The oxychlorides in Nb-6 cluster chemistry

The Nb-6 oxychlorides based on Nb6L18 units that we have isolated, as well as another one recently reported in the literature, are reviewed. Each of t hem is structurally described through a relevant example : Cs2LuNb6Cl17O, C s2UNb6Cl15O3, ScNb6Cl13O3, Ti(2)Nb6Cl(14)O(4) and KLu3Nb6Cl15O6, the struct ure of the latter has just been solved. They are discussed by comparison wi th the Nb-6 chlorides and Nb-6 oxides, considering the electronic and steri c evolution of the Nb6L18 unit upon increasing O/Cl ratio. The environments of the trivalent cations will be compared, specially those involving extra halogens in KLu3Nb6Cl15O6 and Ti2Nb6Cl14O4.