Study on New VOPO_4-Intercalation Compounds with Metal- and Organometallic Complexes

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Ferrocene, its alkyl derivatives, and ferrocenylalkylammonium cation derivatives have been intercalated into the VOP0_4 interlayer to form the intercalation compounds ; VOPO_4・H_2O・(FcR)_x [Fc = (C_5H_5)Fe(C_5H_<4^->) ; R = H, Me, Et and (CH_2)_nNR'R"_2^+ (n = 1, 2 ; R', R" = H, Me) ; x = 0.17-0.45]. The V(V) site is reduced by the ferrocenyl (Fc) center and the I^- ion as the counter anion of the ferrocenylalkylammonium compounds, resulting in the inclusion of the Fcderivatives. Some ferrocenylalkylammonium cations with the NH_3^+ and NHMe_2^+ groups are arranged approximately perpendicular to the VOPO_4 sheet in the interlayer space owing to the possible proximity of these ammonium groups to the V(IV) site. On the other hand, the ferrocenylalkylammonium cations with the -NMe_3^+ group cannot approach the V site, leading to the arrangement of the molecule parallel to the VOPO_4 sheet. Furthermore, the Fc group in the proximity to the V(V) site is oxidized leading to the Fc^+ center, while the Fc group located more or less remote from the V site exists in the unoxidized form in the interlayer space. The ESR signal of the V(IV) ion is broadened by the paramagnetic Fc^+ center located in the proximity of the V(IV) site, which is caused by the rapid spin-relaxation process. Several intercalation compounds of gel-V_2O_5 with the guest molecules of the ferrocenylalkylammonium cations have been obtained. They are arranged approximately parallel to the V_2O_5 sheet with the Fe(III) center, which is due to the rather short adjacent V-V distance. Molecular arrangements and electronic states of the guest molecules in the VOPO_4 and V_2O_5 interlayer spaces are concluded to be determined by the extent of the proximity of the V(IV) site to the Fc center and the ammonium groups.