Pavel Matějka

Intercalation of Cyclic Ethers into Vanadyl Phosphate

Two cyclic ethers, tetrahydrofuran (THF) and tetrahydropyran (THP), were intercalated into vanadyl phosphate and characterized by X-ray powder diffraction, thermogravimetry, and IR and Raman spectroscopy. Both compounds contain one molecule of ether per formula unit of VOPO(4) and show high thermal stability in comparison with VOPO(4) intercalates with other organic guest molecules. Both ethers are anchored to the VOPO(4) host layers by their oxygen atoms, which are coordinated to the vanadium atoms of the host. The probable arrangement of the tetrahydropyran molecules in the host interlayer space is derived from molecular simulations by the Cerius(2) 4.5 program.

Intercalates of Vanadyl Phosphate with Dinitriles

Intercalates of vanadyl phosphate with aliphatic dinitriles (malononitrile, succinonitrile, glutaronitrile, adiponitrile, pimelonitrile and suberonitrile) were prepared and characterized by X-ray powder diffraction, thermogravimetric analysis, IR and Raman spectroscopies. The basal spacings of all the intercalates prepared are practically identical. The dinitrile content in the intercalates decreases with increasing chain length. The dinitrile molecules are anchored to the host layers by an N–V donor–acceptor bond and their aliphatic chains are parallel to the host layers. The dinitrile intercalates are generally more stable in air (at relative humidity 40–50%) than nitrile intercalates and the guest molecules are slowly replaced by the water molecules.

Intercalates of Vanadyl Phosphate with Aliphatic Nitriles

Intercalates of vanadyl phosphate with aliphatic nitriles (acetonitrile, propionitrile, butyronitrile, valeronitrile and hexanenitrile) were prepared and characterized by X-ray powder diffraction, thermogravimetric analysis, IR and Raman spectroscopies. The basal spacings of all the intercalates prepared are practically identical. The nitrile intercalates (except acetonitrile) contain one nitrile molecule per formula unit. The nitrile molecules are anchored to the host layers by an N–V donor-acceptor bond and their aliphatic chains are parallel to the host layers. The acetonitrile intercalate contains two guest molecules per formula unit. Only half of them can be bonded to the vanadium atom, the second half is probably anchored by van der Waals interaction. The intercalates prepared are moisture-sensitive and the guest molecules are easily replaced by water molecules.