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W.-J. Wang et al.
easily decomposes to Cu(0) and free ligand. At the same time, they
observed the redox couple of Cu(I)=Cu(II) at E¼þ0.6V. In our system,
we also observed a stripping peak at Epc¼ ꢁ0.13V in the reduction
region and a reversible couple at E¼þ0.685 V in the oxidation region.
Hence, the former corresponds to the reduction of Cu(I)=Cu(0), and the
latter is the reversible oxidation of Cu(I)=Cu(II). In contrast to the tri-
phenylphosphineanalogue complexes [22], the redox behavior of PPh3
at Epc¼ ꢁ1.60 V undergoes irreversible reducꢁtion. Finally, we determ-
ined the irreversible redox couple of Iꢁ=I3 at E¼þ0.36 V in the
oxidation region, in agreement with the redox behavior of Iꢁ from
CuI at E¼þ0.36 V.
CONCLUSIONS
We have synthesized the diimine ligands benzylidene-3,5-Di(20-
pyridyl)-4-amino-1,2,4-triazole (L1) and N-benzylidene-3,5-Di(20-
pyridyl)-4-amino-1,2,4-triazole (L2) which were used to prepare
complexes 1 and 2 with Cu(PPh3)3I. The two copper complexes were
structurally characterized by X-ray and 1H-NMR methods. The
absorption spectra of complexes 1 and 2 showed an MLCT bond in
the region of 345–545 nm. We have also measured the emission
properties of complex 2 which was shown to have a kmax ¼ 636 nm.
Cyclic valtammogram of complex 1 showed the redox couples of the
copper center at E ¼ ꢁ0.545V and E ¼ þ 0.685 V, the former corre-
sponds to the reduction of Cu(I)=Cu(0), and the latter corresponds to
the reversible oxidation of Cu(I)=Cu(II).
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