Intercalation of primary monoamines in the lamellar protonic oxide HNb₃O₈ · H₂O

Abstract

The intercalation of alkyl monoamines in the protonic oxide HNb3O8 · H2O is quantitative for the amines NH2CnH2n+1 with n ranging from 1 to 9. The intercalated oxide NH3CH3Nb3O8 is anhydrous at room temperature whereas monohydrates NH3CnH2n+1NbO3 · H8O2 are the stable form at room temperature; these latter oxides can be dehydrated into the oxides NH3CnH2n+1Nb3O8 without any destruction of the structure, their zeolithic character is observed. The structural evolution of these compounds is interpreted in terms of a transversal orientation of the amine chains with respect to the [Nb3O8]− layers and compared to the one of the N3HCnH2n+1TiNbO5 oxides.

Structure and Raman Spectra of Layered Titanium Oxides

“…The acidity of HCa Nb O , therefore, could be controlled by incorporation of Ti in the Nb site. A general trend showing that protonated niobium oxides are more acidic than protonated niobium-titanium oxides, which have higher acidity than protonated titanium analogs (13,15), supported this assumption.…”

Pillaring of Ruddlesden–Popper perovskite tantalates, H2ATa2O7(A = Sr or La2/3), with n-alkylamines and oxidenanoparticles

“…This result supports the pillar formation between the silicate layer based on many previous reports. [1][2][3][4][5][6][7][8][9][10][14][15][16][17] The isotherm of Fe-H 2 SrTa 2 O 7 does not show a high uptake at low relative pressures, and its surface area (14 m 2 g 21 ) is much lower than that of FeSi-H 2 SrTa 2 O 7 . The presence of unexpanded perovskite layers possibly caused by an intercalation of Fe 3+ cations, as observed by XRD, should result in a relatively low surface area.…”

“…18 Schaak and Mallouk reported that the Ruddlesden-Popper perovskite tantalate, H 2 SrTa 2 O 7 , delaminates upon reaction with alkyl ammonium cations and forms perovskite scrolls. 23 Pillaring of layered metal oxides with inorganic oxide clusters is a promising way to prepare porous layered solids [1][2][3][4][5][6][7][8][9][10][14][15][16][17][30][31][32][33][34][35] with high thermal stability, specific surface area, and catalytic activity. From the viewpoint of catalysis, pillaring of oxide particles between the layers having semiconductive or acidic properties is of special interest, because the interlayer surface can act as photocatalytic or acidic sites.…”

Efficient Microwave-Assisted Functionalization of the Aurivillius-Phase Bi2SrTa2O9

“…Aurivillius phases constitute a closely related family, in which the perovskite layers are separated by bismuth oxide layers. 27−30 Functionalization of these materials by intercalation of organic compounds has been widely described in the literature, following the pioneering work on the functionalization of layered niobiates, 31 titanates, 32 and titano-nobiates 33,34 by acid−base reactions with amines. Such functionalization process involves first the transformation of the layered perovkites into their protonated forms.…”