Modulare Synthese von diskreten porösen organischen Käfigverbindungen
Schneider, Markus Willibald
FacultiesFakultät für Naturwissenschaften
This thesis is the basis for the modular synthesis of porous, covalent bonded, discrete organic cage compounds and their sorption properties. The syntheses of cage compounds were carried out in a one-pot reaction through imine condensation of triaminotriptycene with various substituted dialdehydes. Depending on the used dialdehyd a [2+3]-, [4+6]- or [8+12]-cage compound was obtained. All isolated cage compounds have hydroxyl groups either orientated towards the periphery or to the interior of the cage. Moreover, they form a stabilizing six-membered ring via hydrogen bonding to an adjacent nitrogen atom. Nitrogen sorption measurements of cage compounds showed, that the specific surface area dependent on material morphology, crystalline, amorphous or spherical amorphous. Furthermore, the nitrogen sorption capacity strongly depends on the substituents in the periphery of cage compounds for the crystalline materials. With increasing size of the substituents, the nitrogen uptake dropped, as well as the surface area, due to the formation of closed voids. In contrast, the specific surface area of amorphous materials is independent on the substituent in the periphery of the cage compounds. For the syntheses of [2+3]-cage compounds a connection was identified between the influence of flexible precursors and the resulting yield of the cage compounds. With increasing flexibility the yield dropped. The void space in the interior of [2+3]-cage compounds was adjustable with bissalicylic aldehydes of different lengths. However, the specific surface area did not increase with increasing void space. In addition, the influence of hydroxyl groups on cage stability was investigated. Therefore, cage compounds were postfunctionalized with various substituents in the cage interior.
Subject HeadingsKäfigverbindungen [GND]
Clathrate compounds [LCSH]