Tetrahedral onsager crosses for solubility improvement and crystallizationbypass

Pure organic molecules exhibiting a suitable concave rigid shape are expect ed to give porous glasses in the solid state. Such a feature opens new oppo rtunities to avoid crystallization and to improve molecular solubility in r elation to the high internal energy of these solid phases. To quantitativel y explore the latter strategy, a series of rigid tetrahedral conjugated mol ecules nC and the corresponding models nR have been synthesized. Related to the present purpose, several properties have been investigated using UV ab sorption, steady-state fluorescence emission, differential scanning calorim etry, H-1 NMR translational self-diffusion, magic angle spinning C-13 NMR, and multiple-beam interferometry experiments. The present tetrahedral cross es are up to 8 orders of magnitude more soluble than the corresponding mode l compounds after normalization to the same molecular length. In addition, they give concentrated monomeric solutions that can be used to cover surfac es with homogeneous films whose thickness goes down to the nanometer range. Such attractive features make cross-like molecular architectures promising for many applications.