Theoretical study of spin interactions in stacked acetylene radical ions

✍ Scribed by S. Ramasesha; Bhabadyuti Sinha

• Publisher: Elsevier Science
• Year: 1991
• Tongue: English
• Weight: 511 KB
• Volume: 179
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(91)85170-2

✦ Synopsis

The search for organic ferromagnets has so far focused on radical ions of cyclic conjugated systems which have a doubly degenerate highest-occupied molecular orbital. However, recent theoretical studies on dimers of such systems have shown that the ground state is a singlet and not a triplet as expected. In this paper, we demonstrate that an acetylenic radical ion system possesses a high-spin ground state which is stable with respect to different geometries of packing and substitutions. The stability of the highspin state is attributed to the degeneracy of the atomic orbitals involved in conjugation. We suggest that these systems are prime candidates for observing organic ferromagnetism.

* Communication No. 746 from the Solid State and Structural

Chemistry Unit.