Descripción del proyecto
Se sintetizan por primera vez los ciclacenos, compuestos de carbono en forma de anillo
Los ciclacenos son compuestos policíclicos con forma de aro donde se fusionan moléculas aromáticas para formar estructuras de anillo. Las singulares propiedades químicas, electrónicas y estructurales de estos compuestos de carbono en forma de anillo permiten utilizarlos en electrónica orgánica y espintrónica. A pesar de décadas de esfuerzos de investigación, todavía no ha sido posible producir ni un solo ejemplar representativo de esta clase de sustancias. El equipo del proyecto TACY, financiado por el Consejo Europeo de Investigación, iniciará nuevas estrategias sintéticas pioneras para generar ciclacenos. El método propuesto es altamente modular, lo cual permite variar la estructura de los precursores de tipo cinturón, y en consecuencia de los ciclacenos, mediante la introducción de diferentes sustituyentes en los bordes. La investigación del proyecto, combinada con técnicas de caracterización molecular y actividades informáticas de última generación, proporcionará una visión inédita de la relación entre la estructura y las propiedades de la topología conjugada en zigzag de los ciclacenos.
Objetivo
Cyclacenes, i.e. cyclic versions of acenes consisting of linearly fused benzene rings, were first discussed in 1954 by Heilbronner, but - despite considerable synthetic efforts over decades - have remained an elusive class of compounds. Theoretical investigations suggest that cyclacenes are highly reactive due to pronounced polyradical character and significant ring strain. All prior attempts to synthesise cyclacenes failed, mainly because the final synthetic step of establishing a fully conjugated π-system was energetically prohibitive. Despite these challenges, cyclacenes remain intriguing synthetic targets because of their unique chemical, electronic, and structural properties as well as their potential applications in organic (opto-)electronics or spintronics. In this collaborative project, we will develop novel synthetic approaches, which synergistically combine efficient and high-yielding synthetic strategies of belt-type precursors that we will transform to cyclacenes by extrusion of suitable leaving groups under cryogenic matrix isolation conditions, on surfaces, in the solid state, and ultimately even in solution. Our synthetic approach is highly modular and allows to structurally vary the belt-type precursors, and thus the cyclacenes, by placing different substituents at the rims, including peri-annulation or isosteric substitution of CH units by heteroatoms. This research, combined with state-of-the-art computational investigations and characterization even on the single-molecule level, will provide unprecedented insight into the structure-property relationship of the fully conjugated zigzag topology present in cyclacenes and address fundamental questions of chemical reactivity and the interplay of aromaticity, strain and polyradical character. This knowledge will finally allow us to synthesise interlocked structures based on cyclacenes and to apply cyclacenes in controlled reactions on surfaces for creating further elusive materials such as polyacenes.
Ámbito científico
Programa(s)
- HORIZON.1.1 - European Research Council (ERC) Main Programme
Régimen de financiación
ERC-SYG - ERC-SYGInstitución de acogida
69117 Heidelberg
Alemania