ja2014746_si_002.cif (16.56 kB)

Isolable p- and m-[(tBu2MeSi)2Si]2C6H4: Disilaquinodimethane vs Triplet Bis(silyl radical)

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posted on 20.04.2011, 00:00 by Takeshi Nozawa, Michiyo Nagata, Masaaki Ichinohe, Akira Sekiguchi
Isomeric p- and m-disilaquinodimethanes 2 and 4 were synthesized by the reductive dehalogenation of the corresponding p- and m-bis(halosilyl)benzenes 1 and 3, respectively, and were isolated and structurally characterized. The X-ray diffraction and solid-state NMR studies of 2 revealed its singlet quinodimethane structure featuring two exocyclic SiC double bonds with some singlet biradical contribution. In contrast, the X-ray crystallography and EPR measurements of 4 disclosed its biradical nature, described as a triplet ground state bis(silyl radical).