Stable structures of neutral (V 2 O 5 ) n clusters ( n = 1−5, 8, 10, and 12) are determined by density functional calculations (BP86 functional with a double-ζ (V)/triple-ζ (O) valence basis set augmented by polarization functions). Comparison is made with calculations for the periodic structure of solid V 2 O 5 . The most stable structure of the smallest cluster is doubly O-bridged, OV−O 2 −VO 2, and by 184 kJ/mol VO 2.5 less stable than the periodic bulk structure. From the tetrahedral V 4 O 10 structure on (41 kJ/mol VO 2.5 above the crystal energy) polyhedral cage structures are the most stable isomers: trigonal prism (V 6 O 12 ), cube (V 8 O 20 ), pentagonal prism (V 10 O 25 ), 16-hedron (V 16 O 40 ), dodecahedron (V 20 O 50 ), and truncated octahedron (V 24 O 60 ). The polyhedra have vanadyl groups at the apexes and bridging oxygen atoms on the edges. Differently from the crystal structure, vanadium is 4-fold coordinated and 3-fold coordinated oxygen is avoided. The energies relative to the periodic solid are 22.1, 12.4, 9.4, 5.5, 3.3, and 3.4 kJ/mol VO 2.5, respectively. Structures that correspond to fragments cut out of the crystal structure (examined up to n = 8) are significantly less stable. The IR spectra of cage-type structures will show bands in the 1040−1080 cm -1 and in the 800−925 cm -1 regions (terminal V O (1) and bridging V−O (2) −V, respectively), but not between 650 and 750 cm -1 or around 500 cm -1 (V−O 2 (2) −V double bridges and triply coordinated oxygen, respectively).
No takes yet. Share an insight, caveat, or question.
Vyboishchikov et al. (2001) studied this question.