Details

Autor(en) / Beteiligte

• Yeong, Hui-Xian
• Zhang, Shu-Hua
• Xi, Hong-Wei
• Guo, Jing-Dong
• Lim, Kok Hwa
• Nagase, Shigeru
• So, Cheuk-Wai

Titel

An Amidinate-Stabilized Germatrisilacyclobutadiene Ylide

Ist Teil von

• Chemistry : a European journal, 2012-02, Vol.18 (9), p.2685-2691

Ort / Verlag

Weinheim: WILEY-VCH Verlag

Erscheinungsjahr

2012

Quelle

Wiley-Blackwell Journals

Beschreibungen/Notizen

• The synthesis and characterization of new amidinate‐stabilized germatrisilacyclobutadiene ylides [L3Si3GeL′] (L=PhC(NtBu)2; L′=ËL; Ë=Ge (3), Si (7)) are described. Compound 3 was prepared by the reaction of [LSiSiL] (1) with one equivalent of [LGeGeL] (2) in THF. Compound 7 was synthesized by the reaction of 2 with excess 1 in THF. The bisamidinate germylene [L2Ge:] (4) is a by‐product in both reactions. Moreover, compound 7 was prepared by the reaction of 3 with one equivalent of 1 in THF. Compounds 3 and 7 have been characterized by NMR spectroscopy, X‐ray crystallography, and theoretical studies. The results show that compounds 3 and 7 are not antiaromatic. The puckered Si3Ge four‐membered rings in 3 and 7 have a ylide structure, which is stabilized by amidinate ligands and the electron delocalization within the Si3Ge four‐membered ring. Heavier cyclobutadiene ylide: The new germatrisilacyclobutadiene ylide 3 was synthesized successfully by the treatment of 1 with 2 (one equiv) in THF (see scheme). The 29Si NMR resonances of compound 3 reveal that the Si3Ge four‐membered ring has a ylide structure. The X‐ray structure of 3 comprises a puckered Si3Ge four‐membered ring, with the GeSi and SiSi bonds as single bonds. Theoretical studies suggest that the ylide structure in 3 is stabilized by the amidinate ligands and weak electron delocalization.