Chemistry of Metallic Rings and Their Hybrid Rotaxanes

Abstract

Abstract One of the Cr(III) ions in the homometallic ring [Cr8F8(OCtBu)16] can be replaced by Ni(II) and result in the formation of the anionic heterometallic ring [Cr7NiF8(O2CtBu)16]-. This heterometallic ring has a spin of S=1/2, and it can be used as a qubit in quantum information processing (QIP). The presence of cationic ammonium [H2NR2]+ is necessary for the formation of the monoanionic ring{Cr7Ni}. Furthermore, the capability of connecting weakly interaction of two or more of these heterometallic ring {Cr7Ni} is necessary for the fulfilment of QIP. Here, threads 2-phenyl-N-{[4’-(pyridine-4-yl)-(1-1’-biphenyl)-4-yl]methyl}ethanamine (B), 4- phenyl-N-{[4-(pyridine-4-yl)butan-1-amine (C), 4-(pyridylphenyl)isobutylamine (D) and 2,2- dimethyl-N-(4-(pyridin-4-yl)benzyl)propan-1-amine (E) were synthesised to be used as cationic templates for {Cr7Ni}, and functionalised a pyridyl group at one end, in order to connect them via coordination chemistry to different paramagnetic metals. [2]rotaxanes 45, 46 and 47 were successfully synthesised from threads B, C and D respectively. However, thread E was reacted in a manner similar to threads B, C and D, in order to prepare [2]rotaxane 48. Unfortunately, the resulting crude product formed during the preparation of 48 could not be eluted using column chromatography and unable to be isolated.