Organometallische π-Systeme

Daniel Fink, Michael Linseis and Rainer F. Winter

Organometallics, 2018, 37, 12, 1817-1820

Two constitutionally isomeric tetraruthenium macrocycles were constructed from either symmetrically (2-S) or unsymmetrically (2-A) functionalized thiophene-based building blocks. Both compounds were fully characterized by NMR spectroscopy and high-resolution ESI MS. Despite their identical composition and close structural resemblance, the two isomers exhibit vastly different electrochemical and spectroscopic properties as a consequence of the different extensions of their π-conjugated subunits. In particular, mixed-valent 2-A^+/2+/3+ absorb weakly in the near infrared as a consequence of electronic through-bond coupling between neighboring oxidized and reduced sites, whereas 2-S^+/2+/3+ do not.

https://doi.org/10.1021/acs.organomet.8b00057