 120 K

  • 0.20 × 0.10 × 0.08 mm

Data collection
  • Nonius KappaCCD diffractometer

  • Absorption correction: multi-scan (SADABS; Bruker, 2003[Bruker (2003). SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.289, Tmax = 0.558

  • 6097 measured reflections

  • 1276 independent reflections

  • 1133 reflections with I > 2[sigma](I)

  • Rint = 0.035

Refinement
  • R[F2 > 2[sigma](F2)] = 0.024

  • wR(F2) = 0.054

  • S = 1.03

  • 1276 reflections

  • 79 parameters

  • H-atom parameters constrained

  • [Delta][rho]max = 0.67 e Å-3

  • [Delta][rho]min = -0.59 e Å-3

Table 1
Selected bond lengths (Å)

V1-O5 1.613 (2)
V1-O1i 1.9677 (19)
V1-O3ii 2.007 (2)
V1-O2 2.0098 (19)
V1-O4 2.039 (2)
V1-O6 2.2300 (18)
Se1-O1 1.6718 (19)
Se1-O3 1.7060 (18)
Se1-O2 1.7151 (18)
Symmetry codes: (i) [-x+{\script{1\over 2}}, y+{\script{1\over 2}}, -z+{\script{1\over 2}}]; (ii) [-x+{\script{1\over 2}}, y-{\script{1\over 2}}, -z+{\script{1\over 2}}].

Table 2
Hydrogen-bond geometry (Å, °)

D-H...A D-H H...A D...A D-H...A
O4-H1...O7iii 0.82 1.86 2.671 (3) 171
O4-H2...O3iv 0.81 1.88 2.689 (3) 174
O6-H3...O5v 0.82 2.16 2.906 (3) 151
O6-H4...O2vi 0.82 1.97 2.777 (3) 165
O7-H5...O5 0.81 2.03 2.801 (3) 158
Symmetry codes: (iii) -x, -y+1, -z; (iv) [x-{\script{1\over 2}}, -y+{\script{1\over 2}}, z-{\script{1\over 2}}]; (v) [x, -y, z-{\script{1\over 2}}]; (vi) [-x+{\script{1\over 2}}, -y+{\script{1\over 2}}, -z].

The H atoms were located in a difference map and regularized [O-H = 0.82 (1) Å and H-O-H = 104 (2)°], then treated as riding atoms in the final refinement cycles with the constraint Uiso(H) = 1.2Ueq(O) applied.

Data collection: COLLECT (Nonius, 1998[Nonius (1998). COLLECT. Nonius BV, Delft, The Netherlands.]); cell refinement: SCALEPACK (Otwinowski & Minor, 1997[Otwinowski, Z. & Minor, W. (1997). Methods in Enzymology, Vol. 276, Macromolecular Crystallography, Part A, edited by C. W. Carter Jr & R. M. Sweet, pp. 307-326. New York: Academic Press.]); data reduction: DENZO (Otwinowski & Minor, 1997[Otwinowski, Z. & Minor, W. (1997). Methods in Enzymology, Vol. 276, Macromolecular Crystallography, Part A, edited by C. W. Carter Jr & R. M. Sweet, pp. 307-326. New York: Academic Press.]), SCALEPACK and SORTAV (Blessing, 1995[Blessing, R. H. (1995). Acta Cryst. A51, 33-38.]); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: ORTEP-3 (Farrugia, 1997[Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565.]); software used to prepare material for publication: SHELXL97.


Supplementary data for this paper are available from the IUCr electronic archives (Reference: SQ3246 ). Services for accessing these data are described at the back of the journal.


Acknowledgements

The author thanks the EPSRC National Crystallography Service (University of Southampton) for the data collection.

References

Amorós, P., Marcos, M. D., Beltrán-Porter, A. & Beltrán-Porter, D. (1999). Curr. Opin. Solid State Mater. Sci. 4, 123-131.
Bircsak, Z., Hall, A. K. & Harrison, W. T. A. (1999). J. Solid State Chem. 142, 168-173.  [CrossRef] [ChemPort]
Blessing, R. H. (1995). Acta Cryst. A51, 33-38.  [CrossRef] [details]
Brown, I. D. & Altermatt, D. (1985). Acta Cryst. B41, 244-247.  [CrossRef] [ISI] [details]
Bruker (2003). SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.
Dai, Z., Shi, Z., Li, G., Lu, X., Xu, Y. & Feng, S. (2003). J. Solid State Chem. 172, 205-211.  [CSD] [CrossRef] [ChemPort]
Duc, F., Gonthier, S., Brunelli, M. & Trombe, J. C. (2006). J. Solid State Chem. 179, 3591-3598.  [CrossRef] [ChemPort]
Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565.  [CrossRef] [details]
Finn, R. C., Zubieta, J. & Haushalter, R. C. (2003). Prog. Inorg. Chem. 51, 421-601.  [ChemPort]
Fratzky, D., Worzala, H., Goetze, T. & Meisel, M. (1999). Z. Kristallogr. New Cryst. Struct. 214, 9-10.  [ChemPort]
Geupel, S., Pilz, K., van Smaalen, S., Büllesfeld, F., Prokofiev, A. & Assmus, W. (2002). Acta Cryst. C58, i9-i13.  [CrossRef] [details]
Huan, G., Johnson, J. W., Jacobson, A. J., Goshorn, D. P. & Merola, J. S. (1991). Chem. Mater. 3, 539-541.  [CrossRef] [ChemPort]
Hutchings, G. J. (2009). J. Mater. Chem. 19, 1222-1235.  [CrossRef] [ChemPort]
Johnston, M. G. & Harrison, W. T. A. (2007). Acta Cryst. C63, i28-i30.  [CrossRef] [details]
Le Bail, A., Férey, G., Aromós, P., Beltrán-Porter, D. & Villeneuve, G. (1989). J. Solid State Chem. 79, 169-176.  [CrossRef] [ChemPort]
Leonowicz, M. E., Johnson, J. W., Shannon, H. F. Jr, Brody, J. F. & Newsam, J. M. (1985). J. Solid State Chem. 56, 370-378.  [CrossRef] [ChemPort]
Meng, L., Ma, Y., Zhang, X. & Xu, Y. (2009). Acta Cryst. C65, i45-i47.  [CrossRef] [details]
Mentre, O., Koo, H.-J. & Whangbo, M.-H. (2009). Chem. Mater. 20, 6929-6938.  [CrossRef]
Nonius (1998). COLLECT. Nonius BV, Delft, The Netherlands.
Otwinowski, Z. & Minor, W. (1997). Methods in Enzymology, Vol. 276, Macromolecular Crystallography, Part A, edited by C. W. Carter Jr & R. M. Sweet, pp. 307-326. New York: Academic Press.
Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.  [CrossRef] [details]
Verma, V. P. (1999). Thermochim. Acta, 327, 63-102.  [CrossRef] [ChemPort]
Whittingham, M. S., Song, Y.-N., Lutta, S., Zavalij, P. Y. & Chernova, N. A. (2005). J. Mater. Chem. 15, 3362-3379.  [CrossRef] [ChemPort]
Yakubovich, O. V., Steele, I. M. & Dimitrova, O. V. (2008). Acta Cryst. C64, i62-i65.  [CrossRef] [details]
Yang, G., Liu, H., Ji, H., Chen, Z. & Jiang, X. (2010). Electrochim. Acta, 55, 2951-2958.  [CrossRef] [ChemPort]


Acta Cryst (2010). C66, i61-i63   [ doi:10.1107/S0108270110016707 ]