Coupling of Disilane and Trisilane Segments Through Zero, One, Two, and Three Disilanyl Bridges in Cyclic and Bicyclic Saturated Carbosilanes
2013 (English)In: Organometallics, ISSN 0276-7333, E-ISSN 1520-6041, Vol. 32, no 2, 396-405 p.Article in journal (Refereed) Published
Several six-membered cyclic and [2.2.2]bicyclic organo-silanes with varying proportions of silicon atoms in the bridges have been prepared following a stepwise approach that exploits dianionic polysilanes. Focus in our analysis was placed on the bicyclic compounds which all have silicon atoms at the bridgehead positions. Quantum chemical calculations of these compounds revealed the possibility to enhance the coupling through a single cisoid tetrasilane cage segment by replacing one or two of the other -SiMe2SiMe2- bridges with -CH2CH2- bridges. UV absorption spectroscopy revealed a red shift in the lowest visible transitions when going from a bicyclo[2.2.2]octane with three -SiMe2SiMe2- bridges to those with two or one such bridge. However, these red shifts are deceptive, as the lowest vertically excited singlet states, which are dark according to TD-DFT calculations, do not display the same trend. Still, since these compounds have (i) excellent structural rigidity, (ii) provide potentials for functionalization through their exocyclic trimethylsilyl groups, and (iii) display electronic structure variations with the number of -SiMe2SiMe2- bridges, they could be interesting for further studies: e.g., in single-molecule electronics.
Place, publisher, year, edition, pages
2013. Vol. 32, no 2, 396-405 p.
IdentifiersURN: urn:nbn:se:uu:diva-196040DOI: 10.1021/om3006678ISI: 000314332100007OAI: oai:DiVA.org:uu-196040DiVA: diva2:609059