Shoji Okuno

Intercalation of ferrocene and its alkyl derivatives into the vanadyl phosphate interlayer space

Abstract Ferrocene (Fc) and its alkyl-substituted derivatives (RFc; R=1,1′-Me 2 , Et, Bu n , HOCH 2 and HOCH 2 CH 2 ) intercalated into VOPO 4 ·H 2 O·EtOH in ethanol and EtOH/acetone to afford VOPO 4 ·H 2 O·(Fc + ) 0.35 , VOPO 4 ·H 2 O·(Me 2 Fc + ) 0.21 , VOPO 4 ·H 2 O·(EtFc + ) 0.19 , VOPO 4 ·H 2 O·(Bu n Fc + ) 0.08 , VOPO 4 ·H 2 0· (HOCH 2 FC + ) 0.23 and VOPO 4 ·H 2 O·(HOCH 2 CH 2 Fc + ) 0.31 , respectively (RFc + =the ferrocenium cation and its alkyl derivatives). The cobaltocenium cation (CoCp 2 + ) also intercalated into the VOPO 4 interlayer space in the presence of the iodide ion in ethanol to afford VOPO 4 ·H 2 O·(CoCp 2 + ) 0.52 . The intercalation compounds are constructed with layered VOPO 4 moieties in both V(IV) and V(V) states and the ferrocenium cation and its alkyl derivatives producing a single interlayer spacing. Based on the interlayer distances of the VOPO 4 moieties determined by the X-ray diffraction patterns, Fc + and Me 2 Fc + cations are concluded to be stably located in the VOPO 4 interlayer space, the cyclopentadienyl rings being approximately parallel to the layers at the first stage, followed by the change to an orientation perpendicular to the layers after a long period of standing. In contrast to this finding, the EtFc + and Bu n Fc + cations are stably located between the VOPO 4 layers, the rings being perpendicular to the layers. Electronic states of the VOPO 4 moieties and the guest molecules are discussed on the basis of ESR, IR, X-ray photoelectron, electronic absorption and reflectance spectra.

Preparation and spectroscopies of layered zirconium organophosphonates containing pyridinium and its derivative cations

Abstract Zirconium organophosphonates containing the pyridinium, 3-cyanopyridinium, 4-cyanopyridinium and isoquinolinium cation moieties and bromide ion as the counter anion with layered structures were synthesized. The bromide ion can be exchanged by chloride and iodide ions without leaching of these cation sites from the interlayer space. Their electronic reflectance spectra exhibit charge tranfser bands between the halide ions and these pyridinium sites in the solid state.

Spin-Crossover Phenomena of Iron Complexes in the Montmorillonite Interlayer Space

Abstract Spin-crossover phenomena of four iron complexes, [Fe(amp)3]2+ (amp = 2-(aminomethyl)pyridine), [Fe(acac2trien)]+ (H2acac2trien = N,N-bis(1- metnyl-3-oxobutylidene)triethylenetetramine), [Fe(sal2trien)] (H2sal2trien = N,N′- disalicylidenetriethylenetetramine), and [Fe(acpa)2] (Hacpa = N-acetyl-2-propylidene) −2-pyridylmethylamine), intercalating into the montmorillonite interlayer space were examined by the magnetic susceptibility measurement and 57Fe Mossbauer spectroscopy. Confinement of the complexes in the 2D space brings some dispersion and drop of the spin-crossover temperature in comparison with those for their spin equilibria in solution. Twisting deformation of the complexes was proposed to be responsible for the observed variation of the relative stability between high-spin and low-spin species.

Analysis of polypropyleneglycols using electrospray ionization mass spectrometry. Effects of cationizing agents on the mass spectra.

In electrospray ionization mass spectrometry (ESI-MS) of polypropyleneglycol (PPG), effects of cationizing agents were examined. When NaI was used as a cationizing agent, the distribution of multiply-charged ions in the spectra was greatly affected by the ratio of cationizing agent and PPG. However, the distribution was not affected by the use of CH3COONH4. With an increase of cone voltage, fragmentation occurred by in-source collision-induced dissociation (CID) when CH3COONH4 was used. On the contrary, no decomposition of the PPG backbone was observed with NaI. Instead, the intensity of the lower-charged ions, whose mass-to-charge (m/z) ratios are larger, increased because of the elimination of Na+ with increase of cone voltage. Under optimum conditions for ESI-MS analysis, PPGs that have different molecular weights, different initiators or end groups were easily and accurately characterized. A tandem mass spectrometry (MS/MS) study of NH4+ adduct ions of PPG indicated that a vinyl-terminated linear structure is formed at the end group during the fragmentation.

