A flexible cyclophane: Design, synthesis, and structure of a multibridged tris-tetrathiafulvalene (TTF) macrocycle

The tris-tetrathiafulvalene (TTF) macrocycles 3 with a large end-cavity wer e effectively synthesized from the readily available tetrakis(cyanoethylthi o)TTF by means of a selective deprotection/realkylation sequence followed b y an intramolecular coupling reaction. Crystal structure analyses revealed that the neutral molecules include two (3a) or one chloroform molecule (3b) as solvent of crystallization inside the cavity, whereas the I-3(-) salt o f 3b, obtained by electrocrystallization, has a molecular structure which i s different from that of the neutral molecule in that the cavity has comple tely collapsed.