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David Scheschkewitz

Publications and source records attributed to David Scheschkewitz.

11 recordsLinked to original sources
PubMed2005

Activation of a Si=Si Bond by eta1-coordination to a transition metal.

Reaction of the disilenide 1 with Cp2ZrCl2 yields 2, the first transition metal complex with an eta1-sigma-bonded disilene moiety. The compound 2 exhibits a strongly red-shifted UV-vis absorption, resulting in an intensely green color. The Si=Si bond in 2 is considerably activated as shown by the rearrangement to a silyl-substituted zirconocene 3. X-ray diffraction studies on 2 reveal that the Si=Si bond is significantly longer than that in the precursor 1. Conversely, the Zr-Si distance is considerably smaller than the corresponding distance in 3, suggesting a certain degree of electron donation toward the 16e- zirconium center.

Journal Article↗
PubMed2002

Singlet diradicals: from transition states to crystalline compounds.

Singlet diradicals are usually not energy minima. As observed by femtosecond spectroscopy, they readily couple to form final sigma bonds. Substituent effects allow lifetimes to increase into the microsecond range. Taking advantage of the properties of hetero-elements, a diradical has been prepared that is indefinitely stable at room temperature. The availability of diradicals that can be handled under standard laboratory conditions will lead to further insight into their chemical and physical properties, raising the likelihood of practical applications, especially in the field of molecular materials such as electrical conductors and ferromagnets.

Journal Article↗