An unprecedented self-assembled porous framework constructed by intermolecular S···S contacts

An unprecedented self-assembled porous framework is constructed with a multi-sulfur donor molecule with ferrocenyl group (FcVET). The solvent-specific framework maintained by intermolecular S···S contacts forms one-dimensional hexagonal channels (Φ ≅ 7.5 A) filled with the solvated molecules. A careful evacuation of the solvated FcVET crystals leaves solvent-free FcVET crystals in which the identical framework structure with the same intermolecular S···S contacts is maintained. In contrast to the polar hydrogen bond donor-acceptor pairs, thiol-containing moieties are not regarded as good hydrogen bond tectons due to their insufficient polarity. On the other hand, although it is not directional, the intermolecular S···S interaction can be used in forming functional molecular assemblies as exemplified in the sulfur-rich molecular complexes of 4,5-bis(ethylenedithio)tetrathiafulvalene (ET) and metal-bisdithiolene complexes. These intermolecular charge transfer complexes need close contacts in solid states to exhibit electrical conductivity or magnetic properties, and the S···S interactions provide favorable interactions among the molecular components. The significant strength of this intermolecular interaction originates from a complementary electrophile-nucleophile interaction, or can be explained by a polar flattening model