Novel hexagonal {VO}6-containing sandwich-type cluster accompanied by in situcarbon–carbon bond formation of organic cations

Abstract

Two novel sandwich-type polyanions containing hexagonal {VO}₆group (H₂tpy)(Hbpe)₃H[(VO)₆(SbW₉O₃₃)₂]·2H₂O (1) and (H₂tcy)₆(Hbpp)₆H₄[VW₁₂O₄₀][(VO)₆(SbW₉O₃₃)₂]₃·30H₂O (2) (tpy = 4-(2,3,4-tri(pyridin-4-yl)butyl)pyridine, bpe = 1,2-(4-pyridyl)ethene, tcy = 1,2,4,5-tetra(pyridin-4-yl)cyclohexanol, bpp = 1,3-bis-(4-pyridyl)propane), were reported. Both compounds are built upon the complex hydrogen bonding networks of C–H⋯O and N-H⋯O occurred among inorganic anions and organic cations. Unusual in situ organic reactions involving C–C coupling are also observed in 1 and 2 regardless of the rigid bpe or flexible bpp. Compound 2 represents a rare case in which nano-sized α-Keggin [VW₁₂O₄₀]⁴⁻ and sandwich-type [(VO)₆(SbW₉O₃₃)₂]⁶⁻ anionic clusters are present in a common crystal framework.