Structural Chemistry of a New Chiral Anhydrous Phase of Ru(bipy)3(ClO4)2 Established from Powder X-ray Diffraction Analysis

A new anhydrous chiral phase of Ru(bipy)3(ClO4)2 (bipy = 2,2′-bipyridine) has been prepared both by mechanical grinding followed by annealing of the known chiral hydrate phase of this material and by solid-state dehydration of the chiral hydrate phase at high temperature. The new phase is obtained from these processes as a microcrystalline powder, thus limiting the opportunity to carry out structural characterization by single-crystal X-ray diffraction. Instead, our structure determination of the new chiral anhydrous phase has exploited the capabilities of modern powder X-ray diffraction techniques, employing the direct-space genetic algorithm technique for structure solution followed by Rietveld refinement. The structural properties of the chiral anhydrous phase are discussed, particularly with regard to assessing the structural relationship to the parent hydrate phase.