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Electrochemistry of Heteroleptic Tris(phthalocyaninato) Rare Earth( III ) Complexes
Author(s) -
Zhu Peihua,
Pan Na,
Ma Changqin,
Sun Xuan,
Arnold Dennis P.,
Jiang Jianzhuang
Publication year - 2004
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.200300510
Subject(s) - chemistry , lanthanide , phthalocyanine , homo/lumo , lutetium , electrochemistry , yttrium , ligand (biochemistry) , cyclic voltammetry , redox , perchlorate , crystallography , inorganic chemistry , ion , molecule , organic chemistry , electrode , biochemistry , receptor , oxide
The electrochemical characteristics of a series of heteroleptic tris(phthalocyaninato) complexes with identical rare earths or mixed rare earths (Pc)M(OOPc)M(OOPc) [M = Eu...Lu, Y; H 2 Pc = unsubstituted phthalocyanine, H 2 (OOPc) = 3,4,12,13,21,22,30,31‐octakis(octyloxy)phthalocyanine] and (Pc)Eu(OOPc)Er(OOPc) have been recorded and studied comparatively by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) in CH 2 Cl 2 containing 0.1 M tetrabutylammonium perchlorate (TBAP). Up to five quasi‐reversible one‐electron oxidations and four one‐electron reductions have been revealed. The half‐wave potentials of the first, second and fifth oxidations depend on the size of the metal center, but the fifth changes in the opposite direction to that of the first two. Moreover, the difference in redox potentials of the first oxidation and first reduction for (Pc)M(OOPc)M(OOPc), 0.85−0.98 V, also decreases linearly along with decreasing rare earth ion radius, clearly showing the rare earth ion size effect and indicating enhanced π−π interactions in the triple‐deckers connected by smaller lanthanides. This order follows the red‐shift seen in the lowest energy band of triple‐decker compounds. The electronic differences between the lanthanides and yttrium are more apparent for triple‐decker sandwich complexes than for the analogous double‐deckers. By comparing triple‐decker, double‐decker and mononuclear [Zn II ] complexes containing the OOPc ligand, the HOMO−LUMO gap has been shown to contract approximately linearly with the number of stacked phthalocyanine ligands. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)