Geraud Dubois, Willi Volksen, et al.
Journal of Sol-Gel Science and Technology
The cyclobutapyrazine derivative, endo-3,4-pyrazinotricyclo[4.2.1.02,5]nonane (3), has been synthesized and subjected to a spectroscopic investigation. An inequivalence of the two faces of the pyrazine π system is revealed by the measured relative polarization directions of the 1nπ* and 1ππ* electronic transitions and is ascribed to a delocalization of the pyrazine orbitals into the low-symmetry saturated polycyclic system. A striking red shift of the 1nπ* transition in 3 relative to 2,3-dimethylpyrazine and a similar shift of the n+ionization energy to lower values are ascribed to an enhanced through-bond coupling of the two nitrogen lone-pair orbitals due to distortion of bond angles at carbons 2 and 3 and to the resulting enhancement of the p character of the σ bond orbital through which the coupling occurs. © 1982, American Chemical Society. All rights reserved.
Geraud Dubois, Willi Volksen, et al.
Journal of Sol-Gel Science and Technology
Ilya Zharov, Anil Saxena, et al.
Inorganic Chemistry
Jeroen J. L. M. Cornelissen, Eric F. Connor, et al.
Chemical Communications
Zouheir Sekkat, Jonathan Wood, et al.
Journal of the Optical Society of America B: Optical Physics