Spin-crossover Phenomena of Iron Complexes in the NaTSM Intercalation Compounds

The spin-crossover phenomena of iron complexes accompany with molecular deformations such as symmetric breathing and trigonal torsion. Thus they can serve as a sensitive probe to molecular surroundings. A confinement effect into interlayer spaces of a clay host compound, NaTSM (sodium fluorotetrasilicic mica), was studied for iron complexes by magnetic susceptibility and 57 Fe Mossbauer spectroscopy. Guest complexes examined are [Fe II -(amp) 3 ] 2+ (amp=2-aminomethylpyridine), [Fe III (acpa) 2 ] + (Hacpa= N -(1-acetyl-2-propylidene)-2-pyridylmethylamine), and [Fe III - (sal 2 trien)] + (H 2 sal 2 trien= N , N ′-disalicylidenetriethylenetetramine). A remarkable reduction of the high spin-low spin energy gap in the interlayer space was observed.

Intercalation of ferrocenylalkylammonium cations into the layered lattice of VOPO4

Some ferrocenylalkylammonium iodides, [FeII(C5H5){C5H4(CH2)nNR2R′}]+I–(n= 1 or 2; R,R′= H or Me), benzyldimethyl- and benzyltrimethyl-ammonium iodides reacted with VvOPO4·H2O·EtOH suspended in ethanol to afford intercalation compounds of VOPO4·H2O with 0.45[FeII(C5H5)(C5H4CH2NHMe2)]+, 0.20[FeII(C5H5)(C5H4CH2 NMe3)]+, 0.43[FeII(C5H5)(C5H4CH2 CH2NH3)]+, 0.17[FeIII-(C5H5)(C5H4 CH2CH2NMe3)]2+, 0.54PhCH2NHMe2+ and 0.45PhCH2NMe3+. Ferrocenylalkylammonium chlorides, [FeII(C5H5)(C5H4CH2 NHMe2)]+Cl– and [FeII(C5H5)(C5H4CH2 CH2NH3)]+ Cl–, were also intercalated to give compounds of VOPO4·H2O with 0.29[FeIII(C5H5)(C5H4 CH2NHMe2+Cl–)]+ and 0.18[FeIII(C5H5)(C5H4 CH2CH2NH3+Cl–)]+. The intercalation compounds comprise layered VOPO4 moieties having both the vanadium-(IV) and -(V) states and the ferrocenylalkyl-, benzyldimethyl-, and benzyltrimethyl-ammonium cations as well as ferrocenium-substituted alkylammonium chlorides, [FeIII(C5H5)(C5H4CH2 NHMe2+Cl–)]+ and [FeIII(C5H5)(C5H4CH2 CH2NH3+Cl–)]+, in the interlayer space, producing VOPO4–interlayer spacings of 9.8–21.0 A. The molecular arrangements of these alkylammonium-substituted ferrocene and ferrocenium species in the interlayer space and the electronic states of the guest and host moieties are discussed on the basis of powder X-ray diffraction patterns, and IR, ESR and X-ray photoelectron spectra.

Direct intercalation of pyridinium-derivative cations into the α-zirconium phosphate interlayer by a redox reaction and fluorescence behavior of the intercalation compounds

Abstract N -Alkylquinolinium (R-Qu + ), -isoquinolinium (R-isoQu + ) and -acridinium (R-Ac + ) (R=Me, Et, Pr n , Bu n ) cations were directly intercalated into the α-zirconium phosphate (α-ZrP) interlayer space by redox reactions of their iodide salts. These pyridinium-derivative cations fluoresce intensively even in the α-ZrP interlayer, the fluorescence band being similar to the band observed in solution. The fluorescence decay curves measured for the intercalation compounds suspended in acetonitrile were reasonably fitted by assuming a double-exponential model. The compounds contain cation components with short fluorescence lifetimes compared with those observed in acetonitrile, which is explained by self-quenching due to high densities of these cations in the interlayer space.