1,4,7-TRIS(2,2'-BIPYRIDYL-5-YLMETHYL)-1,4,7-TRIAZACYCLONONANE (L(1)), A POWERFUL TRIS(2,2'-BIPYRIDYL) CHELATING MACROCYCLIC LIGAND - X-RAY STRUCTURE OF [RU(L(1)H)][PF6](3), A COMPLEX CONTAINING A STRONGLY TRAPPED PROTON

A new powerful tris(2,2'-bipyridyl) chelating ligand, 1,4,7-tris(2,2'-bipyridyl-5-ylmethyl)1,4,7-triazacyclononane (L(1)), has been synthesised and characterised, and an X-ray structure of [Ru(L(1)H)](3+) obtained; in the complex all three bipyridyl groups are coordinated, with a fairly regular octahedral Ru-II geometry, and although the azamacrocyclic nitrogen-atoms are non-coordinating to Ru-II, in aqueous solution they trap a single proton in the cavity between the macrocycle and the Ru-II, and which cannot be removed even at high pH.