SYNTHESIS AND STRUCTURE OF GERMANIUM-BRIDGED AND TIN-BRIDGED MACROCYCLES - GERMA-CALIXARENES AND STANNA-CALIXARENES

Macrocyclic compounds are obtained in one step by the reaction of hete rocyclic dianions (N-methylpyrrole and organothienopyrazine) with bis electrophiles such as Ph2GeCl2 and Bu2SnCl2. Spectroscopic studies sho w the formation of predominant germa- and stanna-calix[4]arenes. The X -ray structure of the tetrameric tin compound shows an almost planar m acrocycle. The compound crystallises in space group P bar 1, and the m olecule contains an inversion centre. The n-butyl groups exhibit a sev ere disorder.