Author: Isabella Pyka

0000000001304552

AUTHOR

Isabella Pyka

Application of Rigidity-Controlled Supramolecular Affinity Materials for the Gravimetric Detection of Hazardous and Illicit Compounds.

The combination of an (-)-isosteviol-derived building block and 9,9'-spirobifluorene or tetraphenylmethane generated highly potent new affinity materials for the detection of volatile organic compounds (VOCs). Comparison of their affinity behaviour with different core structures showed remarkable influence on selectivity and sensitivity due to structural rigidity and their pre-organization. Their unique supramolecular properties were investigated in an affinity assay using high fundamental frequency quartz crystal microbalances.

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The Role of Side-Arms for Supramolecular Affinity Materials Based on 9,9′-Spirobifluorenes

An eightfold functionalized D2d-symmetric 9,9' spirobifluorene was condensed with a collection of diketones with elaborated structural features to form three-dimensional supramolecular architectures with active surfaces. Gas sorption measurements by quartz crystal microbalances revealed remarkable indications about the molecular interactions for the application as affinity materials for the detection of volatile organic compounds. Single-crystal X-ray structure analysis further gave insight by packing motifs and for potential host-guest interactions.

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Solvent-Adaptive Behavior of Oligospirobifluorenes at the Surface of Quartz Crystal Microbalances-A Conformational Process

Oligospirobifluorenes represent promising building blocks for the generation of microporous sensor materials based on their restricted flexibility. The contact with specific solvents leads to a change of the three-dimensional spirobifluorene structure. The single fluorene moieties unfold to an open structure with an increased volume due to intermolecular interactions with the solvent, detectable by NMR spectroscopy. The induced microporosity was further investigated by affinity comparisons of aromatic analytes with high fundamental frequency quartz crystal microbalances.

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Synthesis of 9,9′-Spirobifluorenes and 4,5-Diaza-9,9′-spirobifluorenes and Their Application as Affinity Materials for Quartz Crystal Microbalances

Two different classes of aza analogues of 9,9'-spirobifluorenes have been synthesized. These were obtained by either furnishing the spirobifluorene with additional pyridyl moieties or by installing the aza function directly into the spirobifluorene core. These structurally rigid compounds were then evaluated as affinity materials for quartz crystal microbalances and proved to be highly potent for the detection of volatile organic compounds.

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