Popis: |
The single-crystal X-ray structure of [Eu2(LH2)(Me2NCHO)5] has been recently described as an approximately tetrakisdimethylformamide solvate (L=C88H104O88-, 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) � , 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. |