Drawbacks Arising from the High Steric Congestion in the Synthesis of New Dendritic Polyalkylaromatic Polyradicals
作者:Daniel Ruiz-Molina、Jaume Veciana、Fernando Palacio、Concepció Rovira
DOI:10.1021/jo9622385
日期:1997.12.1
The synthesis of the highly strained tris(alpha,alpha-bis(pentachlorophenyl)-2,4,5,6-tetrachlorotolyl)methane (8), which is the precursor of the first generation of the polyradical series III, has been achieved by exhaustive chlorination of compound 11. Stepwise divergent synthesis, by successive Friedel-Crafts reactions, of the precursors of dendritic series II and III was not possible since the limit generation was reached in the earlier synthetic steps due to high steric congestion. Several polyradical mixtures derived from 8 have also been prepared, being stable under ambient conditions. The formation, electrochemistry, and magnetic properties of these polyradical species are discussed. The steric hindrance of highly chlorinated hydrocarbon 8 prevents the formation of tetraradical 15.