Paracyclophanes Bridged by Si, Ge, and Sn

A one-pot reaction gave the two different organosilicon macrocyclic compounds concomitantly. The structures of these metacyclophanes, 

They have also examined the formation of the ir-complex between the silacalixarenes and silver cation by FAB mass spectrometry. Similar 77-complex formation with silver cation was observed for hexasila [2,2,2]paracyclophanes 37 (41). 

Trisila[l.l.l]orthocyclophane (46) was prepared by the reaction of 3,3,6,6,9,9-hexamethyl-3,6,9-trisilacyclonona-l,4,7-triyne and a-pyrone. The structure of 46 determined by X-ray crystallographic analysis (Fig. 28) indicates a twisted saddle conformation (10). 

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