A New Vanadium Oxide Bronze: [NH3(CH2)6NH3]10[V15O37(Cl)]2[V15O36(Cl)](OH)3(H2O)3 with Clusters [V15O36(Cl)]5− and [V15O37(Cl)]6− Textured by Diaminohexane

✍ Scribed by Thierry Drezen; Marcel Ganne

• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 448 KB
• Volume: 147
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1006/jssc.1999.8416

✦ Synopsis

A novel mesostructured mixed-valence polyoxovanadate with formula [NH 3 (CH 2 ) 6 NH 3 ] 10 [V 15 O 37 (Cl)] 2 [V 15 O 36 (Cl)] (OH) 3 (H 2 O) 3 was synthesized hydrothermally under autogeneous pressure at 443 K for 5 days from an aqueous mixture of NH 2 (CH 2 ) 6 NH 2 and V 2 O 5 in acidic HCl (1 M) medium. Its structure was solved from single-crystal X-ray di4raction data at room temperature. It crystallizes in the orthorhombic symmetry (space group Pnma) with a ‫؍‬ 23.616( 5), b ‫؍‬ 44.785(9), c ‫؍‬ 18.568(4) A > , V ‫؍‬ 19638.3(5) A > 3 , and Z ‫؍‬ 4. Two types of polyoxovanadate clusters, [V 15 O 37 (Cl)] 6؊ and [V 15 O 36 (Cl)] 5؊ , have been characterized, around which the stacking of hexanediamine dications is di4erent. XPS measurements are in reasonable agreement with the calculated average vanadium valence state of 4.60؎0.1 in this hybrid compound. All things being similar, hexanediamine appears to be slightly less reducing than octyldiamine and therefore has been placed below octyldiamine in a phenomenological diagram implying the 99e4ective:: redox potential of diamines which have to be compared with that of V V /V IV couple in the solid.