p-Carborane Conjugation in Radical Anions of Cage-Cage and Cage-Phenyl Compounds

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388963%3A_____%2F18%3A00489518" target="_blank" >RIV/61388963:_____/18:00489518 - isvavai.cz</a>

Result on the web

<a href="http://dx.doi.org/10.1021/acs.jpca.7b10885" target="_blank" >http://dx.doi.org/10.1021/acs.jpca.7b10885</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1021/acs.jpca.7b10885" target="_blank" >10.1021/acs.jpca.7b10885</a>

Result language

angličtina

Original language name

p-Carborane Conjugation in Radical Anions of Cage-Cage and Cage-Phenyl Compounds

Original language description

Optical electron transfer (intervalence) transitions in radical anions of p-carborane oligomers attest to delocalization of electrons between two p-carboranes cages or a p-carborane and a phenyl ring. Oligomers of the 12 vertex p-carborane (C2B10H12) cage, [12], with up to 3 cages were synthesized, as well as p-carboranes with one or two trimethylsilylphenyl groups, [6], attached to the carbon termini. Pulse radiolysis in tetrahydrofuran produced radical anions, determined redox potentials by equilibria and measured their absorption spectra. Density functional theory computations provided critical insight into the optical electron transfer bands and electron delocalization. One case, [6-12-6], showed both Robin Day class II and III transitions. The class III transition resulted from a fully delocalized excess electron across both benzene rings and the central p-carborane, with an electronic coupling H-ab = 0.46 eV between the cage and either benzene. This unprecedented finding shows that p-carborane bridges are not simply electron withdrawing insulators. In other cases with more than similar to 1/2 of the excess electron localized on a [12], large cage distortions were triggered, producing a partially open cage with a nido-like structure. This resulted in class II transitions with similar H-ab but massive reorganization energies. The computations also predicted delocalization in radical cations, but complexities in cation formation allowed only tentative experimental support of the predictions. The results with anions provide clear evidence for carborane conjugation that might be exploited in molecular wire materials, which are classically composed of all pi-conjugated molecules.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

10403 - Physical chemistry

Project

—

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2018

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Journal of Physical Chemistry A

ISSN

1089-5639

e-ISSN

—

Volume of the periodical

122

Issue of the periodical within the volume

3

Country of publishing house

US - UNITED STATES

Number of pages

13

Pages from-to

798-810

UT code for WoS article

000423653100007

EID of the result in the Scopus database

2-s2.0-85041180410