ABSTRACT

π-Conjugated molecules with an even number of π-electrons usually have a closed-shell ground state. However, recent studies have demonstrated that a certain type of molecules could show open-shell singlet ground state and display diradical-like (diradicaloid) behavior. Their electronic structure can be understood in terms of the “diradical character” and “aromaticity” concepts. They display very different electronic properties from traditional closed-shell π-conjugated molecules and could be used as next-generation molecular materials.

This book provides a comprehensive review on the chemistry, physics, and material applications of open-shell singlet diradicaloids. Particularly, it elaborates the fundamental structure–diradical character–electronic property relationships both theoretically and experimentally. The book has been written by leading scientists in the field from Japan, Germany, Spain, Italy, China, and Singapore.

chapter Chapter 5|37 pages

Phenalenyl- and Anthene-Based Diradicaloids

chapter Chapter 6|24 pages

Zethrenes and Related Molecules

chapter Chapter 7|33 pages

Extended para-Quinodimethanes and Quinones

chapter Chapter 10|33 pages

Photo-Responsive Diradicaloids

chapter Chapter 11|51 pages

Porphyrinoid-Based Diradicaloids

chapter Chapter 13|45 pages

Polyradicaloids and 2D/3D Global Aromaticity