Selective Formation of Conductive Network by Radical-Induced Oxidation

Cd-based coordination networks having channels were formed selectively by using a redox-active aromatic ligand 2,5,8-tri(4-pyridyl)1,3-diazaphenalene (TPDAP, H(+)1(-)). An electron-conductive network having a π-π stacking columnar structure of TPDAP formed in the presence of a trace amount of TPDAP radical (1(•)). In contrast, a nonconductive network having a dimer unit of H(+)1(-) formed in the absence of 1(•). These results suggest the presence of a unique oxidation mechanism of TPDAP induced by formation of H(+)1(-)-1(•) dimer, which was initiated by a trace amount of 1(•). The dimerization increased HOMO level of H(+)1(-) moiety within the dimer to generate further radicals that could not form when H(+)1(-) was well isolated in CH3OH.