2+ ion as its trifluoroacetate or trifluoromethanesulfonate salt. The structure of the compound was confirmed by X-ray analyses. The anions establish hydrogen-bonding interactions with all four bridging OH groups. Density functional calculations afford bonding parameters in close agreement with the observed structure and indicate that the cluster is best described as a valence-delocalized Mo 3 13+ species. The five metal electrons are distributed among an a-type (z 2 ) orbital, which accounts for

Zinc reduction of Cp*2W2O5 in an acidified water–methanol medium affords the green 3‐electron trinuclear cluster [Cp*3W3O4(OH)2]2+, isolated and crystallographically characterized as the triflate salt, 1. Upon exposure to air, this complex is oxidized to a related 2‐electron cluster, [Cp*3W3O6]+, which was crystallized and characterized in three different salts, 2–4. The 3‐electron cluster exhibits a near‐tetragonal frozen‐glass EPR spectrum, and it shows evidence of coupling of the unpaired electron to only one of the three W atoms. The two‐electron cluster is diamagnetic. An electrospray ionization MSn study revealed a stepwise expulsion of neutral [Cp*WO2] units as the main fragmentation process. DFT calculations unveiled the intimate details of the electronic structures of these complexes and fully rationalized the structural and spectroscopic properties.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

A novel [Pb 2(µ -atrz) 2(µ -CH 3 COO)(CH 3 COO)] n (atrz = 3-amino-1,2,4-triazole) complex was synthesized and characterized by IR spectroscopy, thermogravimetric analysis, and single crystal X-ray diffraction. The molecular structure shows that the complex is a coordination polymer in which there are 2 different lead(II) ions with coordination number of 5, Pb(2), and, with a coordination number of 4, Pb(1). Each atrz acts as a bridging ligand between 2 Pb(II) ions through the 2 adjacent nitrogen atoms of the triazole ring. The acetate anions show different types of coordination mode: one acts as a bridge by coordination of the same oxygen atom with Pb(II) ions and the other as a monodentate coordination by one of the oxygen atoms with Pb(2).