Spiroconjugation in spirodicorrolato-dinickel(II).
In the present work the effect of spiroconjugation on the electronic spectrum of the recently synthesized metal complex hexadecaethylspirodicorrolato-dinickel(II) (5) (the corrole units in 5 are isoforms) is investigated. To have a suitable reference compound at our disposal, tetraethylhexamethylisocorrolato nickel(II) (7) has been prepared. On comparing the electronic spectra of this reference compound and the spiro-complex, bathochromic shifts of all absorption bands in the NIR/Vis-region are observed for the latter as well as marked changes in the spectral intensities. A detailed analysis of the spectra supported by semiempirical calculations reveals that at least part of the observed changes can be unambiguously attributed to the spiro effect. This effect is further affirmed by electrochemically measured redox potentials.
Hohlneicher
Georg
G
Institut für Physikalische Chemie der Universität zu Köln, Luxemburger Strasse 116, 50939 Köln, Germany. gehohln@pc.uni-koeln.de
Bremm
Dominik
D
Wytko
Jennifer
J
Bley-Escrich
Jordi
J
Gisselbrecht
Jean-Paul
JP
Gross
Maurice
M
Michels
Martin
M
Lex
Johann
J
Vogel
Emanuel
E