Cholesterol porphyrin-appended

Scheme 14 Porphyrin-appended cholesterol LMOGS. Addition of [60]fullerene reinforces the gelation ability of 38-n...

I.T. Ishi, J.H. Jung, S. Shinkai, Intermolecular porphyrinefulleiene interactioncan reinforce the oiganogel stracture of a porphyrin-appended cholesterol derivative. J. Mater. Chem. 10, 2238-2240 (2000)... 

In the same connection, the gelation test of a [60]fullerene-appended cholesterol gelator, (S)-39, was performed in 28 solvents. (S)-39 could only gelate dichloromethane at 25 °C at above the concentration of 16.2 mM, whereas the inverted epimer (R)-39 was inactive in all solvents tested [61] (Scheme 15). CD spectroscopy studies indicated that the [60]fullerene moiety in (S)-39 is chirally oriented in the gel state. The effect of zinc porphyrin/[60]fullerene interaction was investigated by adding Zn TPP into the gel of (S)-39. Interestingly, the addition of Zn TPP disrupted the gel, which is in contrast to the behavior of 38-n in the presence of fullerene. 

Similar incorporation was also examined in a cholesterol-based organogel. Porphyrin-cholesterol 2a is incorporated into the gel fiber composed of nucleobase-appended cholesterol gelator (Fig. 1) [15]. fii the mixed gel system, porphyrin moieties with large jr-area are able to intercalate between the nucleobase moieties oriented outside the one-dimensional column of cholesterol stacking. 

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