Phenylacetylene macrocycles with two opposing bipyridine donor sites: syntheses, X-ray structure determinations, and Ru complexation

Reaction of the known macrocycle 1a, which contains two bipyridine units in opposing sides, with two equivalents of Ru(bipy)2Cl2] furnishes the doubly exocyclically complexed macrocycle 8a in 55% yield. Synthesis of the shape-persistent macrocycle 1c by Hagihara-Sonogashira cross-coupling chemistry of suitably functionalized building blocks is reported. This macrocycle was also converted into a Ru complex (8c). X-ray analysis of single crystals of 1b and 1c shows a layered structure that contains "channels" filled with solvent molecules and parts of the flexible chains, with which the cycle is decorated for solubility reasons.