Calixarene phosphonous acids

This review groups the information published on degradation of the main families of extractants studied in the frame of long-lived minor-actinide and fission-product recovery (1-4) (see Chapter 1) alkyl-phosphorus compounds (phosphates, phosphonic acids, bifunctional compounds like CMPO), amide compounds (dialkyl-amides, malonamides, and diglycolamides), N-donor compounds, and macrocycles like crown ethers and calixarenes (Table 8.1). The multicomponent systems based on the chlorinated cobalt dicarbollide process have not been considered. 

Several reports in the literature show that calixarene derivatives play a crucial role in controlling the size and stability of MNPs [106-108]. For example, Raston reported on the synthesis of p-phosphonic acid calix[8]arene-modified Ru, Pt and Pd nanoparticles in aqueous solution (Fig. 37.16) [109]. The macrocycle was demonstrated to exert a control over the shape and size of the produced nanoparticles by acting as stabilizing agent. Molecular modeling revealed that 12 molecules of the macrocycle surround 2-nm Ru particles, where a H-bonding network among calix[8]arenes contribute to the interfacial self-assembly. 

In the phosphorus(V) acids area, there has been continued interest in the preparation of phosphates from elemental phosphorus, and also of compounds derived from the calixarenes. Apart from these, there has been little of real significance in the phosphate field. A much greater interest has been shown in enantio- or diastereo-selectivity in synthesis and reactivity of phosphonates and... 

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