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Fumaric acid diesters are important building blocks for organic synthesis. A class of zwitterionic organocatalysts based on an amide anion/iminium cation charge pair were found to be effective in catalyzing the isomerization of maleic acid diesters to give fumaric acid diesters. Comparison of the performance of different zwitterionic organocatalysts toward the reaction revealed that nonclassical hydrogen bonding was involved in the stabilization of the Michael adduct intermediate.

2,3,9,10-Substituted pentacene tetraesters and pentacene diester-dinitriles were synthesized. These pentacene derivatives underwent an unusual solid state [4 + 4] thermal dimerization with good efficiency and complete stereoselectivity. This observation indicates this series of pentacene derivatives adopt π-π stacking geometry with large mutual overlap in solid state. This notion was confirmed by molecualr dynamic simulation.

Headgroup-counterion interactions have been studied for a homologous series of sodium dialkyl sulfosuccinates (SDAS) with propyl, butyl, hexyl, octyl, decyl, undecyl and dodecyl chains as Aerosol-OT analogues. Raman scattering and IR absorption spectra were recorded and compared with those for dimethyl sulfosuccinate monohydrate, diethyl sulfosuccinate trihydrate and diheptyl sulfosuccinate dihydrate, whose crystal structures are known. The spectral features of the C=O and SO3- stretch modes directly reflect the interaction between the polar group and the Na+ ion and depend strongly upon the environment of hydration. The results may be summarized as follows. For the SDAS monohydrates in the solid state, there exists a strong interaction between the β C=O group and the Na+ ion, as a consequence of coordination of the β C=O to the Na+ ion, resulting in splitting of the C=O stretch modes. In particular, the common Raman (IR) bands observed at 1705- 1707 (1706-1708) and 1730-1732 (1732-1733) cm-1 may be assigned to the β C=O group coordinated to the Na+ counterion and the hydrated α C=O group, respectively. The extent of splitting of these bands is a measure of the strength of this C=O···Na+ interaction. Coordination of the β C=O to the Na+ ion also affects the C=O deformation modes of the O-C=O linkage. An increased hydration number and longer hydrocarbon chains induce a weak interaction between the C=O group and the Na+ ion. The SO3-···Na6+ interaction reflects the SO3- stretch modes, depending upon the extent of hydration. Furthermore, for the SDAS samples in the organic and aqueous microphases, Raman (IR) bands characteristic of the C=O and SO3-1 groups have been used successfully to account for the interaction between the polar group and the Na+ ion.