Coordination Chemistry of the Calixarenes. III. A 2nd Phase of [Eu₂(LH₂)(Me₂NCHO)₅].Me₂NCHO Solvate (LH₈= p-t-Butyl-Calix[8]arene)

Abstract

The single-crystal X-ray structure of [Eu₂(LH₂)(Me₂NCHO)₅] has been recently described as an approximately tetrakisdimethylformamide solvate (L=C₈₈H₁₀₄O₈^8-, the octaanion of p-t- butyl-calix [8] arene; Me₂NCHO = N,N- dimethylformamide ). A second phase, a sesquidimethyl-formamide solvate ('β') has been isolated and also subjected to structural characterization; crystals are triclinic, P1, a 14.85(1), b 26.70(2), c 35.16(2) Å , α 102.72(4), β 92.07(4), γ 101.61(4), (Z = 4 formula units); R was 0.12 for 14618 'observed' reflections. The two aggregates of the 8-phase, surprisingly in view of the expected flexibility of the large macrocycle, closely resemble that of the α-phase.