Unexpected Drastic Decrease in the Excited-State Electronic Communication between Porphyrin Chromophores Covalently Linked by a Palladium(II) Bridge

被引：18

作者：

Abdelhameed, Mohammed ^{[1
]}

Karsenti, Paul-Ludovic ^{[1
]}

Langlois, Adam ^{[1
]}

Lefebvre, Jean-Francois ^{[2
]}

Richeter, Sebastien ^{[2
]}

Ruppert, Romain ^{[3
]}

Harvey, Pierre D. ^{[1
]}

机构：

[1] Univ Sherbrooke, Dept Chim, Sherbrooke, PQ J1K 2R1, Canada

[2] Univ Montpellier 2, Inst Charles Gerhardt Montpellier, UMR CNRS 5253, F-34095 Montpellier 05, France

[3] Univ Strasbourg, Inst Chim, UMR CNRS 7177, F-67000 Strasbourg, France

来源：

CHEMISTRY-A EUROPEAN JOURNAL | 2014年 / 20卷 / 40期

基金：

加拿大自然科学与工程研究理事会;

关键词：

carbenes; forster theory; palladium; porphyrins; singlet energy transfer; RESONANCE ENERGY-TRANSFER; N-HETEROCYCLIC CARBENES; ELECTROCHEMICAL PROPERTIES; EXCITATION-ENERGIES; DIMERS; COMPLEXES; TRANSFERS; SINGLET; DONOR; APPROXIMATION;

D O I：

10.1002/chem.201403146

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

A dyad built up of a zinc(II) porphyrin and the corresponding free base, [Zn-Fb], fused to N-heterocyclic carbene (NHCs) ligands, respectively acting as singlet energy donor and acceptor, and a bridging trans-Pd12 unit, along with the corresponding [Zn-Zn] and [Fb-Fb] dimers were prepared and investigated by absorption and emission spectroscopy and density functional computations. Despite favorable structural and spectroscopic parameters, unexpectedly slow singlet energy transfer rates are measured in com- parison with the predicted values by the Forster theory and those observed for other structurally related dyads. This observation is rationalized by the lack of large molecular orbital (MO) overlaps between the frontier MOs of the donor and acceptor, thus preventing a double electron exchange through the trans-Pd12 bridge, and by an electronic shielding induced by the presence of this same linker preventing the two chromophores to fully interact via their transition dipoles.

引用

页码：12988 / 13001

页数：14

共 62 条

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