Aluminium-fused bis-p-tert-butylcalix[4]arene: a double cone with two π-arene ⋯ H interactions for included methylene chloride

Abstract

Treatment of p-tert-butylcalix[4]arene 1 with [H₃Al(NMe₃)]₂ results in trimetallation and deprotonation by the tertiary amine, yielding the bis(calix[4]arene), [{(1– H₄)Al}₂]^2–[HNMe₃]⁺₂, 2, which has been isolated with included methylene chloride; distorted five-coordinate O-bound aluminium centres [Al–O 1.74(1)–2.35(1)Å] fuse the slightly flattended cone calixarene units with the methylene chloride H-atoms residing over two opposite aromatic rings in each cone, C ⋯ ring centroid 3.54 Å.