Synthesis and Structure of Germanium- And Tin-Bridged Macrocycles: Germa- And Stanna-Calixarenes

Abstract

Maorocyclic compounds are obtained in one step by the reaction of heterocyclic dianions (N-methylpyrrole and organothienopyrazine) with bis electrophiles such as Ph 2 GeCI 2 and Bu 2 SnCI 2 . Spectroscopic studies show the formation of predominant germa-and stanna-calix[4]arenes. The X-ray structure of the tetrameric tin compound shows an almost planar macrocycle. The compound crystallises in space group Ρ bar 1, and the molecule contains an inversion centre. The n-butyl groups exhibit a severe disorder. IntroductionAlthough macrocyclic structures with bridging carbon have largely been studied, there is little information regarding tin-and germanium-bridged macrocycles 1, . We report here the synthesis and structure of a new variety of calixarenes in which the metal centres (germanium and tin) are connected by conjugated organic fragments like N-methyl pyrrole or organothienopyrazine.

Synthesis and Structures of an Unusual Germanium(II) Calix[4]arene Complex and the First Germanium(II) Calix[8]arene Complex and Their Reactivity with Diiron Nonacarbonyl

“…Calixarenes are highly useful macrocyclic compounds which have a variable cavity size and have a variety of applications in the areas of molecular self-assembly, ionic and molecular recognition, and catalysis. [1][2][3][4][5][6][7] A number of transition-metal and main-group complexes using these species as ligands have been prepared, but calixarene complexes containing germanium are rare [29][30][31][32][33][34][35] and of these few examples only three materials having germanium bound directly to the calixarene oxygen atoms have been synthesized and structurally characterized. 33,34 These include the calix[4]arene complexes [Bu t calix]Ge 2 33 and the two struc- tural isomers of [Bu t calix (TMS)2 ]Ge.…”

2,2,7,7,12,12,17,17-Octamethyl-21,22,23,24-tetrathia-2,7,12,17-tetragermapentacyclo[16.2.1.13,6.18,11.113,16]tetracosa-3,5,8,10,13,15,18,20-octaene

“…For syntheses and structures of heteroarylgermanes, see ; Barrau et al (1997); Kö nig & Rö del (1997). For properties of heteroarylgermanes, see : Hockemeyer, Valentin et al (1997). For a description of the Cambridge Structural Database, see: Allen (2002).…”