Supramolecular Complexation of Fullerenes and 1,2-Dicarbadodeca-Borane(12)

Abstract

Calix[n]arenes, n = 5, 6 and 8, and cyclotriveratrylene (= CTV) form host-guest complexes with C₆₀ in toluene, and in toluene in mesoporous silica with 5.4 nm pores. Hostguest complexation is the primary process and the associated polarisation of the fullerene can lead to micelle like aggregation of the fullerenes. For CTV complexation the final aggregates are ≥ 5.4 nm in diameter whereas in the solid state the fullerenes form polymeric arrays of fullerenes at the van der Waals limit with each CTV molecule forming a perched structure with a fullerene. p-Bu^t-calix[8]arene can be used for purification of C₆₀, the structure of the complex based on ah aggregate of three fullerenes in a triangle with each calixarene in a double cone conformation and spanning an edge of the triangle. Fullerene C₇₀ forms complexes with various calixarenes. o-C₂B₁₀H₁₂ [= 1,2-dicarbadodeca-borane(12)] which like C₆₀ is icosohedral, also forms a perched complex with CTV with the H-atoms attached to carbon residing over two of the aromatic rings; theory for CH_carborane ….π-benzene predicts an inteŕaction energy of 2.717 kcal mol^-1; 6-3IG*.