Pentiptycene-based concave NHC-metal complexes.

Roman Savka,Sabine Foro,Herbert Plenio

doi:10.1039/c6dt01724j

Roman Savka, Sabine Foro + Show 1 more

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https://doi.org/10.1039/c6dt01724j

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Abstract

The reaction of 1-amino,4-hydroxy-pentiptycene with diacetyl or acenaphthene-1,2-dione gave the respective diimines, followed by alkylation of the hydroxyl groups, and cyclization of the alkylated diimines to the respective bispentiptycene-imidazolium salts NHC·HCl. The azolium salts, being precursors to N-heterocyclic carbenes, were converted into metal complexes [(NHC)MX] (MX = CuI, AgCl, AuCl) and [(NHC)IrCl(cod)] and [(NHC)IrCl(CO)2] in good yields. In the solid state [(NHC)AgCl] displays a bowl-shaped structure of the ligand with the metal center buried within the concave unit.

Highlights

Iptycenes are a class of aromatic molecules with arenes fused to a bicyclo[2.2.2]octane framework,[1] which have found numerous applications in polymer chemistry,[2] molecular machines,[3,4] materials science and in host–guest chemistry.[5,6,7] Triptycene, the first representative of this family of compounds was published by Bartlett et al in 1942 (Scheme 1).[8]
All reactions involving metal complexes were performed under an atmosphere of nitrogen
Preparative chromatography was done on Merck silica 60 (0.063–0.2 mm)

Summary

Introduction

Iptycenes are a class of aromatic molecules with arenes fused to a bicyclo[2.2.2]octane framework,[1] which have found numerous applications in polymer chemistry,[2] molecular machines,[3,4] materials science and in host–guest chemistry.[5,6,7] Triptycene, the first representative of this family of compounds was published by Bartlett et al in 1942 (Scheme 1).[8]. The reaction mixture was cooled to room temperature and a yellow precipitate filtered off, washed extensively with diethyl ether, and dried in vacuo to provide 77.0 g (88% yield) of a yellow product. Synthesis of imidazolium salts 6a·HCl and 6b·HCl. A flame dried Schlenk flask containing diimine 5a (600 mg, 0.546 mmol) was evacuated and back-filled with nitrogen three times.

Results

Conclusion