Publications by authors named "Malte von Seebach"
Diastereomeric meso- and d,l-bis(bicyclopropylidenyl) (5) were obtained upon oxidation with oxygen of a higher-order cuprate generated from lithiobicyclopropylidene (4) in 50 and 31 % yield, respectively. Their perdeuterated analogues meso-[D(14)]- and d,l-[D(14)]-5 were obtained along the same route from perdeuterated bicyclopropylidene [D(8)]-3 (synthesized in six steps in 7.4 % overall yield from [D(8)]-THF) in 20.
View Article and Find Full Text PDFThe radical cations of dicyclopropylidenemethane (2) and its octamethyl derivative (2-Me8) are prone to rearrangements into those of (2-methylallylidene)cyclopropane (2a) and its octamethyl derivative (2a-Me8), respectively, by opening one three-membered ring. In contrast to the radical cations of bicyclopropylidene (1) and its octamethyl derivative (1-Me8), 2*+ and 2-Me8*+ are stable to opening of the second ring, because in this case the resulting species would be a non-Kekulé hydrocarbon with a quartet ground state. Similarly to 1, octamethyl substitution in 2 promotes the tendency to rearrangement.
View Article and Find Full Text PDFArticle Synopsis
- Bicyclopropylidene and its octamethyl derivative undergo ionization via X-irradiation in solid argon, leading to the opening of cyclopropylidene rings and formation of radical cations.
- The radical cations, identified as tetramethyleneethane derivatives, display a broad near-infrared (NIR) band, with one variant revealing two similar interconvertible species based on spectral analysis.
- Computational methods suggest these species have different singly occupied molecular orbitals, and while similar structures are predicted for the octamethyl derivative, experimental evidence is lacking; however, it's noted that spin localization differs between the two radical cations.