An exceptionally large size cuboctahedral imine cage is obtained from small size organic molecules in a thermodynamically driven [8+12] cyclocondensation. This is a demonstration of the role of entropy of symmetry as a driving force in reversible reactions.

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More than a protecting group: The trityl group senses the chirality of an alkyl substituent in chiral trityl ethers. The CD spectra of trityl‐protected alcohols are highly sensitive to the chirality of the alcohol. The use of a trityl CD sensor provides new insight into the structure and mode of action of chiral molecular bevel gears and shows the relation between the absolute configurations of molecules and their Cotton effect patterns.

It is demonstrated that chirality of molecules composed of 1,2,4,5‐benzenetetracarboxydiimide (pyromellitic diimide) or 1,4,5,8‐naphthalenetetracarboxydiimide units is reflected by their exciton Cotton effects. The analysis is based on the calculated (ZINDO/S) excited states of the model diimide chromophores 1a and 2a. Rotation of the diimide chromophores around the C‐N bond in diimides 3–5 is evaluated from the dynamic 1H NMR data. A comparison of chiroptical properties of bis‐diimides 3–5 with the CD spectra of bis‐imides 6–8 is also presented. Chirality 12:263–268, 2000. © 2000 Wiley‐Liss, Inc.

Thermodynamically driven cyclocondensation of (R,R)-1,2-diaminocyclohexane and 1,3,5-triformylbenzene yields solely a [4 + 6] spherand type product. This is a unique example of spontaneous formation of an organic compound of permanent chiral tetrahedral (T) symmetry.