Syntheses and properties of carboranylpyrroles
Synthetic routes to mono- and di-carboranylpyrroles (1-5) bearing the carborane groups linked either directly to the 3- and/or 4-positions of the pyrrole ring or via one or two methylene spacers are described. Several X-ray structures of key intermediates are presented and discussed. Carboranylpyrroles can be cyclotetramerized to afford carboranylporphyrins in low to moderate yields, depending on the number of carborane cages and their linkage to the pyrrole ring. The best yields of porphyrin were obtained with pyrrole 3, bearing a two carbon spacer between the carborane and pyrrole units. The electrochemical polymerization of pyrroles 2 and 3 gave functionalized conducting polymer films with increased overoxidation resistance and thermal stability compared with unsubstituted polypyrrole. Dicarboranylpyrrole 4 did not electropolymerize under a variety of experimental conditions, whereas pyrrole 5 formed only soluble oligomers. Copyright © 2005 Society of Porphyrins & Phthalocyanines.
Publication Source (Journal or Book title)
Journal of Porphyrins and Phthalocyanines
Clark, J., Fabre, B., Fronczek, F., & Vicente, M. (2005). Syntheses and properties of carboranylpyrroles. Journal of Porphyrins and Phthalocyanines, 9 (10-11), 803-810. https://doi.org/10.1142/s1088424605000915