Cage compound sensors

K D Schierbaum and W Gopel, "Selective Chemical Sensing Molecular Recogmtion with Cage Compounds and Polymenc Permselective Layers", m G Harsanyi (Ed), "Polymer Films and Sensor Technologies", Technomic, Lancester (USA) 1994, in press... 

In this meaning also sensor properties of cage compounds are of general interest for the detection of host guest interactions in solution and can be used further for analytical applications. 

Container molecules in general show an increasing number of applications and so do the container molecules based on imine type ligands. Many different shapes of open or nearly closed ones could already be synthesised. Those cages are known to encapsulate different types of guest molecules. This encapsulation can be selective and permanent or reversible. The container molecules described are also used for stabilisation of different compounds such as the allotrope P4. They can be used as gas or optical sensors. One of the described cages can also be opened and closed selectively. 

In a great number of cases, zeolites are used as auxiliary elements. They may act either as a framework to stabilize the sensor material, as filter layers (either catalytic or size restrictive) to enhance selectivity of a sensitive film, or as a preconcentrator of specific analytes from diluted solutions. For example, due to excellent chemical and thermal stability, zeolites can be used as a substrate to prepare compounds and devices with desirable fundamental physical and chemical properties (Xu et al. 2006). For example, inorganic or organic compounds, metal and metal-organic compounds, and their clusters can be assembled into the pores and cages in zeohtes. Some nanosized metal or metal oxide particles have been successfully inserted into the caves and the pores or highly dispersed on the external surface of zeohtes. 

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