Abstract:
The diphosphadiazanediyl, [(µ -NR)P·]2 (R = bulky substituent), is a four-membered heterocycle with a significant open shell singlet biradical character (25%) and is known to readily activate small molecules with single and multiple bonds. Starting from the chemistry of this P-centered biradical, this talk covers the synthesis of new P-centered bi- and tetraradical systems such as the linkage of two monoradical species using suitable spacers, new five-membered biradicals and the embedding of radical centers in macrocycle. The synthesis, structure, and properties are discussed, particularly with respect to the activation of small molecules and the use of these species as molecular switches.