1.956(4) (V) for L=OH-to 2.152 (5) (I) and 2.164 (5)/k (II) for L = OH 2. The variations in the other ligands notwithstanding, the complexes (I)-(V) provide an unusual series of dimetal centres supporting the oxo, hydroxo and aqua bridging ligands. 67 mm -1, F(000) = 672, T= 295 K. 3951 unique reflections with I> 3e(/) were used to refine 248 variables on F giving agreement factors of R = 0.030 and wR = 0.033. The cation has a slightly distorted square-planar geometry at the platinum atom. The acetone ligand is coordinated to the metal atom as a Lewis base through donation of an sp 2 electron pair on the oxygen atom. The carbon-oxygen double-bond length of 1.225 (7)A in the acetone ligand shows no significant lengthening. References

A series of biphenyl-based N(3)O ligands, 2, 4, 6, and 8 were synthesized and their Cu(II) complexes prepared. These complexes were characterized by a combination of elemental analysis, FAB-MS, UV-vis spectroscopy and electrochemistry. The structure of [Cu(N(3)O-mpy-NO2)Cl2], 12 [N(3)O-mpy = 2-(3-pyridylmethylimino)-2'-(2-methylaminophenol)biphenyl], was solved and showed that the ligand coordinates through the three nitrogens with the phenol oxygen uncoordinated. Titration of azide anion into solutions of the complexes in methanol resulted in the appearance of a new band between 485-495 nm at the expense of the starting peak at 380 nm. Cyclic voltammetry studies indicated that the complexes undergo quasi-reversible one-electron reductions in acetonitrile at potentials between 0.13-0.58 V vs. Ag/AgCl. The complexes were found to be weakly active for the oxidation of di-tert-butyl catechol (DTBC).