Intercalation of Ferrocene and Its Derivatives into VxNb1-xOPO4(x= 0, 0.06, 0.11, and 0.21) Interlayer Spaces

Ferrocene, FcH [Fc = (C5H5)Fe(C5H4)], (ferrocenylalkyl)trimethylammonium iodides, [Fc(CH2)nNMe3]+I-(n= 1 or 2), and 1,2-diferrocenylethane, FcCH2CH2Fc, have been intercalated into the V0.21Nb0.79OPO4interlayer space. The V(V) ion is reduced by the iodide ion and/or the Fc centers, the Nb(V) ion being not reduced. The long-axis direction of the guest molecules is arranged approximately parallel to the swelling V0.21Nb0.79OPO4sheet. Some Fc centers of FcCH2CH2Fc and FcCH2CH2NMe3+are not oxidized in spite of their proximity to the metal ion site of the V0.21Nb0.79OPO4lattice because most of the V sites are isolated from other V sites owing to the low V contents. Ferrocenylalkylamines, FcCH2NMe2and FcCH2CH2NH2, have been intercalated into the VxNb1-xOPO4(x= 0, 0.06, 0.11, and 0.21) interlayer spaces, accompanied with the protonated amino groups and the Nb(V) and reduced V(IV) sites. ESR signals of the V0.06Nb0.94OPO4intercalation compounds exhibit hyperfine structures due to the V(IV) nucleus (I= 7/2). With the increase of the V content in the host lattice, ESR signals are further broadened owing to the dipole–dipole and/or exchange interactions among the V(IV) sites.