PROPERTIES OF MIXED-LIGAND CYCLOMETALATED PLATINUM(II) COMPLEXES DERIVED FROM 2-PHENYLPYRIDINE AND 2-(2-THIENYL)PYRIDINE - VOLTAMMETRIC, ABSORPTION AND EMISSION STUDIES

被引：39

作者：

KVAM, PI ^{[1
]}

PUZYK, MV ^{[1
]}

COTLYR, VS ^{[1
]}

BALASHEV, KP ^{[1
]}

SONGSTAD, J ^{[1
]}

机构：

[1] RUSSIA STATE PEDAG UNIV,DEPT CHEM,ST PETERSBURG 191186,RUSSIA

来源：

ACTA CHEMICA SCANDINAVICA | 1995年 / 49卷 / 09期

关键词：

D O I：

10.3891/acta.chem.scand.49-0645

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

The spectroscopic and electrochemical properties of some cyclometalated Pt(II) complexes derived from 2-phenylpyridine, [Pt(ppy)AB], and 2-(2'-thienyl)pyridine, [Pt(tpy)AB], have been compared. A and B represent various monodentate and bidentate ligands. When exchanging ppy with tpy the metal-to-ligand charge transfer, MLCT, as viewed by the structured absorption and emission bands, is shifted by ca. 3000 cm(-1) to lower energy. The redox potentials for the two series of complexes, however, are most similar and depend only on the additional ligands A and B. The radiative lifetimes of the lowest excited state of the tpy complexes are significantly longer than for the ppy complexes. The various data indicate that the lowest excited state of the tpy complexes has a larger contribution from the pi-character of the cyclometalated ligand. Since tpy complexes, contrary to most ppy complexes, are luminescent even at room temperature, it is concluded that this class of complexes are better candidates for promoting luminescent species. The redox potentials of the complexes are linearly related to Lever's electrochemical parameters, E(L), with a slope of ca. 0.55 for reduction and ca. 0.65 for oxidation. The linear relationship breaks down for oxidation potentials when A and B represent sterically hindered phosphines, presumably due to oxidation of the heteroatoms.

引用

页码：645 / 652

页数：8