The interlayer cations of uvanite can be exchanged quantitatively by n-alkylammoniumions according to
M+[UO2V3O9] + CnH 2n+1NH3+⇄ CnH2n+1NH3[UO2V3O9] + M+.
In the stoichiometric compounds the alkyl chains of the cations (n= 6-18) are poorlyordered in monolayers and oriented nearly perpendicular to the uranyltrimetavanadatelayers though the space filling is unfavorable with this arrangement. During the cationexchange at pH = 7-9 additional free amine molecules are taken up yielding 1:1 intercalationcomplexes
(CnH2n+1NHs) (CnH an+1NH2) [UO2V3O9]
with close-packed, well ordered monolayers of alkyl compounds. With excess of pureamines or pure alkanols 1: 3 intercalation complexes
(CnH2n+1NH3) (CnH2n+1NH2),[UO2V3O9] or
(CnH2n+1NH3) (Cn·H2n+1OH )s[UO2V3O9
(n, n′ = 6-18] are formed with the alkyl chains ordered to bimolecular layers. These
complexes rearrange at higher temperature into new phases as a consequence of rotationalisomerisation of the alkyl chains.