Carborane functionalization

The final class of polymers containing carboranyl units to be mentioned here is the polyphosphazenes. These polymers comprise a backbone of alternating phosphorous and nitrogen atoms with a high degree of torsional mobility that accounts for their low glass-transition temperatures (-60°C to -80°C). The introduction of phenyl-carboranyl units into a polyphosphazene polymer results in a substantial improvement in their overall thermal stability. This is believed to be due to the steric hindrance offered by the phenyl-carborane functionality that inhibits coil formation, thereby retarding the preferred thermodynamic pathway of cyclic compound formation (see scheme 12). 

Fig. 11.15 Examples of multi-functional SERS probes, (a) Carborane-functionalized nanoparticles [94], (b) SERS-coded gold nanorods [95], (c) fluorescent SERS probe [71], and (d) magnetic SERS probe [74]...

PAR Parrott, M.C., Valliant, J.F., and Adronov, A., Thermally induced phase separation of carborane functionalized aliphatic polyester dendrimers in aqueous media,... 

Synthesis and Characterization of Carborane Functionalized Dendronized Polymers as Potential Boron Neutron Capture Therapy Agents... 

The obtained results show that hydrophobicity, steric bulk, and lack of Jt-interactions make the carborane functionality ideal scaffolding for use in the binding channel of TTR. Similarly, these same properties are detrimental when applied to COX inhibitors. Consequently, it has been shown that the substitution of a carborane moiety for a phenyl ring in NSAIDs with known TTR tetramer stabilizing activity retains the TTR potency of the compound while dramatically reducing the... 

Bis(metfl-carborane) (67) was obtained by copper-mediated C—C coupling of monolithiated meta-carborane. Functionalization of the C—H groups of 67 with amidophosphites gave P-chiral (68) and achiral (69) bisphosphonite derivatives (Scheme 2.10). 

Hao, E. Fronczek, F. R. Vicente, M. G. H. Carborane functionalized pyrroles and porphyrins via the Suzuki crosscouphng reaction, Chem. Commun. 2006,4900. 

Similarly a CH vertex in a polygonal hydrocarbon or polyhedral carborane functions as a donor of three skeletal electrons. The external hydrogen atoms in BH and CH vertices can be replaced by other monovalent groups without affecting the number of skeletal elections donated by the vertex in question. 

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