Metal-Ion Induced In Situ Ligand Oxidation for Self-Assembled Clusters: from Bis(5-(2-pyridine-2-yl)-1,2,4-triazole-3-yl)methane to Alcohol or Ketone.

Hydrothermal reactions of metal nitrates and ligand bis(5-(pyridine-2-yl)-1,2,4-triazol-3-yl)methane (H2 L1 ) gave three cluster compounds, {Cr2 }, {Zn12 } and {Fe8 }. Notably, methylene group of H2 L1 was in situ oxidized either to hydroxymethylated (L2 -O)3- in the metallo-ring {Zn12 } or to a rigid carbonylated (L3 =O)2- in the screw-type {Fe8 }. In light of comparative experimental results, NO3- was deduced to be of a catalytic role in the ligand oxidation. Metal ion could be regarded as an "induced" tool for clusters generation in self-assembly process.